427 Assembled

[tpepmeie]

Starting to look like an engine now... I really don't know if it will even a) start, b) hold together, and c) make decent power, but it has been quite the learning experience.

http://i1036.photobucket.com/albums/a441/tpepmeie/IMG_2794.jpg
http://i1036.photobucket.com/albums/a441/tpepmeie/IMG_2800.jpg
http://i1036.photobucket.com/albums/a441/tpepmeie/IMG_2796.jpg

[Demps]

Beautiful! Nice Dunn head. What headers are those?
Ted

[ZZZZZR1]

Wow beautiful motor!!!

Can't wait for the dunk numbers on that one!

[USAFPILOT]

i'll take one!

[DaveK]

That looks really sweet! :thumbsup:

(we need a wolf whistle smiley!)

[Paul Workman]

Ah! Congratz, Tod! Now, the suspense is killing us, but I'm sure you have butterflies in your stomach 'bout now too!

Well...Let the BIG DOG howl!:thumbsup:

I propose a pre-lightoff toast: May your project advance the LT5 to new horizons! :cheers:

P.

[FU]

A thing of beauty :cheers:

[GOLDCYLON]

Looks great. I wonder what its going to put down? It looks fast just sitting there.

[Polo-1]

Not to worry GC your 380ci TT will take it :mrgreen:



Looks good Todd:worship:
equal length, merge hand made headers turned out nice too:wave:

[rudolph schenker]

Wow! Very Pretty! :cheers:

[ZR1@gmx.com]

That is one sweet labor of love! Bet is Starts and screams right off the bat!

[Tyler Townsley]

I notice you did not go to siamised (sp) plenum. I know your flow on the head is damn good, will the 2 runners flow that volume? I figure you have worked them so what size are they? According to Geoff the injectors are located in the wrong place for max power I don't remember what you did to the IH.

Tyler

[tomtom72]

WOW, it looks great.....these have to be the among the best looking motors in the world! Good luck with her Todd! :handshak: I hope she blows you away!
:cheers:
Those headers are purdy! LT5 porn at a very high quality! :mrgreen: Coating by Afterburner?

:o They will fit in a C4? I know stupid Q.

[-=Jeff=-]

Looks good..

I too am curious on the headers.. wild looking

[mgbrv8]

What length studs did you run on the headers? And man dose that thing look good.

Dave




Starting to look like an engine now... I really don't know if it will even a) start, b) hold together, and c) make decent power, but it has been quite the learning experience.

http://i1036.photobucket.com/albums/a441/tpepmeie/IMG_2794.jpg
http://i1036.photobucket.com/albums/a441/tpepmeie/IMG_2800.jpg
http://i1036.photobucket.com/albums/a441/tpepmeie/IMG_2796.jpg

[Pete]

I got wood. :-D
I thought porn was not allowed on this forum.

Nice very nice.

Pete

[Hog]

Looks awesome!!

Just curious, what are you using for cam followers?

peace
Hog

[limey]

You Sir, have a disease! Amazing looking motor and massive congrats, can't wait to know what power it makes.

[Tyler Townsley]

You Sir, have a disease! Amazing looking motor and massive congrats, can't wait to know what power it makes.

How about a picture of that LIME GREEN lambo you are doing. I see you picked up your seats.

Tyler

[rhipsher]

Is it a 427 stroker or stock crank?

[Nacho_ZR1]

I got wood. :-D
I thought porn was not allowed on this forum.

Nice very nice.

Pete

LOL I was fixing to say the same thing. Give me 20 minutes and a bottle of champagne, and I will show that motor things its never seen before
:bootyshak:icon_boun

[Nacho_ZR1]

Hey tpepmeie, I just noticed you are in Indianapolis? As luck would have it, I am also here in indianapolis until Friday. If your shop is close by, maybe I could come over?

[HIZNHRZ]

Is it a 427 stroker or stock crank?

Unless it's something very unusual, I'd say stroker.

Stock Stroke: 3.660
Stock Bore: 3.900

427 Stroke: 4.000
427 Bore: 4.125

[Kevin]

why didn't you go with the dropped plenum and Siamesed runners? looks good all bolted together

[tpepmeie]

It's a 4" Bryant crank. 4.1255 bore.

The headers I got many years ago from a forum member. I believe they are ex-Baker racing headers from the road racing program in the 90's. Had them re-coated this year. 2 in. primaries / 28 in. long. They fit in a C4, I had them in my 91 previously. Torque is improved over the standard Watson/Jeals.

Did the sums and could not see the need for full siamesed runners. There is plenty of area as we have done it. The divider is removed in the plenum. Would have liked more plenum volume, but cost/benefit trade wasn't appealing.

Todd

ps. why didn't I clean up that pwr steering pump? Looks like @#% on a fresh motor.:icon_scra

[Kevin]

well there's still time todd, giddy up

[DaveK]

That engine is a dream - a 427 LT5? Wow... magic to the eyes and ears... I have no idea what that cost to put together but geez... I can only dream!

