427 Assembled

[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.

[tpepmeie]

Originally Posted by 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

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

[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!


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



Tom

[tpepmeie]

Originally Posted by XfireZ51

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]

Originally Posted by tpepmeie

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]

Originally Posted by XfireZ51

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]

Originally Posted by 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

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]

Originally Posted by tpepmeie

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??



P.