Finally got around to putting the Tarret Bar I picked up via the infamous Group buy.

Old Set up: Stock Sway and 140's on rear = tail happy in tight turns.

New Set up: Full soft on the Tarret sway and 140's on the rear and the car pushes some now.

Anybody with experience with these bars? It is advertized as equivalent to a 22mm solid bar in stiffness. That would be 80% stiffer than a 19mm solid bar. My guess is they used a roughly 1 inch O.D. bar with a 5mm thickness to get the 22mm equivalent??... just a guesstimate since the welded ends don't let you measure tube thickness.

I am thinking of stepping up to 180 springs in the rear but want to see what other's might recommend. Car rides fine with Koni red's all the way around and I don't think I will have any disappointment with a stiffer rear.... after having old KYB's in the rear to start with... almost anything feels like a smoother ride.

Hum. Something is weird. I just did a Tarret install last week and used 100lb springs in the rear with new Bilsteins F+R (no rear bar) and the car is well balanced with the bar set 1/2 inch back. The car is very neutral. Oh. Stock torsion bars.

Can you give me the ride height on the car from ground to fender lip through the center of the wheel/hub on F+R. I'm wondering if you have the weight balance of the car out of whack.


B

What about your tires?

Have you checked or changed the air pressure? You could have been compensating for your lack of suspension adjustments with your air....?????

I will make the measurements later tonite and get back on that.

I may not get another chance to push the car to the limit until next weekend. In the mean time there are a couple other things I can say.

1) Correct me if I am wrong, full soft setting on the sway bar is as shown in my picture with the drop link out at the end of the adjustable arm

2) I only got a chance to really push the car to the limit on Saturday... post install but prior to taking it in for an alignment. Before the alignment, it was my rough set up that was surely off and had more toe-in than was correct.... at that time it was definately a push in tight corners as I could get the front of the car sliding out first. The next day, Sunday, I took it in for alignment. It was set for:

Toe in: 0.3 degrees
Camber: -0.3 degrees
Caster: 5.7 degrees

Rear within what ever specs they had.. don't recall right now.

When I took it out after the alignment, it drove straight... as it should.... turned in a lot easier with the reduced Toe in and I noticed the "heavy" push was gone but I "thought" it still might be pushing when I came around a big sweeper on an on-ramp... could have been my imagination from the definate push I had on the previous day. I did not get to push it super hard after the alignment, so I may find that much of the push is gone now when I test it harder later??

Dumb question #1, how does alignment impact push in a turn.

Dumb question #2, do you have any standard methods for testing front and rear stiffness ballance. I just take the car into hard turns and see which end tends to go out first... hopefully in an area where I won't kill myself or someone else.

3) Koni Red's were on Full Soft. I have never checked the torsion bars, but this car was abosolutely stock in every area when I picked it up, so I can't imagine the torsion bars being stiffer than normal.

4) I used some washers to shim the sway bar bushing block so that there was no binding at all on the bar when the mounting bolts were all tightened up. The bar moved very freely and I of course set up for zero preload on the drop links with wheels on the ground.

5) Does the Tarret Bar only come with one diameter? or is it possible they sent me a thicker/stiffer one by mistake? Like I said in my original post, I recall that the bar was nearly and inch in diamter, 25.4mm, maybe slightly smaller, but I wasn't too surprised since it was hollow and that would lower the stiffness I thought to something like the advertized 22mm equivalent.

- Dave

ok, a few things ...

first, i had a similar experience with the tarret bar, 22mm is a big step up from nothing or even 19mm ...

second, yes, your bar is on full soft right now.

third, for testing, find a empty parking lot or larger patch of asphalt, go in 2nd gear, drive a tight circle at steady (slow first) speed then go increasingly faster until you feel the car either pushing or oversteering.

if you get understeer, disconnect one droplink (disableing the bar) and try again. if you now get oversteer, the bar was too much, alas you need to step up on the rear spring rate.
assuming everything else is OK on the car.

that is exactly what happened to me ...
Andy

The bar is 1” in diameter with a .094” wall thickness. That’s the only size we make and it’s equivalent to a 22mm solid bar. If the design was the same it would be 80% stiffer than a 19mm bar, but with the solid bushings and rodends, it’s effectively at least 2.5 times a stiff as your stock 19mm bar.

Even still, you shouldn’t need to go to 180 lb rear springs to balance it out. I have guys running 21mm torsion bars with 180 lb springs and my bars, so you should be ok with the stock torsions.

I’m not an expert in 914 alignment settings, but -.3 of camber doesn’t sound like much to me. I’m running -2.25 on my car. Maybe someone else can comment on that.

Like Brad and Mike mentioned, your weight balance or tire pressures could also be causing the push. You still have some things to try before going to stiffer rear springs.

Ira

That's what you have to like about this board... the manufacture comes on line to comment on the product. Thanks for the insight Ira.

If the Tarret bar is 2.5 stiffer than a standard 19mm bar, then it must be more than 6 times stiffer than my stock 15mm bar that came off the car.... that is a lot of change.

Yes on the Camber... 0.3 degrees negative is nothing.
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Brad... here are the ride height numbers, floor to bottom of fender lip and psi measurement cold.

I have 195/55 Dunlops on Fuchs, so Ride Height is nominally about 0.8 to 0.9 inches below that with stock tires.

Height, psi cold
LF: 24 1/16", 30 psi
RF: 24 3/16", 30 psi
LR: 22 1/2", 30 psi
RR: 22 5/16", 32 psi.

I have 21 MM front T bars, 225 lb rear springs and I just moved my "Ira" bar to full soft in the attempt to get rid of the push.....in the tight sections. I've been softening it in half inch increments. Finally said the hell with this and moved it till it won't move no more. I can always go back.

Won't know if it works till Sunday. If not, 250lb rears are next.