C4 Corvette classification?

[blueray]

Hoping y'all can shed some light ... pondering buying an 86 Corvette. It's been raced in NASA but never SCCA. I've never done NASA but running IT for a few years now. Seller says he was told it would fit in ITE. I don't see anything to verify that.

Before moving forward with the purchase I'd like to get some feedback from people with wayyy more knowledge than me! I looked through GCR and didn't see anything for the C4.

Thoughts? Does it not happen?

Thanks!

[Ron Earp]

The C4 Corvette (1984 Crossfire 205hp model) was just classed in ITR. Have a look around on the forum and you'll find some more threads about it. One is under construction in the NE by a forum member.

The 1986 Corvette isn't classed in ITR but with 230 stock horsepower it seems like it could be. Around 238-240 hp is the upper limit for ITR. But beyond that, an EX-NASA Corvette is almost assuredly going to have modifications that are illegal in SCCA ITR.

The car might fit into ITE, but ITE is a regional class only and rules vary from region to region. Check to see what your local region calls ITE. Here in NC it'd fit into ITE as long as it meets safety specs for IT in general; there are few other limitations so if it had an IT legal cage and safety equipment you'd be ready to roll.

Ron

[924Guy]

There's a small handful of C4's running here at Waterford with the C5's and C6's... they're running a mix of classes, including ITE and SPO IIRC...

[blueray]

Looks like probably ITO here in the southeast. Trying to get more info on the car. Not sure what NASA class it was prepped for.

Thanks for the feedback, appreciate it.

Now .. to sell the IT7 car!

[JeffYoung]

THe 84 is going into ITR most likely. I'd take a look at that, you can convert the 86 to an 84. Will probably take some work as Ron says but way more competition in ITR than ITO in the SEDiv.

[Andy Bettencourt]

THe 84 is going into ITR most likely. I'd take a look at that, you can convert the 86 to an 84. Will probably take some work as Ron says but way more competition in ITR than ITO in the SEDiv.

84 has to be ITR with just 205hp. The 230hp cars would be about 3385lbs in ITR using similar math...that's kinda heavy.

If you converted an 86 to an 84, you would be the first! We are REALLY worried about the intake in the 84. The runners are just horrible. It will make torque for sure but it won't rev.

[Knestis]

It's a real commentary on how things have changed but when the C4 first came into the ESCORT SS endurance series, it seemed SO FREAKING FAST.

K

[Ron Earp]

We are REALLY worried about the intake in the 84. The runners are just horrible. It will make torque for sure but it won't rev.

Grasshopper, Yankee engine need not rev to sky to make work. Area under the horsepower curve still more big than little Honda.

[Greg Amy]

It's a real commentary on how things have changed but when the C4 first came into the ESCORT SS endurance series, it seemed SO FREAKING FAST.

Yup. There's a guy here in CT with a Vette prep shop that has one of the old Kim Baker Escort C4s, the one run by Carradine et al. I (fondly) remember how bad ass those cars were...still a nice car, with all the records...

[Andy Bettencourt]

Yup. There's a guy here in CT with a Vette prep shop that has one of the old Kim Baker Escort C4s, the one run by Carradine et al. I (fondly) remember how bad ass those cars were...still a nice car, with all the records...

Need that contact.

[Greg Amy]

Need that contact.

You probably know him, Andy; he races a Spec Miata on occasion with KenQ: Ray Zisa, Corvette Center, Newington CT...

Now that I read the article below again, it may be a Corvette Challenge car I'm thinking of. Regardless, it made the neighborhood kids sit up and take notice when he pulled it out of his trailer (and, sadly, none of them had the gumption to come over and learn more...)

http://berlin.patch.com/articles/res...s-a-profession

http://www.corvettecenter-ct.com/

[JohnRW]

As an irrelevant point of interest: The Rochester Products / Delphi Engine /GM guys refer to those '84-ish and later series "Crossfire" motors as "Cease-Fire" motors. For good reason.

[ShelbyRacer]

As an irrelevant point of interest: The Rochester Products / Delphi Engine /GM guys refer to those '84-ish and later series "Crossfire" motors as "Cease-Fire" motors. For good reason.

