What's your ultimate vision for your ZR-1? [Archive]

Aurora40

11-17-2005, 06:58 PM

What do you have in the works for your Z, or what things would you like to one day do to it? You can also list any fantasy Z's you'd like to have, but I'm more interested in things you reasonably plan on doing.

I'm sure for some of you you've already done these things.

I'd like to change my car in the following ways, and these are mostly in order:

Headers (with emissions equipment)
Exhaust: I'm not sure what I want to go with just yet. I like Corsa's straight-through aspect. It seems the ultimate way to go for that pipe size. Plus they aren't that heavy like glasspacked mufflers. I'm not sure the tips look right to me for an '80s Corvette, though, and I have to think about what kind of sound I want
Port and polish. I like the idea of a 350, but getting some free extra power out of it is sure cool. On the street, what difference does it really make if you have 475hp or 1000hp. I'm sure both are fun to drive (as is 375hp). But ~500hp seems like a good place to be at, especially in a motor that will still be smooth and such.
Brakes upgraded to 6-pistons in front and stainless lines. Nothing crazy, or for racing, just a step up. I do like how the stock rotors fill the wheels, though.
Wheels maybe. I like the 5-spokes, but I really dig OZ Mitos
I'd like perfect paint. Mine is pretty nice, but not perfect. Not sure if I'd want a respray, though, as it's only new once.
I think the Callaway aerobody is cool, but I kinda think I would keep a stock body even if I had a lot of money to toss around. The 1990 is distinct, only one year and one model looked like this.

I also think it would be cool to have a totally stock 1990 in Steel Blue to keep. It was just a cool color. But red/red is so sweet, albeit common, that I just had to get that. :)

What would you like to do to your car?

Edit: I also meant more mod stuff than maintenance stuff. But other things I am planning are changing the diff fluid, new tires, and new injectors, in addition to whatever else pops up. :cheers:

Z Factor

11-17-2005, 07:27 PM

My goal when I started was to be able to reverse any modification to make it bone stock if needed for resale value. So with that in mind I have put on headers, X-pipe, and B & B exhaust, but I have kept the stock manifold/cats and exhaust. I will go with a performance chip once I decide on the best one, and I'd like to get a Dyno Tune from Aaron at SGC. I might go with a P & P of the plenum and IH, but that is about it. If I were to change the rims, I'd keep the stock ones, and if I were to upgrade/change the brakes, I would still be able to reverse them if needed.

So while some of the guys are going for the ultimate in HP :thumbsup: , I'll be content to get around 400 rwhp.

:cheers:

11-17-2005, 08:25 PM

The 93 Green LPE/LSV 385 will stay as it is. And will be enjoyed during good weather. Yes the car gets used in the rain.

The White 91 415 is pretty well done up also. But it may go for sale come spring time.

cuisinartvette

11-17-2005, 09:46 PM

Callaway Z Speedster....

For mine:

-New leather on the seats
-Top end porting job
-Headers, bullet cats, Corsas
-A Molds
-Lowered 1-1/2 in. in rear
-Hurst shifter
-Paint & tires (done)

Good enough for me...

95ZR1#418

11-18-2005, 12:08 AM

I consider mine done outside of maintenance items. This winter will be replacing the ZF, water hoses/TS, fluids, plugs, belt and finally more Zaino. :mrgreen:

Patton

11-18-2005, 01:18 AM

- Headers (CA legal) into RT cats into X pipe into B&B.
- Port & Polish the pleunm and IH.
- RC fuel injectors,... and,.......
Wait a minute what the hell am I talking about. I just want to fix my GODDAMN vacuum leak!! :sign10:

Basically I want 400rwhp with a stock look, even under the hood, except for maybe a smooth air intake and slotted/drilled/zinc washed rotors and a caliper that lets go of its heat better than these.
I would like to get a fiberglass roof too.

We Gone

11-18-2005, 08:14 AM

Just P&P and a good tune Other than that its just how I want it. :mrgreen:

Mods so far

Open air filter
Flowmaster catback
tuned chip
cross-drilled rotors/GS calipers
5-spokes

Kevin

11-18-2005, 11:17 AM

Repaint to get rid of orange peel
Port/polish/pc cam covers/plenum
redue interior
headers/cats/stock 94 system w/flowmasters
new tune
C6 Z06 Calipers
gears (maybe) I like hitting 120 in third
bypass the TB coolant line
reroute the IAC
shifter
c-beam plates
Keeping it out of the hands of an NCRS guy.......priceless

Kevin

11-18-2005, 11:54 AM

I would like to get a fiberglass roof too.

