Suspension advice needed please...

[jester911]

I am looking for a little input on which direction to go with my cars suspension. I am doing more track days/ DE's and this last weekend my instructor and I agreed that I need to dial out some of the body roll.

The car is really handling well at this point so I don't want to do too much to the setup but the better I get driving the more I will need to do. I am feeling the car being about neutral i.e not too much under or oversteer.

Right now the car has bilstein sports in the front and heavy duty shocks in the back. I think in that respect it is stiff enough for now.

I am pretty certain the sways and torsion bars are all stock.
I have not changed the bushings here yet and I know that needs to happen but if I am going to different sizes here I will address that then.

The car is still more street than track but after putting race seats and a roll bar in I think I am past the worries of a harsh ride on the street.

Oh yeah the car is an 86 coupe.

Here is a pic from the track last weekend just for effect.

[rfuerst911sc]

First off what did your instructor suggest? I added to my SC the same sway bars you have on yours which are 22mm front and 21mm rear. I have Bilstein Sports in the rear with H.D. in the front and all new suspension bushings. But the biggest difference was the larger torsion bars front and rear. The car is still a street car with a good,firm ride but handles great. You could sell your sway bars as they are desireable as upgrades to earlier cars and go with adjustable heavier versions. You can go to Elephant Racings website and see the various "packages" and see what they consist of.

[lateapex911]

Well, if I read you correctly, you think the overall ride is stiff enough.

Now, you might be referring to just the shocks (dampers) as being as stiff as you want to go, but, keep in mind that damping rates need to rise as spring rates rise. So, IF the springs and dampers are well matched now, you might have to go with a more aggresive damper should you decide to upgrade the spring rates with new Torsion bars.

That said, sway bars (or anti roll bars), operate in roll and are more or less transparent in the straight ahead mode.

So,, certainly a new ARB setup would be the first item on the list.

For most guys, I think the Smart Racing set up is a terrific way to go. First, the quality blows most competitors (Weltmeister, etc) out of the water. Second, the geometry is tops. Third, the bars are modular, which means you can choose a bar for the current spring rates/tires, etc, then if you decide to later upgrade, you just swap the actual bar...the rest of the kit stays.

Finally, they are totally and easily adjustable, so balancing the car front to rear should be a cake walk.

The downside? You guessed it: $$ I bought one of mine off ebay, and one new. I got my new one from the fellow Pelicans at: http://motomotions.com/product/index.htm

Finally, if you are going to be increasing the loads the ARBs will produce, you should strongly consider replacing the ARB mounts on the rear. WEVO sells the gold standard here. There is no second choice.

If you go the Smart/WEVO route, you will never need to redo the setup except for tuning, and if you do need to swap bars, there is always a good market for the used ones.

[stlrj]

I dialed out most of my body roll by getting my car aligned as close to factory spec as I could.

The results were amazing, very neutral, predictable and tossable in tight turns as well as rock solid in long sweepers.

Cheers,

Joe
74 911 w/ SC flares, 7.5&9x16's 993 wheels, 86 3.2

[jester911]

He suggested bigger torsion bars and lowering the car as much as I can stand. rfuerst911sc I see you have 22mm/30mm in your sig.

That sounds like the direction I need to go. My car is lowered but I guess I can follow my instructors advice and drop that sucker on the ground.

I just like to make sure I have the fact right before making changes like this to the car.

Right now the car budget is a little tight so I will have to find some used ones.

[jester911]

Jake that is good info. I really don't have the budget for the big $ upgrades right now. I feel pretty good about the general feel of the car on the track right now but I don't think more stiffness would hurt.

I am just now getting to the point of being able to really feel the cars balance and how to deal with that on the track. I even somewhat got the hang of throttle steering this past weekend. That was a total blast.

The main thing is going thru turns pulling side G's the car definitely has a little more side roll than I would like. It isn't extreme but it is there.

This truly is a slippery slope. I am afraid I have gone way past the point of no return.

[lateapex911]

LOL,,, well if you want to keep it simple, just do the ARBs, and save the whole torsion bars for later. Torsions won't, in my opinion, make the car much faster, but will speed up transient response....meaning you'll need to change your inputs.

Tires are a consideration as well, As you get more serious with the stickier tires (Hoosiers) you need better susp control, IMO.

At this point in your DE career, I think good ARBs will give you the biggest bang for the buck...and they will match whatever you decide to do later. Adjustabllity is a very nice advantage, and you can dial them "up" or "Down" as well as balance the front or rear.

And be careful about over lowering the car...you can get into trouble with weird bump steer issues.

[jester911]

This is why I posted here. Info here is priceless.
Thanks for the tips Jake. I appreciate it. At this point I am not trying to make it faster. Hell I would just like to bring my abilities closer to the cars.

[Chuck Moreland]

Do you have any class requirements you need to comply with?

Even if you are just doing DEs today, if you continue to progress you will likely be looking to participate in a specific class for TT or eventually wheel-to-wheel. Think about this now and build the car accordingly.

The short answer is that you can reduce roll with stiffer Tbars and / or stiffer sways. Your best effect will come from stiffer tbars AND Adjustable sways. This will allow you to reduce body roll and have adjustment on under/oversteer balance.

You can also effect body roll by adjusting the roll center height vs. center of mass height. This is important as you progress, but baby-steps first - address the tbars and sways. This is quick and easy bang for the buck - provided your class will allow.

[jester911]

Chuck, no class requirements. If I do make the jump to W2W etc. I will buy a car that is race ready. I want to go the DE route for a couple years and see where that takes me. With a kid in college and another one going in 3 years my racing budget is pretty slim.

Not to mention just needing more seat time. DE's will give me seat time at a much lower cost and hopefully when I can afford a little more my driving abilities will be more up to par for going W2W.
Thanks for the tips guys.

[Ray B]

Jerry, I agree with most said. Basically, it's springs ( or T-bars), shocks that match spring rates, and fine tune with anti-roll bars- in that order. If you simply slap huge anti-roll bars on you'll soon be re-welding your mounting points. I'll be at the Mitty this weekend or PM me if you'd like to drive my DE car. I'm just up the road from you. Cheers.

[jester911]

Ray, it looks like I may not make the Mitty this weekend. I spent all last weekend at the track so I would be pushing the envelope going 2 in a row.

I would be interested to see what you have done with your car. I will pm you and see if we can't get together.

Thanks