L5wolvesf
L5wolvesf Dork
12/10/23 11:53 a.m.

RallyCross car prep?

Yes, I said book. I'm kinda ole fashioned and like to have something I can read that is not on a lap top etc.

Something similar to "How To Make Your Car Handle" or the Carroll Smith books.

Thank you

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
12/10/23 1:21 p.m.

Nope.  The sport is way too new, and if you ask 5 people you will get 6 opinions...

L5wolvesf
L5wolvesf Dork
12/10/23 8:52 p.m.

Well that sucks. And only 6 opinions, I would have guessed 8 or so. smiley 

Coming from a road race background I used pyrometer readings to adjust tire pressures and camber settings. That worked very well for me. For rallyX I’ve been told to air-up tires to prevent debeading. That effectively eliminates the usefulness of pyrometer readings. How does one figure out what camber settings and tire pressures are optimum?

EvanB
EvanB MegaDork
12/10/23 9:01 p.m.

Really depends what your local surface is like. Most courses will change over the runs and you have to drive it in a way that works for you. 

My strategy is a stock alignment and drive as hard as I can. Other than that it's trial and error or talk to other people running a similar chassis and see what they are doing.

dps214
dps214 SuperDork
12/10/23 9:07 p.m.

Yeah the reason for six different answers is because different surface/course type combinations will want different things.

In general I agree, leave everything stuck until/unless you find some major handling deficiency, then fix that.

For tire pressures, start high and work down until either you hit a speed plateau or you start running into debead issues. In general, assuming a "typical" soft surface.

stuart in mn
stuart in mn MegaDork
12/11/23 8:58 a.m.
L5wolvesf
L5wolvesf Dork
12/11/23 10:53 a.m.

The surface here is a flat parking area with very small gravel over somewhat hard packed dirt. It is rutted (from rain runoff) and gets more so as the day goes on. It usually gets “raked / dragged” during the noon break and sometimes more often.

I plan on keeping the car (2000 S’cort ZX2 S/R) stock – except for wheels/tires.

Re tire pressures: what do y’all typically run?

Re camber: what do y’all typically run?

L5wolvesf
L5wolvesf Dork
12/11/23 10:54 a.m.
stuart in mn said:

I found this, but it's dated 1984: https://www.amazon.com/Drive-complete-rallycross-Foulis-motoring/dp/0854293264

I saw that but there is no description as to whether it is about the sport or driving or car set up. And it would be a bit dated too. Thank you

Keith Tanner
Keith Tanner MegaDork
12/11/23 11:23 a.m.

Seems to me there's probably some good info in the Staniforth books for you. Not pure rallycross, but he doesn't write about pure track racers either. It's out of print, but if you can find a copy of the Race and Rally Car Sourcebook it's top quality stuff. Mine's the 2002 printing, I don't know how much they were updated.

Under $12 on eBay

dps214
dps214 SuperDork
12/11/23 11:37 a.m.
L5wolvesf said:

The surface here is a flat parking area with very small gravel over somewhat hard packed dirt. It is rutted (from rain runoff) and gets more so as the day goes on. It usually gets “raked / dragged” during the noon break and sometimes more often.

I plan on keeping the car (2000 S’cort ZX2 S/R) stock – except for wheels/tires.

Re tire pressures: what do y’all typically run?

Re camber: what do y’all typically run?

Camber: stock, is that even adjustable?

Tire pressure: as low as you can get away with, you have to figure out what exactly that is

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
12/11/23 12:30 p.m.

camber means nothing, toe means very little.

 

low tire pressures are Bad if you have low power.  For reference it felt like my Golf's top speed on rally tires at 24psi was about 50mph.  Lots of rolling resistance.  After that I kept rally tires aired up to 35ish.

L5wolvesf
L5wolvesf Dork
12/12/23 12:22 p.m.

reply to: Keith Tanner

some good info could be worth $12 so I grabbed it. Thank you

reply to: dps214

Yes, Camber is adjustable with eccentric camber bolts, front and rear.

reply to: Pete

Camber means nothing and toe means very little? Please explain.

Pete. (l33t FS)
Pete. (l33t FS) MegaDork
12/12/23 6:34 p.m.

In reply to L5wolvesf :

between body roll and surface irregularity, and if you are on rally tires the nature of them, camber does not mean much as long as it is not crazy far away from zero.  likewise the steering inputs tend to be fairly exaggerated so as long as toe is not wildly out of whack it is okay.  no sense measuring with a micrometer when we are cutting with an axe.

L5wolvesf
L5wolvesf Dork
12/13/23 5:21 p.m.

In reply to Pete. (l33t FS) :

OK I get that. Thank you

You'll need to log in to post.

Our Preferred Partners
wzaiz44UTLkW5yg6K2fpm5L6kVagtHfjbJHj6x8KIsSV0BSJXKs0qU1Ele1mXVzE