924Board.org

[jprestidge]

I'm considering running in the porsche speed championship next year and would really appreciate some advice on a suitable car. The choice basically boils down to a 924, a 924s or a 924 turbo. The first two would run in the up to 161bhp class and the turbo would run in the up to 204 bhp class.
So, basically it comes down to whether I buy a 924 and tune it up to 150-160bhp (from what I've heard, not particularly easy) or plump for a 924s or a turbo and put up with higher maintenance costs. The standard 924 appeals because the engine doesn't have the same problems as the 2.5 in the 924s, but I am not sure whether the horror stories about this engine and its propensity to wreck itself without regular adjustment of the timing belt are actually true. Similarly I have heard that the turbo has some horrendously expensive parts and goes through the turbos themselves on a regular basis. Has anyone got any experience of any of these problems?
I'm looking at a budget of around £3000, including the installation of some lightweight seats, and stiffer springs and dampers. What would be my best bet?

Thanks.

Jonathan Prestidge

[Lizard]

ok you are correct getting the 924 na up to the 150-160 bhp mark is alittle challenging, I personally would go with a 931 (924 Turbo) as the head has been redesigned and is alot better, I also wouldn't go with the 924S w/ the 944 engine due to the timing belt.

the turbo for the 931, is an ok unit but it has a unique 3 bolt exhaust flange, you can swap out to an aftermarket turbo but it would require having a custom exhaust manifold fabricated.
keep in mind the 931 is an interference engine as is the 924S, however the timing belt is about a $12 part and is VERY easy to change, and if you know how to change a timing belt and you check the marks 3 times and turn the engine over manually and slowely before putting it all back together you wont have a problem.
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3 928s,

[Joes924Racer]

yea go with a 931turbo period or use the 931 head without the turbo on the 924 and do all the other mods and you should be close to your 1st mark though its alot of work if you can find a complete turbo 931 motor do that.. and the 924s is a good start to make serious horsepower though it can get spendy cause you would maybe want a special intercooler and turbo setup like powerhause offers.
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1979 porsche 924 Na
1980 porsche Turbo 931GT Replica
Have u ever driven a turbo.

[924RACR]

I would definitely go with the turbo, cheapest speed and power for the money. You will have to put up with it being a bit of a rare bird; you need to find a sympathetic ear who runs a garage that specializes in Porsche turbos; closest thing is a 930. And who of course doesn't mind hot-rodding a waterpumper!

Second choice would be the 924S; more expensive, very expensive race motors, but more common.
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

[IanJ]

Jonathon,
Keep an eye out for a new website called www.mad4motors.com (Should be up and running in the next day or so)

We have just purchased a 924s and are looking to do exactly as you are trying to do!

Good luck,
Ian@mad4motors.com

[simsport]

Hi there
I know a bit about the UK speed championship as I co-wrote the regs and have driven in it from its start some 10 or 11 years ago.

We came up with the hp splits to accomodate the full range of cars both aircooled and water cooled models. There was no aim to make the classes suit any particular model and hence weight, engine characterisitics etc etc all combine to filter out the best cars for each available hp band.

If a 924 is your choice then you have 2 classes you can run in if the engine is std, P4 (160BHP) or P3 (205BHP) you can also be in P2 with the CGT or P1 with the GTS/R etc but I have yet to see one of these running in the championship and dont suppose I ever will.

I started with the standard 924 because I had to as it was all I had. Even so, the car proved itself to be immensly competative with just handling and weight changes. In the early days most of tire to tune the std 924 and yes, we also found it to be tricky and costly. However, small gains (I got 148bhp best) added to less weight and good handling package meant the car could outrun much more powerful cars and most of those Porsches that fell into the same hp class.

The great strength of the 924 in NA form is its durability and its cheapness to run. The car has no traps to catch out the unwary and is a smooth, forgiving and safe start to a speed or race hobby.

You will find that things have moved on a little now though as Dave Dennet has a 160hp 2.4 ltr car, which whilst it has cost money to develop, is still very good value compared to the cost of purchase and running of the P4 band of 911s.
The key for him was to do the engine work and to remove a huge amount of weight from the car (it comes in at 840 kilos!) which gives it a power to weight ratio favourable with other cars in the other hp classes and has made it impossible to catch for the other current p4 drivers. He will win this years championship in that car , easily I think.

The 924 turbo is not, in my humble opinion, a good choice for our championship due to lag. The car is great for road use but the problem is not on the sprint events (high speed events on race tracks) but on the many hillclimbs we do (much slower with tight low gear uphill bends etc) . Although I accept that there are now much better turbo packs than standard the problem of lag has shown the car to be uncompetetive so far (I say so far as I may be proved wrong one day!). Keith Calder ran his for several years and can advise (he is in the Porsche Club)

The good bit of the 924 Turbo is its handling (same as NA car) and brakes which should be transferred to the NA 924 thus giving great brakes on a car with no lag and good balance , perfect for the beginner.

The 924s is a great car and will give you top P4 class power in the same package as the NA 924. It will handle well and although perhaps not always as responsive as the NA 924 is ultimately quicker in most situations.
However even this car cannot beat an 840 kilo 2.4Ltr NA 924!

The down side (small in my view) is that the 924s has the more complex 944 engine and must have been well looked after with belt changes etc. This though has yet to be a problem with speed championship drivers and the model has been driven to a championship win by Paul Clare and is now driven by others in the class to good effect.

A good thing about the 924s is that it can be easly boosted in power later by either dropping in a larger engine model from the family line(2.7, 3.0 allowable in the regulations) or even supercharged via several kits on offer.

And my car?
Well, having gone the route of tuning and developing the NA model I chose to go for more power in that package as I didnt want to have to sell the whole car to do so.
I chose to combine the best of both (3?) worlds by supercharging a 924T engine hence getting a P3 car with no lag and all the handling/brake benefits of the earlier NA car.
I has proven to be very effective although it does sometimes struggle for grip to compete with the 911 3ltr cars.

So which car to choose?
For cheapness and ease to work on whilst being a great 'starter' car I would recomend the NA 924 with 924T brakes. Sort the handling out with decent dampers , drop it a little and up the roll bars. If you can lose as much weight as you can and you will have a great little car. To win with a NA 924 if Dave Dennet is still out in his next year you will need a 2.4 ltr engine. To learn the venues and enjoy yourself leave the motor alone.

If you have a better budget get a 924s, take some weight out and do the same handling mods to dampers and roll bars. The car will be quick and will be flexible enough for all the venues, but it still wont be quick enough if Dave has his 2.4 out!

Or you could get a 924T and supercharge it like me, but then you'd be as potty as I am!

The final comment is about realistic expectations.
You may be a fab driver and actually know the venues already, in which case go out there and win my son!
However you may be new to the sport and venues and in my view you would be best getting a mild car sorted to learn how it all works. Most of the best drivers in the championship did just that.

Feel free to email me off list if you want to chat further about this, hope to see you out there next year.

Cheers
Simon
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Blown is always best!