rocketrider2

I do not want to slam my car but basically lower to ROW specs. I am putting on new wheels/tires which are about .7'' greater in circumference as well. My question is how many labor hours/dollars should I be looking at to have a shop do this?
Any suggestions as to what the specs should be to lower the car and what specs to run for alignment? The car will see manily street with some auto-x and hopefully a DE here and there. The new rims and tires are 18x8.5 and 18x11 Kinesis Supercups with Pilot Sport Cups 225/40 and 315/30's.
Any feedback from the experts here are greatly welcomed.

ZCAT3

Have you done any other suspension upgrades? If you are still running the original shcoks you may want to consider going to Bilstein HDs as well. Lowering the front is easy - you can do this yourself. There is just 1 set bolt per side that you crank in or out. This pushes against the torsion bar and raises and lowers the car. The rear is much more complicated. I think to lower front and rear and have the car aligned and corner balanced you could be looking at 4-6 hours of labor (or more). That is the reason I asked about other changes. If you plan on changing shocks or doing anything else then it would be best to do it now and pay for the corner balance and alignment only once.

PT

Why not start with the Euro spec - ride height & alignment?

If you don't have to re-index the torsion bar to get the desire ride height, it won't be too bad. As Bill said, in any case you'll want to re-align & corner balance the car afterwards.

Re:tire size - I suspect 8.5 & 11 might be a bit unbalanced. Most people uses 9/11. And when you want to jam 315 in the rear, I think you should at least consider 245 in the front.

jetskied

I run 8.5 and 10.5 X18 speedline wheels with 225/40 and 295/30. It dose not rub and my car sits at 25.25" fender to floor. To lower the rear might take some reindexing. The best thing to do is to find out where does the club racers in Chicago go to align the car. Thoes shops can corner balance, align and lower the car. I would suggest that you might want to increase the size of your torsion bar. Most Auto Xers run 22 front and 29/30 mm in the rear. If your car is mostly street driven and like comfort then use 21 and 28. You will notice a big improvement in handling. When I did my car in LA,CA I spent $450 on the bars and $350 on all the labor, but that was 3 years ago.

rocketrider2

I considered 245's up front but was told there would be clearance issues, so i stayed away from those this time around. Currently no other changes to the stock suspension but next year I hope to do coilovers and new sway bars. So for now I was just thinking about lowering to ROW and an alignment, I will corner weight once I do coilovers.
Please keep up the comments guys.

Lane

PorscheDavid

245 fronts, 315 rears...RoW ride height...no rubbing...cornerbalanced to within a pound at the corners...very balanced and stable...feels great...

PorscheDavid

Coilovers on a 930 seemed pretty harsh to me...I know of several people that changed back as well...if it is primarily for street use, stay with the Bilstein HDs

ZCAT3

I actually find the coil overs to be more comfortable than the torsion bar setup for street driving. The one suspension change that made the most dramatic difference was going to adjustable sway bars. The difference in handling is amazing. The car can actually be set to have neutral handling from front to rear - not something you expect in a 903 but an awesome feeling. It actually gave me goose bumps the first time I drove the car set up like this.

As for ROW ride height, I believe using the informal method of measuring from the ground to the fender lip (bisecting the wheel at the center cap) you want to see 25.5 front and 25 rear.

jetskied

I tell you that coil over are great, but at what price. I was told that to make them handle better than the torsion bar they have to be really stiff. If thay are not stiff then they really have no advantage over torsion bars. Think of the price difference $2500 to $450. As far as shocks the 930 has stock bilstein HD. If your shocks are good there is nop need to change them. There is a bilstein sport setting which I have. Its about 15-20 % stiffer. Also the RSR coil over will make the front diffucult to align. I'm no expert, but I was told this by my suspension shop. Ask arround.

alvin ulan

i highly recomend perfect power in libertyville. ask for sol. he will know exactly what to do. 847-367-8837. perfectpowerinc.com

MitchB

I'll offer a simplistic approach...
First - I have 18 inch 225's Fr and 285's Rear. It's a street car and so I like a comfy ride - not easy with 18's. I'll be going to 245's and 315's when it's time for tires...
The 80's 930's are softly sprung - I think everyone agrees, but it's fine for me - for now. I have stock susp. with Bilstein HD's and the Smart Racing Bump Steer kit. It's abt the limit of comfort for normal street driving with the 18's. It does squat badly under hard acceleration, but it's tolerable.

If you just want to lower the car - like I did - it can be fairly simple. The simple and fastest method is to measure from the ground to the top of the fender. Decide how much lower you want - write it down. As mentioned, for the front, there's a adj. bolt at one end of the torsion bar. 11mm socket on 3/8's ratchet. Loosen a couple of turns, drive around the block, measure the fender height, repeat. A couple of tries and the front is done - you don't even have to jack up the car!
The rears are tougher - but you might get lucky. The spring plate is adjustable. Two large nuts - 22mm maybe - one is the adjustment bolt, the other holds it in place.
Jack up the rear (use jackstands!), remove the lower shock mounts and wheels. Measure from the bottom of the brake backing plate to the floor. Loosen the spring plate adj bolts (they're tight!) and turn the adj bolt to get the measurement you want, i.e., your previous measure plus the amnt you want to lower. Button it all up and enjoy the improved look.

I know that was VERY simplistic - but it really isn't that hard - provided you don't have to pull and re-index the T bars.

If you do decide to do it yourself, I'd suggest getting the Smart Racing ride height wrench. Also if you go very low at all - you'll need a bump steer kit. I like the ERP from Smart Racing...

One final note - however low you go, the fender height should always be a half inch HIGHER in front to give you the correct Fr/Rear ratio.

rocketrider2

One other reason I couldn't go with 245's up front is because they do not make a Pilot Sport Cup in 245's, only 225 or 265's.

I will contact the shop in Libertyville to see what they can do for me. The car is currently at the Last Detail coming out of storage and having the engine bolt-on mods done. I am not sure though if they have done a 930 suspension set-up and I know they do not do alignments. So I wanted some place that can do both. Then the next stop is the Porsche Exchange for the 30K maintenance, they agreed to do this one free as a condition of me buying the car last year from them. So at least that won't be out of pocket but between the engine mods and new rim/tires I have dropped about 10K already and really want to try and conserve some at this point. The other half is ready to shoot me
If I can find a good t-bar and sway bar set-up at a good price I might consider going this route instead of coilovers next spring.
Keep it coming guys, thanks

alvin ulan

rocketrider2,

do yourself a HUGE favor and just take your car to perfect power for everthing. the exchange is a joke. the last detail sends their cars to sol so you might as well just start up a relationship with perfectpower as soon as possible. i know you dont know me from adam, but trust me sol is the man. considering the car you have, to go anywhere else is inconceivable.

rocketrider2

Alvin I will definitely check this place out. I kind of figured this was the place Last Detail sent out there cars too for alignment. The 30K maintenance being free from the Exchange, I will let them do this service. Thank you for the heads up on this place, I was looking for a well qualified and recommended service center. Thank you very much. I guess you must be from the Chicago area, are you still around the area? I am looking to meet other P'car enthusiast to hang out with and chat with. Talk to you later.

Lane

alvin ulan

lane,

if you want to take your car to the exchange to have them stare at your car and do nothing be my guest. they are not clueless, but experts on an '87 turbo? no way. free 30K service? you will get little more then you paid for. i bought my car from the exchange and some of the guys there are pretty cool and i hate to say bad things about them, but if this is your first porsche i just want to make sure you get the best service.