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Discussion Starter #1
Has anyone taken their car to the limit in the Super Stock Class. I'm not sure what is legal.
Thanks hbjoin
 

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1. Lower car as much as possible using stock bolts
2. Competition alignment with corner weighing and weighting
3. Penske shocks
4. CCW or Kodiak wheels with SS allowed +0.025" offset
5. Hoosier or Kuhmo AutoX tires. I prefer Hoosier A3S04 in 275/40x17F and 305/30x18R
6. Brey Krause or Hardbar harness bar
7. Simpson or Team Tech 6 point Harness
8. Cryo'd stock rotors
9. Racing Brake Fluid, either Motul 600, AP600 Wilwood EXP, GS610
10. KFP Gold racing pads
11. If hot, run 70/30 Water/Coolant ratio with 2 bottles of Red Line Water Wetter
12. 178 degree TStat
13. Nology Hot Wires
14. Nology HD Engine Grounding Strap
15. Beru Silverstone racing Plugs
16. Corsa "Z" Series Titanium Race Exhaust System (CAT Back)
17. You can run a T1 or Hotchkis front sway bar as an option but we have found the OEM Z06 bar to be suffiicent.
18. K&N Air Filter
19. Optional 0.020" overbore max.
20. Silkolene 0W20 Racing Synthetic Oil with Friction modifiers
21. ACPF44, K&N, Mobil 1 or Moroso Racing Oil Filter
22. 1/8 tank Sunoco GT100 Unleaded Racing Fuel


Note 2005 Solo II Rule Books will be available from the SCCA in January
 

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Discussion Starter #3
Autocross mods

Thank you for your reply. You clearly have significant knowledge in this area. I would love to use R compounds but i don't think there allowed in the stock classes. I'll check i could be wrong. With regard to the racing fuel, does the CPU recognize the octane difference and adjust the timing accordingly.The process begins for my car tomorrow at Guldstrand Motorsport in Burbank Ca where it will be courner balanced aligned and lowered. From there in order of importance what would you suggest next. By the way as a test i will be trying out some Nitto R compounds that may work as a street/track solution for some wear rating100 check themout at http://www.gmhightechperformance.com/tech/0203gmhtp_rippin/
thanks hbjoin
 

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Once you have it aligned, the most potent change to make is to use R-compounds; yes, they're legal in SS. Hoosiers or Kumho 710s are the main choices here. Kumho V700 Ecstas will also work. Other tires choices will be an improvement over the OEM tires but are a step down from Hoosiers or the Kumhos.

If you're not a national champ driver, the Nittos would work just fine along with the other competition tires listed at Tirerack.

You can add a cat back for $550 or so (Borla Stingers) but it's mainly for the sound. :thumb:
 

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After lowering and a competition alignment, the correct tires will give you the most performance increase.

A mistake that many newcomers make is trying to compromise on tires and alignment settings between street and track use on a dual use car. The problem arises that their skill level quickly exceeds the performance capabilities of a street worthy tire and the necessary mild alignment settings. There really is NO compromise that works well.

1. I suggest that you first have your alignment technician mark an aggressive street setting and a full competition alignment setting on your suspension adjusters and then switch back and forth at the track.
2. You really need a seperate set of dedicated race wheels and proper tires.

Many newcomers are also confused with the "R" tire designation and the claims of HP tire manufacturers.
R tires are just that, full race tires for road course , with a DUR rating of 30-35 (soft).
There is another class called DOT R and DOT A, which are like and have R tire compounds but are built to DOT specs. R's and A's are similar except that the A's have a lower heat range and therefore are more suitable for AutoX, whereas the R's never have enough time to heat up to a nominal operating temp (they are more suitable for road course)
DOT A's have a DUR rating of 40-45.

For AutoX what you need is either Hoosier A3S04's or Kuhmo V710's on either CCW's or Kodiak wheels. These wheels are lighter and stronger ahd can be ordered with the SCCA allowed +0.25" offset advantage.

