Camber / Caster / Toe-in For sport driving
09-23-2010, 04:59 AM
#1
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Camber / Caster / Toe-in For sport driving
Dear Sirs,
I have just finished with the engine build and it is now time to drive the car around.
So you will be having me busting your b@lls
I need some data for the set up of my car.
Can you please advise me for front and rear:
My car is a 1977 350ci with a Dart block (estimated 450hp).
The beauty is to be driven (fast) on road and some times on track.
I think suspension is stock, but you let me know:
Shocks are KYB.
Many thanks for your assistance.
Alexis
I have just finished with the engine build and it is now time to drive the car around.
So you will be having me busting your b@lls
I need some data for the set up of my car.
Can you please advise me for front and rear:
- Camber
- Caster
- Toe-in
My car is a 1977 350ci with a Dart block (estimated 450hp).
The beauty is to be driven (fast) on road and some times on track.
I think suspension is stock, but you let me know:
Shocks are KYB.
Many thanks for your assistance.
Alexis
09-23-2010, 03:47 PM
#3
Racer
Member Since: Dec 2004
Location: Wichita Kansas
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I ran mostly AutoX and hopefully one of the road course guys will sound off. The problem is; what is good for the track will cause uneven wear of your tires on the street. Also your front tires are a bit small, I ran 295/35/17's all around on 9 1/2 inch wheels. I would suggest 1 to 1 1/2 degrees negative camber in front with all the caster you can get, (which won't be much) and 0 toe. You might want to increase the front camber, (I ran all I could get, about 2 1/2 degrees.
The rear 3/4 to 1 degree negative camber and at least 1/8 toe in. My suggestion would be to mark your rear adjusters at 0 toe and 3/16 inch total and change them at track day to save tire wear.
Nice Car!
The rear 3/4 to 1 degree negative camber and at least 1/8 toe in. My suggestion would be to mark your rear adjusters at 0 toe and 3/16 inch total and change them at track day to save tire wear.
Nice Car!
09-23-2010, 05:08 PM
#4
Team Owner
Is that car loud?
I agree with Jim to a point. I've never had to run very agressive camber numbers front or rear. If I even ran a whole 1.0 degree negative it would burn up the insides of my tires front and rear on both the track and street.
I think that individual C-3 frame flex and other items contribute to why you get so many opinions about what works the best. Vette Brakes & products has a list of setting on their web site.
You might want to look into installing a front bump steer kit.
I agree with Jim to a point. I've never had to run very agressive camber numbers front or rear. If I even ran a whole 1.0 degree negative it would burn up the insides of my tires front and rear on both the track and street.
I think that individual C-3 frame flex and other items contribute to why you get so many opinions about what works the best. Vette Brakes & products has a list of setting on their web site.
You might want to look into installing a front bump steer kit.
09-23-2010, 05:14 PM
#5
Race Director
I run Vette Brakes advanced street settings. I have offset front upper A arms so I can run the 4 1/2 degree castor they recomend. You have somevery different tires there. The fronts have a very tall sidewall and the rears are short. I would try to run a 40 series front tire and in the 245 to 255 range for better performance.
09-23-2010, 08:44 PM
#6
Le Mans Master
Some good posts already. 
IMCO what will work best for you depends so much on not only how modded is your car, but also very much on where and how you drive, that it would be hard to nail down exact settings you can simply apply and forget. That said, for spirited driving on the open road I'd suggest VBP's advanced street alignment settings are likely as good a baseline as any from which to start. As "sport driving" can mean different things to different people, here are a few other considerations that come to mind...
Your tires are the key factor in finding an alignment sweet spot, so if you wish to really dial things in you need to purchase a pyrometer and learn how to read your tires. (BTW, I agree your fronts are way small.) An IR gun type will do, and has many other uses, but should you ever find yourself tracking your car (AX or RR) a probe type is much preferred. It would be hard to overstate how vitally important measuring and evaluating tire temps are to precision chassis tuning.