Wrap that up in a Dark Red ZR-1 and that would be my idea of heaven :thumbsup:

[tpepmeie]

Wrap that up in a Dark Red ZR-1 and that would be my idea of heaven :thumbsup:

How about a 7k mile Ruby? :thumbsup:

[DaveK]

How about a 7k mile Ruby? :thumbsup:

That would do! :-D

[scholtmj]

How about a 7k mile Ruby? :thumbsup:

Pretty stealthy with the stock looking plenum. What do you anticipate the idle characteristics to be?

[Paul Workman]

Todd, I love this dynamics stuff; flow numbers, resonance, reversion, etc etc. Would you mind sharing what program you used to crunch the numbers for your runners and lift, and so on? (Or, did you just whip out your trusty slide rule and pad of paper during your lunch break one day, and just "do it like a man"?;) JK)

I'm sure there are lots of us out here with our fingers and toes crossed. Always interested whenever someone pushes the envelope a little further!

P.

[tpepmeie]

What do you anticipate the idle characteristics to be?

in a word... "ridiculous".

These are the biggest cams ever used in an LT5. I consciously made that sacrifice in driveability and idle characteristics in the quest for >700hp. I just pray it starts and doesn't self destruct.:pray

[tpepmeie]

Would you mind sharing what program you used to crunch the numbers for your runners and lift, and so on? (Or, did you just whip out your trusty slide rule and pad of paper during your lunch break one day, and just "do it like a man"?;) JK)


Paul,
lots and lots of calculations and engineering rules of thumb. For software, the two I use most are the Lotus engine simulation (full version), and PipeMax. Blair's book on 4-stroke simulation is top notch with a lot of emperical formulas.

And for some of the really complex stuff (like cams, and port design), I let the experts who do it for a living have free reign. I know my limitations. I'm not a trained engineer... I'm a finance guy by trade.

Todd

[Paul Workman]

Paul,
lots and lots of calculations and engineering rules of thumb. For software, the two I use most are the Lotus engine simulation (full version), and PipeMax. Blair's book on 4-stroke simulation is top notch with a lot of emperical formulas.

And for some of the really complex stuff (like cams, and port design), I let the experts who do it for a living have free reign. I know my limitations. I'm not a trained engineer... I'm a finance guy by trade.

Todd

Thanks for the info, Todd.

Well, maybe you should sell some tickets and pop some popcorn for the GRAND OPENING! Maybe make back some of your investment? (I'll buy a ticket and popcorn ... Just say when! ;)) Oh, sheeiiit...a "grand opening" is probably NOT the right choice of words for an engine's first run.:o However...I'm betting all will be fine.

P.

[todesengel]

I logged back in to pm someone for some parts I am picking up, and seen this thread. Amazing work. I hope all your goals are achieved!Paul,
lots and lots of calculations and engineering rules of thumb. For software, the two I use most are the Lotus engine simulation (full version), and PipeMax. Blair's book on 4-stroke simulation is top notch with a lot of emperical formulas.

And for some of the really complex stuff (like cams, and port design), I let the experts who do it for a living have free reign. I know my limitations. I'm not a trained engineer... I'm a finance guy by trade.

Todd

[Pete]

I'm a finance guy by trade.

Todd

Seems your good at that also.:)

Hey Todd,you a genius?what's your IQ? i'm 169 :-D
Pete

[USAFPILOT]

If it works I want to build a clone

[A26B]

Todd's always been quiet and unassuming by personality, but always way over my head in tuning & combustion engineering. All I can say is formal education is not the only path to being an engineer.

Heck of a job Todd! Are you going to have a first start video?

[tpepmeie]

703

[tomtom72]

703

:handshak::mrgreen::mrgreen::mrgreen::mrgreen:

:cheers: & May God Bless You!

Tom

[tomtom72]

:o oh, I am speachless.....so I forgot to say WOW Todd.


You Be Da Man!!

[DaveK]

Awesome! :cheers:

[QB93Z]

WOW - Congratulations!

Jim

[Kb7tif]

Cant wait to see the car on takeoff!!

[FU]

Congratulations Todd :worship: :worship:

[4DSZR1]

Friggin WOW Outstanding!!!

[Kevin]

703
i'm going to assume that the flywheel hp...

[Polo-1]

703

Holy Smokes.......=D>

Hey Jim we are going to need a big NOS jet to keep up on the 402:(

[ZZZZZR1]

OMG....

I haven't bought a newsletter in 5 years and this year I am! I want to "see" the writeup on this one.

congrats!

David

[mgbrv8]

Will there be a video??

Dave

[Nacho_ZR1]

TITTT

(take it to the track!)

[Pete]

703

HEE HAW
703 ponies
Congrats Todd

Pete

[Paul Workman]

Was that the envelop cracking that we just heard?? Something like 1.64 hp/ci, NA is significantly above most big inch LT5s.
WOW! Congratz, congratz, congratz, & KUDOS to you Todd!:fahne:

You can do some serious terrorizing with that!!

P.

[tpepmeie]

Once we hit the target on the second full 7k pull, I cashed in my chips and we called it a succesful day. No sense beating the hell out of it for a few more hp. It is a safe tune at this point... not living too close to the edge.