I may have a red one from a 91

Nick

11-18-2005, 12:38 PM

I think I'm done with this one. Planning for the next one, though! :mrgreen:

Jeffvette

11-18-2005, 01:42 PM

I think I'm done with this one. Planning for the next one, though! :mrgreen:

:???: You going to get a yellow one for Anne?

Patton

11-18-2005, 03:54 PM

Kevin,
Hmmmm,... Wonder how much it would cost to paint it.

Would you like to sell it? Assuming a 91 would fit on a 94... I think it would, anybody know for sure?

Thanks Kevin!

Kevin

11-18-2005, 03:59 PM

I'll check to see if I have it still when I get home

A1990

11-18-2005, 04:22 PM

Kevin,
Hmmmm,... Wonder how much it would cost to paint it.

Would you like to sell it? Assuming a 91 would fit on a 94... I think it would, anybody know for sure?

Thanks Kevin!

Yes it would fit. 89 and up are same.
http://www.ecklers.com/images/vette/34262.jpg

A1990

11-18-2005, 04:24 PM

Watch out guys, when the mod bug bites you are done for. There is never enough power. Once you get used to 400rwhp, you will want 500.

wonder how I know this...:confused:

Patton

11-18-2005, 04:35 PM

I was bitten by the mod bug when I was about 18, been infected ever since. Trust me, it isnt the lack of desire for more power,... Its the allocation of resources (or lack of resources!) to provide that power that stops me! :cry:

tomtom72

11-18-2005, 05:45 PM

That's why I bought a ZR-1...they are almost mod proof. Everything costs way too much for my budget.

"speed secrets are like military secrets...very fleeting, indeed..."

:mrgreen:
Tom

Patton

11-18-2005, 07:46 PM

mod proof,... I like that. It sure the hell is isnt it?

Seems like if you want to do ANYTHING over a damn air filter you are going to spend over a grand.

bobbyhi

11-18-2005, 11:28 PM

Next purchase will be headers, port & polish, and add some color under the hood. Just have to decide if I want long headers or go with the cats connected to the Power Effect exhaust. All on my Christmas list from Santa:rolleyes:

tomtom72

11-19-2005, 10:11 AM

mod proof,... I like that. It sure the hell is isnt it?

Seems like if you want to do ANYTHING over a damn air filter you are going to spend over a grand.

Yea Patton and the jury's still out on the A/F thing!! :sign10:

Figure from my perspective & I've been absent for 20 yrs from vette ownership. You used to rebuild an entire sb chevy for less than 1/2 the cost of a set of headers for a ZR-1! Talk about sticker shock? I rebuilt an entire 72 LT-1 mechanically back in the late 70's for alot less than a trip to Mr. Haibeck for top end P & P w/ doing the heads and chip & headers & exhaust! That's like almost $10,000.00 and I'm not saying it's a bad price...just alot different from the late 70's! I rebuilt the suspension, brakes, cooling, motor, trans, rear, and A/C sys & heat in my 72 for less than $5,000.00 back in 78.

God, I'm soooo out of touch! But I love this car sooo much even if it's stock!! :mrgreen:

:cheers:
Tom

Aurora40

11-19-2005, 10:14 AM

I rebuilt the suspension, brakes, cooling, motor, trans, rear, and A/C sys & heat in my 72 for less than $5,000.00 back in 78.

$5,000 in 1978 is the equivalent of $15,276 today.

Patton

11-19-2005, 04:09 PM

That's like almost $10,000.00 and I'm not saying it's a bad price...

I am!! Who the hell prices this shyt? They have such unreasonably high prices because there isnâ€™t much demand for them so they have to make a killing with every sale, AND they know the majority of ZR-1 owners aren't counting pennies... being in the minority freakin sucks. :thumbsdo:

I wonder how precise you have to be when porting,... I know anybody can polish their own stuff, just get a dremmel and a nice accessory kit with bendable arms and such. But I wonder if porting is feasible for your average gear head.

And donâ€™t get me started on the headers,... a couple of SS pipes welded together for $1000? Give me a goddamn break, highway robbery is what it is... If someone competed with these guys, he could make a killing. The problem is to compete like that and sell less expensive solutions you have to sell a crap load of them to come out on top and there arent enough ZR-1s to support that... sooo we end up exactly where we are. At least we dont have to pull the engine and spend 10k to change the belts! Poor ferrari owners...

tomtom72

11-19-2005, 04:14 PM

$5,000 in 1978 is the equivalent of $15,276 today.

