Supercharged 968 powered 944 racecar

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Supercharged 968 powered 944 racecar - Dubai944 - 11-16-2009

Well, unfortunately no video for Round 2. After two days of preparation a drive shaft CV decided to die on the formation lap for the race start. The vibration was so bad I thought the wheels were coming off and had to limp into the pits just as the rest of the field got the start light. Mega frustrating, but as always it's the unexpected small things that get you in racing!

Supercharged 968 powered 944 racecar - Ben_968CS - 11-19-2009

Sorry to hear! I know the feeling of starting a race and then having to quit right at the start: all the trouble and time for nothing and no fun in return. Next time more luck! How did the supercharger run in practice?

Supercharged 968 powered 944 racecar - Dubai944 - 11-21-2009

The engine ran without a problem all weekend. Temperature was a lot cooler than last month, about 35C. I moved the idler pulley and rerouted a longer belt for a lot more belt wrap on the supercharger pulley. This seem to have got rid of any slip and now have 7psi showing at 6600rpm. The car is noticeably quicker than it was in the first round.

Supercharged 968 powered 944 racecar - 333pg333 - 12-06-2009

Steve, great to see your progress since we last communicated. In many ways I think you've chosen the right system for forced induction for what you want. I'm sure your car is pretty light now and getting up around 300whp is going to be pretty darn quick.

I'm interested in your Motons and to be specific, your spring rates. They're pretty hefty and I wonder what the car has been like since you went to this setup? It should afford you the ability to set the car pretty low which can be good. I'm also interested in your incoming upgrades to the body to allow the bigger wheels. I think you will enjoy the wider tyres but keep the stagger pretty close. The closer the better in my book. I was running 285/295 at the end of our season and running near to square really suits our cars.

The brakes seem to work very well indeed. A couple of questions. Did you keep all the stock hydraulics? Also did you notice any issues with going up to such a large rotor, unsprung weight and inertia etc?

Love to see more film and get some pics too. Nice driving! [img]style_emoticons/<#EMO_DIR#>/wink.gif[/img]

Patrick from OZ.

EDIT: Just saw some pics on the site that your videos are on. So you've gone for the 968 turbo look. The fit looks good in the pics. Which brand of bodykit did you use and how hard was it to get the fitting done? Did you cut away any of the stock fender underneath? We found that in the stock front fenders that we just opened up the aperture and pulled them only very slightly to allow for the same NT03 18x10" w 285 in the front.

Supercharged 968 powered 944 racecar - mattipuh - 12-08-2009

Guess with Moton's can take stiffer springs without getting too harsh ride. Anyways, f900/r1100 sounds really stiff, especially for rear setup. still, haven't heard much experience of using motons, so if it works, it must be good. [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img] Friends street car felt superb with LEDA f450/r700, still quite comfortable. but then again, racing is different stuff.

Supercharged 968 powered 944 racecar - Dubai944 - 12-08-2009

Hi Patrick, great to hear from you again.

There is a story behind the pics you saw on the site... At that point only 3 of my 4 CCW wheels had turned up in Dubai which was a real pain. The CCWs are 18x11s front and 18x12s rear but the offsets are custom and they sit right at the limit of my new bodywork. However, with only three wide wheels and the bodywork already done, I had to mix my old and new rims so I ended up with my new fronts rims with 285/650/18s on the rear and my old rears on the front with an old set of 260/640/18s. It worked ok for the weekend but was not the optimum setup I had planned.

I ran the full new setup last weekend after finally getting a replacement for the missing rim. Now it sits on 300/650s on the rear and 285/650s on the front, absolutely fills out the bodywork and looks pretty mega [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img] As far as the bodywork is concerened the flares are just GT Racing fibreglass with some handy cutting and paint work by some friendly locals. We did cut the fenders up 2 inches to clear the tires but learnt a lesson that we had not cut them high enough when I got some tire rubbing in practise on the weekend. As a result I ha to jack up the rear about an inch for the race which screwed up my setup quite a bit. Right now the car is sitting on a hoist with another couple of inches of metal removed and rewelded, so I can lower the back down to where I like it.

