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**Fair!** · 07-27-2004, 01:29 PM

Dean's Corvette ideas for SM2?

The geometry change is really noticable in Stock category, where the differences are the greatest between the "S1" and "S2" C4 corvette set-ups. In BSP, the differences can be mostly overcome, and SM2 it is not much of an issue...

The biggest advantage of an S1 C4 is WEIGHT. But its not enough less to trade the "Good" stuff of the later C4s, namely the interior and ZF6 transmission.

Sure, you could buy a roller C4 and swap over the LT1, trans [not as easy as you'd think! its tied into the torque arm and floorpan], the interior and the updated exterior... but what a pain in the ass.

Talk to Ramey about his BSP car. He apparently swapped the S1 suspension stuff to his '96, but i dunno if it helped as much as he liked, and i know it was a bunch of work. He also got a BUNCH of weight out of the car. SM2 is not going to be a very competitive class for anything over 1800 pounds, in my view, so i wouldn't throw gobs of money or effort at a SM2 C4 anything.

Mike Sen-Roy has a 396 LT4 in his 96 SM2 vette, too. Cool car... very cool car.

I am still eyeing the FRC C5's myself, and when they dip under $20K... will be hard to resist. The quad-butt of the C5 is the only thing holding me back.

The C6, tho, is so much prettier... but so much mo money.

that roller, with exterior upgrades, ir prolly worth $4-6K, depending on overall cleanliness, paint quality, and interior condition. Expect to spend another $10K to get it running and driving, at least. And another $5-10K to become "Regionally competitive" in SM2.

my advice: stick with the 96 and have fun.

also: move this discussion to the dang bimmer-performance forums!

fair

**Fair!** · 07-27-2004, 01:30 PM

Dean's Corvette ideas for SM2?

good tips from mcclure:

Dean,

For starters, the Vette suspension design changed in '88. The '84 - '87
cars have the same geometry. If you want to read up on all the different
suspension changes, spring rates, sway bars sizes, brakes, oprtion packages,
etc. go buy The Corvette Black Book at any major bookstore for about $15.

The '84-'85 cars won't have ABS and the '86 -'87 cars that do have ABS have
a pretty crappy system. In other words, if you plan to build a early track
car, you will probably want to plan on upgrading the brakes.

The manual trans for an early C4 is the T-10 4 speed with an electronic
overdrive know as the 4+3. It is not as strong as the newer ZF 6 speed that
came with the later C4's.

I have no idea what a nice '85 roller would would be worth. You can find
complete '85 Vettes for $4k-$6k just about anywhere. My best guess is that
a roller with a nice interior and good suspension would be worth
$1500-$3000.

Mike

07-27-2004, 02:16 PM

vette ideas

Well;

cost is always the balance;

it is about 1500 to swap all the old front suspension under the new vette

it is probably 8000 minimum to swap a stock lt4 and zf 6 into an older vette.

both are a fair amount of work

either car is cool; the 96 is nicer, the 85 is about 100 pounds potentially lighter.

really a matter of taste on the interior and amount of work.

either setup you will want some c5 or aftermarket front brakes probably. The 88-96 brakes just don't work for autocross cold, and they still fade pretty badly for road courses.

The c5 setup works well cold and does better with heat.

Personally, I preferred my c4 to the z06, assuming power was equal, but the chassis stiffness is a real bummer and the thing is fairly difficult to work on.

I have not worked on a c5 so I have no idea of any ease or difficulty there. Compared to the c4, I really hate the z06 seats and lack of a rear hatch. I am not a big fan of the interior quality either, or the 'feel' of the car's body and interior. I also really don't like the looks.

If I had more time, I might consider going back to a c4 and putting a cage and some real chassis stiffeners in it myself. And at least 700 horsepower.

**Dean!** · 07-27-2004, 02:28 PM

Dean's Corvette ideas for SM2?

I didn't know it'd be ~$1500 to put the old suspension onto the new...
How much camber will that net you ?

Also, what are some of the top 10 weight saving tips in a C4 ? I hear you got down to 3030lbs?!?? How can I do that?

