Torsion bars for circle track/road race?

homer · Post by **homer** » Tue Jun 01, 2004 10:43 am

I've gotta get new torsion bars for my '71 Ghia that I run at autocrosses and want to run on road course track days.

I'm hearing probably 27mm - 28mm but wonder if anybody has used 30mm on circle tracks or road courses or autocrosses.

Thanks,

Jeff
'71 Ghia
"You can't turn a pig into a racehorse, but you can make a really fast pig."

Post by **Marc** » Tue Jun 01, 2004 11:21 am

Will it be a full-weight car or will you be gutting it? On light (~1800lbs w/driver) cars that had torsion-bar-only rear springs I never found anything more than stock Squareback (23.5mm) bars was needed...on smooth paved oval tracks where you seldom have more than a couple inches of suspension travel, anyway.
With the addition of some ~300lb Carrera coil-overs the stock bars were generally adequate even on somewhat heavier (~2000lb) cars.
I would think that 27 or 28mm should be good unless your car is a porker and/or the course has major undulations.
If the rules and body clearance allow it I'd definitely recommend making up the mounting points for the coil-overs so you can dial in spring rate and not just ride height.

Brent Bousman · Post by **Brent Bousman** » Tue Jun 01, 2004 12:18 pm

I haven't used the 30mm but I can say the 28mm works well on a stock weight Ghia for autocrossing to keep the front tires on the ground. Beware the stock rear torsion bars will give you a lot of air time which of course gives you a bad understeer situation. For road racing I would use at least a 28mm torsion bars since you will have longer harder compressions at the high speeds.

Brent Bousman
SCCA WDCR SOLO2 Ghia

homer · Post by **homer** » Tue Jun 01, 2004 12:38 pm

Marc, it's pretty much gutted now... interior stripped out, all glass out and replaced by Lexan... I'd guess maybe 1500lbs.

Brent, yes, the air time was what was happening a lot with the inside front wheel lifting on acceleration out of turns.

Is there any downside of going with SAW 30mm torsion bars? Even though I'm also running Solo 2 now, I'd like to buy bars now that could handle track days like at Road Atlanta and it's high speed crests and dips.

Also, what is your guys take on the adjustable spring plates to dial in ride height, cross weights, and left to right spring variations? Seems like they'd add 10 to 20 lbs at the rear that I don't want. Alternative is welding in a central adjuster in the middle of the torsion bar housing, right? And then you'd only be able to adjust L&R together.

Thanks,

Jeff

Post by **Marc** » Tue Jun 01, 2004 1:00 pm

You can adjust the L&R sides independently but it's a P.I.T.A. to have to get the car up that far safely for access to the adjusters, then drop it to check the results/repeat as req'd.
We used to make adjustable end caps for the outer ends of the bars, which added some weight (maybe as much as adjustable plates, but slightly further forward). Our rules allowed slotting the inner fenderwells so the "weight jacks" could protrude through into the cab, it only took a few moments with a ½" ratchet and extension through the rear ¼ window to crank up or down, then a couple more to tighten down the lock-bolts once the desired height is set - usually possible without even removing the tire. If this'd be legal for you I can send you sketches of what I'm talking about. Uses ~3/8" steel plate and a big (3/4" or so) bolt & nut, requires quite a bit of cutting & welding to fabricate but the design is pretty simple.

homer · Post by **homer** » Wed Jun 02, 2004 3:05 am

Marc,

Yes, that'd be great if you could send me the drawings. I'm running in a modified Solo 2 class so suspension is free.

jkryder "at" bellsouth.net

Thanks much,

Jeff

Brent Bousman · Post by **Brent Bousman** » Wed Jun 02, 2004 4:56 am

Now that I know you have a 1500lb mod car at Atlanta I'd say the 28s will do the job however, if you have a big hp motor and are aggressive enough you will compress the outside long enough to lift the inside front tire and you may prefer the 30s. A test day at the track will give you more feedback and enable you to make suspension changes that will work for you.

jakriz · Post by **jakriz** » Wed Jun 02, 2004 4:12 pm

I use stock torsion bars in mine , with KYB heavy duty shocks & a non adjustable 19mm sway bar, seems to work fine & it's a heavy car, 2017 without me in it, ready to race.

regards
Jak

http://www.thesamba.com/vw/forum/album_ ... 13910e8c16

Brent Bousman · Post by **Brent Bousman** » Fri Jun 04, 2004 3:47 pm

Jak,

I notice you are using a Mcpherson (sp?) front which tracks completely different than a torsion beam set up which Homer and I have. Most bugs and ALL Ghias start to squat under acceleration and or cornering and the front inside wheel comes off the ground. In an auto cross this is more or less just a PITA but on a high speed track it can be dangerous.

Nice SB by the way. BTW if you drive on the other side of the car you can get the whole tire on the ground. ; - )

Theo · Post by **Theo** » Fri Jun 04, 2004 3:55 pm

I'm running a set of 28mm in my Ghia. It is set up for autocross. I haven't run it much but the bars work great. I also have the adjustable whiteline swaybar up front and it seems to help keep the tires on the ground.

The adjustable rear spring plates are well worth the weight for the fine tuning you can do.

I was worried the 28's would be harsh but they are fine. In the rough the KYB's have a hard time with the rebound. I have Koni's but they are not installed yet.

Sure would be nice if we had a road race / autocross forum.

Theo

homer · Post by **homer** » Sat Jun 05, 2004 12:24 pm

Man, it would be cool to have a road race/circle track/autocross forum.

Jak, do you know Greg Ward? He helped me with a lot of advice on making my Ghia perform and turn.

Brent, what class are you running in for the SCCA autocrosses? Some folks from Atlanta went up for the National Tour event there last weekend and said the incline made for some extra adrenaline.

Jeff

Brent Bousman · Post by **Brent Bousman** » Mon Jun 07, 2004 5:08 am

You guys are right - we definitely need a race forum.

Jeff,

I used to run EP and sold that car after 2 regional championships in 2001 and 2002. Now I support my son in SCCA FJr and my wife in BStock. I occasionally run the slalom at the Bug Out and I have another ghia, which I run SCCA Rallycross (off road). I'm thinking about putting together a SOLO2 SM2 ghia since there are many cars in that group now.

The SCCA National Event runs at a huge lot at FedEx field (where the Redskins play), which has enough elevation change that you can't see across half of the lot so it's a real kicker!

rsrnate · Post by **rsrnate** » Mon Jun 07, 2004 9:11 am

i put 28 mm torsion bars in my 68 bug that i auto x and road race. for auto x they are ok but for high speed tracks i still lift my inside front wheel. if i could do it again i would go with the 30 mm .

Theo · Post by **Theo** » Fri Jun 11, 2004 3:09 pm

rsnate, do you have a front swaybar? The whiteline unit seems to help with the wheel lifting.

Theo