Hey Guys - I need some quick suspension advice. My car's in the shop right now waiting to get a 4 wheel alignment done. I'm eventually going to be installing some larger torsion bars to deal with the squat from the extra HP, but the turbo is probably not going to be back in for another year. Is there any advantage to installing larger torsion bars now before the alignment is completed? Or do different torsion bars have no effect on how an alignment should be completed? I hope my question makes sense. I'm just trying to do the upgrades in a sensible sequence.

Thank you,

"trying to do the upgrades in a sensible sequence."

Then only get the 4 wheel alignment after installing the new torsion bars and whatever else you may finally change like cold flowed dryrotted old rubber suspension bushings and possibly worn ball and tie rod joints.

You can change front torsion bars without affecting front end alighnment if the ride height and corner balance is the same as before.

If the rear suspension is stock the spring plates have to be unbolted from the trailing arms and torsion bar tube and removed to get at the torsion bars and that totally undoes the previous rear suspension alighnment so it needs to be redone from scratch and it's repetitive hit and miss toe, camber, and ride height/corner balance adjustments until you get it right after the car is back on the ground and everything is settled because the car can not be on the ground while indexing torsion bars and making those eccentric bolt rear wheel toe and camber adjustments in the spring plate.

Thank you - this was exactly what I needed to know. According to Pelican's chart, it looks like all normally aspirated and turbo models had 19mm Front Torsion Bars:

http://forums.pelicanparts.com/uploa...1305742008.jpg

So, should I be OK to upgrade only the rears and leave the fronts at 19mm? If so, I think I'll shoot for 27mm Rears.

Hey Andy,

with your power levels you will want at least 30s with revalved shocks to suit. 930s with 300hp squatted a fair bit...

It's a good path you're going with heavier torsion bars, I went with helper coilovers and really dont like the feel.

Spence

Hey Spence - thanks for the input! I did some digging around in the 930 forums and spoke with Chuck at elephant racing. I decided to go for 29mm rears and 22mm fronts. I'm in a bit of a hurry as my car's already in the shop waiting for the alignment to be completed. I figure if 29mm rears are not enough, I can always swap them out for some beefier ones once the turbo is back on!

Quick Update
 

P-car is still in the shop getting some work done. The new tires have been mounted/balanced and a bunch of service-related items are complete. Other items to be installed: Sanders torsion bars (22mm front / 29mm rear), Elephant Racing rubber bushings - sport hardness where relevant (Strut mounts, control arms, trailing arms and spring plates), turbo tie rods and front Bilstein Sport Shocks. I replaced the rears with Beilstein Sports about 5,000 miles ago. Once that's all done, we'll do an alignment, corner balance and set the ride height. I'm not touching the sway bars yet, as budget is a concern.

Any recommendation on ride height settings? I see that a lot of guys go with the Euro ride height. I'm aiming for an aggressive street vehicle that will be fun to drive on the track. This won't be a daily driver, but I would like to take it on an occasional road trip where it may see a speed bump or two. The body is 100% stock '87 Carrera, with 17" C2 Turbo Replicas, and I'm planning to install a rotor cooling kit.

By the way, I'd like to pass along what a positive experience it has been working with Mark Burkit of Specialty Cars in Allentown. He's an incredibly nice and patient guy. This started out with 4 new tires for state inspection, and Mark agreed to squeeze me in. It has since snow-balled into a suspension upgrade, and he's been very flexible.

Summer Update
 

Hey Guys,

I just got my car back from Mark at Specialty Cars in Allentown, PA, and man-oh-man is it running nicely! I had a number of maintenance-related items completed, but the fun stuff included a suspension refresh and upgrade. Here's the scoop:

22mm front & 29mm rear Sanders hallow torsion bars
Bilstein Sports on all 4 wheels
Elephant Racing bushings
Turbo Tie Rods
4 wheel corner balance and alignment
Ride height lowered about 1.25" from stock