I was thinking about inflation, that is a heep o cash but I was young, stupid, single, etc. Now I'm the same except for the young part. I just paid the car off about three months ago. I hope I can use it awhile before my second childhood makes me look for stuff for the Z to spend more cash on. If I get some spare cash I'd like the 400 rwhp package from Haibeck, that would be nice. :mrgreen:

tomtom72

11-19-2005, 04:26 PM

I hear ya Patton! It's like you said...a small group of cars to work on so the stuff is like custom stuff...pricey for sure.

I have taken a dremel to old sb cast iron heads back in the bad ole days. I'm not so sure I'd be brave enough to do it to stuff ya can't get in any junk yard. I mean sb stuff used to grow on trees & was about as cheap! I'm not so sure I'd have the stones to mess with LT5 stuff except to use a cotton swab on it! :o

I port matched my LT-1 exhaust manifolds because no body made headers for a sb vette that took the A/C mounting brackets! Talk about needing a brain tune up! Man what a dunce I was but I swore up & down it made a difference! :mrgreen:

bobbyhi

11-19-2005, 05:26 PM

I have to disagree with Patton somewhat. I do not have the knowledge to do some of the work on my Z. I know knowledge is learned by doing but being not too mechanically minded I have to turn to others for most major mods. When Marc works on my car I have the confidence that he knows 110% of what is right and what is wrong. I cannot do all of the things I would like because of budget restraints but look forward to the day I bring my car back to Marc.

Watching your posts and replies it is apparent that you have the moxy to be able to do what you do. I sometimes wish I had the know how that so many of the members have. I have been very impressed with the answers to many of the tech posts. Sometimes I don't have a clue what you guys are talking about but it is enjoyable to read. My hat is off to all of you!!!!! Thanks for all of the, maybe sometime, information that I might use.=D>

Aurora40

11-19-2005, 06:26 PM

I wonder how precise you have to be when porting,... I know anybody can polish their own stuff, just get a dremmel and a nice accessory kit with bendable arms and such. But I wonder if porting is feasible for your average gear head.
You basically just explained why it's expensive. A person has to develop a product first, then sell it. So the fewer you sell, the more R&D cost you have to put on each unit. It's not like it's a bunch of money-grubbers selling this stuff.

I'm sure you could port your own stuff if you knew what you were doing. One thing is the risk and cost associated with that risk. A new TB from GM is about $1,900, a plenum is $1,300. At least the IH's aren't so bad. So if you mess one up, you aren't going to save much money. Compare that to having Marc port those for $2,800 including a chip for your car and the labor, and it's about how much risk are you willing to absorb.

For headers, I guess it seemed to me that $1000 is kind of par for the course for a lot of cars. 4-banger headers seem to be around $400 or so, multiply that by 2 for a V8. I dunno... It's not cheap, for sure, but at the same time it's not way out there.

Just my thoughts. Of course I wish stuff were cheaper too, though. Especially regular replacement parts. Some of those prices are insane.

tomtom72

11-20-2005, 09:28 AM

You are right A! People have to make a profit, this isn't a communist system. You guys that have kept up with the car stuff over the last 20+ yrs are used to the numbers. I've been away so it's more like sticker shock at the numbers, without taking inflation into the mix. If you take inflation into the mix the prices are about the same. I remember back 20-25 yrs ago sb headers came in two types: those that worked & those that were BS! Ya got what ya paid for, as always. I remember back in the 70's that machine shops that had flow benchs were few & far between!

I would only add one thing to my Haibeck wish list, send the my car to zfdoc for the tranny blueprint. So now I gotta really save my nickles to do my wish list. Can't beef up the motor without the tranny getting some work.

Would you attempt the headers & exhaust by yourself in your garage? How do you feel about just taking the plenum & I/H's & sending them out for a P & P? The headers & exhaust look a bit tough to do to me. I guess I'm not used to working on a C4. The old C3's were a bit easier, or at least it seemed that way.

