924 Carrera GT Project X
Discussion
Here's my 924S with a Carrera GT bodykit and 968 running gear. A bit of back story; I bought an original 924GT in 2007 to use as a track day car. I took it to a few circuits, including the Nurburgring where it performed well but wasn't exactly the track focused animal that I wanted it to be.
Five points if you can identify the ex-Formula one racing driver in the passenger seat.
I considered adding a roll cage and upgrading the suspension, brakes etc, but there would have been more changes required because it had a tendency to run hot on track so the cooling would also have to be sorted. The two-litre engine is fairly basic spec: two-litre single overhead cam. It's turbocharged and intercooled to get a very high specific output, but it isn't what you would call a "sweet" power unit.
I couldn't get comfortable with losing the GT's originality, and I also didn't fancy searching for replacement original polyurethane wings and bumper if I had an accident. I tried to sell the car in 2009 and 2010 and it wasn't easy. It went through a Coy's auction without meeting what now would be a laughable reserve price, and I had very few calls about it after that. In the end a guy responded, was genuine, and he took it inside a week for a price I was happy with. The car has since been sold at least once and is currently up for sale for multiples of what I paid for it. In hindsight I should have just stored it, but who knew?
Backing up a little, I'd already found the replacement, a 1988 924S that had 968 running gear installed. Later Specialist Vehicle Preparations and EMC Motorsport in Birmingham added a GT replica bodykit and generally sorted the car. EMC still take care of the car and recently rebuilt the cylinder head after an unfortunate experience with another Porsche specialist.
This is the 924GT two-litre engine:
The GTS. Intercooler moved to the front and different fuel injection unit:
And my 968 engine installed in the 924S engine bay:
Sorry you can't see the full bay, but there is plenty of space in front of the engine where the air intake is on the 924GT. I don't know how hard it is to swap the running gear from 924S to 968, but there isn't much obvious chopping about that I can see. I barely inspected the car, it cost about 1/3 what my 924GT was worth, and the seller seemed genuine, so I virtually bought it on the spot. I've had it five years and love it to bits. I know if I ever sold this I'd regret it instantly.
Basic spec:
968 engine, transaxle, fuel tank, DME, brakes, RS29 pads
924S interior stripped apart from dashboard and centre console
Safety Devices roll cage
Deutschnine GTS headlights
I run it on Dunlop Direzzas and it's epic on track.
Oulton Park full: 2:05
Donington National: 1:23
Bedford full: 3:00
Spa: 3:10
Most of these are at 9/10ths. I might have another couple of seconds if I put my foot AND toes down. I'm thinking about adjusting the throttle linkage to give me WOT when the pedal is 1/2 pressed
.I timed myself once BTG on the Nurburgring and did 8:30, but the car should be at least 15 seconds quicker than that. Despite running a website about the Ring, I'm no expert there and drive it about 8/10ths; I'm changing up at 5,500-6,000 (6,750 redline) and coast a fair bit on the straights. I should man up and drive it properly, but the thought of a big accident keeps me off the limit.
I recently drove an E46 M3 at the Ring and there's no doubt it was far quicker than my 924, but the M3 is bigger and heavier (1,500kg? vs 1,100kg), and I couldn't help thinking that at smaller UK circuits I'd prefer mine. The M3 was very fast and was stuck to the road even on Federal 595 road tyres and with DSC off. At my 8/10ths it was easy enough to be one of the faster cars on TF and most other cars jump out of the way when they see an M3 coming. If you want to drive to the Ring in comfort, go fast on track and then drive home I think this is the perfect car to do it in. No wonder it's probably the most frequently seen car there. I would like to try a 996 to compare. I prefer the Porsche on roads and on paper I think it should be even faster than the M3 on the Nordschleife.
My 924 is showing its age now and could do with a rebuid/refresh. I've had a few electrical issues (dead alternator, fuel pump relay, general messiness around the fuse box). A friend of mine is working on the car so he might pick up this thread. I followed his 996 Project Leichtbau on 911 UK:
http://911uk.com/viewtopic.php?t=106137&sid=f5...
and managed to persuade him to work on my 924. It doesn't require a drastic lightening project like the 996, just tidying up in many areas.
As you can see, he's a Porsche fan.
https://www.facebook.com/CarreraLightweightRacing/...
I should knock this on the head - it's Mike Wilds. He was a tutor at a Snetterton track day.
https://en.wikipedia.org/wiki/Mike_Wilds
In terms of differences between the running gear, the turbo obviously had lag, but nothing like you read about in the magazines. I never remember boost getting the better of the GT, but the increasing rate of acceleration felt great as the turbocharger did its thing. I miss that slightly in the replica.
The 924/944/968 suspension elements are fundamentally the same, as is the 49/51 weight distribution, which I think is where front engined Porsches have an advantage over many other sports cars in that the gearbox is at the back in line with the rear wheels. You can definitely get the power down early coming out of a corner, and even use it to generate more traction.
https://en.wikipedia.org/wiki/Mike_Wilds
In terms of differences between the running gear, the turbo obviously had lag, but nothing like you read about in the magazines. I never remember boost getting the better of the GT, but the increasing rate of acceleration felt great as the turbocharger did its thing. I miss that slightly in the replica.
The 924/944/968 suspension elements are fundamentally the same, as is the 49/51 weight distribution, which I think is where front engined Porsches have an advantage over many other sports cars in that the gearbox is at the back in line with the rear wheels. You can definitely get the power down early coming out of a corner, and even use it to generate more traction.
mattnoss said:
Lovely car.