It was a great experience, and Marc is terrific to work with. I've still got a lot of driveability tuning to do, once the engine is back in the car. The cams are wicked to say the least. Funny thing, we were both noticing how (relatively) calm the thing was at 2000 rpm while breaking it in. Hmmm, maybe this won't be so bad.... Then we idled it down to 1000, where the cal was set. :eek: OMG, what a difference. It was shaking everything attached to it at that low idle. The manifold vacuum was ridiculous, significantly lower than 415/440's on Stage 3 cams. So we decided 1100 minimum idle speed, and it seemed a little happier there. We'll see what it's like with a car around it.

It actually made 700 hp +/- from about 6500 to 7000.

Oh, and 588 lb-ft torque.

(my neighbors are gonna hate me for the noise!)

Todd

[-=Jeff=-]

Todd,

if you don't mind me asking where did you dyno it at?

[tpepmeie]

Jeff,
Due to confidentialities, I can't disclose the location. Sorry.

[RICKYRJ1]

Impressive to say the least :worship::worship::worship::worship:
Is this going to be a one off or be made available in one form or another to your humble Z Brothers?=D>

[tpepmeie]

Impressive to say the least :worship::worship::worship::worship:
Is this going to be a one off or be made available in one form or another to your humble Z Brothers?=D>
It's one of one. But make me an offer.... :)

[RICKYRJ1]

It's one of one. But make me an offer.... :)


If your married would you be interested in a sister-wife? Hardly used and a proven track record of delivering beautiful sons. Italian but in the spirit of full disclosure she doesn't cook. Looking for your engine + some cash ;)
Let me know, I can have her on a plane early next week :mrgreen:

[-=Jeff=-]

Jeff,
Due to confidentialities, I can't disclose the location. Sorry.

Understood

[GOLDCYLON]

(my neighbors are gonna hate me for the noise!) Todd


Always room in AZ ;)

[GOLDCYLON]

If your married would you be interested in a sister-wife? Hardly used and a proven track record of delivering beautiful sons. Italian but in the spirit of full disclosure she doesn't cook. Looking for your engine + some cash ;)
Let me know, I can have her on a plane early next week :mrgreen:

:-D Glad to see barter is alive and well :cheers:

[USAFPILOT]

Wow that's nuts...i doubted it would hit 700. Great work! I think you could probably name your price; but most of us want to see you run it a few times first.

Also offering my wife, two kids, three cats, all some or none.

[Locobob]

Excellent! Hope you are going to do a solid write-up on this for the online magazine.

[-=Jeff=-]

So now I have to ask

you think it will HOOK on a launch ?

[ZR1FUN]

Outstanding job on those engines. They are beautiful and no plastic covers just the great LT5.

Doug:cheers:

[SAM/CH ZR-1]

Congratulations Todd :handshak:

703 is the number to beat.

Sam

[Aurora40]

What kind of rwhp do you expect that to turn into? I have no concept of what the loss is on a 700hp engine. Will it be in the 6's?

[Paul Workman]

What kind of rwhp do you expect that to turn into? I have no concept of what the loss is on a 700hp engine. Will it be in the 6's?

Good question, Bob.

The 15% "rule of thumb" probably generally applies to drive train losses within a range of hp outputs. I'm somewhat dubious of that "rule" as it applies to big hp motors especially. I dunno. So, dyno RWHP will be interesting. 703 x .85 = 598ish. If my hypothesis is correct, then RWHP would be in the 600s. Should be interesting to see (keeping in mind the testing so far has been on an engine dyno).

P.

[XfireZ51]

Todd,

Do you think there any LT-5 CWs this motor either confirms or defies? If so, what are they? :cheers:

[zrss]

703

Holy Smokes.......=D>

Hey Jim we are going to need a big NOS jet to keep up on the 402:(

Nope. Just leave the jet out and plumb straight from the NOS bottle into the plenum. We don't need no stinkin jets!:dancing

[Pete]

Nope. Just leave the jet out and plumb straight from the NOS bottle into the plenum. We don't need no stinkin jets!:dancing


Or plumb it straight to the driver if you loose you'll have a good laugh.:-D

Pete

[tomtom72]

Todd,

Do you think there any LT-5 CWs this motor either confirms or defies? If so, what are they? :cheers:

:redface: Please, I'm lost on the "CW's" ..... "conventional wisdom's"? Thanks Dom.

Todd, I have a Q born of curiosity with respect to the extensive modifications to the combustion chambers and the cylinder head ports. Would any of those ideas be related to what the "next LT5" would have been if GM had chose the 4v/DOHC format over the LSx motor format?

I'm curious because Mr. McLellan said that they had a 4v/DOHC that would fit in a C5 chassis/body configuration, but it was a different motor than the LT5's that were used in the C4.

If you don't want to answer, I understand.

:cheers:
Tom

[Paul Workman]

:redface: Please, I'm lost on the "CW's" ..... "conventional wisdom's"? Thanks Dom.
:cheers:
Tom

Cripes, Tom!! Where the hell were you when Dom was handing out his "My Oft Used But Seldom Understood Italian Acronyms" book!? Sheesh!:sign10:;)

P.

[Polo-1]

Or plumb it straight to the driver if you loose you'll have a good laugh.:-D

Pete

Nope. Just leave the jet out and plumb straight from the NOS bottle into the plenum. We don't need no stinkin jets!:dancing

No problem I can put a tee in the line... 1 for driver, 1 for motor ;)
Motor should be good for 800hp,driver good for 800 feet:dancing

[tomtom72]

Cripes, Tom!! Where the hell were you when Dom was handing out his "My Oft Used But Seldom Understood Italian Acronyms" book!? Sheesh!:sign10:;)

P.