Compared to even RR setups, AX setups can be very aggressive and can certainly chew up tires, so I too would adjust between street settings and AX settings for either specific use. There's no one-size-fits-all setup that's going to be optimal for every occasion, perhaps not even from session to session on the same course. FWIW I've found ~1/8 front toe out can improve low-speed corner turn in, but IMHO you won't want that for everyday driving. Bumpsteer blocks will reduce unwanted front toe steer with suspension travel and slightly increase Ackerman, the latter of which may also help low-speed corner entry with less or no toe out necessary. Don't even think about rear toe out with the C2/C3 layout.
A lot of guys like a lot of caster, but with manual steering (got rid of PS for several reasons) I've found ~2* much to my liking. As with toe, this too depends a bit on where it is between more nimble and more stable you prefer your chassis' reactions. I adjust camber and tire pressures strictly by pyrometer readings.
Another thing to possibly adjust is to reduce rear camber gain. Modern and/or wide tires don't seem to need as much, so as a rule of thumb you can lower your inner camber strut links ~1/2" below OEM height at the diff. More might or might not work for you, but IMHO you'll need that pyrometer to know for sure. FYI, the top of the slot in VBP's Smart Strut bracket (available separately for those who don't want/need the entire kit) is ~1/2" lower than stock.
Don't forget that ride heights are a big part of the suspension geometry equation. If not already done and you're sincerely after better handling, lowering as near to Chevy Power book Corvette chassis section heights as any clearance issues allow you to get away with (account for lowering the camber struts in your math) will lower front and rear roll centers and CG.
It's worth noting that higher spring rates might become necessary to counter bottoming when lowering significantly, but that's another topic altogether, as are shocks, bars, bushings, sidewall stability, corner weights... Still, it's hard to separate out one portion of vehicle dynamics from the overall package when you start pressing hard. In any event, install a spreader bar between the front towers.
Lastly, sneak up on your car's limits with caution. I don't know your spring/shock/bar combo, but just keep in mind that a seemingly neutral car may well feel awesome when driven at 7 or 8/10ths only to turn around and bite you with unexpected oversteer when pushed to 10/10ths. And, you don't want find that out when you've run out of margin.
Hope that's worth $.02
TSW
Hey Jim, I think I saw somewhere your former shark has already been AX'ing with it's new owner.
IMCO what will work best for you depends so much on not only how modded is your car, but also very much on where and how you drive, that it would be hard to nail down exact settings you can simply apply and forget. That said, for spirited driving on the open road I'd suggest VBP's advanced street alignment settings are likely as good a baseline as any from which to start. As "sport driving" can mean different things to different people, here are a few other considerations that come to mind... Your tires are the key factor in finding an alignment sweet spot, so if you wish to really dial things in you need to purchase a pyrometer and learn how to read your tires. (BTW, I agree your fronts are way small.) An IR gun type will do, and has many other uses, but should you ever find yourself tracking your car (AX or RR) a probe type is much preferred. It would be hard to overstate how vitally important measuring and evaluating tire temps are to precision chassis tuning.
Compared to even RR setups, AX setups can be very aggressive and can certainly chew up tires, so I too would adjust between street settings and AX settings for either specific use. There's no one-size-fits-all setup that's going to be optimal for every occasion, perhaps not even from session to session on the same course. FWIW I've found ~1/8 front toe out can improve low-speed corner turn in, but IMHO you won't want that for everyday driving. Bumpsteer blocks will reduce unwanted front toe steer with suspension travel and slightly increase Ackerman, the latter of which may also help low-speed corner entry with less or no toe out necessary. Don't even think about rear toe out with the C2/C3 layout.
A lot of guys like a lot of caster, but with manual steering (got rid of PS for several reasons) I've found ~2* much to my liking. As with toe, this too depends a bit on where it is between more nimble and more stable you prefer your chassis' reactions. I adjust camber and tire pressures strictly by pyrometer readings.
Another thing to possibly adjust is to reduce rear camber gain. Modern and/or wide tires don't seem to need as much, so as a rule of thumb you can lower your inner camber strut links ~1/2" below OEM height at the diff. More might or might not work for you, but IMHO you'll need that pyrometer to know for sure. FYI, the top of the slot in VBP's Smart Strut bracket (available separately for those who don't want/need the entire kit) is ~1/2" lower than stock.