Here's a shot of the specs Mark put together for me:

http://forums.pelicanparts.com/uploa...1312727147.jpg

The handling and steering is vastly improved over stock. It's planted and uber responsive. I was aiming for a good balance between street and track performance, and I couldn't be happier. Working with Mark was an all-around excellent experience. He probably spent about 2 hours on the phone with me chatting about what I wanted and explaining the various options. He was very accommodating in letting me source my own parts. While my car was at his shop, I sold an extra Motronic chip that was sitting in my glove box. Mark was kind enough to ship it out for me. He's an all around great guy to work with - excellent service and fair labor rate. I'm a happy customer :)

Next weekend is the brake upgrade! I'll be swapping the stock Carrera brakes for 996 C2 calipers and rotors, as well as upgrading to a turbo master cylinder. 911t Fanatic (Barry) just finished powder coating the calipers, and they look fantastic! Can't wait to see them in person. Here's a few shots of how they came out:

http://forums.pelicanparts.com/uploa...1312728253.jpg

http://forums.pelicanparts.com/uploa...1312728273.jpg

http://forums.pelicanparts.com/uploa...1312728286.jpg

FYI - Barry is another excellent guy to work with. It turned out that the stripping and coating process was much more involved than either of us anticipated. He was honest and fair in sorting through it with me. Pelican rocks.

Guys - I figured I'd share an update since it's been a while.

It was my intention to complete the turbo conversion over this winter. However, after discovering that the compression on all of cylinders is shot and that another rebuild is needed, I've had to drop back and re-evaluate this project. After being off boost for over 3 years now and learning that I'm another hefty sum of money away from making any further progress, I've decided to give up the boost dream for now and build an N/A car.

Feel free to PM if you're looking for any take-offs. Here's what I've got yet:

Westech Oil Scavenge Pump - http://forums.pelicanparts.com/porsche-911-used-parts-sale-wanted/660094-fs-new-westech-oil-savenge-pump-hi-flo-osp-2-930-911-turbo.html
Air Filter Plumbing
Intake Charge Plumbing
Lots of clamps and silicone bends/couplers
AMS Headers w/o heat - thick flange and low miles - Rated for 550HP
Muffler, Gauges, WG and BOV sold already

I'm planning to build a twin plugged 3.4L street rod with 98mm Mahle Cylinders and 10.4:1 static compression pistons. I'll be running Motronic induction initially, with dreams of ITBs down the road. Planning to run Elgin Super C2 cams with Motronic. Once I get further into the build, I'll post a link to the new build thread.

Thanks to everyone who has helped me along the way. Perhaps I'll be back here at another stage of life.

Sorry to hear this Andy, any idea why your compression is poor on such a fresh engine? Or you don't want to talk about it? Understandable.

At least you're not throwing in the towel, your new NA engine will no doubt be a hoot.

Hey Spence - I ultimately think that the fellow who rebuilt the engine was simply unfamiliar with 911 engines and the common pitfalls of rebuilding one. The engine is going through too much oil and the compression is low on all 6. The leak down, however, is pretty good across the board. My mechanic tested and retested compression with the same results. He's a pcar pro who has been in the business a long time and always treated me very fairly. I trust his findings. He thinks it could be caused by poor cam timing. Another contributing factor could be that the deck height was never measured when rebuilding the engine.

There are just too many issues for me to feel comfortable driving the car, much less adding a turbo. I've come to grips with the fact that I must rebuild. And unfortunately, a proper rebuild is going to sap any finances I had to complete the turbo conversion. I'm at the point where I just want to drive the car! I'll take 250HP today over 400 HP in 3-5 years.

Yes, I'm looking forward to the N/A car. It should be a lot of fun and grow old with me!

Haven't seen this thread till today., sub bump

Thank you! Once I start my N/A build, I'll post the new thread URL here.

FYI - I've put my headers up for sale:

http://forums.pelicanparts.com/porsche-911-used-parts-sale-wanted/660352-fs-ams-headers-930-911-turbo-t4-flange-thick-wall-supports-700hp-25-psi.html

For those that have been following, I started another thread for my 3.4 na build in the engine building forum. The car should be back on the road in the coming weeks! Thanks to those of you who have helped over the past few years :)

http://forums.pelicanparts.com/911-engine-rebuilding-forum/660638-my-twin-plugged-3-4l-street-rod-build.html