930 High Street/Track Performance Project

[Tomy]

I just start my new project. I would like to build 930 to high performance level where first aim is to have 80% street car (highway car) 20% track. So I need to choose suspension set up, engine upgrade, interior upgrade, and new paint in the end. As far I divide in to 3 project stages: STAGE I: Car performance- power As far I choose Brian (LarlyL8) muffler in two option one with left side waste gate pipe and right side exhaust pipe and second let say classic with exchaust pipe on left side I will put K27 turbo, new 0.9 bar RUF waste gate spring, Andial intercooler, and Andial boost controller (mechanical). STAGE II: Car performance - suspension I would like to lower so need to have rase spindle so Here I have two ideas (thanks Chuck!) to go withouot coilovers or with : Strut Front (Racing "RSR") Valving 220/100, Spindle rasied 19mm. Bilstein RSR strut insert Raise Bilstein spindles - rsr type struts - 30mm Racing Bump steer kit, weld-on steering knuckle type for 30mm raised spindle, with boots Von Street level 2 sealed gas shock 22mm Torsion bar, plated & plugged hollow PolyBronze control arm bearing Low-friction control arm mounts new Ball joint rear Camber plate rubber replacement bushing kit, Von Street level 3 sealed gas shocks, single adjustable, 30mm Hollow Plated & Plugged torsion bar PolyBronze spring plate bearings factory plates, Rear monoball sealed 935 X - QuickChange strut brace Hollow front sway bar Backer plate kit for front sway bar Hollow sway bar rear Rear sway bar mounts Stage III performance overall I would like to put Wevo shifter So any idea ? If you have some suggestion you are welcome, remember that I need to have more street than track car but for high speed as well for track days two.

[David]

If you're going to have a boost controller, you probably need a lower pressure spring like a 0.6 or 0.7

Before any track driving, I'd put it on a dyno and check the AFR's.

[Tomy]

David,

why I need lower pressure spring , I think that if I have boost controller I can only go down from 0.9 (if I have 0.9 bar spring) I am wrong?

[GT2EvoGuy]

On the front suspension maybe you could consider a 935 style front suspension for better adjustability and a nice weight savings? Smart Products offers the ERP 935 front suspension. Seeing as you want to use the car 80% for street use you might want to ask them how it affects ride quality. I recall that they have 2 versions - a race only and a more streetable version. I have the race only version on my car (and a full race suspension everywhere else) so I dont know how much the 935 setup would impact ride quality. Not much I would think........

I highly recommend the Wevo shifter as well

[RarlyL8]

A boost controller requires using a boost spring that matches or exceeds the lowest setting desired. The reason is the controller can only adjust up not down.

[Tomy]

Ok clear I have take a look at boost controller scheme and see now. Thanks

[gumba]

For a street track suspension set up I would go with the Smart Racing Fox adjustable front shocks and Wevo Ohlins adjustable rear shocks. This would allow you to soften the suspension for street driving, and stiffen for the track. The Fox shocks also have an adjustable spindle height.
I've run the S/R F10, F30 & F40 re valved shocks. I had the F30 re-valved shocks in our street/track car. It was great for the track, but too stiff for the street. I'm using the F10 set up on my turbo. Good for the street, but I think it will be too soft for the track.
I would also go a coil-over helper spring in the back as other folks have recommended. You could snug it up at the track to deal with turbo squat.
I have the 935 front suspension setup on our race car. I don't see any benefit for the street, and would spend that money somewhere else.

[Tomy]

And what about yours set up experiments? What is worth to do what not?

[911st]

What do you mean by track? Is that DE/TT's? What is your track expertience.

Track speed is about the driver first, tires & alignment second, suspension & brakes next.

Motor:
Right exit straight through w left exit WG
.9 bar spring.
K27-7006 turbo if you can find one.
Andial IC
no dial a death knob!
port intake
SC cams.
Added cooling capacity w extra cooler and or larger center unit.
Work the distributor and add MSD.
net of about 360-400hp.

Suspension:
22/30 torsion bars (torsions can take you way past to stiff for street).
Larger than 22mm equivalent (SRP 27/27's?) adjustable sways (can stiffen for track events)
Reinforce rear sway mounts.
Sport Bilstein's or custom valved shocks (lower compression, higher rebound)
35mm raised front spindle (better matches rear camber curve).
bump steer kit.
ER adjustable strut top or Camber King (may have to remove shock hats for full range).
ER Offset ball joints.
Strut brace
PB or ER rubber bushings.
Proper corner balance and aliment.


Brakes:
external cooling/ducting
PFC 97 pads for track.
Castor SPF fluid.
new brake lines.
ER adjustable spring plates.
remove brake shealds

Other:
Good sport or race seat.
17" rims so can run Nito NT01's or if still 16's Kuhmo XS's in 225/265's for a street/ track-able tire.

I am not an expert on this but the above will be much faster than most drivers and should still be livable on the street. Going full race or further than this will probably be to stiff for the street and not much faster on the track for most drivers.

Spend on track time and instruction.

Enjoy.

[Tomy]

You see for track I have much more faster car... Stealth B6. I like to have set up for my 930 to be close to track car without loosing too much of street comfort. I don't think I will race with this car ( no I will not...). But like to drive this 930 2 -3 times a week from spring to autumn let say on high way here and in Germany ( no speed limit on some roads!) it will give 3000 to 6000 mils a year. And one a month track day. So it could be stiffer than typical more direct and less comfortable set up but not hardcore as race car.
I just like to have perfect balance high speed high way car.

[911st]

22/30 torsion bars are about 170% stiffer than stock.