Bobbyhi, I am envious of you! You live within reasonable distance to one of the ZR-1 wizzards. I'd give one of my n#ts to have Mr. Haibeck work on my Z! :notworthy
Thanks for putting me in with the owners that know how to work on these cars. I'm just a graduate of "plenums 101" though! I did the most elementary operation an owner can do, it's like Jeff said..."hey guys, this isn't brain surgery!" I did my work out of necessity...I figured that why let some one work on my LT5 who never has...I never have so what makes them more qualified than me? I felt if some one is gonna cut their teeth on an LT5 it isn't gonna be my LT5...heck with all the knowledge here & the shop manuals I thought I should try. It could have turned out bad or I could also fix my troubles. It was a simple repair, complicated in steps due to the sheer number of little things in the way. In the end it was just like Jeff said, not brain surgery. The best part was that I need to see things & put my hands on them to really understand what's going on, and by doing a simple thing I learned by seeing. I now have a better understanding of at least one of the systems on a ZR-1. I feel it was time well spent for me. Ya know if I lived close to Mr. Haibeck's shop the "neighborhood play rule" would have come into effect..."ah heck while you've got the plenum off, you might as well just do...." Then I'd be in debt up over my nose! :mrgreen:

:cheers:
Tom

Aurora40

11-20-2005, 10:21 AM

Would you attempt the headers & exhaust by yourself in your garage? How do you feel about just taking the plenum & I/H's & sending them out for a P & P? The headers & exhaust look a bit tough to do to me. I guess I'm not used to working on a C4. The old C3's were a bit easier, or at least it seemed that way.
I'm not sure who you were asking, but I'd try headers and exhaust myself. I think the exhaust wouldn't be that hard, usually the hardest part is removing the old fasteners. Having a propane torch usually helps a lot. The headers, I'd probably try it. I suspect they are like the plenum, the idea isn't really hard, there is just a lot of stuff in the way.

I actually am probably going to send my plenum and IH's out to Marc. I can't for the life of me get my idle thing fixed. It seems definitely the TB because if I pop the hood and press hard on the throttle assembly to close the butterflies, the idle will drop from about 1500 down to 1200-1000. I don't know why it won't drop to 650 unless it leaks and sticks or something... Anyway, I've pulled it twice and can't noodle it, so I'm going to send it off. I'll do the injectors at the same time.

I guess I'll be running the stock exhaust for a while then...

cuisinartvette

11-20-2005, 11:45 AM

Yup, specialty work/parts is never cheap, they get paid for what they know. The sticker shock is there, but that's to be expected when you own one of these cars. Trying to do as much of it myself as I can, but sometimes these things are best left in the hands of experts who do it everyday. I have no fear of diving into an intake or a set of 2v heads, but I'm not familiar with the LT5 heads, and would hate to discover a water jacket by accident. Not like you can just go pick up a new casting at the parts store...Its all relative.

Nick

11-20-2005, 01:20 PM

:???: You going to get a yellow one for Anne?

Maybe a turq! :mrgreen:

Jeffvette

11-20-2005, 01:21 PM

I am!! Who the hell prices this shyt? They have such unreasonably high prices because there isnâ€™t much demand for them so they have to make a killing with every sale, AND they know the majority of ZR-1 owners aren't counting pennies... being in the minority freakin sucks. :thumbsdo:

I wonder how precise you have to be when porting,... I know anybody can polish their own stuff, just get a dremmel and a nice accessory kit with bendable arms and such. But I wonder if porting is feasible for your average gear head.

And donâ€™t get me started on the headers,... a couple of SS pipes welded together for $1000? Give me a goddamn break, highway robbery is what it is... If someone competed with these guys, he could make a killing. The problem is to compete like that and sell less expensive solutions you have to sell a crap load of them to come out on top and there arent enough ZR-1s to support that... sooo we end up exactly where we are. At least we dont have to pull the engine and spend 10k to change the belts! Poor ferrari owners...

Francisco, a polish job does nothing for air flow, it would be a waste of time and money. And a dremel isn't going to cut it. You just can't remove the material. I'm offering porting and powder on the top end for 1K for the package. Nobody else can touch that cost period.

Headers, picture spending hours upon hours of cutting, welding, mounting/unmounting, cutting, welding... and so on, then you start to see the R&D time on making these things. It's not like working on a open frame hot rod where you don't have to be precise, you are working on a closed vehicle with fiberglass floorboards and wiring harnesses. You make a mistake and you either melt a car or destroy a harness. 1,000 for headers is justifiable.

With 6,939 (minus the ones that have died) cars sitting on the ground then subtract all the cars in collectors hands that will never ever be driven, or modified and you're left with a handful of cars to work on. That market is slowly drying up. LPE I think has done maybe 2-3 ZR-1's in the pst 2 years. SGC has slowed down on LT5's, Vette Dr.s who knows and DRM is unkown.

