ian

The black 85 928S I currently have in the garage could best be described as rough (from a cosmetic point of view). I am trying to decide what to do with the car, and I am leaning towards turning it into a track car.

The body and interior are both beat up, but the engine and LSD 5 speed are both in perfect working order. So I figured I could strip some weight from the car, throw in a set of race buckets, stiffen up the suspension, and take her to the track (yes I know there will be more to it than that).

So what does the 928 crowd say to the idea? good idea, bad idea, or somewhere in between?

Cheburator

Bad idea... Sooner or later you will destroy the 2/6 conrod bearings... Unless you put a dry sump on it... By the time you chuck all the cash at it - buy an E36 M3 and be done with it...

docmirror

Brakes would likely upgraded for the 85. The larger brakes bolt on, but aren't cheap.

GlenL

It's an overall good idea but Chebs has put a finger on the 928's primary mechanical fault. There are several solutions and much discussion around it. I use a complicated windage kit and that's been successful. A full dry sump is better.

If you use a good oil, shift at 6000 RPM and monitor oil chemistry you'll both avoid problems and see it before a catastrophic failure.

It's a really fun track car especially on longer tracks where the power is useful and the weight is less of an issue. I like tracking my 944 N/A, too, but it's underpowered. A 951 is a good first track car among Porsches. Older Boxsters are getting cheap.

Common track cars are Miatas, Subaru WRXs, BMWs and Corvettes. But d'ya wanna go there?

Courtshark

If you're OK with a little insanity (https://rennlist.com/forums/928-foru...our-928-a.html) then yeah, go for it. Yes, the 2/6 oiling issue is probably the biggest concern, but shifting no higher than 6k RPMs is a good idea, as is adding the OB oil pan spacer (something I'm going to be doing here shortly). I absolutely love driving my 928 on the track, so much so that driving it on the street totally sucks now. I'm in a similar boat, too; the body on mine is a 15 footer at best. Bad respray by former owner, and a few too many dings.

That said, tracking ain't cheap (again, see my link). As a one of my instructors told me, if it's going to break in 6 months, it will break right away on the track.

Good luck with your build if that's the route you take. Hope to see you at VIR! (not too far from you)

ian

Glen,

Over the last year I had been working a 951 track car, and she was just about ready for track duty when I got an offer on the car I couldn't refuse. So I am back to square one in my quest to prep a track car. I have been around the 944 family of cars long enough to know that they have some issues with the #2 rod bearing, but that those issues can be kept at bay through some preventative maintance and monitoring oil temp / oil levels at the track (and as you said keeping RPMs to a resonable level). I had been hoping the same would be true of the 928 lump. Fresh rod bearings, and baffles in the oil pan were going to be a my list of prep work before the first track day.

If I don't use this 928 as a track car I will open up my search to some cars, I have been wanting to built a 924 GTS tribute car for years and I know of a local sun roof delete 924S shell that would be a perfect starting point. And LS1 powered 924S w/ GTS bodywork would make for a fun track toy. But that sort of project would take me years, and I think I can get a 928 tracked prepped by the end of the summer.

GlenL

You know what you're getting into, then. Search around Rennlist. There are a lot of threads on preparing track and high-perf 928s. There are many approaches and combinations of approaches. I forgot to mention the re-drilled crankshaft. Add that to a dry sump and the rod issues diminish to levels like any other car.

One problem with the analysis of bearing problem resolutions is the difficulty in separating engine use from mechanical changes. People may report good results but that's for them on their car at the tracks they run the way they drive.

ian

Sure switching to the 4 pot brembos of the S4 or GTS would be nice, but I have a feeling a refreshed stock system with aggressive pads will be more than up to the task of track driving. I would much rather put money into a suspension and tires than big brakes.


Thank for the link, good to see you are enjoying your 928 on track.

I will get back to VIR in this 928, or some other car, in the not so distant future. It is my 2nd favorite track, just behind Watkin Glen. I figure the 5.0L 32V would be very happy at VIR, it would be nice to have the torque out of corners I never had in my 951.

I will do some research on the bearing issue, but thankfully it seems like there have been plenty of people who have gone down this road before. Trying to seperate good information from bad is always a challenge on the internet, but I think I am up to the task.

