Porsche Enthusiasts Club Forum

progress has been slow as been busy with customer work, and a few other projects.

the car is getting closer to completion, the current job is I cut the original area under the battery tray out as it had a few small rust bubbles, and I know this is a problem area so decided to catch it before it got worse, as the rest of the car is 100% rust free so wanted to make sure this was perfect. just have to weld a new bit in and a bit of sealer and job done. will add some pics of a lot of the work carried out very soon

cheers

couple of pictures of the intercooler setup all installed.







more pics of other jobs and underside etc to come soon

Any updates bud...

hi mate, no updates at the minute, been putting my caterham 7 back together after paint, so this has taken a back seat for a while. I hope to get back on it very soon, although its not far from complete really now!

I will try get it on a ramp and take a load of pictures of it soon.

did I see you have a cgt replica now? what are you doing with that?

cheers

btw anyone that has a 924 dash lying about I would be interested in, condition isn't important, I will get it flocked. please get in touch

many thanks

well my evo track car has gone, and my caterham is nearly built and finished, so I have started to pick up on this again recently. I have been doing lots of odds and sods jobs getting everything working right and little details.

the car sprung a fuel leak the other day when moving it, where 2 braided lines were joined. I decided, due to the fact the car had been sitting a while, the fuel lines could be perished, and so I started collecting bits to replace the whole fuel system.

today I bought new fuel lines from the tank to pump, pump to accumulator, and accumulator to hard line. from here I will be replacing with new braided lines to and from the engine. I also got a new fuel pump for piece of mind.

one of the front calipers kept sticking even after freeing it off, so I also have 2 new front calipers coming Monday, and a new full set of braided lines as again I cant be sure of the condition of the old ones and as a critical safety item along with the fuel system I want to be sure they are correct.

I will start taking a load of pictures of the work being carried out, I am also likely going to remove the engine, and go through it replacing gaskets, hoses, pipes etc, aswell as fitting a new refurbished turbo I picked up a while ago.

I will also post up pics of how clean everything is on the underside of the car, most components are like brand new, and the shell itself is the best I have ever seen! should make a very nice race/track car

made he decision the car is going to get the refresh it deserves. due to the fact the car had been sitting for a few years before I bought the car, I thought it would be best to replace all the items that could have aged and deteriorated such as the fuel lines, brake hoses, and all the engine hoses/gaskets etc.

it also gives me a chance to replace anything else that looks like it might be worn or tired.

the car is so clean I thought it deserved a proper refresh. the majority of parts are like new underneath anyway, and the shell is 100 percent rust free and has been acid dipped in its life as there is no sign of any sealer.

I am going to remove the whole running gear, so engine, torque tube, gearbox, and complete rear suspension setup. aswell as the front suspension.

today saw most of that done, I started at 12pm and finished at 4 and all I have left to do is undo the 2 engine mounts and drop the motor with a crane, then drop the rear end off the car which takes all of 2 hours. one of the easiest engine removals I have done, and with the car having had a full rebuild before going away into storage, everything came apart perfectly, not a single tight nut, or snapped stud etc!

will keep updated with pics of the rebuild. I have already been buying all the parts to replace the fuel system, hoses, pump etc

cheers

any advise on worthwhile modifications/jobs to carry out while its all apart welcome. ways of simplifying the engine etc or making it work better/more reliable etc

the main thing is just to run through and replace all the little niggly pipes/hoses etc that have aged, and get it all 100%.

Loose the exhaust centre box and get an AFR sensor/gauge fitted
Install a top port to the stock wastegate for an in car adjustable boost controller/boost gauge
Fit a 951 rad + fans + expansion tank

yes I was going to remove the centre box anyway, I noticed the exhaust has a blow, it turned out to be the downpipe flange to the back of the turbo has cracked most of the way around the weld so will be repairing that aswell!

the car already has an adjustable bleed valve fitted in the line to the wastegate, and a boost gauge in the car. would be good to plumb the valve inside the car though so it can be adjusted while driving. do you use an electronic boost controller?