Yea, I thought they said trains and I missed mine! :redface: That's okay, wait till I ask for the list of "CW's"......then Dom will send the black hand after me!:mrgreen:

[XfireZ51]

Yea, I thought they said trains and I missed mine! :redface: That's okay, wait till I ask for the list of "CW's"......then Dom will send the black hand after me!:mrgreen:

There was a major bust yesterday in NY and NJ so I won't be able to access the registry from Sing Sing! ;)

[tpepmeie]

Todd,

Do you think there any LT-5 CWs this motor either confirms or defies? If so, what are they? :cheers:

I dont know, Dom. The motor did everything I designed it for. I wanted/expected peak power at 7k, and we pretty much got it. Based on the last couple pulls, I can say it peaks around 6900. My calculations say it is airflow and valve-lift limited at just over 700 hp, and thats what we saw. Could have ran the water temp way down in the 170's, leaned it out, and cranked in more spark advance. Maybe another 10hp in it? Hard to run 170 water on the street, though.

Everyone said the inlet ports were too small, yet it made real good power. The torque peak was about 400 rpm higher than I expected (5800), so that may tell that the exhaust cams were too long. The open chamber also had us concerned it might be more detonation prone than the tight quench design. Wasn't. We ran the usual spark advance, with just a spot around 5000 rpm of light knock retard (2d). Pretty standard result.

Interesting, at peak power, the manifold vaccum was about 1.0" Hg. I suspected the throttle body might be a little small, and I think that's confirmed. Maybe 10 hp there, with less vaccum? Cant go any bigger with the factory body, though. A bigger plenum volume might have crutched it some.

The cams really come in hard about 4000 rpm, and the fuel curve takes off at that point. Again, that profile is consistent with the VE curve I saw on the 1-d simulation. We really had a hard time giving it enough fuel up top.

So, no, I don't think it re-wrote basic engine theory or anything. 95% of the power we saw is due to the unique porting and camshafts as designed.

Todd

[XfireZ51]

"Everyone said the inlet ports were too small, yet it made real good power."

Good one.

"...unique porting and camshafts as designed."

Not sure you're giving yourself enough credit for pushing the envelope on lift/duration/overlap milestones.

"We really had a hard time giving it enough fuel up top."

Sounds like it was leaning out. Was bumping the secondary injector multiplier one of the ways you tried compensating? Be nice to have the electronic VariableFPR scheme the ZR1 has for something like this.
Or maybe slightly larger injectors with a change to the BPC. On the VE tables, I'm assuming you were topping out above 100% VE.

Should be interesting to see if the behavior changes much in a real world install.

Hats off!:notworthy:saluting:

[tpepmeie]

Was bumping the secondary injector multiplier one of the ways you tried compensating?

On the VE tables, I'm assuming you were topping out above 100% VE.


We got there in the end through the VE tables and injector size.

VE in the cal ended up way, way above 100%. 120's-130's in fact, to keep it nice and safe up there.

[tpepmeie]

Just got off the dynojet..about 640 rwhp SAE corrected. Hot hot hot coolant, and no tuning. 12:1 afr. Will post sheet later.

Todd

[ALZR1]

Just got off the dynojet..about 640 rwhp SAE corrected. Hot hot hot coolant, and no tuning. 12:1 afr. Will post sheet later.

Todd


Todd you just gotta bring Da pain to the corvette challenge on the 9th of Sep.:-D

AL.

[Demps]

Todd,
Great seeing you back and the engine in a car for you to enjoy.
Ted

Great numbers by the way...

[Blue Flame Restorations]

Wow! I'm only 20 minutes from Indy. I'd love to see and hear that thing run.

[LGAFF]

740hp at the crank?

[tpepmeie]

740hp at the crank?
Well last January = 703 bhp@ STP. A little more broken in by now, so maybe 720? Drivetrain losses aren't a fixed percentage, like you might believe.

There was at least another 10hp in it. Coolant was way over 200F, and the air was really bad. A/F wasn't bad at peak power, but was on its way to 12:1 by the end of the run. We recorded wheel spin, and had it above 6000 rpm, so who knows what it really made.

Crap day for tuning, as my Autoprom took a dump after the second run, so couldnt tune the damn thing. Fuel curve is basically what came off the engine dyno minus 5%.

Cant figure out how to post the graph yet.

[LGAFF]

Are these the same cams, etc?

[tpepmeie]

Are these the same cams, etc?
yes all the same. Just in the car instead of bolted to an engine dyno.

[XfireZ51]

yes all the same. Just in the car instead of bolted to an engine dyno.

So Todd are u bringing the bad boy to Morocco on the 9 th? We'll need all the firepower we can get.

[Pete]

That is the highest HP LT5 N/A and probably has nice street manners.

Tell us more how she drives,how she feels at WOT on the street.

Congrats Brotha
See u at Morocco :)

Pete

[tpepmeie]

Here is the dyno chart, in SAE corrected values. Overall a frustrating day really. Didn't really tune it because the damn equipment died. Only made three full pulls... first one got tire spin from 5000 rpm up. Added some sticky spray to the rollers, and got this result. Tried to duplicate it, but intake air was hotter, and lost 3 degrees timing across the board, so 10hp lower.