In regard to springs, the 900/1100 setup worked very well when I was running the 235/260 combination, I evolved to that from a 700/900 setup and the car was ultimately quicker. With the new squarer setup I initially dropped the rears down to 900 also to get the front working, but still got too much oversteer. Also the 900s were a bit soft and the car was rolling too much. I plan to go back to 1100s in the rear and run 1200s up front, but I have quite a few sets of springs to play with so the final spring setup will ultimately be determined with track testing.

It may sound stiff, but you have to remember I am running true Dunlop race slicks that are very sticky, the Motons cope better with stiffer springs than some shocks and I am running pretty wide rubber on a maximised wheel track. The car generates some serious cornering forces and I am getting a sore neck after races these days.

I also run on a relatively new and smooth track facility in Dubai. In February I even get to run on the Yas Island F1 track as our GTs will support the Aussie V8 circus which is coming to town...woohoo!

I'll post up some more pics and video soon.

Supercharged 968 powered 944 racecar - flash - 12-08-2009

why don't you just increase the sway bar diameter or rate to correct the roll?

i presume you have laterally braced the lower suspension mounting points, which are responsible for a LOT of chassis twist, which is frequently a cause of body roll

Supercharged 968 powered 944 racecar - Dubai944 - 12-08-2009

Flash,

Its a case of matching the relative spring rates front to rear to the tire setup first so the bars can be used for fine tuning the steer characteristics.

I probably overstated the notion of the car rolling too much. The car doesn't actually roll that much, certainly not compared to a road car, but the roll angle on the rear based on some pics I have seen from the last race is currently more than it should be. The main reason is that to accomodate the extra front grip from my squarer tire setup, I have had to run the rear bar full soft even with a full stiff front bar because I have too much rear spring relative to the front, (or too little front spring relative to the rear)... with the 900/900 setup and that wheel/ tires combo.

I want to get the spring rates back to a point where I can run both bars closer to the centre of their rate range and achieve a fairly neutral car. then the bars become useful tuning tools again. I could drop the rear spring rate further and achieve the same thing as going stiffer up front, but I like the way my car drives with the heavier spring rates.

As far as bracing the car up, I hear you! No, I don't have a dedicated lateral brace underneath, something I might look into as I am currently doing some mods to the body and cage.

Supercharged 968 powered 944 racecar - Dubai944 - 12-08-2009

Patrick,

Regarding the brakes, the Stoptech 355mm rotors run with lightweight hats. The whole assembly is a fair bit lighter than the MO30 factory rotors even though its bigger, so no issue with unsprung weight or inertia. I have currently kept the hydraulics stock including the ABS. I added a 5/33 bias valve and it feels just about right. I originally planned to ditch the booster and ABS and run a pedal box and balance bar for a better control, but this setup is working so well I may not bother.

Supercharged 968 powered 944 racecar - flash - 12-08-2009

i thought i had a lot of roll too - i was swapping out springs trying to correct it, going stiffer and stiffer - then i took some flex measurements - then i braced the lower suspension points - then as soon as i upgraded the swaybars to something bigger than the M030 stuff, i really noticed how much of what i thought was insufficient spring rates really turned out to be chassis flex and resultant roll - the lower bracing limited the flex and let everything work better

a certain amount of flex is good, but too much can be very misleading - the same can be said of spring rates - stiffer is better, but there is a point where it can be too stiff, and the chassis stops being able to do what it needs to do to balance the car

i have no idea what kind of cage you have and what it does for the chassis, but you may well find that once you prevent the lower mounting points from collapsing and moving that you no longer need such stiff springs, and what you really need is stiffer sway bars - you'll know in a hurry though

have fun and be safe

Supercharged 968 powered 944 racecar - 968 GUY - 12-08-2009

Dubai, Enjoyed the vids, look forward to more. You have a good grasp on the handling for your car. Like the headlight conversion.
Ken

