930 suspension

[Garrison]

Put the car on the track for the first time yesterday, and man what a hoot. For a 26 year old factory suspension the car did rather well...BUT I think it is time to start putting a package together that I can drive on the street and put on the track and feel confident.

What are the thoughts out there? Coil overs or bigger torsion bars? I have thought about a coil over conversion for sometime, but have always been a fan on the torsion bar cars...so I am torn.

Trying to put it all together on somewhat of a budget, that I am sure will grow as needed, but give me your thoughts, what you have found works best, didn't work at all, etc .

Thanks!!!

[911st]

A 930 has and advantage out of the gates with the wide wheel base and good camber curve with the rear 930 suspention arms.

What are your goals? Track car, street car with a couple of driver edds a year?

A stock 930 with fresh bushings, sticky tires, a sport alignment can be a very capable car.

[A930Rocket]

If you want to do lots of DE's I'd either go with bigger T-bars or coil-overs with beefed up mounts. If you are doing occasional DE's (2-3 per year) and mostly street then I'd go coil overs without the beefed up mounts.

I'm using the biggest solid T-bars I could find back in 2001, which were 23 and 30mm I want to say, with urethane bushings all around, Weltmeister sway bars and strut tower brace, Koni Sport shocks in back with Bilstein HD in front. No real complaints or squeaks to date, but Weltmeister is the bottom of the barrel. As many DE's as I've done, I would have gone with coil overs (Rebel Racing) and a better sway bars/strut tower brace, (TRG or Tarrant) if I knew about them then. Bushings would be Elephant Racing. Just can't see spending the money on them now, as I doubt my times would drop enough to justify.

Just my .02.

[Garrison]

Thanks for the feedback guys.

I am looking for a car that I can drive on the street, but something that is set up for the track. I like feeling every pebble on the road when I drive over it. That to me is what these cars where supposed to be.

I really like the idea of coil overs on the car. I have seen the Rebal Racing stuff, and it seems top notch. I think Elephant also now has a coil over kit too...

Not sure how deep I want to go, but have read that you need to make the body stronger depending on the size of coil over you put in???

[911st]

Some special things can be done with coil over like progressive springs however that it not of much use on a 911 for most.

Springs are pretty much springs. Coil overs is mostly about about extending the spring rate beyond where torsion bars leave one off. Rear coil overs do make height adjusting a bit easer however, adjustable ER rear arms for torsion bars make it even easer. Coil overs on the front can limit front tire width but that is not typically an issue on a Turbo body car unless you want to run 275's up front. Coils can also limit the amount of neg camber possable

Based on your note, 22/30 or and agressive 23/31's are going to stiffen up the ride a bunch as they are about 70 to 100% stiffer than stock bars.

Add to this properly valved shocks, race oriented tires, a competition alignment and you have a very capable car.

Adjustable sways can help to stiffen it up further depending on size (25mm) and allow one to balance or tune the handling.

Shocks, torsion bars, bushings, sway bars, corner balance and alignment can cost $3k plus. The sways can come later but it is good to do the other all at once.

One issue with 911 based cars is getting enough neg camber in the front.

Tires and the driver are probably the most important part of making a 930 go fast.

[Garrison]

I agree that the driver is the biggest part of the entire equation for sure, and by no means do I think I am putting down consistant times in this car. However, the car really feels like it lifts above 100 mph, and gets light. Scary feeling for sure. I also have a spindle/bearing issue on the drivers front that I will need to address, and hence why I am looking to do it all at once if possible.

Does running coil overs just up front or just in the rear cause an unbalanced car, or can it help? Seen lots of narrow bodies with coil overs in the front and torsion bars in the rear... have read on here about 930's with helper springs in the rear to help with squat, but still a torsion bar car... SO many options.

[911st]

Never seen CO's in the front only. Have seen in the rear. Again, a spring is a spring. Should not matter what type, only if the rates are balanced.

If willing to make the investment, improving the front camber by having the struts worked to raise the spindle raised and decambered can be done for about $800 including a bump steer kit. This restores you travel on a lowered car and better matches the front camber curve to the 930 rear's.

Hight speed stability can be helped with tires, alighment, stiffer shocks, and a bit more of a front down attitude. Still nothing helps like stiffening up the suspension.

It seems that anything up front more than about a 22mm torsion bar seems to start to get a bit stiff for everyday street use. That is about 80% stiffer springs than stock. A set of torsion bars is about $250. Converting the coil overs can be over $600.

Again, unless you need racing spring rates it is just added expense.

http://www.rebelracingproducts.com/Suspension/Steering.html

[911st]

Springs help with squat and weight shift under acceleration & braking.

Sways have no effect on that or two wheel bumps (speed bump). They had some half there spring rate in a one wheel bump, and help a lot with sway in a corner.

Adding modest springs and aggressive (24mm plus) sway bars can make a car still street able and let it work well on the track. A 930 with 22/30's and 24mm front and rear sways will be about two times stiffer than stock. Bushings, shocks, and tire choice can magnify or mitigate this to a degree.

