Camaro Iroc VS TPI C4
Thread Starter
Melting Slicks
Joined: May 2006
Posts: 3,385
Likes: 4
From: King George VA
Camaro Iroc VS TPI C4
I just found a old time slip of my 87 Iroc. How would it compare to a stock L98 (TPI 350) C4?
R/T .709
60 ft 2.088
1/8 9.257
1/4 14.383
MPH 96.75
Temp F. 74
Rel. Humidity 86
Absolute Baro 29.36
R/T .709
60 ft 2.088
1/8 9.257
1/4 14.383
MPH 96.75
Temp F. 74
Rel. Humidity 86
Absolute Baro 29.36
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Team Owner
Joined: Oct 2004
Posts: 81,241
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From: altered state
St. Jude Donor '05
What I was wondering. most were 15 sec 305s. THere were some 350 5 speeds but from what I recall not too many. I only saw one, an ins rebuilt car from Hawaii I really wanted to buy. nice ride.
Le Mans Master
Joined: Aug 2005
Posts: 7,392
Likes: 218
From: Merritt Island, FL
There were no 350 5-speeds from the factory, at least not that anyone has been able to document. All 350s were automatics.
I miss my 88 IROC (swapped in an LS1, sold it), but next toy up for me is a C4.
I miss my 88 IROC (swapped in an LS1, sold it), but next toy up for me is a C4.
Le Mans Master
Joined: Dec 2004
Posts: 5,488
Likes: 1,352
You could get a 305 TPI Iroc with a 5 speed or a carbed 305 with a five speed but the 350s were automatics. I had a 86 305 TPI auto and it ran 15.70s with an open rear end, man it would smoke the one tire like crazy 
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
I remember it being an all black 89 (??it was a LONG time ago), what a beautiful car. At the time it was practically brand new.
I bet 65Z01 may know how many of them were built. Guess for emissions in the states a 350/5 sp was not allowed.
Last edited by cv67; Aug 8, 2007 at 10:14 PM.
Le Mans Master
Joined: Aug 2005
Posts: 7,392
Likes: 218
From: Merritt Island, FL
I'll believe it when I see an RPO tag that has L98 or B2L, and the MM5 code for the 5-speed manual. From everything I've read, it wasn't emissions concerns that led to the restriction -- it was the inability of the 5-speed manual trans to handle the torque of a 350 TPI.
Again, show me an RPO tag, and I'll shut up
Again, show me an RPO tag, and I'll shut up
The one I looked at was originally delivered as a Hawaii car, it was originally a 350 5 sp, believe it or not. Impossible to find out here, as you said they were 305s.
I remember it being an all black 89 (??it was a LONG time ago), what a beautiful car. At the time it was practically brand new.
I bet 65Z01 may know how many of them were built. Guess for emissions in the states a 350/5 sp was not allowed.
I remember it being an all black 89 (??it was a LONG time ago), what a beautiful car. At the time it was practically brand new.
I bet 65Z01 may know how many of them were built. Guess for emissions in the states a 350/5 sp was not allowed.
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Let me hop in my time machine and warp back about 15 yrs ....The car was an ins rebuild. I suppose the guy could have stuck a 350 inthere but with almost no miles I dont know why. It was a 5.7 is all I can say???
....The car was an ins rebuild. I suppose the guy could have stuck a 350 inthere but with almost no miles I dont know why. It was a 5.7 is all I can say???
Heel & Toe
Joined: Jul 2007
Posts: 15
Likes: 0
From: HUNTINGTON NEW YORK
I'll believe it when I see an RPO tag that has L98 or B2L, and the MM5 code for the 5-speed manual. From everything I've read, it wasn't emissions concerns that led to the restriction -- it was the inability of the 5-speed manual trans to handle the torque of a 350 TPI.
Again, show me an RPO tag, and I'll shut up
Again, show me an RPO tag, and I'll shut up
Thread Starter
Melting Slicks
Joined: May 2006
Posts: 3,385
Likes: 4
From: King George VA
I loved the sound of the Iroc I had hooker storties,no cats, and flowmaster 40 series. I miss the grunt that the vette doesnt have. But on the other had if I put the same setup on the vette it would sound mean too.
Instructor
Joined: Mar 2006
Posts: 107
Likes: 1
From: Concord Twp OH
I have both. A 1987 Iroc with almost 25K original miles with the 5.7L (3.27 Borg Warner posi rear end) and a 1988 C4 Vert 4+3 with almost 37K miles. Although both have the L98, the "feel" of that engine is different between the two cars. Also, the sound is different. This is comparing two completely stock cars. The Iroc feels a bit more "raw", sounds a bit more "throatier" and actually has a bit more of a "kick in the pants" feeling when shifting into second gear compared to the C4. I used to have a 1987 C4 Vert (stock) that had an automatic (same 700R4 as the Iroc) and it felt different than the Iroc as well; my mechanic attributed part of that to the way the drive train is implemented between the two cars; also, one has an independent rear while the other has a solid rear axle. Overall, comparing stock cars, the C4 is a bit quicker while the Iroc feels and sounds a bit more "raw". Both are fun to drive.
Drifting
Joined: Jul 2004
Posts: 1,356
Likes: 291
From: MA
I had an '83 Z28 305 HO with Iroc Rims & Tires Tricked suspension stiffer springs (moog) front& rear, Tockico adj. Shocks, Roll cage, Dana 44 3.92 gears, Spicer Aluminum driveshaft, T-5 trans. Compucam 2030, Slight head port by me (first time doing porting did not go crazy because I really did not feel to confident) Edelbrock TES headers, Dynomax cat and 3" exhaust.
Car weighed 3630 with me in it!
Best ET with 305 was a 14.5 at 93 mph!
Respectable even when the 350 Irocs came out.
But stock the car ran 15.7 at 84 mph.
Then I slipped a ZZ3 in it and dropped over a second in the quarter mile and trapped 104-105. By the way top speed was 164 with the ZZ3motor (don't ask)
Car felt like it was going to fall apart.
Fast car but I cracked the subframe,broke the shock towers behind the rear seat (learned how to weld Flux Mig) and went through T-5 and then installed a Richmond 6-speed (broke this three times). Finally put my T-5 back in and stopped racing it.
Sold the car and bought my GS. No regrets I loved my Z28 it just got tired and very loud!
Car weighed 3630 with me in it!
Best ET with 305 was a 14.5 at 93 mph!
Respectable even when the 350 Irocs came out.
But stock the car ran 15.7 at 84 mph.
Then I slipped a ZZ3 in it and dropped over a second in the quarter mile and trapped 104-105. By the way top speed was 164 with the ZZ3motor (don't ask)
Car felt like it was going to fall apart.Fast car but I cracked the subframe,broke the shock towers behind the rear seat (learned how to weld Flux Mig) and went through T-5 and then installed a Richmond 6-speed (broke this three times). Finally put my T-5 back in and stopped racing it.
Sold the car and bought my GS. No regrets I loved my Z28 it just got tired and very loud!
Le Mans Master
Joined: Jul 2001
Posts: 5,297
Likes: 0
From: Stamford VT
I'm a thirdgen guy myself. In addition to my Corvette, I own an 88 GTA and my IROC... both of which I've owned longer than the Corvette. Very soon I think I'm going to sell the Corvette to fund a major drivetrain upgrade to the IROC (6.0 Gen 4 motor, T56 & 9" or 12 bolt rear), and transfer the IROC's 350 and T5 into the GTA for daily driver usage. I like my Corvette, but I really have a soft spot for thirdgens. Most of what I like about the Corvette is the power, so my IROC should more than satisfy that once things are done. 