Air temp in the dyno bay was 92F, and the coolant was over 200F. Plenum was heat soaked. Intake air temp in the air horn was >150F!!! Next time I am bringing the ice bags for the plenum.

The chart is a little funky, with the data dropout right about the worst spot (6800), but this is the best I could get on this day.

http://i1036.photobucket.com/albums/a441/tpepmeie/427dyno6sae.jpg

[tpepmeie]

That is the highest HP LT5 N/A and probably has nice street manners.

Tell us more how she drives,how she feels at WOT on the street.

Congrats Brotha
See u at Morocco :)

Pete

I have a ton of work to do on the calibration. Wishing now that we would have done more work on the engine dyno, instead of trying to do it now on the street. It's not smooth at all below 3000 rpm yet, nor at tip-in, due to lean mixture I think.

But, keep your foot in it long enough, and the cams come in like a bomb at 5000 rpm. The VE table jumps 20 pct from 4500 to 5000, and you can feel the kick. Its pretty scary to loose grip from the 20year old GSC's at 80 mph.

Its a finicky bitch right now, but I think it will be a blast once I get the tuning right. Oh, and it already fouled one set of plugs from too much idle/low speed running. Great :censored:

[XfireZ51]

Todd,

What size injectors and at what FP r u running?

[tomtom72]

Awesome performance and the potential that seems to be untapped as yet is just too astounding for me to wrap my brain around! Kudos Todd! =D>


When you're finished I'm sure your grin will look like this! ---->:mrgreen:


:cheers:
Tom

[tpepmeie]

Todd,

What size injectors and at what FP r u running?

Funny you should ask that. They are supposed to be new 26 lb/hr Delphi's from FIC. However, on the dyno we had to set the injector constant all the way down at like 22 lbs/hr to richen it up top. Still maxing the VE table from 6000-up. (138 ish.) I've got to just send these injectors off to be sure what they really flow at our rail pressure (52 psi).

Tried to find a LPE adjustable regulator a couple years ago, but no joy :(

[XfireZ51]

Funny you should ask that. They are supposed to be new 26 lb/hr Delphi's from FIC. However, on the dyno we had to set the injector constant all the way down at like 22 lbs/hr to richen it up top. Still maxing the VE table from 6000-up. (138 ish.) I've got to just send these injectors off to be sure what they really flow at our rail pressure (52 psi).

Tried to find a LPE adjustable regulator a couple years ago, but no joy :(

See if u can get the Injector Bias v Bat V from Delphi. You may need to increase the time needed for the injectors to open. More flow will do that. Does the VE table look like it has a bathtub shape to it?

[tpepmeie]

See if u can get the Injector Bias v Bat V from Delphi. You may need to increase the time needed for the injectors to open. More flow will do that. Does the VE table look like it has a bathtub shape to it?

I don't even have the delphi part number, and even if I did, what are the chances they would share that info?

[tpepmeie]

I found the FIC part number from when I ordered them a couple years ago. Says Delphi 26 lbs... 6932 FXC

I thought Jon was on this board sometimes, maybe he could provide a Delphi cross reference number for these. They just don't act like 26'ers.

Todd

[XfireZ51]

I found the FIC part number from when I ordered them a couple years ago. Says Delphi 26 lbs... 6932 FXC

I thought Jon was on this board sometimes, maybe he could provide a Delphi cross reference number for these. They just don't act like 26'ers.

Todd

What FP are they rated at for 26#s? For instance, the Accel Ford injectors a number of us use are rated 21# but 39psi. So in the 45+psi range they are performing like 23# inj.
I'd be interested in seeing the datalog and reviewing the injector duty cycle. You could be going static. Even assuming 26# fuel, I would investigate how much "headroom" you have. You'd like to have 20-25%.
And yes Delphi should publish the Inj. Bias #'s. Bosch and Ford do. That information is pretty important for emissions tuning in order to maintain consistent fueling over a variety of conditions.

[Paul Workman]

Well last January = 703 bhp@ STP. A little more broken in by now, so maybe 720? Drivetrain losses aren't a fixed percentage, like you might believe.


Yeah, a while back, Bob G and I were discussing the validity of a fixed drive train loss factor; is it constant or just a "rule of thumb" applicable for a certain set of parameters/conditions? Drive train loss is a combination of friction and drive train inertia (when measured on a chassis dyno); two separate entities with independent affects.

So, we too are dubious about a fixed loss factor. Furthermore, comparing RWHP vs. stated FWHP numbers measured and published on the stock C6 Z06, it seems to suggest too that the RWHP/.85(factor) results in a FWHP number bigger than GM's "505" hp figure for the LS7 Corvettes. So, your statement seems to support what Bob and I and some others have questioned for some time.

But, all that asside, it sure would be grand to see that beast at the Crown Point Corvette Challenge in Morocco IN on Sept 9th! Think you can make it??

:cheers:

P.

[tpepmeie]

So, I took the car back to the DynoJet today. Actually, two DynoJets, one in the morning and one in the afternoon to confirm.

Hit 638rwhp (SAE) in the morning session. 548 rwtq.