Prioritized I would do
1. Lowering, Alignment & Shocks
2. Wheels & Tires
3. Brakes

Octane alone will not give you any performance advantage. The ECM will only decrease the advance if it sees knock due to low octane.
It may offer a "piece-of-mind" factor if running hard and hot in competition on a hot day.....knowing that you will probably avoid knock and the ECM will not be retarding the advance timing. Thus you will not be loosing any HP but won't be gaining any either from a high octane.

However some unleaded racing gas does have a performance advantage beyond octane alone. For instance Sunoco GT100 and GT Plus (104) are:
- Double refined
- have a more aggressive racing additive package
- are oxygenated and have a higher oxygen content (Tot. Cont. %) which gives a faster and more complete burn and higher BTU's ...thus increased HP. (this is not to be confused with RFG formulation oxygenation)
 

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Henry, since you are in the LA region might I suggest you come out to Cal Speedway on the 21st and autocross. This is a fairly fast region and most all of your questions can be answered there.
PS everyone here in SS is on 710's as were 1,3,4,5,6,7,9,10 at the Nat's.
 

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Discussion Starter #7
Autocross mods

Bob.. Thanks for the reply, I will be at the AutoCross on the 21st. For the past several months I have been at most all So Cal events, not with my ZO6 but with my Street Mod Silver Mini Cooper. I blew my clutch at the NSX AutoCross about a week ago,so I started driving the corvette again.
My plan was to use the Mini for AutoCross and the Corvette for track days, but now I'm concidering AutoCrossing the Corvette. I know the 710's are great tires with decent longevity, but since I have a couple of track events coming up I thought I would try the Nitto NT555Rll Extreme.
It's an R compound tire with a wear rating of 100. It can be driven on the street without picking up every piece of gravel on the road. Certainly it won't have the grip of the Hoosier or Kuhmo but it could be great for practice events and testing. If your interested in checking them out there avail at http://www.discounttiredirect.com/direct/findTireProductCategoryDetailBrnd.do?tpc=NITHZ5&shopping=froogle
Thanks Again for your reply I'll se you on the 21st
 

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Tires are the number one mod that you can make.....pretty much always. Alot of people run the Victoracers here in Las Vegas...they all seem to run the best times.....however, most of those cars arent Z06's....Either way, get some great tires and then work on your skill.


CHRIS :coo:
 

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Again, The Nitto's ARE NOT an R compound tire.

They are a HP street tire with a soft compound. But the 100 rating is no where near an R compound 30. They are a good tire for DE and short track event but expect a true R compound shod car to lap 5-6 seconds a lap better.
 

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DJWorm said:
2. Competition alignment with corner weighing and weighting
3. Penske shocks
2. what should the alignment settings be? Would this be streetable?
3. Penske better than 04-Z06 shocks? what part # and est. price?

Thanks
 

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Discussion Starter #11 (Edited)
R compounds

Dear DJWORM,

What's the point of arguement over High Performance Street vs R compound, typically tires with a tread wear of 100 or less that are designated by the manufacturer as track tires could be concidered R compounds. These are not Nitto's street tire NT555R they are a brand new tire NT555Rll NO THEY ARE NOT HOOSIERS but if you would have read the link that I gave in an earlier post you would have notice that they out performed Kuhmo 700Victoracers in lap times
 

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1. A proper track or AutoX alignment is NOT streetable in that you will prematurely wear out the street tires. However these settings can be marked on the suspension adjusters and quickly be switched between events at the track.

Base Line Alignment settings:
Aggressive Street / Road Course / AutoX

Front:
Camber: (degrees)
-1.3 / -1.8 / -2.4 (max'd out)

Caster: (degrees)
Always as much positive as you can get without sacrificing Camber. Set Camber first. The more negative Camber the less positive Caster you can attain. Range = +4.5 to + 7.0. Caster should also be set equal on both sides (no Caster Lead).

