From my very brief understanding. Front wheel drive cars tend to have the rear suspension very stiff as to fish tail corners and place all the weight on the front tires to give better traction (soft front comared to the rear).

As for drag, i have no idea...but plz share!

I'm looking to get he basic jist of the differences...go specifics if you wish...never hurts

 

I can only share my knowledge of AutoX car setup.

FWD Honda type vehicles

goals
(reduce understeer, minimize weight transfer, limit body roll)

Hardware:
Shocks: Adjustable Type - Stiff in Front, Stiffer in Rear.
Springs: Again, Stiff in Front, Stiffer in Back (Lighter cars need stiffer springs)
Sway Bars: Biggest Rear Sway bar, with decent Front Sway Bar

Alignment
Camber: Negative in front (2-3 degrees), Minimal Negative in rear (.5 degree)
Caster: Not usually adjustable but more positive is better.
Toe: Run 1/16th Toe-Out in the front, and 1/16th Toe-In in the Rear


And, as always, reduce unsprung weight!

 

Thats good info.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ginsu2k &raquo;</TD></TR><TR><TD CLASS="quote">I can only share my knowledge of AutoX car setup.

FWD Honda type vehicles

goals
(reduce understeer, minimize weight transfer, limit body roll) -- weight transfer is good

Hardware:
Shocks: Adjustable Type - Stiff in Front, Stiffer in Rear. -- change to softer springs in front

Springs: Again, Stiff in Front, Stiffer in Back (Lighter cars need stiffer springs) -- change to soft shock settings in front.

Sway Bars: Biggest Rear Sway bar, with decent Front Sway Bar -change to smaller front sway bar

Alignment
Camber: Negative in front (2-3 degrees), Minimal Negative in rear (.5 degree) --reducing rear camber is only a bandaid fix to cure understeer

Caster: Not usually adjustable but more positive is better.

Toe: Run 1/16th Toe-Out in the front, and 1/16th Toe-In in the Rear --0 toe in rear, no toe in


And, as always, reduce unsprung weight!</TD></TR></TABLE>

I don't agree with at least 50% of what you said but thats just my opinion.

edited to show what i would do differently. setups are work for different people so not everyone might not like what i do or what he does.


Modified by ryan12321 at 10:06 PM 4/12/2004

 

It would be helpful if you pointed out which parts you dis-agreed with and gave your opnion on the matter.

 

I know you guys know info on this stuff.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by issues4 &raquo;</TD></TR><TR><TD CLASS="quote">It would be helpful if you pointed out which parts you dis-agreed with and gave your opnion on the matter. </TD></TR></TABLE>

he did

-- weight transfer is good
-- change to softer springs in front
-- change to soft shock settings in front.
-change to smaller front sway bar
--reducing rear camber is only a bandaid fix to cure understeer
--0 toe in rear, no toe in

 

Lots of the setup stuff really has to do with driver comfort..for instance if i could on the GS CRX, i would run toe-out in the rear. (it becomes a handfull yes..but your working on getting the car to rotate)

When I coach, if a driver wants something i might not do, but he is more comfortable with it and its faster for him then I say go with it.

So look at the info above, and try both approaches. The good news with this is we can change (and heck..changing and testing is half the fun)

To drag racing differences...with FWD your enemy of course is weight transfer to the rear, taking needed weight/ballance off of the front wheels. In autocrossing this means they dont want to point in as well (hence the understeer) and in drag racing this means weight off the front wheels at launch, and wheelspin.

For autocrossing we stiffen up the rear so that it has less give, or mechanical grip, meaning it would be the end that may slide first (rather than the front) Notice I didn't say "will slide" its still all about ballance, just having massive oversteer isn't a good thing either.

One benifit of running a stiffer rear autocross setup is that it would limit weight transfer to the rear on launch also, actually making it a slightly better straight line car as well.

In a perfect world maybe you could just spot weld the rear shocks for drag racing a FWD car..but then the problem becomes controlability at the far end of the track. Some of the FWD guys actually use wheelie bars in the FWD cars to stop rear weight transfer at launch, but then still have a setup thats controlable once the car settles and is going down track.

I would love to hear Lee expand on some of this..my theory would be a hard high speed damper setting (for the launch) then a softer low speed damper setting for high speed control on a drag run.

Jon K
http://www.seat-time.com

 

That was well put and well understood. You coach auto-cross then?

 

i coach autocross sometimes..mostly friends when i am playing. But i also coach roadracing, including helping people sort cars (shocks, spring settings, sway bars..driver coaching..etc)

Currently I have been working with a Formula Continental Driver and a PCA Porsche 944 driver on a regular basis at events.

I also instruct at track days, and have instructed for PCA, FCA..etc

I love playing with setup shocks and such...thats why the knowledge about the drag racing...I like to know the differences so that i can know the why's of stuff.

Jon K
http://www.seat-time.com

 

i don't have alot of experance, but i disagree.


i don't think you can generalize a setup for every driver out there. i mean there are many drivers out there that use smaller rear sway bars and do just as good, as drivers who use bigger rear sway bars. like others have stated its all about what makes the driver feel comfortable because when the driver feels comfortable, and secure he will be able to drive to the best of his abilities.


this argument offten comes up when deciding to run a 19 or 21 mm sway bar ( just two comment sizes). some people say "bigger is always better". but that simply isn't true, for one it might be dangerous with prolonged use of a larger sway bar but softer rear spring rates (subframe brakeing).

like racerjon1 said its really about trying different things out and finding something that YOU like and that YOU feel in control of.

 

Personaly I very much respect the intese R&D Honda put into there cars and how they handle

So when I change things like how the car steers I don't try to necessarily dispell understeer just raise the point at which it occurs as high as possible

I can see how stiffening the crap out of the rear is good Auto - X but on a high speed course they seem rediculously twitchy and rough

Personally I think a car that is easy to drive is more enjoyable is going to suit me, when I have to fight with the steering wheel because suddenly a Miata seems to come from off track nowhere and my natural reaction is to lift

Anyway I suggest you practice more and slowly raise the level of the car to it's fullest before trying to change it's balance

 

most of the people in this forum know mainly about rr/ax, so I'll lend my knowledge on drag setup, which i admitedly know not much about.

shocks/springs - stiffer than stock in front, nothing too stiff. Softer should provide more mechanical grip. Rear, really stiff, like 900#, to prevent squatting when launching.

camber - zero camber in the rear, -1 in the front, because the front end will raise when the car launches and the camber should be around zero.

toe - zero rear, 1/16" toe in front, so that there will be zero toe when the car launches


I can't garauntee that these settings are optimal, since I have never been drag racing or even been to a drag race, but I've had the rr vs drag racing suspension setup conversation a few times before and this is what I gathered.