Yeah unfortunately the options are tightly tied to what is run in your area. We run Cup here in PNW but do so under ITS prep, which limits us to the same 'number and type' of suspension devices. That translates to no coilovers in the back. So we just run Konis. I run 450lb springs up front and hollow 30mm-effective torsions out back, pretty much a spec configuration.

If you run under PCA as others have said you are more wide open. NASA and PCA just aren't as heavily supported here in the PNW, so we run under SCCA.

A side note: Lindsey offers a Cup discount and carries a variety of setups. I got my Koni stuff from Paragon and I always get top notch service from them.

 

I've seen a few spec guys run in cup (with spec-legal cars) and do quite well. You're still talking about 150HP and the same contact patch, so a good driver probably makes up all the difference.

 

t bars vs rear coil overs:
I was only thinking coil overs in the rear for ease of adjustments but after looking into it, I don't think I could go coil over without converting the rear to late offset, which I don't want to do. Not to mention the cost of 30mm torsion bars vs the rear coil over conversion kit. T bars it is...

Which class:
As for spec vs cup, If I stick with t-bars then I should be fine for either class. Unless as you say there is a Lb limit on the front springs and strut insert. I was hoping to go for 500+lb springs up front and have the koni sports revalved. Sure the revalve will cost a little but i really wanted the stiffer front end. I suppose i could start out with the 350lb springs and off the shelf koni inserts and give it a try and save the stiffer stuff for a later season. Cost of replacement springs is not bank breaking. Also, looking at the racers edge bushing and they are mostly delron, again legal for either class.

Last night I had a total of $4100 bucks worth of suspension in my cart @ paragon. Now maybe I don't really need to replace 'every' bushing day 1 but if the hands are dirty, do once...

Too bad Obama didn't come out with a stimilus / tax break for want to be racers :P

Tom

 

Ground Control.






Professional Racing and Driving Coach

 

I run the 450 lb on yellow Koni's and that is the upper end of what you can get away with without a revalve. I ran 350lb last year but still had too much dive under hard braking. With 968 M030 bars and LSD this setup seems to be pretty good for me so far. I use the Ground Control coilover kit on the front camber plates as well.

 

I've long since given up on the Konis. We're running Bilsteins on my car, all around, and a mix of Bilsteins and QA1 double-adjustables on my teammate's car. All Bilsteins are custom valved Motorsport units, not reheated street shocks. My car has 34mm t-bars in the rear, 600# front springs; teammate's car is softer at 30mm/350#, but with much bigger swaybars - Weltmeister adjustable vs. my stock front and 19mm rear. IT rules prevent us from running coilovers in the rear.

Rear shocks on the early cars are easier than late cars; just bore out the holes to 1/2" and you can fit any generic tube shock or coilover. Much cheaper etc.

I haven't driven my teammate's car recently, but I do sorta wish I had adjustables in the rear of my car, since the lack of adjutability of the Bilsteins limits chassis tuning options without changing shocks. OTOH, they're so cheap, comparitively ($120 or so per shock, plus valving changes), since they're circle-track shocks - having multiple shocks isn't a problem!

Front is a (Bilstein Motorsport) VW A1 Prod strut, but they turned out to be not only shortened, but very low indeed! Had to machine some custom inserts for the upper strut hats and crank in a bit of preload to get the car up to IT-legal ride height (5").

EDIT: Forgot to mention. This setup has allowed us to own the class track record at Mid-O for going on 2 years now. By a half-second margin over the previous.

 

944 spec rules limit the rear t-bars. As such you really cannot go as high as 500lbs front springs. Simply the balance front to rear won't work. Your allowed any spring rate in front and a max of 30 mm effective rate in the rear.

You should be able to get a very nice balance between front at rear when using 300 to 400lbs front springs with 30 mm t-bars. Also at 2600lbs with driver the overall stiffness is quite good. There is some roll that you can detect if you are sensitive, but overall body roll is very well controlled and there is no wallowing in anyway. If you want to run at 2900lbs then these spring rates are probably too soft, but still very good at 2600lbs with driver. The car could be a few tenths faster at 500lbs-in all around, but that difference is much less than the learning curve for most drivers.

 

Exactly what Joe said.

I can further add that, while I do run the higher spring rates, and I prefer the way they feel and probably have a bit of an advantage on a smooth track (I've not run on any rough enough for this to be a problem) - I can definitively state that they're not for the novice driver. They're much harder to run at the limit - the sweet spot is much narrower, more tending to like a "true" racecar.

So, in this respect, the 944Spec setup is better - much more tolerant of a wider range of driving skills.

...with all apologies to my wife, who's now learning to race in my super-stiff high-strung racecar.

 

Hey Guys, I really appreciate all the feedback / info. Very helpfull.

Tom

 

I have (used) front and rear Weltmiester anti sway bars if you are interested, 22 mm rear, 28 mm front with the front drop links. All parts to bolt them on are included.

 

I have numerous parts/spares for sale. I will be posting pics and info when I do a better "inventory" count. I have a 944 ITS f/s, 924 ITA, 951 roller, 924 roller, 931 roller, tons for parts...
m.jensen68@yahoo.com

 

Are you F'in me?!? Do you know how many people have bugged me asking about IT-prepped 2.0L 924's???

Dude, gotta post that schizzle! Seriously, please drop me a line when you have your 2.0L inventory together - will cross-post on 924board.org for you.

I actually have a line on a ITA 924 in Detroit (hasn't run since the move to ITB), but haven't quite convinced anyone to jump on it yet...

 

Guys,
Anyone have any opinions / experiences they wish to share about actually converting the front struts to coil over ? my early 84 struts come right apart for changing out the cartridge(top cap is threaded). How do you go about installing the threaded sleeve for the ride height adjustment / lower spring perch ? My friend who does suspension work says they sometimes weld on the sleeve and other times it literally drops down over the strut and nothing to attach other then a set screw. Obviously I'll have to grind of the original lower spring perch. Trying to get an idea if it's worth the money to let the local shop do the work. I'm not one for farming out work, I do all I can, when I can.

Tom

 

The front coilover sleeve is typically slipped over the tube after removing the nut, and sits in the stock spring perch. Can't be welded to the tube, as the sleeve is aluminum. Removing the stock spring perch - well, good to remove some of the excess weight, but you need to leave something for the sleeve to sit in. On one set I had, before I went to a true race shock, we removed the spring perch on a lathe, except for a little collar, the very base, that was then turned to fit snugly into the bottom of the sleeves. No room for wiggling. Very nice and clean. But not trivial.

The install is not complicated enough to have a shop do the work, waste of money. DIY, no spring compressor even needed.

 

Very easy. Here is is my 84. I just removed the standard coil sping, put the threaded sleeve on and then used the top mount and camber plate. very easy. It will be loose when you jack it up which seems odd, but works fine in practice. Some times when lowering you can hear it pop in place. You should zip tie the spring to the upper mount.