I have been killing the sidewalls of my front tires each time I've gone to Lime Rock park. I feel I've gone as far as I can with added tire presure(48psi Hot). Tires are goodyear F1's. I ordered the Works camber plates and the Road Race 25mm rear bar. What alignment spec's should I shoot for with an otherwise stock car. Car is an 03, but I have a front helicoil LSD from rallysport on order from ZR1.

 

The point of the camber plates is that you can change your camber in a heartbeat.

Start off with the alignment specs that are suggested elsewhere in this forum. You should also get something to measure the tire's temperature with. Then go out drive, check the temps and make adjustments until the temperature is even the whole way across.

There should be plenty of drivers at the track to help you learn to do this accurately. You could also take a Dial-In class somewhere.

On a side note: I have GoodYear F1's and killed them too. Corded on the outer edge because I was trying to enter corners way too fast. I switched to Kumho's and started braking earlier. The GoodYear's are probably good tires, but I like the feel of the Kumho's better and they are $50 a piece cheaper.

 

Actually, the plates are needed to add more neg. camber than avail. stock. You are not able to just make a camber adjustment when you arrive at the track, your caster also would need to be adjusted. So you end up needing one setting that bridges the gap. Point taken on the F1's. So anyone using camber plates on stock suspension have some suggestions.

 

I'm not using any camber plates but I can give you some suggestion ... usually when you go to the track you want to make sure you have max neg camber and max castor ... but you also want to make sure that you zero out you toe or else you'll be going through tires quickly. On a track set up EVO you will want to start with 2.5-3 deg Negative camber in the front and 1.5 deg (which comes stock in the rear). Since we use inverted mcpherson struts we don't get any camber gain when the strut compresses unlike Hondas. For the occassionaly track junkie 1.8-2 deg Negative camber in the front will be enough. Remember changing the camber will change how the car will handles ... you'll find yourself with more grip in the fronts during cornering and less understeer .... I would recommend playing with camber settings before you put on the rear sway bar. If you have maxed out the camber in the front and the car still doesn't rotate as quickly you can then add the rear sway bar or even add some toe-out to the rear tires .... but one thing at a time ...

 

I don't think it matters if the strut is inverted or not, the geometry isn't affected. IIRC, any compression/rebound camber change in a strut suspension, other than that from body roll of course, is due to the inclination of the lower control arm. The effective upper arm length is infinite and is perpendicular to the strut axis.

Dave

 

Strut type suspensions are not ideal because the tire doesnt stay perpendicular to the ground throughout the travel. When going off jumps for instance, the tires treads point way in. This massive amount of positive travel happens often, but its easiest to see in the jump photo. Obviously this would be bad for cornering. Also, when the suspension is compressed little negative camber is gained. So, the massive fluxuation in camber would make the car difficult to tune and the handling is not optimal. That is why you have to increase neg camber on our AWD car ...

A dual A-arm suspension, which I believe is what Hondas use, however, keeps the camber in check. Having 2 horizontal links allows the hub to oscillate more vertically. The camber gain can also be tuned by changing the length of the horz. links in relation to each other. this way you dont have to tilt the shock, and compromise its efficency.

 

agreed, but that still has nothing to do with the fact that the strut is inverted. The inverted struts save some on the unsprung weight. Less unsprung weight, the better off you are.


howie944,
I am not sure what to recommend for your alignment. I would suggest you take a pyrometer and measure your tire temps accross the width of the tire. when the temps are even, then you have the optimal camber (for that track).

I would not go crazy with the front or rear camber settings. Too much camber in front will affect your straight line braking, too little camber in the rear will make the car prone to snap oversteer (fun in an autocross, not so fun on the track)

 

chrisw, what would you consider "crazy camber" I'm thinking 2 1/2 neg in the front and 1 1/2 neg. in the rear, and start with the bar on full soft.

 

I'm no expert, but that sounds like a good starting point. I have JIC's, and I currently run 2.8f and 1.5r, although I am thinking about redoing the fronts at 3.0 or 3.2.

 

Even Honda's gone to struts up front in the last year or two, at least on the Civic.

The big key to camber gain in a ULA is that the upper arm is shorter than the lower. That and their relative inclinations means that in compression the top of the hub is pulled inboard.

Dave

 

That's not a bad starting point. I would keep the toe at 0 degrees on the front and rear too until your comfotable with the setup. I have run that alignment before while autocrossing. Good turn in, the rear of the car was glued causing some understeer on corner exit. You will have issues with body roll, but you can't do much about that until you get coilovers.

Should be a pretty good alignment for the track.

 

I was running about -3.3 degrees in the front and it made a world of difference.

The front grip was amazing, tire temps were very even and my treadwear was much more even. I would suggest leaving off the rear bar untill you tune the alignment a bit. My car was neutral in med. speed corners, tending to more oversteer in higher speed turns.

With stock suspension and RA-1's my car pretty much 3 wheeled every corner (and I have the photos to prove it ) which means that more rear roll stiffness is going to do absolutely nothing for steady state cornering.

In my opinion if you want to do something with the suspension beyond aggressive alignment you need to add roll stiffness on both ends, either with springs or a balanced set of sway bars.

 

Howie994: As Chrisw said that is a good starting point, zero out the toes F and R ... also the most camber you add not only will it affect you straight line acceleration and braking but you may also encounter your steering wheel wanting to pull itself one side or another when you go over bumps and grooves in the road ...

 

I know this sounds weird, but the problem is too much air in your front tire. In your attempt to 'jack' up the front tires off the sidewall, you are adding more air to the tire.

Here's the problem: your tire acts as a spring along with the steel coil, but as you add air to the tire, it increases the spring rate, or how hard you have to push on the spring to deflect it.

THIS CHANGE OF SPRING RATE WILL CAUSE THAT CORNER TO SUPPORT MORE OF THE CAR'S WEIGHT.

So what's happening is that as you add air to a tire, you ask it to support more of the cars weight, and to do more work in a turn.

The fix is easy, reduce your front tire pressure and increase the rear tire pressure.

RA1s and most street tires like to be about 40-44 psi hot in the front, cold doesn't matter.

Keep jacking up the rears until the cars starts to feel neutral.

 

I'm currently running -1.8 front and -1.5 rear with good track results. I've also got
Eibach pro-kit springs and a Hotchkiss rear bar set at full stiff.
I bought a set of Ground Control camber plates for the front, but never put them on, as my driving seems to fit the settings I've got now. I'm also using cheap tires for street use, as the camber settings tend to eat them faster.

BTW: the camber plates are available- $200 incl shipping.