track alignments

[Catwood]

Stock '09 with stock wheels.

What is every one else running?

I'm thinking 2.2* camber front with very little toe out (1/16")
1.6* camber rear with about 1/8 toe in.

Comments.

 

[bushido]

Carl, are you going to run at Laguna Seca this thursday?

 

[Catwood]

nope....too far away for me.

 

[mjorgensen Woodhouse]

That will be fine, the toe out in the front may be a little twitchy at speed and under braking. FWIW

 

[Catwood]

That will be fine, the toe out in the front may be a little twitchy at speed and under braking. FWIW

I ran that in the 2000 without issue on wider tires and slicks. Think it will be worse?

 

[SoCal Rebell]

nope....too far away for me.

Carl, would your car even pass the 91db sound max at Laguna, even stock?

 

[Leslie]

Stock '09 with stock wheels.

What is every one else running?

I'm thinking 2.2* camber front with very little toe out (1/16")
1.6* camber rear with about 1/8 toe in.

Comments.

I am in an '01 GTS, I am running 2 camber front, 1 camber rear. No toe out in front and .2 toe in for the rear.

The toe out in front will probably help you with turning in on the track, but as mentioned already might make the car a bit twitchy under hard braking. I prefer the toe in for stability.

I have found that car setup such as suspension, ride height, driver weight, tire pressures, what track you are running and driving style do play a part on the alignment as well.

 

[Viper X]

Carl,

Your setting will work fine. I'm running more front camber and more front toe out - car is very stable and not "twitchy" at all with 305's or 315's up front, 335's or 345's rear.

For rear camber, most guys are running 1.2 to 1.5 negative with 1/16 to 2mm toe in per side. The SRT doesn't seem to like as much rear camber as the GTS does.

Ran 1:31.2 at Willow Springs last weekend. Had fun passing F430 Scuderia, Nissan GTR, a new Lambo Gallardo and many Z-06's.

Could have had fun with another fast Viper.

See you at the track,

Dan

 

[Catwood]

Carl,

Your setting will work fine. I'm running more front camber and more front toe out - car is very stable and not "twitchy" at all with 305's or 315's up front, 335's or 345's rear.

For rear camber, most guys are running 1.2 to 1.5 negative with 1/16 to 2mm toe in per side. The SRT doesn't seem to like as much rear camber as the GTS does.

Ran 1:31.2 at Willow Springs last weekend. Had fun passing F430 Scuderia, Nissan GTR, a new Lambo Gallardo and many Z-06's.

Could have had fun with another fast Viper.

See you at the track,

Dan

That's my primary concern is what's different from my GTS to the SRT10. Interesting you say it doesn't like as much camber. I do know it pushes at speed in the stock alignment...so much so, I am afraid of taking turn 8 without doing something. Might be touching the brakes for once as I go in. Running a 31.2 is getting there and you're getting faster. congrats. Another .6 and you'll catch my best GTS time

I suspect I'll be back to .35s in this car though....

 

[Viper X]

Yeah,

I ran that time on Kumhos. I tried a few sets of Dunlop race tires on my GTS and they are the stickiest yet. Can't seem to get any more of those used and won't pay the 2K plus price for new ones.

I'll be back running with West Coast Racing in a couple of weeks. I'll likely kill the Kumhos on Saturday and run a fresh set of Hoosiers on Sunday, hoping for good weather. 1:29.99 here we come!

Any chance you'll be there?

Dan

 

[Catwood]

I''m planning on OTR the following Wednesday. You can sometimes get the Dunlap slicks from Berget Tire. He had two compounds soft and hard. The softs lasted about 15 laps on the Viper but they were fast. $400 for the set a couple of years ago.

 

[YLW DRM2]

On a related topic, what kind of off set one would want to run as an weekend race warrior? Basically, I race my car 5-7 times a year on a Kumho street tires. I race it hard in the advanced group and I want as much advantage as possible on the race track, but at the same time I don't want to completely shot my street tires and have a wrong set car for the street. What kind of offset would be a good middle ground to be still somewhat aggressive on the track and at the same time ride it comfortable on the street?

 

[Catwood]

Are you asking about Wheel offset or ?

 

[99 R/T 10]

Quick question. Probably don't want to use this setting ont eh street, but is the a happy medium alignment setting that would be good for both?

 

[Achilles99]

What kind of tires are you using?

On PS2's, 1.5 camber in back works great but on R888's they will wear too much on the inside. I'm going to try negative 1 next week to see if it's better. 2.2 should be fine on the front.

Get a tire pyrometer, you can check to see how your tires wear. I've more than paid for mine by increasing tire life.