Patton

11-20-2005, 03:29 PM

Jesus Jeff, looks like a touched a sore spot! ;)

If you read my post carefully I was griping about paying the huge price but explained why they are so high at the end because of supply and demand and there can be no mass production items because there is no mass to produce for!
That bieng said I didnt think about the crap it takes to design headers, Its not like GM is going to happily hand over their R&D work to help you any, very good points.

I'm offering porting and powder on the top end for 1K for the package. Nobody else can touch that cost period.

SAY WHAT? You do top end work?? Jesus, I didnt even know, so top end porting nd powder coat for 1k? Now see, thats what I am talking about! Competition is beautiful. I would send my stuff to you WAY before anbody ealse. I think your closest competitor is 2k! Thats kick ***, way to offer us Z guys another solution. Hopefully, within a year I'll be asking you to have mine done.

That market is slowly drying up. LPE I think has done maybe 2-3 ZR-1's in the pst 2 years. SGC has slowed down on LT5's, Vette Dr.s who knows and DRM is unkown.

I know, Im not even in the buisness and I can feel it happening. I just hope I can get my stuff done or know enough people before the well is all dried up. LPE used to sell different performance parts for the Z like headers and what not,... I checked about a month ago and they dont have ANYthing except their insanely priced packages.

How much does it cost to ship the top end?

Thanks for the info Jeff.

Kevin

11-20-2005, 04:33 PM

Jeff will be getting my top end as soon as I can afford to fly him out.

Patton

11-20-2005, 04:59 PM

Bobbyhi, Aurora40, Cuisinartvette...

Ahhh hell I know why they cost so much, Im just bitching and moaning cause I dont have the money!! :sign10:

Factoring in the R&D and the fact that its a rare car makes the 1k for headers understandable. But the port/polish/powder type stuff for about 2-3k is just too much. Now all of that for 1k sounds very reasonable! I would take Jeff up on that in a heartbeat, and I will the moment I have the money to play with! :thumbsup:

Locobob

11-20-2005, 05:48 PM

SAY WHAT? You do top end work?? Jesus, I didnt even know, so top end porting nd powder coat for 1k? Now see, thats what I am talking about! Competition is beautiful. I would send my stuff to you WAY before anbody ealse. I think your closest competitor is 2k! Thats kick ***, way to offer us Z guys another solution. Hopefully, within a year I'll be asking you to have mine done.

Jeff does the powder and I do the porting, you can see some of our work on the Corvette Forum. Just finished one a few weeks ago, maybe I'll put up some pics here if people are interested in seeing it.

Z Factor

11-20-2005, 08:15 PM

Jeff does the powder and I do the porting, you can see some of our work on the Corvette Forum. Just finished one a few weeks ago, maybe I'll put up some pics here if people are interested in seeing it.

I believe many people would, myself included, so please do.:thumbsup:

:cheers:

tomtom72

11-21-2005, 08:47 AM

Okay now it's my turn to own up to being :sleepy1: Jeff & Bob do top end work! That is choice!! :thumbsup: Looks like I have to save some more nickles. Oh, damn this is starting to get baaaaad. There goes my original premise for buying this car...mod proof...ugh! Oh well I gotta keep up with the C5's I hang with on cruises.

Okay, Aurora I know you had another C4 so you are more familiar with the car than I. I should go do some research & eye up my car to see what's up with headers. Good luck with the T/B & P & P work. I don't get that idle thing at all. I guess I was lucky it did not happen to me. I would like to know anything that Marc says about what caused that to go wrong. If you would not mind sharing, that is. I would also be curious what the results of a P & P job would be on a car w/o headers? You are doing the headers at the same time as the P & P job or waiting to recover a bit?? I apologize for being nosey. I'm just thankful for whatever info you may want to share! :thumbsup:

:cheers:
Tom

Patton

11-21-2005, 02:07 PM

Jeff does the powder and I do the porting, you can see some of our work on the Corvette Forum. Just finished one a few weeks ago, maybe I'll put up some pics here if people are interested in seeing it.

:hello:
I had no idea. You guys gotta put the word out, Im sure people would jump at that price!

Pictures Please!!

cuisinartvette

11-21-2005, 02:14 PM

Jeff will definitely be getting my powdercoat work, maybe I won't polish the motor after all...The silver looks awesome.