See my post in another thread

As for the major issues, much of it stems from trying to syncronize the "carbs", and the resulting driveability issues from being unsuccessful. I believe that the biggest issues were worn parts (like throttle shafts) causing vacuum leaks, and those units were especially sensitive to vacuum. One wears and leaks, they get out of sync, and driveability goes into the toilet. On a properly built and maintained/tuned racecar, I believe the engine/fuel system will not be the issue.

I'd stock up on overdrive units...

[lateapex911]

Baker used to make mucho power gains on the car, and GM sent him truckloads Literally) of parts to pick the lightest and best out of for his balance and blueprints. Hondas are too well made to see those gains, LOL.

[Bob Roth]

Anybody know what the weight was specified, the Jan and Feb GCR changes doesn't seem to download. I sure hope they aren't thinking about putting a 205 hp process weight. The thing has 315/355 tires and the lowest CG in the class. About the only good thing I have seen, is that the few attempts I have seen over 20 years is the few attempts of racing against C4 corvettes in a amateur hands, is they are always broken. But I doubt that will stop many from trying.

ps here's a helpful quote from a vette forum on the '84 L83

"Originally Posted by Hib Halverson
Perhaps but I still think the 82-84 "crossfire" engine can be mod'ed up to 230-240 hp and still pass the smog check, but...and it's a big but...it will take someone who knows how to calibrated the engine once the mods are complete.

[Ron Earp]

About the only good thing I have seen, is that the few attempts I have seen over 20 years is the few attempts of racing against C4 corvettes in a amateur hands, is they are always broken. But I doubt that will stop many from trying. .

Why is that good?

Another quote, from the C4 forum:

That 205 hp factory rating was a joke. These things were lucky to break 180 flywheel hp on a cool fall day and were constantly falling prey to Mustangs and IROCs of the same vintage.

They should be processed at 205hp. That is the factory rating, under SAE procedures. Why would the ITAC consider using a value higher, or lower, than the published specifications?

[Andy Bettencourt]

Anybody know what the weight was specified, the Jan and Feb GCR changes doesn't seem to download. I sure hope they aren't thinking about putting a 205 hp process weight. The thing has 315/355 tires and the lowest CG in the class. About the only good thing I have seen, is that the few attempts I have seen over 20 years is the few attempts of racing against C4 corvettes in a amateur hands, is they are always broken. But I doubt that will stop many from trying.

ps here's a helpful quote from a vette forum on the '84 L83

"Originally Posted by Hib Halverson
Perhaps but I still think the 82-84 "crossfire" engine can be mod'ed up to 230-240 hp and still pass the smog check, but...and it's a big but...it will take someone who knows how to calibrated the engine once the mods are complete.

Well they sure as heck used the 205hp figure Bob. Should it be lower? Higher? Process is clear. Stock HP or 'known WHP' Tires will be a plus but the cars will still have to run 8.5" rims so there WILL be a limit.

That quote is helpful only if the author was talking about IT-level mods, which I am sure they aren't. You think the car will dominate at 3085lbs and about 255 crank (210whp) horsepower?

[Ron Earp]

Wait, I remember now. Bob is "Anti V8".

https://improvedtouring.com...t=23290&page=6

OH MY GOD, V8's in ITR

We've already spoiled ITR with V8 Pony cars and now a Corvette! And we're gonna spoil ITS too, as we're building a couple of monster sized V6s Stangs for ITS! We'll all be wearing mullets and sporting gold chains by the end of 2012. Bwwhaaaaaaahaahahhahahaa!

[Bob Roth]

Chill dudes. I expressed an opinion about the capability of a 5.7 liter vet with 315/355 tires, and apparently a 205hp target, nothing wrong with that.

[Andy Bettencourt]

Chill dudes. I expressed an opinion about the capability of a 5.7 liter vet with 315/355 tires, and apparently a 205hp target, nothing wrong with that.

Bob,

Just asking you to clarify that opinion. Do you think using a 205 stock, 256 crank and 210whp target is solid, low or high?

No sure what a '355' tire is but I am thinking that the C4 would work well with a 275/40/17 if wheels are available in 8.5" x 17. Lots of 8.5 x 16's in stock form around. A 275/45/16 is almost identical to the 275/40/17 in all aspects except for a half inch taller sidewall.