Classing my 92 Corvette

[jimbow]

This is not to be a bitch session. I am just trying to understand and take the correct amount of points.

 

It has the Z07 option - bigger sway bars than stock, bigger brakes than stock (in 94 these brakes became standard), adjustable suspension (FX3)

 

Brakes = no points since they became standard equipment in a later year of the same model

Am I correct?

 

I have to continue researching but I'm pretty sure the sway bars in the Z07 package were never on a base model. I think that means I need to take the 2 points for the sway bars - Am I correct?

 

I know I have to take the 3 points for the shocks because they were never standard and have been revalved. The FX3 is disabled, but I can still turn the adjuster. Its a single adjustment shock btw.

 

These are my only questions and I won't see the regional TT director until November.

 

It will be interesting if I wind up in TTA with only 300 hp at the crank. Won't matter TT is a blast!

[Greg G.]

Sounds right.

[mrc24x]

Hi Jimbo,

 

You have it right. The 30 mm solid sway bar was never on the base model C4 so you can't use the "update/backdate" rule. Use your points wisely and your '92 should be able to compete up front.

 

It's cheaper and more competitive in the "B" class IMO. The C5Z's and Evo's are pretty stiff competition in A.

 

Here's a handy link for the suspension changes:

 

http://www.corvetteactioncenter.com/tech/c4/susp_chart.html

 

 

Good Luck,

Matt Carlyle

PTA/TTA Great Lakes

[drivinhardz06]

can always use more in SE TTA

[jason]

James,

I just spent the weekend at Mid-O getting my butt kicked by an L98 C4. I hate to think how bad it would have been with an LT1.

[jimbow]

One more question. I have a camber brace that is basically a "strut tower bar" with only 2 anchor points (the front bolts on the upper A-arm). If I'm reading things correctly thats a no points mod. I don't have it installed yet, just trying to figure if it costs me points.

 

Am I correct??

 

Looks like if I can find some 275 tires for my old sawblades I've got 8 points left in TTB.

 

If I run my old Khumo v710 315's im solidly in TTA.

 

Found more confusion on the exhaust side. If I add headers, install bullet cats, and run true dual 2.5" exhaust to the stock mufflers that is +5 or +6?

I think 25, 26, 27 & 28 apply which would be +6

 

Right now only I think only 26 & 27 apply. My resonator after the cats failed and it was replaced with straight thru pipes. +3

[jason]

Is the car driven on the street at all, or does it have to pass any inspections? For that many points I'd just run straight pipes off the headers and the minimal muffler needed to pass sound checks.

[kbrew8991]

after the stock cats is a "catback" and just +1 if the rest of the exhaust upstream from that is "OEM".

 

a full exhaust is +5 pts total

+ 2 headers

+ 1 for cat change/removal

+ 2 for catback since upstream is modified

Edited August 17, 2009 by Guest

[jimbow]

With the Mustang dead its my Daily Driver for now.

 

I'm still debating on keeping the stock mufflers, its just going to be easy to pull it into a buddys garage, put it on the lift, drop the old exhaust and install the stainless works kit I got for a fantastic price. One cut to hook the pipes to the resonator replacement I have now and its back on the road. I'm a little concerned that the straight pipes would be too loud for the tracks we run on.

 

I'll keep the bullet cats, they don't restrict flow that much.

 

Thanks Ken on the exhaust points clarification!

[Greg G.]

One more question. I have a camber brace that is basically a "strut tower bar" with only 2 anchor points (the front bolts on the upper A-arm). If I'm reading things correctly thats a no points mod. I don't have it installed yet, just trying to figure if it costs me points.

 

Am I correct??

 

26) Add front lower stress/arm brace (two attachment points maximum) +1

27) Add a third attachment point to front or rear strut tower bar (or replace existing 3 point) +1

28) Add or modify other chassis stiffening devices or fabricated parts (such as lower strut braces

or lower arm braces (with greater than two attachment points), subframe connectors,

subframe braces, subframe mounts/bushings, etc) +3

 

No-Points Mods:

46) Add front strut tower bar (two attachment points—bolted in or as component of the cage)

47) Add rear strut tower bar (two attachment points—bolted in or as a component of the cage)

 

Strut tower bars attach to the chassis, not the suspension. Photos may be helpful. We do have a +1 point assessment for front lower arm braces that does not seem to apply. Your upper arm braces are not listed from what I can see, so would probably have to take the +3 point hit (or would just be declared illegal since they are not listed).

[jimbow]

Thank you sir!

 

I'll try to get a picture of where it mounts later. Basically the A arm bolts to a plate on the chassis.

The camber brace is placed between the two plates and is held in place by the same bolt that holds the A-arm to the chassis.

 

Sounds like its not allowed then, maybe a rule change for next year?

No problem either way, I've driven the car with and without it. It helps keep camber from changing because of chassis flex.

[jimbow]

Two pictures attached, I have circled where the camber brace attaches to the car.

 

Shoot attachments is not working, let me find a host. The circles are a little thin, but they are there.