Aurora40

11-21-2005, 05:29 PM

Okay, Aurora I know you had another C4 so you are more familiar with the car than I. I should go do some research & eye up my car to see what's up with headers. Good luck with the T/B & P & P work. I don't get that idle thing at all. I guess I was lucky it did not happen to me. I would like to know anything that Marc says about what caused that to go wrong. If you would not mind sharing, that is. I would also be curious what the results of a P & P job would be on a car w/o headers? You are doing the headers at the same time as the P & P job or waiting to recover a bit?? I apologize for being nosey. I'm just thankful for whatever info you may want to share! :thumbsup:

:cheers:
Tom
Hey Tom, I had an '87 but I never put headers on it. I don't know what prices are good or bad, just that ~$1k for headers doesn't seem so out there? They are stainless, fit well, etc. Toss on some cats and you are talking $1500-1700. Cats are expensive due to the materials in them. I realize it's steep, but no steeper than putting 18" wheels on a Civic or something. But there's a lot more bang for the buck.

Marc thinks the secondaries are hanging up, which seems reasonable. I just can't see where they are hanging up. They close fine when removed, but of course there is no vacuum then working against them. I've tried letting them back slowly and such, still they close fine. You can't see light through them except on the sides a little where the shaft is, which I imagine is quite normal. There's actually even some trace of the dag still left around the blades. I don't want to randomly sand away at stuff trying to fix the hangup, I can't noodle what's wrong, and the TB is too dang expensive. So punching it out to 63mm should remove whatever the problem was.

I won't be doing headers now, probably not for a year or more. With the plenum P&P and new injectors, that's a fair bit of change... Also, my buying experience was a fair bit like yours. The car ran great, seemed well cared for, the guy had held the price for a long time and wasn't budging. I liked the car, it's local, etc... Probably overpaid by a few, but oh well. Still a great car and I'm sure I'll get many years of fun out of it. In the long run it won't matter so much.

Marc includes a chip, so with new mapping, more flow, and non-leaky injectors, it will hopefully be fast and smooth! It will be sort of a sleeper what with the stock exhaust and rather tame note. :)

Jeffvette

11-21-2005, 06:18 PM

It really shouldn't the large secondary blades that are hanging. It usually turns out to the be the primary blade as it doesn't have much tension on it and jams with crud easier.

Take your finger and open the primary blade and slowly let it close.

Aurora40

11-21-2005, 07:28 PM

Well, then pushing on the throttle assembly wouldn't drop the idle, would it? Because the primary doesn't get pulled back by it. Pressing on the little primary tang didn't do anything when it's in high-idle mode. Also, easing the secondaries closed would also ease the primary closed. :)

The primary is spotless, no crud. I cleaned it up well. It definitely has gaps around it, but these are mechanical in nature from the idle-stop screw. It doesn't make contact with the bore anywhere, so I wouldn't think it could hang up from interference. I didn't want to mess with the idle-stop, though, as the car didn't used to idle high until I did the plenum pull and cleaned the TB.

It only happens after heavy throttle, though this doesn't automatically rule out the primary since it too is open during heavy throttle. But light blips of the gas don't fix it, I suspect because the secondaries aren't being blipped. In gear hard blips will sometimes bring it down, I assume because then it's possible to blip the secondaries. Blipping it out of gear, the engine revs too fast to get the secondaries in. I wouldn't want to blip the motor up and back to 4-7k or anything, I don't believe that's very good to do?

Jeffvette

11-21-2005, 07:36 PM

You shouldn't ever have to touch that idle control screw. if you are you are just masking another issue(s). When Merc received those, they did not adjust them, they were bolted on and left at the predtermined point. The IAC does more to control the idle.

I've played witha few TB's and have seen the primary bore hang open when slowly being closed. When snapped shut it closes. I hate to see you spend money on a 63mm when you shouldn't have to.

Patton

11-21-2005, 08:47 PM

WOW,... I thought ZR-1 mods are pricey until I got curious about other exotics and went lookin. A Lamborghini Diablo (early 90's) muffler,... 3000 dollars.... A whole cat back system is 9,000 and the headers are 4000. Thats not taking into consideration that its gonna require you to pull the goddamn engine to do it.

Ya,... I take it allllll back! Thank God for GM :dancing

tomtom72

11-22-2005, 09:11 AM

You got that right Patton! What was it some one said? "If you have to ask how much, you can't afford it!" Well , that's me!

Aurora, Yes you & I are a similar with our buying experience. I shrug & just chaulk it up to buying a used car. I am in no way less jazzed about the car, it's too amazing to me that I actually own a ZR-1! That I get to drive it whenever I want is like a drug. I'm addicted to this car. My previous owner was a book maintenence type guy, except for the coolant & oil. The rest he let the dealer take care of & it wasn't much except for recalls. Heck, he didn't even complain about the old chip & the idle problems. I'm down with you on the price but I consider the well kept cars will always carry a bit of a mark-up over the norm. I was well pleased with what I got for my 24,900.00. But that is in the eye of the buyer & it's subjective.

