VGLNTE1

Blew the cobwebs off the car today and noticed the cars rear suspension bottomed out when i hit a bump at about 150mph. I smelled some burnt rubber afterwards...didnt think much of it. When i checked it out when i got home, i noticed the tire burned the inner fenderwell..so obviously i need a higher spring rate. I run T1 shocks now and im not even sure what the rates are for those shocks. The car is only lowered on stock bolts. The car has a 69" full rear wing so im guessing it needs to be coilover time. Any idea at what spring rates i will need? The rear gets about 800lbs of downforce at 170mph....roughly.

Also, ive gotten so used to my m3, the vette just feels sloppy at speed. R comp tires, suspension, T1 sways, lowered, aero, and a stock m3 feela alot more secure at 140+...kinda pisses me off. What is something to do to stiffen up the steering and the car??? Steering feel is just to sloppy...i want this thing to feel like its on rails at high speeds

Any info is appreciated

FlamingZ06

What have you done in the front to offset the 800 lbs of downforce in the rear?

Just out of curiosity, where are you doing these speeds (150 to 170)?

Gray Ghost GS

I think you're running too much downforce on the rear. Adjust some of the angle out of your rear wing. What size front splitter is installed on your C5, and is it functional? You don't need 800 lbs of downforce at that speed to keep your car planted in the esses. You're bottoming out the rear while raising the front (steering wheel feels sloppy) because of the unbalanced aero on your C5. Ensure you have sufficient rake in the car - might want to raise the rear .5" on the bolts.

VGLNTE1

I could prob use some more splitter i guess, but the 800 lb may be over what it really is. Id have to look at the data sheet. And i do those speeds on the road. I live in the middle of the country. But this isnt about a butthurt thread about "omg your speeding?!" Thread

TriplBlk

Im thinking the same thing!!! He'd be the first track guy Ive seen go that fast on any track besides the Nurburgring

According to Kognition's website and taking an average of 160mph and 180 and at only 6* its 700lbs!!! lol

Also not dissing your splitter, I mean its cool and all for looks, but the REALLY functional ones are way different (look at wallymans splitter)

This is the best I could find right now:


Your probably having a S*** ton of air pushing up on the underneath of your hood. You need to go to a vented hood (cheap version is what Davidfarmer did)

Another thing is your riding a lot lower to the ground, Id assume just because of the height difference you feel more in the vette.

but again Idk what track your even on but none of these racers are touching 170(not that Ive seen at least) so youll need more work than just a splitter. Maybe some Pfadt heavy rate sways.

VGLNTE1

I have a vented hood now...and taking it easy i was hitting 150 mph. 2 times a lap at road america..bad thing about the splitter deal is, no one makes crap for a c5. Its all floor mats and chrome pieces.

Gman57

Check out Black Dog

http://www.blackdogspeedshop.com

FlamingZ06

I guess.

AU N EGL

No, the back straights of VIR and Road Atlanta, 150 mph is very doable in a C5. and No problems in a C6Z or C6ZR1 into 160s close to 170.

Road America as well.

with taller tires 154 was very common on VIR back straight, 6800 red line, 4th gear C5 400 rwhp

Falcon

You need to get off the J C Whitney and Autozone websites. There are a few good splitters available.

Gray Ghost GS

You need to check out ACP Corvette Racing for real performance mods for the road course. However, I would examine your suspension in addition to correcting your aero.

TriplBlk

Good to know, I never knew that


Kerry Is a great person to deal with and very knowledgeable. He has stuff that has been wind tunnel tested and his product quality is superb.

froggy47

But

FWIW and IMO doing piecemeal aero stuff is pissing in the wind LITERALLY. If you don't or can't quantitatively test the package you are much more likely to mess the car up as make it better.

Buy a proven (race series) package from a major vendor or leave it alone. Aero is not like engine or suspension mods.

Testing the package does not mean getting opinions on forums.

No offense to VGLNTE1 & hope none taken.

Your car looks great.

Merry Xmas!



PS my car with similar suspension mods and NO aero is on rails @ 145 (track).

VGLNTE1

Well, with my areo im constantly changing it up and adjusting..cant really test turns but i use speed to see how the car reacts. Sure, i could use more splitter,.but the main concern i think is the shocks...mine may be toast

VGLNTE1

Good god?!

VGLNTE1

While it looks like a nive front clip...it looks to me just a stock bumper with a aci splitter molded to it....and its about 30x the cost it should be. Acp makes really good stuff, BD im not to impressed with

TriplBlk

What vented hood do you have? Any pics?

brkntrxn

You can hit 150+ at Charlotte as well.

Gray Ghost GS

Go to your local Home Depot or Lowes and pick up a $9 Johnson Magnetic Angle Locator so you can baseline the angle in your rear wing and log your adjustments until you get it right for a given track. I have a APR adjustable rear wing on my Mustang GT that took me a weekend to dial it in to the proper angle. The 2004 C5 Z06 shocks are a good upgrade or check out the Bilstein HD gas shocks.

AU N EGL

Black Dog is close by too you.

I think BD starting making their own parts as they were not happy with ACP products. But I could be wrong