I cannot get enough fuel in it from 5000-6500... no matter what I try, the AFR is 13.5:1. Fuel Pressure is OK, but no amount of change to the fuel table will fatten it up. Conclusion I am drawing is that the injectors are maxed out.

They were allegedly 26lb'ers, but I don't think that can be. Will have them tested, and probably go for 30's next time. I even changed the table offset to try to gain fuel, but wouldn't budge.

The afternoon session on the other side of town was 634 rwhp, with water temps over 200F. So I am pretty comfortable that the morning session is accurate (also made that number last August). It seems to be consistently at this number.

Will post the sheets and maybe a vid later. :cheers:

Todd

[XfireZ51]

Todd,

Sounds like injectors are static. Have u confirmed DC% at WOT?
Also, not sure which injectors you are using but you might check the injector bias tables to see if they match the injector spec. Granted that will make greater diff at lower rpm but it just might give u enough headroom to bring AFR down.
Try increasing them 10-20% and see what happens.

[Schrade]

YiKEs!!!

Pretty big twister!

Looks like you're gonna' need the ZR12 Falconer with extended wheelbase to shoehorn it in!!!

[XfireZ51]

Todd,

Sorry. Just re-read ur post and saw that you had tried the Inj Offset, correct?
Or was that the VE offset.

[cvette98pacecar]

So, I took the car back to the DynoJet today. Actually, two DynoJets, one in the morning and one in the afternoon to confirm.

Hit 638rwhp (SAE) in the morning session. 548 rwtq.

I cannot get enough fuel in it from 5000-6500... no matter what I try, the AFR is 13.5:1. Fuel Pressure is OK, but no amount of change to the fuel table will fatten it up. Conclusion I am drawing is that the injectors are maxed out.

They were allegedly 26lb'ers, but I don't think that can be. Will have them tested, and probably go for 30's next time. I even changed the table offset to try to gain fuel, but wouldn't budge.

The afternoon session on the other side of town was 634 rwhp, with water temps over 200F. So I am pretty comfortable that the morning session is accurate (also made that number last August). It seems to be consistently at this number.

Will post the sheets and maybe a vid later. :cheers:

Todd

Sweeeeet C4 ZR-1 638 RWHP, C6 ZR1 638 CHP.
Once Again...... Sweeeeeet.

[XfireZ51]

Todd,

There's a spot available at the Chicago 1/2mile shootout this June. Not far from the Indy area.

[cvette98pacecar]

Todd,

There's a spot available at the Chicago 1/2mile shootout this June. Not far from the Indy area.

Dom, I think Ronstar was looking for a spot.

[XfireZ51]

Contact Blake Hutchinson at wannagofast.com. I believe any spots available revert back to wgf and there's a waiting list. Ronstar should try there.

[tpepmeie]

Todd,

Sorry. Just re-read ur post and saw that you had tried the Inj Offset, correct?
Or was that the VE offset.


Tried several things, including the VE table offset. These injectors must be very small--VE table is maxed at 140, which clearly is only a band-aid fix to get enough fuel. It's like 13.5 afr from 4700 rpm to 6500. I think there is some more power in it with more tuning.

BTW, for those interested in how much the MAT timing retard affects these motors...on one run the motor was heat soaked and we forgot to turn the external cooling fan on, and it took about 3d spark advance out. Killed it by 20-25 ft-lbs across the board. I zero'd that table, put the fans back on and instantly got it back on the next run.

[tpepmeie]

http://i1036.photobucket.com/albums/a441/tpepmeie/051013run7.jpg (http://s1036.photobucket.com/user/tpepmeie/media/051013run7.jpg.html)

[Paul Workman]

Wow! That is one incredible torque curve!

[FU]

May I ask what kind of compression ratio is in that beast ?

[tpepmeie]

May I ask what kind of compression ratio is in that beast ?

Frank, it's 12:1. If I ever need to rebuild it, I am going higher. I run VP100 in it anyway for insurance (stock headgaskets). Probably would to 14:1 some day...

[XfireZ51]

Try increasing the Inj Offset v Bat V and the Inj. Offset v PW tables.
140 VE% is pretty worthless. Ultimately may need larger injectors.
Based on your results, 30# should give you adequate headroom in injector DC.

[LGAFF]

You can borrow my Callaway microfueler:)

[tpepmeie]

Iphone video of one run. Not the best quality (or camera work).


http://i1036.photobucket.com/albums/a441/tpepmeie/th_427Dynovid.jpg (http://i1036.photobucket.com/albums/a441/tpepmeie/427Dynovid.mp4)

[rhipsher]

Wow! I can tell that monster is no joke. That thing is going be devastating at the drag strip.

[efnfast]

Hoe wee smokes. And it's NA.

[HAWAIIZR-1]

That is just Freakin awesome!!!

[USAFPILOT]

i want one

[tpepmeie]

i want one

I would build another one if somebody wants it. LPE or Haibeck 415 would be cheaper though, believe me. :-D

[rhipsher]

I would build another one if somebody wants it. LPE or Haibeck 415 would be cheaper though, believe me. :-D A 415 doesn't make 638rwhp either. That's hardcore HP.

[tpepmeie]

I'm going to pull the motor later this year and go back on the engine dyno. Calibrating for these cams on the street will take forever and I don't have the patience. Back to the engine dyno to fully map this thing.