A mate and I have been racing a 924s with 968 engine this year and I've enjoyed every minute of it.
I assumed the engine swap would make mine ineligible for most race series. Where do you race yours?A mate and I have been racing a 924s with 968 engine this year and I've enjoyed every minute of it.
Edited by nsa on Saturday 17th September 21:24
I thought you had a different username on here 
.
It's great to see a little more info about this beast. I always liked the idea of such a build. While the 944 Turbo and 968 are great cars in their own right this does come across like a dream build with all of the right ingredients. Jealous? You bet.
.It's great to see a little more info about this beast. I always liked the idea of such a build. While the 944 Turbo and 968 are great cars in their own right this does come across like a dream build with all of the right ingredients. Jealous? You bet
.
A better shot of the engine bay. The battery tray is being cleaned and resprayed, one of about a hundred jobs a friend is undertaking. You can see there's good access at the front of the engine. The white disc is the oil filter. The lights are ill-fitting and currently collect moisture and this should be sorted soon. The fog lights were replaced with intakes, one of which feeds the air filter, the other does sweet FA. I will refit the lights when I can. The bonnet, wings, and front bumper are glassfibre. I don't know the manufacturer. Bonnet stay is a genuine Porsche part
.Marrying the 968 engine to a lighter shell does wonders for the power to weight ratio. Mine is supposed to be 240bhp, although it desperately needs a remap because I've hacked the intake and exhaust systems. I know it weighs 1100kg, giving it virtually the same numbers as the 924GTS. I could go on at length about power/weight but I don't really know what I am talking about in terms of how it relates to lap times. I do know that low weight is good, and I can't think of many cars under 1100kg with 240bhp, without using a turbocharger.
I made the table below for my 924GT.com website in 2008. I know the figures haven't changed but I can't guarantee accuracy on the non 924GT bits because I can't remember what checking I did at the time. The 968CS (1320kg) weighs 140kg more than the 924GT (1180kg), but they use very similar shells and suspension components. I can only assume the 968 engine weighs more (although it is alu where the 924 is iron) and that the 968 has more crash reinforcement, soundproofing, etc. I don't know if you can lose 150-200kg from a 968CS and it still be driveable. I'm going to Google that later.
I fitted a Speedhut GPS gauge to replace the original unit because the speedo cable was broken. I think mine goes to 160mph.
This 4" one slots straight into the hole in the dashboard for early 924/944s and is easy to connect to lighting wires etc. You do need to file down the original plastic dash housing. The sensor sticks to the bodyshell by magnet, and I've found it to be very good at holding a signal. It has 0-60, 0-100 speed tests but to be honest I've never used these. I should get around to doing a 0-60 test at least. I had to order it from the US, can't remember how much I paid in pounds, maybe 200. It's a bit annoying not having KPH, I guess there isn't much call for it in America.
http://www.ebay.com/itm/Speedhut-4-GPS-Speedometer...
I was so impressed with that, I bought their tachometer with shift lights, which can be programmed to come on in stages. For aesthetics I just need to find a way to put a redline behind the glass and / or obscure the 7-8,000 part. The original units obviously stuck out but these have flat screens.
http://www.ebay.com/itm/Speedhut-4-Tachometer-Gaug...
No affiliation with Speedhut, but I'm a happy customer. I also have a SPA water / oil gauge, which I am less thrilled with.
The removable steering boss is from B-G, with a Momo extension underneath. No complaints.
The car is running Gaz adjustable coilovers front and back. The torsion bars have been retained. I couldn't tell one performance damper from another, but these are silver with blue knobs on, and the springs are black. I would recommend using something to protect the silver bodies because mine are now pretty well rusted. Apparently most are like this after a couple of years. If I can find an electronically adjustable damper set for the 944/968 I might buy it.
For track work the car has Dunlop Direzza DZ03Gs, which seem to be the favoured tyre for 924/944/968s and I'm not going to disagree. They have massive grip and have decent life. I run the same size front and back to even wear rates. I used Falken 452s for road and track before I bought a set of the Direzzas. I gather the GT3 guys can use Michelin Sport Pilot Cups as a good road/track compromise, but AFAIK there isn't anything similar for 16" wheels.
Sebring - I can't remember where we've met. I can only assume it's at the Ring, maybe BMW Herschbroich? Can you give me a clue? The jump from 944/968 to M3 is easy to understand. I came very close this summer.
Edited by nsa on Monday 19th September 16:03
nsa said:
I assumed the engine swap would make mine ineligible for most race series. Where do you race yours?
Unfortunately it's not my car, we just hired it to race off the car owner who preps and runs other race cars as well, super guy who's run the car this year for us. Edited by nsa on Saturday 17th September 21:24
It's raced with 750MC in the Roadsports class for the last 3 years as well as AMOC and with MSVT in Trackday Trophy.
nsa said:
Sebring - I can't remember where we've met. I can only assume it's at the Ring, maybe BMW Herschbroich? Can you give me a clue? The jump from 944/968 to M3 is easy to understand. I came very close this summer.
Hi fella,Edited by nsa on Monday 19th September 16:03
We have indeed met on a couple of occasions. But not at the 'ring. Let's just say I am the bloke who bought ProMax's 951 off Kevin a few years ago. Man it was silly to sell that car, but needs must...
You are right about an E46 though. They are the jack of all trades it would seem and I am loving mine!
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