As for me being knowing what I am getting into, we can only hope.......

PorKen

If you keep the stock chips/fuel pressure...

AFAIK, the primary benefit of the bigger brakes is the increased size of the rotor and caliper which can dissipate more heat.
Hotter pads will just overheat the system faster.

docmirror

Most road racers, and knowledgeable track folks will advise you that brakes, not HP is the limiting factor in running fast for a long time. I was just being polite with my suggestion. With a car the weight of the 928, bigger brakes are almost a necessity if you are going to stay out for more than 3-4 laps.

Just before my GT fried the 2/6 rod bearing on the track, I could tell that my brakes were going away and I have very good pads, and all the duct work of the S4/GT family.

However, it's your car, and your money. Enjoy.

ian

Ken,

The stock chips in both of my 85s will be replaced with your chips, but I need to iron out a few issues in both cars before I worry about upping the hp.

And you are of course correct, the larger rotors will dissipate more heat, helping to prevent brake fade. I am not trying to say the S4 / GTS brake system are not an upgrade over the 928S parts, but I am saying for my dollars there are other places more important to spend the budget. The 282x32 mm front brakes on the 928S are still fairly larger, and with some ducting to provide more air flow I think I can keep them cool at most of the tracks I would go to (Carolina motorsports park may prove to be too much for them to handle).

OBehave

The S-3 is a great platform for a track car. I went the big tires and Koni Hypercoil suspension and it wasn't long before I wanted more power.Once I went supercharged and tracked Watkins Glen, I was hooked. And once you go 140 out of the esses and down the back straight to the bus stop you will be definately wanting S-4 brakes or larger.
Do it! You only live once.

txhokie4life

If you have the means -- pull the oil pan and replace the bearings.
Consider adding a crank scraper -- I think the real solution is to cross drill the
crank -- but that might not be possible (easily) with your engine in the bay.

Keep your oil cool -- add a cooler. Use good oil. Keep your rev's down.

How old is that head gasket? I've got an '82 Euro S and a track membership
but I have not taken it on track for fear of tossing my HG.

I've got plenty of other P-car track toys.

I would like the low end grunt of a V8 with the handling of my 951 :-) But so far
I've kept my 928 off track and my p-cars with p-car engines.

I would also look to shed as much weight as I could -- that would help with lots of
things -- brakes, tire wear, acceleration, handling, etc.

Mike

davek9

I'm just starting out, I found the S3 an 86.5 (w/ S4 anti-lock brakes) was a blast. Do it just to see if you like it as a basic starting point, it will at least teach you how to handle your street shark better.

IcemanG17

couple thoughts.....a lightweight "track" (or race) 928 is LOTS of fun to drive.....much more fun than a full street car..... The 85 is not a bad car to start with, 32V that will make PLENTY of power, but with the better Borq warner gearbox.... The downsides are the brakes.....but if you are new to driving on track, the "S" brake isn't that bad....I raced in lemons for YEARS on S brakes...just with steel braided lines and Raybestos ST43 pads.....pad life was around 25-50 hours on track with excellent feel and rotors last for two sets of pads....Sure S4 or GTS are "better" but it takes an advanced driver pushing really hard to cook S brakes.....we drove the 2800lb estate for 8 hours per day, ZERO brake fade...none...granted it was only 215whp, but even on slicks I never-ever faded the brakes...in lemons trim on street tires it was almost too much...too easy to lock up!!!

The 1st thing is change the oil pan......125 hours on track on the Estate engine with only OB oil pan and 3/8 spacer....still perfect oil tests, no indication of bearing wear.... 25 hours on my current racer same story and neither one have oil coolers!!!!!!! I am also a big believer in shifting at 6000max

The E36 M3 is a great platform....I race against some of the best prepped E36 in the country, they are EXTREMELY fast...mostly due to the high level of top notch parts available for them.....but I still prefer my more rare 928.....the V8 sound alone counts for something....

If you want a unique car that is fast and fun to drive on track, the 928 is a good choice..... Especially for DE as you learn.........once making the jump to serious racing, it is harder to find a "good" class for the 928....but can be done with the right application of $$$$$.....