autoxer6

Last weekends trip to Grattan Raceway got me interested in NASA time trials. I am trying to understand how competitive a C5Z is nationally and what set ups are possible for TTA.

1. Can the C5Z compete with the Evo nationally?

2. What set ups are people running?

Here is my thought:
2004 Z06
Factory shocks
Hoosier A6 with 295 wide all the way around on stock wheels
Bigger sway bars. I just dont know which ones. (Pfatty, T1, or Pfadt Street)?

That should be all 19 points.

Thanks,
Chris Shay

yakisoba

I can tell you what I run:
Hoosier A6 275s all round (saves points)
headers (best bang for the buck for 2 points)
intake (replaces stock air box)
no cats
t-1 bars
several no points mods

Get a dyno test done. It's your responsibility to bring a legal car, and at the national level, someone will ask, especially if you win something. Make SURE you do not go over your adjusted wt/hp ratio. If you do, and they catch it, you're done. I've been challenged even in little old Texas region, so be advised.

Make sure you are at the correct competition weight.

I don't know if it's nationally competitive, but I'm about to find out come September.

Come run with us! It's great fun and good people.

autoxer6

Thanks for the input!

Do you think the exhaust changes are worth more than the extra 20mm of tire?

L98Terror

C5 Z06 won the TTA National Championship in '07 actually I believe they were 1,2 & 3 & placed second & 3rd in 2008


So I'll say yes

Falcon

Placed 2nd & 3rd in the 2006 Nationals, too!

GAS2

You should call Joel at Corvette Sports in Sheboygan Falls, Wisconsin. He can work with you on setting up your car. He knows vettes!!! Sorry I do not have his number handy but you can google it.

NASA is at Blackhawk Farms next weekend. You should come and join us!

Geff

varkwso

Yes they are competitive - they are not unbeatable - but they win more then they lose. Evos, supecarged Elise/Exige and STis are formidable cars to run against - but they are not unbeatable.

I like the 295 tire setup personally. BUt you need to find the setup that suits your driving style.

Take all the free mods and get your weight down...

yakisoba

Of the free ones, a lightweight flywheel is one of the best. Also get your power steering pump done right. There's a huge number of things you can dom including just careful tuning, and almost all of it comes down to what you like. If you can get by with no headers or intake, running on 295s works. If I had a fresh engine, that's what I'd do too, but I needed to make 380 horses on a 78000 mile engine, and bolt ons were the way.

drivinhard

The thing with the C5Z is (unless I'm grossly mistaken) if you run the car at min comp weight, you can only make about 352 RWHP (adjusted below 3200 lbs, and capping @ 8.7 lb/hp ratio). So a stock tuned car is gonna be at, or exceed that right out of the box. Of course you can run heavier if you go that route.

re: the tires, just measured Racin' Jason's 295/30/18 hoosiers on his 18x10.5" wheels against my freshly mounted 275/35/18 Hoosiers on my 18x10.5" wheels. The 275's are only ~ 10 mm narrower, not the 20mm that it "should" be. Hoosier specs 10.8" tread for the 295, and 10.3" for the 275, but the 275 comes out a bit wider than 10.3".

You get 4 whopping points back so you can run real brakes, or some types of shocks, or...

Gonna try my 2nd set of 275's this coming weekend, this time on 10.5" wheels. First go around was 9.5" wheels and they still did pretty well.

After this, I will try the full 295's. I'm not even using up the rest of my tire pts for now, I just want to see how the car runs stock with the 275's vs the 295's. If the 275/35/18's prove to be 99% of the tire that the 295 is (I suspect it will) I can formulate where I want to spend my 4 pts heading into 2010

Tom03Z06

275-18 hoos
stock z06 18x10.5
shocks
sway bars
Cold air intake
19pts

Free
PCM tune
Light clutch
Racing seats
harness
harness bar or roll bar
Camber/caster plates
coolers
rotors
brakepads
battery relocation

Jason

Swaybars, 295's, brakepads, big stack of rotors, take the CD case off the visor. (Hat tip to Ken)

drivinhard

Corner worker found my shop garage door opener on the track at CMP, it still works

L98Terror

Oh sure let the secret to winning a TTA National Championship out of the bag, nice

AU N EGL

Yup it was taking that CD case off the visor that did it.

96CollectorSport

Chris,
Even if you don't run at Blackhawk at least stop down and check out a NASA event, stop over by Geff and I (he will be running the black #222 car in TTS), there are always a bunch of Vette guys in TT at the NASA events. This way you'll have some guys to answer some questions and show you around.
Hope to see you there,
Joel

L98Terror

So over the last three years they had 7 of 9 podium positions at Nationals

sperkins

Yeah check out the tread width comparison on these sizes (straight from Hoosier).

drivinhard

yep

but the 285 is a really short tire (you are already down almost an inch in height from the stock rear with the 295-18

and, you only get 1 pt back for 10mm under. you'd think you'd only get 2 pts for doubling that, but they give you 4. that's what is tempting. if it was only 2, I'd only run 295s for sure

sperkins

How would that translate into affecting the gear ratio? I'd like to have a little more gear at some tracks.

drivinhard

it would make your rear gear shorter for sure.

however, a 24.9" tall tire that's 18" wheel dia has a real small sidewall. sidewall is a good thing for forward bite.

Come join us in TTA and test it. I'll be the 275 man, you be the 285 man, and racin' jason can keep flogging us on his 295's till we finally wise up