What has me stumped with this header thing is that I read that you want bigger dia. exhaust after the headers & cats. It seems to me that the ticket is 3" stuff but I only found 2.5" to 2.75" stuff. I have not looked at the designer stuff, only the standard packaged cat back sys from like Flowmaster. It looks like you need to know how to weld or know a shop that's willing to do some fab work. I got stuck on that write up by Hib about his exhaust sys. That seemed like the way to go. I gotta hang out with the local gear heads so I can find out which shops do that stuff in my area. I've been gone too long for me to know. Oh well once more into the breech! Gotta go drum up some side work to fund the ZR-1 project. Mod proof...ha! Now I'm gettin the bug.

If I knew enough to offer info on your problem I sing out...trouble is I don't. Can't wait for you to tell about the stuff when it comes back from Marc! Good luck! :thumbsup:

:cheers:
Tom

Aurora40

11-22-2005, 01:00 PM

What has me stumped with this header thing is that I read that you want bigger dia. exhaust after the headers & cats. It seems to me that the ticket is 3" stuff but I only found 2.5" to 2.75" stuff. I have not looked at the designer stuff, only the standard packaged cat back sys from like Flowmaster. It looks like you need to know how to weld or know a shop that's willing to do some fab work. I got stuck on that write up by Hib about his exhaust sys. That seemed like the way to go. I gotta hang out with the local gear heads so I can find out which shops do that stuff in my area. I've been gone too long for me to know. Oh well once more into the breech! Gotta go drum up some side work to fund the ZR-1 project. Mod proof...ha! Now I'm gettin the bug.

Well, B&B has a 3" system. Callaway has a 2.75". And Corsa and Flowmaster have a 2.5". The stock system seems to be ~2.75" at the cats, 3" back by the mufflers, and neck down to less than 2" into the resonator and back out.

In my opinion, the design matters as much as the size. For example, say you have a 3" system that has two 180-degree bends in the mufflers. Or has a bunch of chambers with offset entry/exits. Or it has baffles in the airflow path. Will that flow better than a 2.5" pipe that has no bends or chambers?

In general, OEM mufflers tend to use bends, though I don't know about the Corvette. Mufflers like Dynomax also use bends. Sometimes the bends are in conjunction with chambers. Flowmaster uses chambers and baffling. Companies like Borla and Magnaflow use perforated straight pipe with glass matting around the pipe. I suspect this is what B&B uses, but I've no real basis and never asked them. Corsa uses resonance chambers around a straight pipe. So the pipe only has one small ring cutout, not perforation.

In general, a given diameter of pipe will flow less when it is heavily perforated than it will when it is solid. And certainly chambers and bends will flow less than straight. So then the question is how much does size matter when you have different constructions? Does a custom 3" Flowmaster system with chambering and baffling flow better than a 2.5" non-perforated straight pipe? I dunno, maybe, maybe not. Flowmaster also has different degrees of baffling/chambering depending on the muffler. The loudness goes up with the less baffling.

As to how much is enough, I imagine that depends too. On a 350ci motor at 7,000 rpm, how much flow is needed? Dual 2.5" pipes have the same cross-sectional area as a single 3.5" pipe. To put it in old-school Corvette perspective, a 350ci motor at 7,000 rpm is displacing as much volume per second (i.e. flow) as a 427ci motor at 5,700 rpm, or a 454ci motor at 5,400 rpm.

I think Corsas in general are neat. I have them on my Aurora and was impressed with the quality, the light weight of the mufflers, and the sound. I just think the tips are too flashy for the '84-90 style of 'vette. But they'd be strong on my list of replacements. I would like a bit deeper/rougher sound, though. The Corsas in Jeff's clips sound like my Aurora on steroids, sort of a refined crips burble, very exotic, though Jeff's car sounds a lot more rough and tumble than the Aurora, as you'd expect from an extra 1.7L of motor. I'm not sure if that's the sound I want or not from the ZR-1. I'll have to think about it. But I definitely like the design of the system. A 2.75" system would appeal even more, though. 3" seems a bit big for a stock motor, but what the heck do I know...

Only mildly related, the Aurora had a stock single pipe of about 2.25" that Y-d into 1 7/8" to the mufflers. The Corsa is 2.5" all the way, and bumped the power very noticeably. VERY noticeably. This is a 4.0L motor that revs to 6,500 rpm, so it is trying to push about 35% less volume out per period of time. Yet it gets by with a single 2.5" pipe quite well. Though, maybe there's even more power left on the table, who knows. I'm sure there is in the manifolds, as it's a big transverse motor with a big tranny, and there isn't much room for the manifolds at all.

