SC performance input

[surflvr911sc]

After this weekends drive, I can’t stop thinking about what I could do to increase the performance of my SC. I’m thinking of handling more than HP. I’m planning a rebuild next year and I might do the exhaust at that time too, depending on how I feel about the smog nazis. I might upgrade the cams too.
So what’s left is pretty much suspension. The suspension is factory, never messed with. I was thinking along the lines of lowering to euro, some negative camber, maybe a Cambermaster, and Turbo tie rods, other than that I don’t have a whole lot of knowledge.
My tires concern me, thanks Jack & Tyson. I’m running P7 225/50 ZR 16’s on the back and P7000 205/55 ZR 16 on the front. Tyson mentioned to me about running miss-matched tires being a no-no. Don’t beat me up too bad about the Pirellis. The rears were brand new when I bought the car but the fronts were shot so I thought I picked a good match not knowing any better, and obviously I still don’t. I was considering changing to 7x16 on the front and 8x16 on the rear. Can I do this if I lower the car without rolling the fenders?
Thanks for all the input I am about to receive. Please use the rule of thumb when you beat me about the Pirellis.

[pbs911]

Ryan, buddy. . . it depends on what you want. I think you are talking about a street car that rips up the Bear Canyon hwy, right? Well, better performance can be made getting the suspension freshened up. Here is what I did for my daily driver and DE car.
1. Poly bushings all around in the front and rear sway bars: . (Check out the thread on zirk fittings to keep them greased up) ($150)
2. Neatrix swing plate bushings in the rear ($50)
3. 22 / 28 torsion bars. Stiffer but not too stiff ($400).
4. Biltein HD front and Sport in the rear ($425) (OK I haven't done them but I ordered them today).
5. Sway bars. I picked up some of an 89 Carrera. 22 f/21R, for $125. How wild do you want to go? If you want to spend some money, I would go with the Weltmeister through the body front @22 ($200 and the Smart Racing 21 for the rear ($350.)
6. Turbo tie rod ends (w/either the $350 drop link kit, Jack O says it is great, or the $25 bumpstear "washers")
7. Lower to 25.5" Front/25" rear.
8. Corner balance and align ($225)
9. Tires - at least match them, but I wouldn't do it until needed (I'm cheap!)
10. F/G front and rear bumpers to get rid of the weight on the ends (I haven;t done this either, but yea I ordered a F/G hood)

Then, DE events. POC, POC, POC. Nothing will improve the handling of your car than an instructor in the passanger seat at a track!

[Doug E]

What's wrong with the P7000's? I am running the exact same tires as you and am just wondering why that is a no-no.

TIA.

[surflvr911sc]

Thanks Paul, that just the kind of input I’m looking for. You’re right, I’m not trying to race here, just want the most out of it when the mood hits. I would like to autocross at some point but not until after the rebuild. Driving with an instructor is definitely on the list too.
Doug, the tires aren’t the problem, it’s that I have P7000 on the front and P7 on the back. Different tires, different tread, different “?”.

[nostatic]

205/55/16 and 225/50/16 are factory spec. Other than convenience (being able to rotate the tires), what is the argument for having the same size all around?

[surflvr911sc]

Good question, would that mean putting 16X7 wheels on the front to match the rear? Looking at my rear wheels though, I don't see how they would fit in the front fenders, especially after lowering.

[nostatic]

I posed a similar question a few days back. I believe it was R22Tech that posted allowable tire sizes for given rim size. I believe you can run 225/50/16 on a 16x6 rim without incident. But, given that you are lowered, I'm not sure if you'd have to roll the fender or not.

[surflvr911sc]

I remember that post. I didn't pay too much attention because at the time I hadn't even considered changing tire size. I'm not lowered yet, but it's creeping up my to do list.
I admit I'm not very knowledgeable when it comes to tires and rims. I had always thought that a certain tire width would only fit a certain rim. I still have trouble seeing how my rear tires could ever fit on my front rims but don't doubt they could.

Where's the SCWDP guys on this?

[curtisaa]

Run it really hard for the next few months. Get ALL of those 3.0 kinks out.. put it 4sale on Pelican or Rennlist. Collect 3-4 '000$'s, then find a 3.6. Do the installation and then invite "Jackie O" back next year. You'll be able to hang with him....and smile the whole time.

