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Lizard · Posted: Thu Mar 20, 2003 2:16 am Post subject: 931 autox and DE

Hey guys I am getting a 2 931s both are 80 with the 16" trash can lids and the M471 options, one is going to be for parts as the frame is bent and the other I am wanting to turn into a Auto X/DE car

my question is, am I still going to be able to do DE, and other events like that if I have fiberglass/carbor fiber front and rear fenders, as I am planning on switching over to the wide body kit like alex roy, and get either a 951, or 924cgt front end, I am also planning on building and welding in a custom rollcage w/ 6 pnt racing harness, but the part I am most concerned of is that they wont allow me to participate if I add an intercooler, O-ring the head, Knife edge the crank, and other items like this
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3 928s,

81turbo · Joined: 03 Nov 2002 Posts: 1065 Location: Oakland, CA

The 931 is not the best cantidate for auto crossing.

Lizard · Posted: Thu Mar 20, 2003 3:10 am Post subject:

I know NA engines are the best for that, but i am just out too have fun
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3 928s,

924RACR · Posted: Thu Mar 20, 2003 4:07 am Post subject:

Sure you will! Just keep in mind that, with respect to competition (in this case autox) you may be punted into a class where you are not competitive. However Driver's Ed is not competitive, it's just a lapping session. It doesn't matter what mods you make to the car, as long as you have equal seating and restraints for both driver and passenger (so that your instructor is as safe as you are - if you have a 6-point harness, make sure you have one for your instructor too!).

With PCA, when and if you start racing, you will go (with that car) immediately to the GT category, but that's not the end of the world.

I will caution you do take the following route-map to your upgrades, though, in order to maximize both fun and safety:

1) Fix anything that must be fixed or replaced in order to get the car stock, both in terms of performance and reliability. This is most important as regards the engine, because you must first have a car that will make it around the course for more than one lap at a time if you're to learn anything! Sounds basic, but you'd be amazed how many wannabe's overlook it! This includes things like wheel bearings, CV's, etc.

2) Upgrade brakes and suspension first, in that order. This flows right out of point 1, since you can expect to need to replace everything in the suspension. Why buy stock rubber when you want poly bushings? This is the only way I'd recommend ignoring rule 1. Furthermore, it will give you the biggest fun factor, especially on track, of all. Keep in mind, I'm in my fourth season of racing the NA car, and still haven't built a motor! My block is still stock! You need handling and braking more than power, and besides you're starting with the 931 anyway, it makes nice power! If you find it lacking as you upgrade the suspension, at least you can just dial up the boost a bit and run better gas. Likewise, why buy a set of street shocks when race/track shocks aren't much more (buy a whole suspension from Morriss, as in my other post, for under $2k tuned and complete!) and work so much better!

3) Safety equipment. Now you're starting to turn some decent lap times, and have an idea how to get the most out of the car. Time for that cage, seats and harnesses... consider strongly installing a fixed, plumbed fire system. A whole lot more expensive than a handheld bottle, but a whole lot more effective too! Do you really want to open the hood in your face with a full fire going on in order to put it out? Just punch the button and bail!

4) Now it's time for the motor. Crank the boost till she blows, then swap in the hotted-up motor you've been building in the garage and have standing by!

5) Then you can justify the bodywork - you can now get up enough speed that you're in need of more rubber, so will need fiberglass widebody to cover them. Thow in a diff too, while you're at it, and a fresh coat of paint - party on! Slap numbers on the side and kick some 911 butt!
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Lizard · Posted: Thu Mar 20, 2003 4:39 am Post subject:

I was planning on going with bilstein for suspension with poly eurathane of course, as I have the second car for parts, I will have a complete drive train to rebuild for performance, as for replacing the cvs and wheel bearings I know how to check them and they would be being repacked or replaced if needed, all the gas lines are good, the rubber isn't cracked at all, the fuel pump is going to be one of the first things replaced, also I am going to have a 6 pnt harness for me but my passenger might only get a 5 point (why do I care if they get sacked

) one of the other things I am going to be doing is replacing all the wiring componants or fuse box, but another question I have is what would be a good CR mainly for track use and getting for the track, ie not street racing or dragging, also would it be worth switching over to EFI, or leave it on CIS?
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3 928s,

924RACR · Posted: Thu Mar 20, 2003 5:09 am Post subject:

Well save yourself the trouble of having to buy the passenger harness twice, get the same type. PCA and most other organizations require identical restraints.

You may not need to replace the wiring, I would wait and see if that's necessary. Fusebox, your call; I've had good and bad results both.

For the CR, I'd go for 8.5:1 on the built motor, leave the stock one as is for now, of course.

I would not bother with even thinking about getting rid of the CIS for now; it's good for a bit over 200hp. Once you get to about 250, then you'll need to think about either modifying or replacing it. Don't rush into that, a lot of money and time, very easy to get discouraged if the car's not already running.

I have heard some unhappy noises about the use of poly bushings without steel sleeves - the bolts wear right through the poly. Need a proper steel center (like the stock rubber bushings) to spread the load and handle the wear. Could always just bore out the poly bushings and press in the steel inserts left over from the old stock parts!

I have also heard that 944Racing.com or Paragon are working on delrin parts for the front a-arms to deal with this. Of course, for the rear trailing arms, presently the only option are the Racer's Edge spherical bearing inserts, just ordered mine, but again I believe these guys may be working on delrin parts...
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Lizard · Posted: Thu Mar 20, 2003 6:08 am Post subject:

is there any real point in changing the rear bearing over as the originals can take alot of abuse, and also thanx for the tip of the steel sleeves on the poly bushings, as I am unable to find a source for them up here I am probably going to have to get stock and make my own, or order from the states which I don't like doing due to shipping costs,

and both of the cars run fine, one of them starts to puff alittle blue after running for abit but oil pressure is fine so the conclusion was a breather issue, which has still to be verified, and if not breather then bearings
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3 928s,

924RACR · Posted: Thu Mar 20, 2003 6:37 am Post subject:

The rears - well, I dunno, I've always been running on rubber. However the issue is the compliance, and the toe and camber changes that come with heavy loading. That's why you go to a hard material, to eliminate or at least reduce those changes and make the car handle much more crisply and consistently.

Good to hear they run well!
_________________
Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

Lizard · Posted: Thu Mar 20, 2003 6:55 am Post subject:

if they didn't both run I probably wouldn't have gotten them
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3 928s,