**MSR** · 10-05-2004, 02:20 PM

humble observations

chris has a much greater range of experience, so keep that in mind when reading my thoughts.

i think the AS cars are proving the S2 C4 suspension is capable. i can't explain why the S2 front-end had such a bad reputation for so long, maybe it really is worse, but i finally have my car to where there's no problem with grip balance.

second, the '96 is lighter than all other S2 C4s. even GM said so, according to published curb weights. my car weighed in at 3270lbs with a full tank, 17x11.5s with victoracers, and no weight loss at all. on the contrary, i even added the front camber brace, and rear harness bar, and i still have the rear spare tire carrier. i'm guessing this means a real SP-trim '96 could be below 3100lbs. (dunno what chris' car weighed, but i think he also had lighter wheels, race seats, etc.)

third, i don't have as much camber as chris' C4 did, i don't think, but i still have a lot. and, it's a completely SP-legal S2 front-end, down to the stock spacers. what i did was buy the offset lower bushings. btw, the bushings in these cars are relatively easy to change, since they're not molded to a sleeve or attached in any way. just poke them out.

fourth, and i think chris will confirm this, most common setups appear to have too much rear spring rate. i run as stiff as anyone does up front, but relatively soft in the rear, and i still sometimes think it's too loose. but, it still does a decent job of putting down what a mild 396 can dish out.

fifth, i like the S2 interior a lot, and i even like commuting in my car. it's rough, but i had to drive it daily for a few months, and i found that i liked it more the more i drove it, which is contrary to my usual experience with cars.

sixth, the car is finally tuned halfway decently, and now i'm just noticing i can't drive it well enough to be super fast. but from how poorly i'm driving relative to how fast i'm going, i'm convinced the car is capable. i think it's capable of ttod at most events as it sits.

seventh, whatever you do, do not listen to VB&P. they will steer you down the incorrect path for sure. and don't but those "xtreme" shocks they sell, they make the car unusable on the street, and unraceable on anything but the smoothest of surfaces. i just ran these shocks for the first time this past weekend, and it was the first time in over a year that i didn't win a regional in SM2.

eigth, you can't have too much power, the chassis is that good.

ninth, it's significantly more difficult to drive well than a C5, so you have your work cut out for you.

thanks.

-michael

**Fair!** · 10-05-2004, 05:14 PM

Dean's Corvette ideas for SM2?

i agree on all points made by MSR and cramey. i like the later ('90-96) interior way more than the disco dash of the early c4 cars, and I like the '94-96 seats and door panels better than the '90-93.

I drove my SS car on Hoosiers back to back with Matteucci and McClure's 87 SS cars on like tires, and my '94 Z07 was always 1+ seconds slower. Matteucci felt the same way, even adding some expletives when he had to drive my car at nationals in '98, about how "horrible" the S2 cars handled in stock form.

I think the changes legal in BSP can and do get the S2 cars closer to similarly prepped S1 cars, but there is still a scrub radius issue on the S2s. I dunno if I'd go hog wild and do a full S1 swap just yet, as I think it involves some welding and such. yuck!

as for C5 vs C4, well, I kind of agree on the inferior looks of the C5, but I do feel the interior is nicer (and a helluva lot easier to get into!) than the c4 materials. still not world class, but better. the c5 shifter is worse, though. C5 FRC/Z06 with trunk vs. c4/c5 coupe hatch area is a tradeoff for the lower weight and added stiffness of the fixed rooof coupe. the trunk should insulate some sound, tho.

i think the improvements in the C6's interior over the C5 is an even bigger difference... and so are the exterior improvements. C6 = dead sexy...

**hancheyb** · 10-05-2004, 06:33 PM

Dean's Corvette ideas for SM2?

I saw a first generation owner driving a C6 this weekend, silver. Hmmm. And by first generation, I mean he's the first to own it. Seems like MOST first generation owners are 60, have gold chains, and a trophy GF in the passenger seat. CRamey and McClure aside. BMWs are the same way.

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