Supercharged 968 powered 944 racecar - 333pg333 - 12-09-2009

Steve,

All great information and feedback. I might be using a lot of your R & D for some components and setup values for my next project. Unfortunately I had a pretty big accident in my 'Sister' car to yours so I am hoping to move to the next level. I hope to be working with the guys from D9 again and they have some interesting new parts coming up. (Amongst those for all you 968 guys is finally a headlight conversion kit that actually looks factory from the early pics I've seen)

That's some interesting info on your suspension. I have the KW Race setup and also picked up a set of Moton Clubsports. I think by what I've read I might switch to the Motons and especially as they have the remote adj too.

I'm sure you're going the right way with the 'square' setup. There are too many guys out there running this with good results. I certainly enjoyed the 285/295 R6 setup on the track.

Drop me a line when you get closer to the support race for the V8s. I'd love to see your race. As usual, get some video...in and out of the car. [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]

As Flash mentioned, do you have any pics of your cage?

Supercharged 968 powered 944 racecar - Dubai944 - 12-14-2009

A few pics from the first outing with the wider wheel setup. The car is riding quite high as we didn't cut the fenders up far enough initially.

Supercharged 968 powered 944 racecar - flash - 12-14-2009

looks like fun

hard to tell, but it doesn't look too high to me - i see a lot of cars that are actually too low and mangle the suspension geometry and end up actually losing speed in the corners

either way, i'm jealous - it has been way too long since i was on the track

Supercharged 968 powered 944 racecar - Cloud9...68 - 12-14-2009

"i'm jealous - it has been way too long since i was on the track "

Yeah, me too. I've never raced competitively, but that looks like an incredible amount of fun. Now that my company is planning to reinstate our pay to pre-recession levels after the first of the year, hopefully I'll make it back to the local driving academy sometime in 2010.

Supercharged 968 powered 944 racecar - 333pg333 - 12-15-2009

Love the pics Steve. Especially the 3rd one. Looks like it's going to be fun to get the weight transition over for the next left hand hairpin!!
How are you finding the extra width tyres? I am sorely tempted to just opt for that widebody type conversion for the ease and price.

Supercharged 968 powered 944 racecar - pmcrespo - 12-15-2009

that 3rd pic indeed rocks! There is sooo much grip on the outside that the inside tires are barely scratching the surface... Nice....

And the track.... looks like built to perfection... some day perhaps I'll get to experience some of those tracks over the pond... for now video simulation in GTR2 will have to suffice... [img]style_emoticons/<#EMO_DIR#>/sad.gif[/img]

Supercharged 968 powered 944 racecar - Dubai944 - 12-15-2009

The wider tires are certainly offering a lot more grip.

Still have to get the balance right with the new setup as the left rear was really suffering. Looking forward to doing some testing in a few weeks with some new springs and corrected ride height.

I will probably have to look at a rear wing/diffuser next...if only because I am now the only car in the series without one [img]style_emoticons/<#EMO_DIR#>/laugh.gif[/img]

Supercharged 968 powered 944 racecar - Dubai944 - 12-15-2009

Heres a couple of race laps on this track configuration which is one of five at the Dubai complex. It's a great track layout which really rewards a good handling car. Should pick up a couple of seconds on this track when I sort out the setup. This time out I was having to feather the throttle through some of the faster corners. This was towards the end of 45 minutes race chasing down an Evo for 3rd place in class.

Supercharged 968 powered 944 racecar - 333pg333 - 12-16-2009

Nice move under brakes to 'over-under' him. Those Stoptechs are very impressive Steve. I'm sure the added lightness doesn't hurt either. Do you know what it weighs now? Looks like plenty of lateral grip too. Gets me very itchy and jealous....but keep them coming. [img]style_emoticons/<#EMO_DIR#>/smile.gif[/img]

NB. We fitted a rear wing late in our season. I can't give any quantifiable data but I like to think it helped. I know the boys from D9 have some exciting projects on the horizon in relation to our cars. I have the time but not the patience.