Given that it idles at about 70 kpa, I am going to convert to alpha-n and map it based on throttle position. There just isn't enough to work with in the MAP based fuel table.

In hindsight I should have spent more time tuning it on the dyno last time, but was more worried about break in and making a full power pull. And a nervous wreck that it didn't break 😳

I'll see if mr. Haibeck wants to help out later this year. Working with him on the dyno last time was great.

[WydGlydJim]

A 415 doesn't make 638rwhp either. That's hardcore HP.

That's true.......I just had to peep my dyno sheet, and it is 686.
;)
I like the fact that the C.I. is 427.
:thumbsup:

[tpepmeie]

That's true.......I just had to peep my dyno sheet, and it is 686.
;)
I like the fact that the C.I. is 427.
:thumbsup:

I've got a copy of that sheet from LPE. 686 is at the crankshaft. A beast of an engine but well short of where I'm at. i think you'll also have the dyno jet numbers for yours which are in the 570 rwhp region if I recall. Again, a great engine from
LPE for sure.

[WydGlydJim]

I've got a copy of that sheet from LPE. 686 is at the crankshaft. A beast of an engine but well short of where I'm at. i think you'll also have the dyno jet numbers for yours which are in the 570 rwhp region if I recall. Again, a great engine from
LPE for sure.


Ahh that makes sense.....the book I have has the dyno slip and pictured near it is the car on a chassis dyno, but I reread, and it says the dyno slip is from an engine dyno............
This place is crazy...........the knowledge base is so tremendous people know more about your car than you do!
:worship:

[alwayscode390]

Beautiful beast of an engine , congrats! :) ---

[rkreigh]

todd, such an impressive achievement. I can't help but think the megasquirt that raptor and corey are putting together might make the tuning effort easier.

tuning the big cams on the LT5 seems to be quite a challenge, and you really know your stuff. thanks for sharing your experiences.

If I ever need to "freshen" the LSV 390, I'm looking to go to the bigger AES liners and if I can swing it, the Raptor TT package so I can go back to milder cams or at least retime my current cams for wider separation.

hoping I can find a decent deal on a fresh set of 93 heads and cams so I can preserve the LSV top end and pass it on to someone who needs.

the turbos will take care of any flow issues I have without the extensive porting.

good luck with the tuning, keep us posted and congrats on the power you are already putting down. like to hear more about the challenges and any driveability issues you are faced with.

I'm considering going back to a dual mass, (or at least a dual disk clutch) to get back a little intertia (even it costs HP) to mellow out the launch and cure the drivetrain rattle which is pretty bad with the Stg II cams (which are actually pretty mild)

I'm amazed with what the ford guys are doing with the little boss engine, clearly we can do more with the LT5!!!

[RHanselman]

I've got a copy of that sheet from LPE. 686 is at the crankshaft. A beast of an engine but well short of where I'm at. i think you'll also have the dyno jet numbers for yours which are in the 570 rwhp region if I recall. Again, a great engine from
LPE for sure.

Ah, the bigger stick comments begin... Can I play? ;)

Todd, one heck of a motor!

[tpepmeie]

Ah, the bigger stick comments begin... Can I play? ;)

Todd, one heck of a motor!

[-X not what I meant at all, and sorry if it came across that way. But, Ron, Bring it!! J/k. I'll have to rebuild this with bigger cams if you don't watch out :p

[RHanselman]

[-X not what I meant at all, and sorry if it came across that way. But, Ron, Bring it!! J/k. I'll have to rebuild this with bigger cams if you don't watch out :p


I do love those CAM'd up motors and the smell of high octane!

[FastMatt]

That is a sweet 427 LT5 you have there! congrats

[tpepmeie]

Some work to do this weekend... 30lb Ford Motorsports injectors. These are Bosch Design III's and are actually 35 lbs/hr at our rail pressure. That should be sufficient. :-D

And the best part is, I have the full injector dynamic characterization for these. Expecting it will improve the light load operation significantly.

A nearly new set of Lucas 26 lb'ers are for sale, if anyone is interested.

http://i1036.photobucket.com/albums/a441/tpepmeie/IMG_0364.jpg (http://s1036.photobucket.com/user/tpepmeie/media/IMG_0364.jpg.html)

[XfireZ51]

"And the best part is, I have the full injector dynamic characterization for these. Expecting it will improve the light load operation significantly."

Nice to know that. Not sure what the problem is w ACCEL in providing that information. Everyone else has it available.

[tpepmeie]

All back together and running good. This is enough injector to support 900 hp so should be sufficient :)

Also found out the valve stem seals aren't sealing that well, had some oil behind the intake valves. At least now I know it's not getting in past the rings. So add to the list for upgrades next time the motor comes out.

[tpepmeie]

"And the best part is, I have the full injector dynamic characterization for these. Expecting it will improve the light load operation significantly."

Nice to know that. Not sure what the problem is w ACCEL in providing that information. Everyone else has it available.

Dom,
use the F*rd injectors. I can give you the offsets.

Todd

[tpepmeie]

So I am gathering some ideas for a presentation on this engine at BG this year. Help me get started... what would you guys like to know more about? Trying to make it different/more detailed than the HOTB article I did 3 years ago.