I was also thinking about fitting a tial wastegate to replace the std item.

just sold a brand new 951 rad which is a bit annoying lol

I have a manual in car controller which feeds counter boost pressure onto the top wastegate port rather than bleed boost from the main control line

The more I think about this the more I cant get making a mega light carrera gt race replica out of my head. Bin all the cis and get it running on modern management and turbocharger. Get it under a ton and 350+ hp would make for a very quick track car!

Reading the tuning the 924 thread it seems the engine could have big potential at higher power, I was considering building my 944 turbo Into an out and out race car but this car seems to have more potential and is already most of the way there!

The fact im now stripping it for rebuild means nows the time to do it if ever!

got the engine and complete torque tube/gearbox/rear suspension all out today.

will likely mount the car on the rollover jig, makes doing work on the underside much easier!

such an easy car to strip, pretty much only a days work to get the car from fully running to having the whole running gear removed from the car







will remove doors, rear hatch, front wings and the seat, then its ready to mount on the jig. parts are on the way to me, and I will likely send a load of parts for blasting/dipping and recoating soon

There's a hell of a lot to like about this car. I like the fact it's basically an unmolested 924 Turbo shell.

The standard Turbo bottom-end will tolerate a fair amount of boost and power if it's been put together well.

Areas to watch as always are the standard cast pistons and particularly the top rings. I discovered recently that a lot of the oversize OEM piston rings are crap. The original 86.5mm rings are ductile iron which stand up better but the 87mm rings I removed in pieces from my engine were grey cast iron which are no good for a turbo'd engine.
Either way, don't allow the engine to knock (I'm sure you know all this). 18-19psi has been run on a stock bottom end with no problem when tuned correctly. Tune to the safe side rather than the ragged edge and you should be ok.

If the engine seems to be in good nick I would run it as is for now. You already have intercooling sorted which IMO is the single most important thing as is heat management. Fit a larger more efficient oil cooler if you haven't already. Stock cooler is no good for the track and oil cooling seems to be mostly overlooked on these cars.
There's a coolant flange outlet on the back of the head that normally supplies the heater before returning via a metal pipe to the thermostat housing. If keeping CIS you can take this off and drill the two outlets on it to ~20mm for the large one and ~10mm for the smaller. Then have these running to a single 32mm silicone pipe via a Y piece before returning to the thermostat housing. This helps equalise the temperature of the head front to rear and keeps cylinder 4 a bit happier.
If you junk the CIS then you can make a single flange outlet instead at 32mm and run this straight to the thermostat housing. These coolant mods assume you get rid of the heater/matrix.

Check out the other 924 Turbo thread for stuff related to crankcase breathing which is marginal to start with. Pace do a dry sump system but it's not a budget option. Baffling the sump is another sensible mod.

Stock fuelling is ok to ~250-260hp at which point you'd need to swap to a larger fuel distributor or some kind of supplementary fuelling for more power. At this point it's probably wise to go standalone management but it depends on your outlook and experience with CIS, and maybe race regs.

Sticking with KKK turbos and it would be wise to source (maybe you already have) the later turbo from the 951 250hp engine, then swap the turbine housings with your original and you have a turbo thats more suited to running 1-1.2bar boost with lower compressor outlet temps.
Standalone ECU makes tuning for these mods so much easier.
Other turbo options are using a K27 cold side or having someone like turbo dynamics make a KKK/Garrett hybrid (expensive).
A blueprinted S1 bottom-end with custom inlet and ported head with the above Garrett is capable of ~280hp at ~15-16psi/1.1bar boost. Get the weight down to a ton or less and with a good suspension set-up you'll have a quick, well-balanced car.

Top-end is generally reliable to 7000rpm with the exception of the cam followers which have been known to break up at the adjuster holes. Solid ones with lash caps are available which solve the problem.
You can go for a cam like Steve's (Piper 270) which will give more mid and top-end without going silly and losing the bottom.

You can go further of course but then you're into forged piston territory and more money. If you want to go through more options I can fantasise about these cars all day long over on the other 924 Turbo thread. Like yourself I often get carried away but struggle to finance my crazy ideas