Toe: (inches)
0.0 / 1/16 Toe OUT each, 1/8 Tot max / 1/8 Toe OUT each, 1/4 max.

Rear:
Camber: (degrees)
-1.0 / -1.3 / -1.5

Toe: (inched) depends on track
1/16 Toe IN each / 1/8 Toe IN each / 1/4 Toe IN each
1/8 Toe IN Tot. / 1/4 Toe IN Tot. / 1/2 Toe IN Tot.

Car should be lowered as far as possible.

Rake should be 1/4" (min.) to 1". 1/2" works best for me.

Front /Rear Weight % should be as close to 51/49 as possible

Cross corner weight % should be as close as possible to 50/50% as possible.

2. Penske, and for that matter JRZ or Moton, shocks are much better than the OEM and T1 Sachs shocks. Although the '04's have improved valving and are good street shocks they can't come close to the Penskes.

I recommend the Penske Double Adjustables with Remote Reservoirs. Penske makes a non Adjustable but they can not be upgraded. The Penskes are true mono tube racing shocks as used on Indy cars. Although they are expensive they are completely rebuildable, revalvable, the shaft and body length can be altered and they can be upgraded to Triple Adjustable & Coil Over. They will be cost effective as they will outlive you and the car, will increase the value of the car or can be resold outright.

Their real advantage is that thay are infinetly tuneable in Compression (Bump) and Rebound.

Shocks are probably the most expensive part of AutoX preperation for Super Stock. Figure on spending at least $3,000 for a new set. (Note: I just sold a used set for $2,000 plus a used and rebuilt set for $2,500)

The Penske system for the C5's are the #8100 Corvette Specials

Mallett did development on these and they have a proprietary installation set up which is the best I have seen. They mount the Reservoirs and Bump adjusters inside the car.

Guy Ankeney is famous for his Auto X valving set up on the Penskes.
 

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If you will be running the stock shocks I would not lower the front all the way. I had to raise mine up a bit to keep from hitting the bump stops on hard turns in bumpy surfaces.

Also, I wouldn't bother with trying to mark your camber settings. Even with it marked you'll probably have a hard time getting it back to the correct settings. I know, because I've tried and when I took it back to get aligned they were all off, some by as much as .3 degrees. Not to mention it's also a pain in the ass screwing around with the cam bolts. Just set your front to as much negative camber that you can get, and the rear to about -1.5. Then just make sure to flip your tires from one rim to the other half way through their wear life.

You can however mark your tie rod ends so you can adjust your toe settings front and rear. These are much easier to adjust and the consistency is much better. My Z06 is my daily driver and the only adjustment I make is to the rear toe setting. One full turn of the tie rod on each side gives me 1/2 inch total toe in, when starting from zero toe in of course. So for daily driving my toe settings are zero in the front and zero in the rear. Then for autocrossing I just dial in 1/2 in toe in for the rear. One word of warning, you do NOT want to run toe in in the rear and get caught in the rain on the highway!!! Bad things happen! :eek:

Just trying to add to the confusion! ;)
 

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I haven't messed too much with the Z06 yet, but with a SmartCamber gauge I've had good luck on resetting camber before/after events with other cars. I agree that trying to use a set of marks is difficult, even for toe.

A question on rear camber. When we did my Z06 (mild autox/aggressive street, for now), my friend, who is a very good tech, suggested keeping the rear at less than -1.0 (actual setting -.60) to maximize tire "footprint" and forward bite. With the front at -1.5 and running 275/40-17 f and 315/35-18 r Kumhos V710, the car is fairly neutral and is not rolling the tires excessively, running 29f/27r cold pressures. I just wonder how much lateral grip I'm giving up and whether I should get more aggressive on the alignment?
I'm thinking of going to -2.0 f/-1.0r with a minimal amount of toe out...in my experience, its toe out that kills tires, not camber (up to a point), but I have no experience with the Corvette.
 

