964 - Project

[Steve Rance]

Another update. Build is now completed

looking forward to collecting the car - will post up driving impressions.

For those of you who are interested the final spec is;

964 C2 with factory LSD and sunroof delete
Big red front brakes
993C2 rears
Castrol SRF
Pagid yellow pads
RS Anti roll bars
RS lightweight flywheel
RS engine mounts
Engine carrier support bracket
KW Clubsport dampers
Heigo rear cage
Lightweight carpet set
RS door cards in leather
Recaro pole positions
Momo wheel
Rear wiper delete
Front strut brace
Radio delete - blanking plate
Teardrop mirrors
Front brake cooling ducts
Replica fuchs
Cup 2 tyres
Set up - 2.5 deg front, 2 deg rear, max caster, RS ride height -20mm
A few other odds and sods..

[Steve Rance]

Lungauer said:

A very good spec and looking very nice indeed.

May I ask - did you source the components yourself or get it all done at by a trusty third party? Mine's off to Centre Gravity tomorrow for fitting Bilsteins and bushes, but I've still got things to do, most of which you've already done, namely:

Door cards (did you delete the electric window mechanism?),
RS carpet set
Recaros
Radio blanking plate

If you know of a good source do please let me know, until then I wish you joy of her and we'll look forward to a running report.

I sourced the components myself. Will happily point you in the right direction. Feel free to send me a PM. I left the electric windows in because I wanted to make it as easy as possible to convert the car back to original spec if needed. Good luck with your car. Chris will make a lovely job of your chassis

[Steve Rance]

Jamie Summers said:

Steve,
That looks spot-on ! Nicely topped off by the Magic Tree hanging from the mirror
Some light exhaust mods and a trip to see Wayne will have you at 300bhp or thereabouts and will keep a 996 GT3 honest. Plenty more weight to come out of the car once you start down the slippery slope....

Jamie you really are a very bad influence

[Steve Rance]

ras62 said:

What was the final weight Steve? Not sure on the ride height tbh, if this was done on low fuel it will be even lower with a full tank and that's before the springs have settled and dropped.

To be honest, I wanted it even lower but we decided to start at RS - 20mm. Good point about the springs settling. Will do another base line after a few days on the circuit. I'll make my mind up on a final geo then. Paul has a similar set up requirement to me so it will probably have a decent balance straight off.

Not sure on the weight. I don't think it will be that light to be honest. Paul advised that we didn't go too far from the standard spec once he realised how good the car was. I'm hoping that a pretty extreme set up, some track focussed dampers/springs and bigger brakes will unlock some decent pace.... Oh and maybe a set of slicks!

I have to say that Paul has been fantastic - particularly in his knowledge of all things air cooled and ability to source lovely cars.

[Steve Rance]

Thanks guys. I am aware that bump steer could well be an issue and am already trying to source some evo uprights. As Neil says, running a stiffer spring rate will make a big difference but there is a pay off with road compliance. This is the main reason that I went for the KW Clubsport package as the spring rate is almost twice that of the Bilstein B10.

I am definitely expecting a degree of bumpsteer. Again as Neil said, it was an issue on the GT3 also. Some very good air cooled drivers couldn't get on with the 996 cup because of the bumpsteer. To a large extent I am used to it. 1000's of laps in GT3's may well prove useful in an air cooled after all! This is one of the reasons that I wanted a little more front brake bias.

Thank you again Gentlemen for taking the time to post. Very good information. I will post up my thoughts in detail once I've tested the car

[Steve Rance]

Lungauer said:

Very kind Steve. PM sent!

My email address has changed to [e-mail] could you please re send?

[Steve Rance]

Thanks Collin. Your advise on set up, damping and all things general has been much appreciated in this project.

[Steve Rance]

Hi Neil

It's pretty crude. I've just put bigger front calipers and discs on it basically. So we have big reds on the front with 964 3.6 discs and 993 C2 rears with 964 RS discs. Pagid yellows all round.