Don't forget that ride heights are a big part of the suspension geometry equation. If not already done and you're sincerely after better handling, lowering as near to Chevy Power book Corvette chassis section heights as any clearance issues allow you to get away with (account for lowering the camber struts in your math) will lower front and rear roll centers and CG.
It's worth noting that higher spring rates might become necessary to counter bottoming when lowering significantly, but that's another topic altogether, as are shocks, bars, bushings, sidewall stability, corner weights... Still, it's hard to separate out one portion of vehicle dynamics from the overall package when you start pressing hard. In any event, install a spreader bar between the front towers.
Lastly, sneak up on your car's limits with caution. I don't know your spring/shock/bar combo, but just keep in mind that a seemingly neutral car may well feel awesome when driven at 7 or 8/10ths only to turn around and bite you with unexpected oversteer when pushed to 10/10ths. And, you don't want find that out when you've run out of margin.
Hope that's worth $.02
TSW
Hey Jim, I think I saw somewhere your former shark has already been AX'ing with it's new owner.
Last edited by TheSkunkWorks; 09-23-2010 at 09:29 PM.
09-28-2010, 11:24 AM
#7
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Some good posts already. IMCO what will work best for you depends so much on not only how modded is your car, but also very much on where and how you drive, that it would be hard to nail down exact settings you can simply apply and forget. That said, for spirited driving on the open road I'd suggest VBP's advanced street alignment settings are likely as good a baseline as any from which to start. As "sport driving" can mean different things to different people, here are a few other considerations that come to mind...
Your tires are the key factor in finding an alignment sweet spot, so if you wish to really dial things in you need to purchase a pyrometer and learn how to read your tires. (BTW, I agree your fronts are way small.) An IR gun type will do, and has many other uses, but should you ever find yourself tracking your car (AX or RR) a probe type is much preferred. It would be hard to overstate how vitally important measuring and evaluating tire temps are to precision chassis tuning.
Compared to even RR setups, AX setups can be very aggressive and can certainly chew up tires, so I too would adjust between street settings and AX settings for either specific use. There's no one-size-fits-all setup that's going to be optimal for every occasion, perhaps not even from session to session on the same course. FWIW I've found ~1/8 front toe out can improve low-speed corner turn in, but IMHO you won't want that for everyday driving. Bumpsteer blocks will reduce unwanted front toe steer with suspension travel and slightly increase Ackerman, the latter of which may also help low-speed corner entry with less or no toe out necessary. Don't even think about rear toe out with the C2/C3 layout.
A lot of guys like a lot of caster, but with manual steering (got rid of PS for several reasons) I've found ~2* much to my liking. As with toe, this too depends a bit on where it is between more nimble and more stable you prefer your chassis' reactions. I adjust camber and tire pressures strictly by pyrometer readings.
Another thing to possibly adjust is to reduce rear camber gain. Modern and/or wide tires don't seem to need as much, so as a rule of thumb you can lower your inner camber strut links ~1/2" below OEM height at the diff. More might or might not work for you, but IMHO you'll need that pyrometer to know for sure. FYI, the top of the slot in VBP's Smart Strut bracket (available separately for those who don't want/need the entire kit) is ~1/2" lower than stock.
Don't forget that ride heights are a big part of the suspension geometry equation. If not already done and you're sincerely after better handling, lowering as near to Chevy Power book Corvette chassis section heights as any clearance issues allow you to get away with (account for lowering the camber struts in your math) will lower front and rear roll centers and CG.
It's worth noting that higher spring rates might become necessary to counter bottoming when lowering significantly, but that's another topic altogether, as are shocks, bars, bushings, sidewall stability, corner weights... Still, it's hard to separate out one portion of vehicle dynamics from the overall package when you start pressing hard. In any event, install a spreader bar between the front towers.
Lastly, sneak up on your car's limits with caution. I don't know your spring/shock/bar combo, but just keep in mind that a seemingly neutral car may well feel awesome when driven at 7 or 8/10ths only to turn around and bite you with unexpected oversteer when pushed to 10/10ths. And, you don't want find that out when you've run out of margin.
Hope that's worth $.02
TSW
Hey Jim, I think I saw somewhere your former shark has already been AX'ing with it's new owner.