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you can use adjustable shocks, but watch the rules, there might be a change coming soon that may remove remote resv. type. From what I have read here you have gotten about the best advice anyone just starting out could get.
Join SCCA, check the National tour results and see witch tires are performing best in SS.
 

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landho said:
I didn't think I could use adjustable shocks in SS...
SCCA Yes...NCCC puts you in Group 2.

DJ, the problem with DA Penskes or Koni's even when sent to Guy is you have to have a huge amount of data and experiance to set them. What did I use the last time I was here? What was the temperature? How many runs did I have on my tires? Even the amount of tight vs. fast sweepers. Alot of data to be logged. The 04 Sachs are at 96% 100% of the time whereas the D/A's are are 98 to 100% about 60% of the time and really bad the rest if you don't have the experiance to adjust them. Then again, I don't trophy at National events either! My $.02
 

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Per SCCA National Solo II Rule Book

"....shocks may have no more than 2 external damping adjustments."

"Remote reservoirs are permitted and holes may be drilled for bolts with which to mount the reservoirs. Bodywork may be additionally cut or drilled to provide for the routing of lines.....but may serve no other purpose."
 

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Bob, I disagree with that analysis totally.

1. The '04 Sachs are no where near the DA Penske's in performance. Even the T1 guys don't use them but rather use the T1 Sachs. Don't get me wrong, the Sachs '04's are a good street shock, but only that.
The C5R's used Penskes and so do a lot of Indy, Cart, GT1, WC and LeMans cars. If the '04's were better THEY would all be using them.

2. The Penske's internal mechanism is far advanced and superior to the Sachs, they are a true racing monoshock that hold more fluid and dissipate heat better and with the reservoir hold about 4 times the fluid which is critical to performance and shock non fade.

3. The tuning of the shocks is NOT Rocket Science and is basically logical common sense. They are a God Send for dual use cars and especially those that are daily drivers and see low speed AutoX and high speed DE events and possibly an occasional drag as well .

4. As to Compression (Bump) there are 6 settings on each reservoir. 1 being softest and 6 being stiffest. For example I set then on 2 for AutoX, if I need more traction then I drop the rears to 1. I use 3 on the street and 4 for Interstates. When I hit the track I use 5 and 6 depending on how the car feels usually running 6 in the front and 5 in the rear to aid traction. When I run an oval I set the outers on 6 and the inners on 4 to weight jack the car. If I run drags the fronts are on 6 and the rears on 2.

5. Rebound is set in the middle (#14 of 28 sweeps) to start. We needed better front grip and turn in so we increased the front rebound to #21. We had a small body bounce in the rear under hard acceleration and decreased the rear rebound to #9. Note that the rebound settings once set are usually good for all types of driving..ie.. we do not change rebound at all now.

Of Course if you have a dedicated car then you could set up the valving for just THAT type of event to tailor the car better. For example for a dedicated AutoX car the 6 compression settings range would cover the normal 1-3 range.

Remember the premiss of this thread was to maximize the performance under the full extent of the rules not to just provide adequate or cost effective changes.
 

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This thread has been a good read -- I like that someone can post a question and a guy like DJWorm and other experienced cats can answer with specifics, even though people may disagree the guys posting back to Henry's question have the info and the experience -- not alot of :bs: talk.

Hey Henry, I'm a big fan of NittoRII's for the Z06, they are great. I got them when the tire first came out (it's my street use tire -- I'm SC'd and F1s just cant handle it) so I'd be interested to hear how they do in an autocross environment they are really meant for.

Guys here who got the RIIs after I did have reported they are: a)awesome on the street, b) pretty drivable and safe in the rain, c) not as good as a dedicated Drag Radial for drag events but still better than F1s.

So if you do run them for auto-x I hope you'll post your impressions. Good luck running the Z.
 
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