 

[Catwood]

I've got the tire pyrometer and will use it. I'm currently on the PS2 stock tires. I've only run once and that was at Coronado on mixed runway and tarmac of the airfield. The inside of the tires barely got past ambient and the car push real bad. I ran bigger numbers on my GTS both front and rear with wider rims and tires on the front. That car was also lowered and corner balanced. I'm trying to figure out what the SRT10 likes and doesn't like. I do know it doesn't like the stock alignment at speed.

 

[Catwood]

Carl, would your car even pass the 91db sound max at Laguna, even stock?

Ron, I missed this. I really don't know. They did let us run parade laps there last spring. We were able to do a few corners fairly fast.

 

[Achilles99]

I've got the tire pyrometer and will use it. I'm currently on the PS2 stock tires. I've only run once and that was at Coronado on mixed runway and tarmac of the airfield. The inside of the tires barely got past ambient and the car push real bad. I ran bigger numbers on my GTS both front and rear with wider rims and tires on the front. That car was also lowered and corner balanced. I'm trying to figure out what the SRT10 likes and doesn't like. I do know it doesn't like the stock alignment at speed.

Actual temperature is less important than relative. You want the inside of the tire to be about 10-15 degrees hotter than the outside. The middle should be the average of the inside/outside. If middle is higher than average, you might be running too much pressure (and thus ballooning the tire). If lower than average, you may be underinflated. Of course, if you need to raise temperatures across the entire tire than generally you need to lower the pressure (although with some r compounds I find that raising the pressure sometimes helps, too... depends on where the sweetspot is for adhesion). On PS2's, 37-38psi hot usually works best.

If you have access to a 4-post lift, doing your own alignments is very easy on our cars. Catwood - you and I have almost the exact same post count and join date. Brothers from other mothers.

 

[Catwood]

ok I backed off a little.

-2.1 camber front
about 5.5 caster
1/16 toe out

-1 .1 camber rear
.75 caster
1/16 toe in

Feels good

Special thanks to the Mike the man at AC Performance. Always willing to go the extra mile to make it perfect!

 

[ACRBruce]

Yeah,

I ran that time on Kumhos ...

Dan

Dan,
I take it you're referring to the V710's, if so how have they been holding up heat cycle wise? When I'm done w/ my V700's, I'm thinking of trying other tires. And do they get greasy towards the end of a session?

Thanks.
Bruce

 

[Viper X]

Carl,

I would not back off too much on the front camber with the 275's. You may want to ask David Andrews what he's running alignment wise as he has about the most experience around running faster times on PS2's and Gen IV Vipers. Terry Rossi sets up his car.

Bruce,

I liked the way the Kumho's felt when they were new but they did wear out the outer shoulders of the rear tires pretty fast at Willow Springs, had to switch them on the rim after about 8 sessions, which is a pain. This was with 1.5 negative rear camber, stiff rear springs and Moton Shocks.

Fronts faired better in terms of even tire wear at 2.7 negative camber. Problem is the Kumhos are only available in 305 front and the car will push at speed as the front tires wear out, which happens pretty fast to these 305s.

Willow Springs is ******* tires.

The Hoosier R6s did wear better and felt a bit faster. I've gone back to 315 fronts / 345 rears with the R6's and think they're about as good a tire as you can currently get for a DOT track tire.

As mentioned above, the Dunlop race tires that you can sometimes get "used" from John Berget are the stickiest, best feeling tire I've run on Vipers. Get the harder compound though as even it wears out pretty fast, like one weekend at a slow track. At Willow Springs, they might not last a day.

Dan

 

[Achilles99]

I agree with Dan on the front camber. My friend runs 2.5 camber on his front stock ps2's, and does great with tire wear and temps. Of course, this varies by track so use a pyrometer. On most tracks, you'll actually find that the best camber isn't necessarily the same on the left and right side.

Catwood - How did you measure caster in the rear? I didn't think that existed.

 

[Viperless]

Russ at Archer's set me up today with:

-2.5 cam front (was -2.5)
-1.1 cam rear (was -2.1L -1.9R)
+6.5 caster front (was +6.5)
0 toe front (was 1/32 in)
1/16 toe in rear

Not a track alignment per se. More of an aggressive street alignment. He wanted to dial the front caster down to +5.0 to + 5.5 but left it as is when I told him I was going to be running the Texas Mile in a couple weeks.

He also corner weighted the car. I was pleasantly surprised to find out the weight was 3250lbs with about 3/8 tank of fuel.

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[Rich Wesorick]

Russ is the man!!!!!!!!

 

[Catwood]

Catwood - How did you measure caster in the rear? I didn't think that existed.

Mike at AC Performance did it, you'd have to ask him. I know he adds equipment to the rear suspension that plus into the the equipment.