[mrc24x]

Greg,

 

It bolts to the front cross member/chassis to keep it from flexing. It does use the same bolts that mount the upper control arm to the other side of the chassis.

 

Vendor Link:

 

http://www.r-dracing.com/Camber-brace.htm

 

 

I don't run one fwiw. 20 lbs of added weight to the front w/ minimal gain. YMMV

[Aardwolf]

I have a Corvette too and would be curious about that as well. Both attachment points are part of the frame/chassis. Doesn't it bolt to the shock tower frame bracing? There are some more pics at Vette magazine. I think I can link them.

 

 

[Greg G.]

26) Add front lower stress/arm brace (two attachment points maximum) +1

27) Add a third attachment point to front or rear strut tower bar (or replace existing 3 point) +1

28) Add or modify other chassis stiffening devices or fabricated parts (such as lower strut braces

or lower arm braces (with greater than two attachment points), subframe connectors,

subframe braces, subframe mounts/bushings, etc) +3

 

No-Points Mods:

46) Add front strut tower bar (two attachment points—bolted in or as component of the cage)

47) Add rear strut tower bar (two attachment points—bolted in or as a component of the cage)

 

Well, it does appear to only have two attachment points. So, the question is whether or not it attaches to the "front strut tower". There really isn't a "front strut tower" on this vehicle, is there? I can't see exactly how/where it attaches on any of the photos due to the overlying hoses, etc. However, either way, I wouldn't want to be the owner of one of these and end up on the back end of a protest with a Race Director or TT Director deciding my fate after I thought that I had won a race or TT competition. Obviously, we can't write rules for every make/model of vehicle. This would seem to be one that may fall into the "maybe yes--maybe no" category. I think that I would have to see the part on the vehicle in person to be of any further help. But again, if a protest is written correctly, and it is determined that the brace is an "upper arm brace" and not a "strut tower bar", then it would be a +3 point mod. If I owned one of these cars, I would only put that brace on my car if I was going to take the three points. I wouldn't want to chance the protest.

[Shawn M.]

Im familair with this bar and it attaches no differently that a strut towered car does.

So to me its the same as an upper strut bar and should be free.

[Varkwso]

......

 

These are my only questions and I won't see the regional TT director until November.

 

It will be interesting if I wind up in TTA with only 300 hp at the crank. Won't matter TT is a blast!

 

Where is the love? You know we are only here to help. Glad the Vette will be back on track. CMP will be a stick and brake track more then HP at Road Atlanta.

 

Your "strut bar" is interesting. As you found out tire size really depends where your car will end up more then anything else. Based on my knowledge of the C4 and the pictures I say it is a no-point mod.

[jimbow]

Right now I'm keeping it off, going to VIR for track daze and mazda drivers event next week.

 

Taking the tire trailer with the old V710's since its all hpde.

 

Going to put the long tubes on over labor day - anyone want to help??

 

I gotta find some good 275 track tires I guess, at almost $300 each the A6's are out for now.

 

Anyone know how well the RA-1's hold up?

[Varkwso]

Right now I'm keeping it off, going to VIR for track daze and mazda drivers event next week.

 

Taking the tire trailer with the old V710's since its all hpde.

 

Going to put the long tubes on over labor day - anyone want to help??

 

I gotta find some good 275 track tires I guess, at almost $300 each the A6's are out for now.

 

Anyone know how well the RA-1's hold up?

 

They are good for one TT weekend - slower then the Hoosier/Kumho guys - and then they are test/tune/DE tires...

[jimbow]

They are good for one TT weekend - slower then the Hoosier/Kumho guys - and then they are test/tune/DE tires...

 

And I was thinking thats all you could get out of a set of A6's

[Varkwso]

They are good for one TT weekend - slower then the Hoosier/Kumho guys - and then they are test/tune/DE tires...

 

And I was thinking thats all you could get out of a set of A6's

 

They wear like iron (unlike A6s) - but slow down considerably.

[drivinhardz06]

A6 - sticker virgin run = awesome

 

2nd heat cycle - slightly slower, but still pretty good

 

3rd cycle - starting to slow down

 

4-8 - not bad, but slower for sure. maybe slightly slower than the R6 with similar cycles?

 

8+ test/HPDE tire

[Kubs]

I have a '90 Vette with the Z51 also. I can take points for the sway bar but what if I disable the FX3 and put a non adjustable Bilstein shock on that is considered an OEM replacement? Would I still have to take +3 points for that? For everything I want to do I am right at 79 points going from TTD to TTA. I do not want to go any further and those 3 points would put me in TTS.

[kbrew8991]

to avoid that +3 I'd use whatever part number came on the non-special-suspension-package 1990 Corvette. OEM refers to whatever came on the base model car - whatever you would get if you ordered the car from Chevrolet with no option boxes checked.

[Aardwolf]

Is that strictly year specific? For example the 84-91 Corvette is all lumped in TTC**. Could the shocks from any of those years be used?