Getting with someone that really knows 930 to help you make your choices is a good idea.

I am not an expert on this, just what I believe so far.

[JFairman]

Sounds like you could use a good front airdamn and maybe new shocks if your car feels light around 100mph and faster.

You should fix your front wheel bearing problem before doing anything else.

[Garrison]

Yeah, trying to put together a package that I can do while I am all ready in there... Figure do it all at once, or at least as much as possible at once.

[onboost]

Garrison...

Don't know what the roads are like where you are but I think you need to consider how much you're going to use this car on the street vs. how often at the track.

The mods recommended are excellent, however wifey will eventually think the Turbo rides like a truck once you start to get aggressive with the suspension mods. It'll be great at the track, but you may find yourself not wanting to use it on the street as much.

Other than some lift, you really didn't state what the car is or is not doing to your liking. Is it wallowy, or are you getting to much lean or body roll etc??

There are a number of ways you can ease into this.. you can go with larger sways & new bushings, and tune/add from there... or

- you can do TBars and shocks.. keeping in mind with some of the aggressive sizes mentioned you will want to use shocks that have been valved work well with those bars..

I've been watching you since you were looking to purchase and you've made out onto that slippery slope bit by bit.. have fun with it!

Paul

[full quack]

Yeh, doing it all at the same time "while you are in there", has it's merits. However, getting the car dialed in after changing everything, can be a little bit of a daunting task.
With so much changed, and so much new character to the car, it can be tough to figure out what is causing what, and simply where to start with the adjustments.
Do you adjust the sways, do you adjust the ride height, do you tweak with the alignment, tire pressures, tires them self, corner balance......oh the humanity!!!

Mark

[911st]

Buget job would be new bushings, torsion bars, shocks, and a good corner balance. (Apx $2000-$2500)

Try: 22/30, 23/31, or 24/33. First is street/DE, second is track/ street, last is mostly track.

Send your shocks out to be rebuilt and set for the spring combo you use if you go past the first combo. I annum you have Bilstein shocks.

Optional: decambering front struts or mono-ball strut plate with strut bar (Camber King $600).

Stage two is adjustable sways ($1k to $1.5k).

Tires, tires, tires...

[Garrison]

Thanks again guys, this is all good info.

The car is completely stock in terms of suspension right now. Even sits at almost factory ride height... yep almost an SUV.

Onboost: I know what you are saying about the wifey, but the funny thing is she wants me to build a track car so we can go racing together. Got to love her!!!

911st: The more I look, the more I think a budget set up is the way that I will go. Prob 23/31 with some new bushings and new shocks/struts to match the torsion bars. Might even get shocks/struts that are sleeved incase I decide to do springs later... That will help a ton and make me a lot happier in a straight line and in the corners.

I might also do new mono-balls while doing the shocks/struts but time and $$$ will tell...

[911st]

If me, instead of a front camber plate I have to be honest, I would send my front struts to RR and have them decambered and the spendles raised.

A more involved approach would be to have the spendles rased, and then lengthen the A arm as this helps improves the scrub radius a bit.

Please verify you plan with a real expert.

[turn9]

Hey Garrison,

Congrats on the new car and on making it to the track, now the message....I respectfully submit to you that you are caught up in the "red mist" of your first track experience and want to make the car better ,etc.

My advise would be to fix the "spindle/bearing issue" and get a good alignment and corner balance the car and stop right there. Next, go drive it a lot, AX, DE's and make your self better with a consistent, predictable car. Learn to play and sense the changes in handling with small changes in tire pressures. What you want and what you expect from the car will change very rapidly as you improve as a driver.

Others have pointed out the Pandora's Box you are about to open making wholesale changes to the car.

Just to give my words some weight, I used to be a driving instructor with POC for years and have seen this kind of thing before...

Good luck and good driving,

t9

[911st]

+1

That is what I am doing. Stock rebuilt suspension, lowered, competition alignment, corner balanced,MPSC tires, pads, fluid but stock.

I toasted a like car with full Smart Racing Products suspension kit. Real fun.

[turn9]

Originally Posted by 911st

+1

That is what I am doing. Stock rebuilt suspension, lowered, competition alignment, corner balanced,MPSC tires, pads, fluid but stock.

I toasted a like car with full Smart Racing Products suspension kit. Real fun.

There are two kinds of drivers: Those who have toasted a car and those who are going to...

[A930Rocket]

Who makes the T-bars you refer to, Sanders?

I've seen solid up to 23/30, but after that they are hollow with no real change other than weight. Our host has Sway-A-Way 23.5mm fronts with a 23mm eff rate, the 32mm rear has a 31mm eff rate and QuickChange Torsion Bars with 24mm fronts and 33mm rears, but it doesn't say what the eff rates are.

Originally Posted by 911st

Try: 22/30, 23/31, or 24/33. First is street/DE, second is track/ street, last is mostly track.

...

[Garrison]

I think Elephant Racing has up to 24 for the front, and offers 31 and 33 for the rear. Not sure of their eff rates though...