23/31 tb's are about 200% stiffer.

24/33 is about 250% stiffer. Put these in and you will not enjoy it at all on the street.

25mm sways are about 165% stiffer than stock.

27mm sways are about 225% stiffer than stock.

Thus, a combo of 22/30 torsion bars w 27/27 sways would be about twice as stiff as stock more or less depending on how the sways are adjusted.

Enjoy.

[full quack]

I've got 23/31's t/b, h/d sport Bilstiens, 22mm Tarett sways, strut brace, poly graphite bushings all around, bump steer kit, Pagid "blue" pads frt. O.E.M. rear pads, wevo rear sway mounts, and the car is way low.

Mine is 100% street, can you say...HARSH RIDE...I think you can! Good thing I have dental coverage. When it comes time to refresh the suspension, I will go down a friendlier path.

Mark

[DDDD]

Originally Posted by full quack

I've got 23/31's t/b, h/d sport Bilstiens, 22mm Tarett sways, strut brace, poly graphite bushings all around, bump steer kit, Pagid "blue" pads frt. O.E.M. rear pads, wevo rear sway mounts, and the car is way low.

Mine is 100% street, can you say...HARSH RIDE...I think you can! Good thing I have dental coverage. When it comes time to refresh the suspension, I will go down a friendlier path.

Mark

That may be mostly your shocks. I would like to upgrade from Bilstein, but even having custom inserts is better than stock.

My friend is a Porsche mechanic and he and also Steve at Rennsports told me that the stock valving on 'sport' Bilsteins is just so wrong. Lack of dampening and also harsh as all get out over potholes.

Bilsteins lack a sudden relief valve when you bottom out so it clunks instead of absorbing the hit. The more expensive style shocks release pressure internally through some kind of valve when they bottom out. Bilsteins essentially just bounce and rattle your teeth.

[gumba]

"Way low" could also mean the shocks are sitting on their bump stops so the shocks aren't doing anything. Unless the shocks were shortened or higher camber plates installed I doubt there is much if any shock travel. I would check that first. Our race car doesn't set as low as "full quacks" and we had about 1 1/4" of shock travel in the front. That was one of the reasons I went to the Fox Shock.

[full quack]

Hey Harold,
I couldn't agree more! That is one reason I've never asked anybody on this forum for handling advise.
I should just get over it, and raise the car back up a bunch, so I can get some real suspension/shock action going. Maybe even install some 19mm raised front spindles.
But.......damn it looks SOOO good this low!

Mark

[gumba]

If your budget would allow it, I would go for the Fox adjustable front. The advantages are you could set the spindle height based on the wheel diameter, and either stiffen or soften the shocks based on your driving habits. There is an adjustment screw on the remote cannister. I mounted the cannisters in the front trunk for easy access.
If your running 18" rims you may be able to get the spindle height pretty high, keep the low stance and still get decent shock travel. Spindle height is based on wheel diameter. I think 19mm is considered max for 15" wheels.
I've been using the Wevo/Ohlins on the rear for a few years on different cars and like the fact that it doesn't have remote cannisters, and the adjustment knob is on the bottom of the shock, to it's easy to get to.
Seems expensive going in, but if you change your suspension set up, wheel diameter, coil over helpers, or full coil over down the road, then your just re-adjusting what you have instead of starting all over again.

[full quack]

Hello Harold,
I'm running 17's frt, 18's rear, so I have a little more latitude with the spindle height. Are the Wevo/Olins for the rear adjustable for travel range?
I don't think it's expensive going in....I know it is, but there ain't, no free ride now is there. If you want it right, you just have to suck it up.
Soon as the economy picks up a bit, I'll investigate some real possibilities.
Thank you for your input, I appreciate the info!
Mark

[gumba]

Are the Wevo/Olins for the rear adjustable for travel range?
I don't think any rear shock is adjustable for travel range. When I had the Konis made for the front of my VW bus I gave Koni the minimum, maximum and ride height measurements and they made the shocks accordingly. With coil overs you would set the ride height, but it wouldn't effect the shock travel range unless it was extreme.
The Wevo shock is shorter than a RSR shock and works either with or without coil overs. I took some dimensions off our turbo body race car which may or may not help.
From the ground through the centerline of the wheel to the fender lip is 24". At that height I have approx. 3.5" of shock travel (-1" for the bump stop if you use it) The shock uses approximately 2" of travel set at the middle setting on the race track. It has a 30 click adjustment range. I have the ones on our street car set softer. I use 500 lb. rear coil overs, not sure what the torsion bar equivalent would be.
When you get closer to doing this I would give Wevo a call. They would be able to answer any questions.

[full quack]

Well now....it looks like I have a whole winters worth of research ahead of me. Perfect thing to do on those rainy/snowy nights. Guess I had better start saving my $ now!!!
Thanks again for the info and positive direction, Hell I might even think about swapping to coil overs all around....cause as we all know, I'll probably end up there in the end anyway, might as well think about now.
Mark

[Tomy]

So I am in the middle of STAGE I now!

I installl K27 7200 turbine and RarlyL8 Muffler and...

It is more then I expected. It is different car at all. Boost is much more faster and even from 0 to 0.6 bar is faster too.
Before I had have max 0.6 Bar and it takes time now boost gauge show 0.7 max but most impressive is how fast it is from 0-0.6 boost.

Muffler - It is biggest surprise . It is not loud as I expect fist. But my feeling is than it is now or at least less back pressure and my 930 feel lighter, fresh as I would install other engine..Thanks Brian.
And what a sound......!!!!!!!
So I awaiting for 0.9 Ruf spring and Andial intercooler to finish stage I.