[Wayne 962]

Becareful that you don't over-design your suspension. Remember that you will be driving it around on normal streets 95% of the time, so don't upgrade to a setup that will knock your fillings out driving on regular roads...

-Wayne

[surflvr911sc]

That's true Wayne. I'm looking for a good all around set-up. I do like taking my wife with me on occasion. If she hates the car, how will she put up with me spending money on it, right?

[Lothar]

I believe that you should be able to get 225s on the front and 245s on the rear of 16 inch wheels. I have also heard of 255s on the rear of 16s. However, I don't think I would run those sizes on 6" rims. I am on 7" frt and 9"rear.

Why run different sizes front and rear? More rubber on the front relative to the rear will add mechanical grip to the front and cause oversteer.

[Jack Olsen]

Ryan, before you write a lot of checks, my advice would be to take it to someone like Steve Alarcon and get the suspension settings set a little more aggressively (maybe two degrees negative camber in back, and a little more than one in the front -- whatever he considers "aggressive street"). Have him give you his opinion on your shocks. Then slowly put together a list of what would be the right package for you.

I think you're actually on the smarter track, even if you did want to start tracking the car. Horsepower is only useful on a small portion of a typical track. Suspension and tires make a difference on the whole thing.

[surflvr911sc]

Well wheels and tires are the easy part once I figure out what I want to do. I'm looking for more suspension suggestions, and maybe rebuild suggestions. I am keeping the 3.0. I don't want to put any fiberglass on, or rip out the rear seats. I kind of like my bells and whistles. Have you seen my CD changer?

[surflvr911sc]

Hey Jack, where's Steve's shop. Could you send me his number?
I'm sure my shocks could be replaced, they pass the "push on the bumper" check but I wouldn’t be surprised to find out that they are the originals.

You ready for your new sticker yet?

[Jack Olsen]

Tires: If it's not too late, get a set of AVS Intermediates from TireRack. You can get a full set of very sticky rubber for close to $200.

Steve Alarcon, of Johnson Alignment/Suspension Specialties, in Torrance: 310 370-6301

Thanks. I'll email you aobut the sticker.

[jmohn]

I have a '78 SC and am using 225x50's on 7x16 Fuchs on the front and 245x45's on 8x16 Fuchs on the rear. There is usually a "spread" of sizes that will fit on a given wheel width (although 245 is about as wide as is useful on an 8" wide wheel). You're using the optimal tire sizes for the rims you have, as you're aware, if you want to use wider tires you'll need wider rims (at least one set of wider rims and move your present rears to the front). No one can tell you if wider tires can be put on the front of your car without rubbing (the rears are no problem unless you get "really" wide). There is quite a variation in clearance under the front fenders of these cars, some mount up wider wheels and tires with no problem others need to have the fenders rolled or at least the inner lip rolled in (some PO had already done this to mine), you really won't know until you try. As to the mismatched tires, you didn't have much choice (unless you bought all new) and you made a pretty good choice, the P7000's are the replacment for the P7's, which are no longer available. However, keep in mind, both of these tires were (and are) considered, at best, average in performance. If it were me and I was contemplating anything competitive I'd at least change the rears to match the fronts, but for semi-spirited street use you should be fine.

Good luck,

Jerry M
'78 SC

[Doug E]

Ryan - sorry for the misread on your original post. I didn't catch the P7 / P7000 difference.

[pbs911]

Ryan, Steve Alarcon did my corner balance and alignment and I am very pleased with the performance. Just don't get a corner blanace and alignment and THEN start tearing apart the suspension. The replacement of suspension bushings, tie rods, torsion bars, or possibly even shocks, will affect the balance, ride height, and alignment. The most economical way to to the work is complete the susension work and then go in for a corner balance / alignment. No sense in paying twice.

[surflvr911sc]

I agree with not wanting to pay twice but I think I might actually go that way. I figure I need to have it set up right the way it is now to feel the difference and get Steve’s recommendations on improvements I can make. I know this will be unnecessarily duplicating some work. Am I way off base here? I'm always reluctant to make big changes all at once. I don't think I want to just write a check and have it set up and hope I like the results.