I plan to spend most of the time on the induction system, since that is where the power is made. What else?

[XfireZ51]

So I am gathering some ideas for a presentation on this engine at BG this year. Help me get started... what would you guys like to know more about? Trying to make it different/more detailed than the HOTB article I did 3 years ago.

I plan to spend most of the time on the induction system, since that is where the power is made. What else?

Todd,

As I recall you also spent a great deal on the valve train and nailing down the cam spec. As Vizard has demonstrated, matching the cam profile w the cylinder head flow is key to making power. I'd be interested in hearing how you went about that and the development of your objectives for the motor. How did that all play into finalizing the configuration you now have. As a sidebar, what challenges did you encounter on tuning this beast?

Totally unrelated, you really need to bring that baby up here for the 1/2 mile in Monee. Just asking. ;)

[Paul Workman]

:pSo I am gathering some ideas for a presentation on this engine at BG this year. Help me get started... what would you guys like to know more about? Trying to make it different/more detailed than the HOTB article I did 3 years ago.

I plan to spend most of the time on the induction system, since that is where the power is made. What else?

I've got a free hand, Todd. I don't know what I can add to your presentation from an engineering perspective, but far as putting words to a set of your bullet points or editing or producing graphics or especially diagrams, I'll help where I can!

Paul.

PS: YEAH...WHAT DOMINIC SAID!! Some shmarty pants LS7 loud mouths need a lesson in DOHC!:p

[SAM/CH ZR-1]

I'd like to see this beast on a quartermile

Sam

[Hog]

I'd like to see this beast on a quartermile

Sam

Here, here x2!

It would be nice to see all the info complied nicely. I'm sure a lot of the info is in this thread, but details about springs, retainers, cams, heads would all be interesting.
Some of the fun, when dealing with mega-dollars highly detailed and customized engines for me personally, is the small tiny details. Getting very specific with measurements, tolerances and metallurgy always pique my interest.
I love the headers used in this build as well, they are sexy beyond sexy.

I glad that all the part throttle and driveability concerns have been dealt with.
I am in complete love with this specific LT5. I get the feeling that Todd absolutley loved designing and building this engine. I would love to send Todd a blank cheque and have him build a Todd 427 LT5 Mark 2. Perhaps a small metion on what you have learned from your build, and what you would do differently if you did it all again?


I would enjoy seeing a 1/4 mile pass. A pass that concentrates on the fastest mph, not necessarily a pass that requires slicks and hard launching for best ET. ALthough that would be interesting as well. I wonder what the car/engine would mph?

Great work Todd! Must be a great feeling to drive such a great engine after all the research and work you have put into it, such a sweet reward for your efforts.
Congratulations!

[RHanselman]

You going to have time to run at Beach Bend on Friday?

[XfireZ51]

I'd like to see this beast on a quartermile

Sam

I would imagine it really shines AFTER the first 1320.

[USAZR1]

I would imagine it really shines AFTER the first 1320.

Yeah,imagine what that car will do in a 1/2 or full mile?

[XfireZ51]

Yeah,imagine what that car will do in a 1/2 or full mile?

Precisely!

[PhillipsLT5]

Even better 1.5 mile

[tpepmeie]

You going to have time to run at Beach Bend on Friday?

Don't know yet. I would like to. The car needs a clutch first.

[RHanselman]

Corey put a nice clutch in my Turbo Car. Holds real well under 575 RWTQ but I haven't challenged it with any sticky tires yet...

[Bob Eyres]

Don't know yet. I would like to. The car needs a clutch first.

Dual Disc?

[Paul Workman]

Pete, Bob G, and Al are using the RAM dual disc clutch developed for the C4, and reports are they're very nice w/o requiring you left leg to be twice the size of your right!

RAM CLUTCH (http://www.ramclutches.com/)

[Bob Eyres]

Looks like a good choice. I'll bet it makes for a smoother launch too.

Aaah, a naturally aspirated 427 DOHC Corvette with 700+ H.P. I've got to see that car do the 1/4mi.:eek:

[tpepmeie]

I think I'm going to focus on the induction system design, volumetric efficiency and how the engine compares to other benchmarks. Will spend some time talking about the valvetrain specifics and important ratios/measurements for high output.

Finally, I'll present the results of the testing both engine dyno and chassis dyno, and future development opportunities.

I really don't want to repeat the stuff that was in the HOTB article, so I will try to find something different to talk about.

Looking 50/50 that I'll have the car down there. Needs a clutch and WOT chassis dyno tuning before it's safe to take down the 1/4 mile. Will try to make it happen.

[RHanselman]

I think I'm going to focus on the induction system design, volumetric efficiency and how the engine compares to other benchmarks. Will spend some time talking about the valvetrain specifics and important ratios/measurements for high output.

Finally, I'll present the results of the testing both engine dyno and chassis dyno, and future development opportunities.

I really don't want to repeat the stuff that was in the HOTB article, so I will try to find something different to talk about.

Looking 50/50 that I'll have the car down there. Needs a clutch and WOT chassis dyno tuning before it's safe to take down the 1/4 mile. Will try to make it happen.

I just sent in a schedule change to match the timeline you gave me. Plan on 0900-1000 on Saturday.

Cheers,
Ron