What is a good caster setting for de powered racks?
 

Hey guys, I de-powered my rack awhile ago but I did not start DD-ing the car till now.

The last alignment was done with P/S, so the caster is set at 5-5.5 degrees. I just cannot live with this anymore (I have a smaller momo steering wheel and I want to autox the car, which would be very hard right now with the steering effort).

So, what kind of caster do you guys run with de-powered racks? I did some looking up, seems 3-3.5 degrees is reasonable. I just wanted some input, especially if you have autox experience on a de-powered rack.

Thanks for the help!

3-3.5*

Thanks dood, I was half expecting you to just tell me to stop being a pussy :laugh:

I'm running 5 on the . but need to dial it down a hair too. Was thinking 4 but might try the 3.5. Just a pain in parking lots and wants to push a bit in the throttle in U turns. Like I'm only using the side walls.

I'm a pretty strong guy and thought 5* on an NA w/depower was tough to drive on the track. 3.5 is much easier and the car seems to handle fine. I believe we put 5* in the power-steering cars to slow-down the rack, but don't quote me.
lol, that too.

A local asked what to use and I demanded he go with 3.75 over the +5° of conventional m.net wisdom Lanny alignment. He argued pretty hard with me about it, but eventually decided to take my advice.

He called me later that week and thanked me for reinstalling power steering back on his car.

Great to hear, ill have to get a new alignment asap.

Thanks guys!

Yep, 3-3.5* caster is pretty much what I end up with on both track cars, both depowered. Tried more, it sucks.

I remember Emilio writing about going back to high caster, but not sure on what car and why. Maybe his DD for highway stability :P

Everyone who bitches about how heavy depowered steering is at speed is either a huge, huge pussy, or runs 5-6* of caster.

All of our shop cars get 3.5*.

The difference between 5-6* and 3.5-4* in caster is huge. I changed to about 3.5* on my depowered DD after trying it at 5+* for months and it was much easier to drive.

The Dallas "adult" crew still runs more camber in the rear than the front, and pretty much disagrees with everything 949 comes up with. I guess that's why we're going faster than they ever did with 60hp less whp, on r-comps (they run Hoosier). lol

I am not a princely track stud as you are, but from just a basic suspension 101 perspective, how can more camber in the rear than the front possibly be an advantage?

Teach me please. It's a question I've had for a while.

Funny thing is my girl drives my depowered '97 with a '93 depowered rack, on 205 BFG's that I think are pretty sticky for street tires, 5deg caster, on the street all the time with no complaints. She just puts her boobs into it. Well, wines about the lack of AC but she'll get over it.

Yes, positive camber would ruin your handing. But this thread is about caster.

I determined that M.net wisdom on Alignment had no basis in what actually worked years ago. I maximize front camber first. then just try to get castor the same on both sides from there. ends up around 4° but I’m kind of a strong guy plus I like to space my steering wheel close so I have good leverage without my arms being fully extended.

The whole preaching that thou shall have 1/2° more camber in the rear than the front thing is also interesting in that it is based on no testing and it is just plain wrong for maximizing performance.

I arrived at pretty much the same conclusions as 949 say through my own independent trials prior to 949 publishing it. And Emilio also keeps coming up with the best products to make my car faster as well. The guy cuts through the BS and gets the picture I’m impressed.

Bob

I KNOW! :facepalm:
Typo on my part. Replace 'camber' with 'caster' which is what I meant. The rest is fine.
Not that it matters much, but is it even possible to set a stock Miata suspension for +5* camber? I doubt it.

Just wanted to post, I just put on a 2" steering wheel spacer behind my Momo wheel. Made a world of a difference, the car is much eaiser to drive (my arms were nearly straight when driving before, knees real close to the wheel). I feel like when I get the caster back to 3.5* she'll feel smooth as butter.

I have the mazdaspeed 360MM wheel and still run max castor and camber in the front. I don't think the steering input is that difficult.

Bob, what kind of camber numbers do you run, and how even are your tire temps? I run 3.0/2.8* in the rental and get even wear, but if I try to run 2.8R in the black car I just cook the insides off the rears. I'm down to 2.5* and the tire wear is still shit (although 0.60* of toe-in isn't helping) but at least the pyrometer is happy now.

BTW - I think that with stock suspension the classic "Lanny" alignment is probably not all that bad, but as soon as you knock up to a 375/250 GC setup or anything in the 5xx/3xx or 7xx/4xx range you should stop sucking and run more front camber.