I just bought my '89 Iroc-Z about a month ago now. Well it seemed to run a bit better than my '88 did stock. If you'll look in my sig I have now run 14.65 with just timing and deleted air boxes. My '88 only went 15.03 with the same thing. Now my question is, my '89 Iroc has the G92 package (1,426 made in '89), and there is a website saying that the G92 package is rare. The website is: www.iroczsource.com/rare.htm But, other than dual cats it doesn't really say that it's any better. To me though picking up that much time between two cars is a bit odd to me. It took headers, no smog, and gutted cat to get my '88 to run a best of 14.62, this one runs 14.65. Are the G92's actually rare, and if so are they that much better? Any help is appreciated. Thanks.

 

They can be rare of course if only a few thousand were made, which is what you are talking about since there were only 1,426 in 89. Stock your 88 had 230HP, 330TQ, and 2.77's. Your 89 has 240HP, 345TQ, and 3.27's so I'd expect a nice difference with G92 since it was usually the difference between an L98 car running low 14's instead of high 14's. Thats really good that you got a faster car.

 

Yeah, but, the thing is my friend just bought an '87 GTA w/3.27 gears with the 350. He bought his one week after I bought mine. Last Friday night at the track I pulled the time in my sig and he went a best of 15.3 w/drag radials, I drove it to a 15.19 with street tires...I have driven these cars a little longer than him. And I know my '89 is rated at a little more hp, but, he put a custom cold air intake to make up for his stock air intake. Is the cam in my car a little bigger maybe? I know the exhaust is supposed to be a little better. Any other ideas? Oh ya he has 93k on his motor and I have 105k on mine.

 

GTA's are heavier and have a more restrictive intake than IROC-Z's regardless and ran slower. The Formulas are the closest thing to what an IROC can do, and yes you have a better cam and a little more power stock already than his car.

 

What kind of options are on all these cars?

 

Well, as far as the '89 Iroc-Z goes, it has the L98 350TPI w/700R4 tranny. G92 obviously, as well as GW6 which is of course the 3.27 gears that go w/o saying due to the G92 option. It includes the "high output" exhaust with 2 cats on it. Factory #'s run 245/345 hp/tq respectively.
LOL, as far as the GTA goes, well I have to say I'm not entirely sure. The only things I know for sure are the L98, it has the 3.27 carrier as well and of course the 700R4 backing the L98. He is running no muffler and has a custom cold air intake trying to make up for the stock restrictive air induction that it came with from the factory. And to my knowledge, there is no difference in the TPI intakes themselves. Stock #'s run somewhere around 220/320 hp/tq. However, the friend that owns the GTA, says he read an article saying that from the factory 1 in 10 of these cars runs exceptionally well. While 3 in 10 run a little slower. And the other 6 are at a normal standard. Sort of like the LS1's of today. Just depends on what you get I suppose.

 

Well as IROCZ already stated the GTA's are generally slower than their brothers because of their air intakes and the fact that they generally come with more options as standard (all those power options weigh the cars down!). Case in fact: there was a L98 GTA trapping at 92mph at the track this friday and I was trapping at 92mph with my LB9 G92 IROC-Z.

 

i dont think the weight makes much of a difference..

i raced a econobox 91 formy with a l98..in my fully loaded lb9 t-5 gta and i took him outta the hole and he didnt get next to me till about 110

 

Back to my original question, is this car considered rare? It doesn't really matter b/c it is going to get a rebuild with many aftermarket parts. I'm just wondering if it is a rare find, or if I just got lucky to find a factory car this fast...

 

It is kinda rare.

 

Bah who cares if it's rare, to me it just means that all the factory high performance goodies are already there. No need to swap them in.

 

Yeah, I was just curious that's all. I'm just glad it runs as good as it does. Like I mentioned, when it gets rebuilt, it won't matter if it's rare or not. Pretty much nothing stock is goin back in it except maybe the lifters. Thanks for the input.