Jeff, I'll PM you about the TB. Thanks. :)

Jeffvette

11-22-2005, 01:54 PM

The Corsas in Jeff's clips sound like my Aurora on steroids, sort of a refined crips burble, very exotic, though Jeff's car sounds a lot more rough and tumble than the Aurora, as you'd expect from an extra 1.7L of motor. I'm not sure if that's the sound I want or not from the ZR-1. I'll have to think about it. But I definitely like the design of the system. A 2.75" system would appeal even more, though. 3" seems a bit big for a stock motor, but what the heck do I know...

Jeff, I'll PM you about the TB. Thanks. :)

On the engine size, the Aurora is lacking 2.0 litres. I'm running a 368. ;)

As far as exhaust, the Corsa with the 2.5" pipe does just fine for a 350, and even up to the 368, although I know I'm probably missing some ponies. Going to a 3" system doesn't hurt either. Most people claim back pressure helps, but after seeing a car with supertraps adding removing discs didn't affect the hp/tq output. The LT5 just wants to move air and it seems to do it no matter what.

Reponded to your PM.

tomtom72

11-22-2005, 08:12 PM

Aurora, thanks for the results of your research. I started to remember some of the HVAC stuff I was taught. Yes bends generally are bad but they can be overcome...that's where the R & D $ goes. I guess it's time to save up for the headers.

Jeff thank you also for the sharing of your experience. I will worry less about what size pipe & more about coming up with the cash for headers and an exhaust system to mate to the headers. I gotta do cats due to DMV regs.

I think I will lean more toward getting space to pull the plenum & I/H to get port work & finish work done by the friendly local west coast duo. I also like stealth! :mrgreen: I know how to pull that stuff off, I'm not so sure I'm ready to do headers & an exh. system with my short experience.

Good luck with the T/B and thanks again for sharing info Aurora! :thumbsup:

:cheers:
Tom

Locobob

11-22-2005, 11:24 PM

For those who wanted to see my porting work I put up a new thread with some pics for you.

Locobob

11-22-2005, 11:36 PM

On the engine size, the Aurora is lacking 2.0 litres. I'm running a 368. ;)

As far as exhaust, the Corsa with the 2.5" pipe does just fine for a 350, and even up to the 368, although I know I'm probably missing some ponies. Going to a 3" system doesn't hurt either. Most people claim back pressure helps, but after seeing a car with supertraps adding removing discs didn't affect the hp/tq output. The LT5 just wants to move air and it seems to do it no matter what.

Actually thats not quite accurate Jeff. When we played with my Supertrapp mufflers on the dyno the car lost about 10hp up top when we added backpressure. I expected the added backpressure to add low and mid range torque but it did not. The car made best power at all rpm levels with the exhaust wide open.
Lesson = LT-5's like to breath.

Jim Jones

12-06-2005, 11:27 PM

I will keep it pretty much stock. I already have an aftermarket exhaust and I am hoping to get a chip from Haibeck next year to help with some of the idle problems. Other than that, I am hoping for a re-paint in a few years, budget willing.

Jim

djpatrick35

03-22-2008, 01:36 AM

This is a REALLY old thread, but I think it's relevant for everyone - especially me after the wreck.

Now that I have the green light to repair my ZR-1, I've been thinking that this is a chance to mod w/o fear of retribution. So if I had unlimited funds, I would:

Make the entire car a black/red combo. I'd keep the exterior black as is, but I'd put on C6 brakes and paint the calipers red.
I'd get Grand Sport rims.
I already have black/red 94-96 base seats for the car.
AND if we could get pics from that carbon fiber interior guy over on CF, I might be interested in changing out the gray center console with a red carbon fiber pattern

Under the hood:
I'd get Hiabeck's 500 hp combo (I don't think I could really handle much more b/c I don't race and I don't drag race, but I do love being thrown back into my seat)
Also I'd powdercoat the LT5 red - I think that would look really wicked with the hood open and red calipers with black Grand Sport rims.

As to what I'll actually achieve in the short term, I'm probably going to get GS rims b/c one of the rims was damaged in the crash. And I'm going to pay for the rest of the car to get painted along with the insurance picking up the tab for the front end. So I should have a nice black paint job by summertime (hopefully).

Other than that, I just want my Z back from the grave!

--Dan