IMCO what will work best for you depends so much on not only how modded is your car, but also very much on where and how you drive, that it would be hard to nail down exact settings you can simply apply and forget. That said, for spirited driving on the open road I'd suggest VBP's advanced street alignment settings are likely as good a baseline as any from which to start. As "sport driving" can mean different things to different people, here are a few other considerations that come to mind... Your tires are the key factor in finding an alignment sweet spot, so if you wish to really dial things in you need to purchase a pyrometer and learn how to read your tires. (BTW, I agree your fronts are way small.) An IR gun type will do, and has many other uses, but should you ever find yourself tracking your car (AX or RR) a probe type is much preferred. It would be hard to overstate how vitally important measuring and evaluating tire temps are to precision chassis tuning.
Compared to even RR setups, AX setups can be very aggressive and can certainly chew up tires, so I too would adjust between street settings and AX settings for either specific use. There's no one-size-fits-all setup that's going to be optimal for every occasion, perhaps not even from session to session on the same course. FWIW I've found ~1/8 front toe out can improve low-speed corner turn in, but IMHO you won't want that for everyday driving. Bumpsteer blocks will reduce unwanted front toe steer with suspension travel and slightly increase Ackerman, the latter of which may also help low-speed corner entry with less or no toe out necessary. Don't even think about rear toe out with the C2/C3 layout.
A lot of guys like a lot of caster, but with manual steering (got rid of PS for several reasons) I've found ~2* much to my liking. As with toe, this too depends a bit on where it is between more nimble and more stable you prefer your chassis' reactions. I adjust camber and tire pressures strictly by pyrometer readings.
Another thing to possibly adjust is to reduce rear camber gain. Modern and/or wide tires don't seem to need as much, so as a rule of thumb you can lower your inner camber strut links ~1/2" below OEM height at the diff. More might or might not work for you, but IMHO you'll need that pyrometer to know for sure. FYI, the top of the slot in VBP's Smart Strut bracket (available separately for those who don't want/need the entire kit) is ~1/2" lower than stock.
Don't forget that ride heights are a big part of the suspension geometry equation. If not already done and you're sincerely after better handling, lowering as near to Chevy Power book Corvette chassis section heights as any clearance issues allow you to get away with (account for lowering the camber struts in your math) will lower front and rear roll centers and CG.
It's worth noting that higher spring rates might become necessary to counter bottoming when lowering significantly, but that's another topic altogether, as are shocks, bars, bushings, sidewall stability, corner weights... Still, it's hard to separate out one portion of vehicle dynamics from the overall package when you start pressing hard. In any event, install a spreader bar between the front towers.
Lastly, sneak up on your car's limits with caution. I don't know your spring/shock/bar combo, but just keep in mind that a seemingly neutral car may well feel awesome when driven at 7 or 8/10ths only to turn around and bite you with unexpected oversteer when pushed to 10/10ths. And, you don't want find that out when you've run out of margin.
Hope that's worth $.02
TSW
Hey Jim, I think I saw somewhere your former shark has already been AX'ing with it's new owner.
As always a quality post! Interesting reading and very helpful
09-28-2010, 05:20 PM
#8
Racer
Member Since: Dec 2004
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[
Hey Jim, I think I saw somewhere your former shark has already been AX'ing with it's new owner.[/QUOTE]
Very good info from all the posts!
Skunk, I'm curious where ol red went. I beleive some where in south Carolina.
Whoever bought it should be fast, it is a very good car.
Hey Jim, I think I saw somewhere your former shark has already been AX'ing with it's new owner.[/QUOTE]
Very good info from all the posts!
Skunk, I'm curious where ol red went. I beleive some where in south Carolina.
Whoever bought it should be fast, it is a very good car.
09-28-2010, 06:45 PM
#9
Le Mans Master
09-28-2010, 09:38 PM
#10
Advanced
Was this on stock suspension? I'm new to C3's and have been wondering how wide I can go with a square set-up. Did your tire installer have a tough time getting 295's on 9.5"? What brand tires were these?
Sorry for the thread hijack...feel free to pm the answers if you'd rather Jim.
Russ