The car that I drove at Silverstone had the same set up and was lovely. I found that driving it in a similar way that I would a GT3 was the most effective for me. A trace of oversteer on exit ( it had standard C2 anti roll bars) but it took full throttle from apex. Absolute joy to drive.. Not like my 993 which is a lot lighter and very easy to drive by comparison. Like the GT3, a well set up diff seems key. A car without one would a bit trickier

[Steve Rance]

I think that it depends on how you prefer to sit. Most racers like to sit upright with the steering wheel close to the body so a deep dish on the wheel and a deep adapter will help bring the wheel forward. This is exactly how my car is set up (see pic). If you prefer to sit with the wheel further from you, a shallower wheel with a smaller adapter will be better.

[Steve Rance]

A quick update.
Have now driven the car on the road on both bumpy suffolk lanes and smoother tarmac. No scuttle shake at all, it feels good and the chassis has no problems at all dealing with the much stiffer spring and damping combo - although i'm expecting flex some flex when it's loaded up on circuit. I was worried that the spring rates would result in an uncomfortable ride but absolutely no probelm at all. The damping is well judged with decent control. Damping has come a long way over the past 10 years. The very low ride height is fine to live with no major issues with front axle bump steer that I was fearing. I think the gamble of running KW Clubsports with the Higher spiring rates has paid off.

The brakes are very strong. On road biased tyres - currently running crappy old carlos fandango rubber - i'd say it's over braked. Very easy to snatch the fronts unless the nose is loaded first. The level of dry grip in the chassis is so great - even on low grip rubber - that there is no need at all to trail on the road. With a set of cups fitted, the car should come to life and allow much later braking points and then the brakes will come into thier own. On saying that, I tend to mince about on the road and leave driving quickly exculsively to the circuit.

All in all, I am absolutely delighted with this little car. I wanted to create something that would be comfortable to drive on the road, be an interactive event at low as well as high speeds and quick enough to be fun on the circuit. Some of the the modifications were a bit of a gamble but in the event are soft enough to be comfortable on the road yet offer serious potetial for track performance.

The only downside so far have been the fuchs - which when fitted with 265 cup 2's refused to fit under the rear arches. The car is just too low. Paul told me to fit 255's and he was right. Luckily they will it on the speedline reps that the car came with. I am really looking forward to driving the car on the cups. If it can be this good on crappy rubber, it will be lovely on cups. I am sure that the set up will need fettling a little to optimise track performance but alreadly I can tell that this will be a very fast little car.

[Steve Rance]

Some useful info for you chaps looking to modify 964s.

I mounted up the Michelin Cup2's on my track wheels and scrubbed them in ready for the first track test. Definately a leap forward from the original Cups. Very easy to get heat into them even at road speeds and the grip levels are noticably higher. The car came alive and the brakes began to make a lot more sense. No longer do they feel overkill and snatchy. Less willing to lock up at the front, now just dropping the nose immediately on even light applications which is exactly what I wanted. The brake pedal is reasonably firm with decent feel which is encouraging. However, the big test will be how they perform under track conditions. I am keen to pass on as much info as I can to other 964 owners looking to modify thier cars so aplogies if this post becomes a little tiresome.

So;

I am very happy with the whole set up on the road which is important to me as the aim is to provide a high level of feel and interaction at lower as well as higher speeds. I have never subscribed to driving like a lunatic on the road but still like to enjoy the feel of a car communicating to me at legal speeds. There is something special about connecting with a vehicle from 1 to 11/10ths. The cups are definately the final peice of the jigsaw as far as the road set up is concerned. The car has a lovely balance and has so much grip that trail braking is just not necessary. No specific driving style is required, such are the reserves of grip that the car just goes where you point it, either on throttle, on trail throttle or on brake ( providing obviously you are smooth if the car isnt straight ). It will take a lot more abuse that say a GT3 before a driver finds himself in trouble. All of the time, the chasis is telling the driver exactly what is going on. The steering is very nice, lots of feedback from straight ahead to full lock. There is kick back which is amplified with the fitting of the cups but it's perfectly acceptable. The cups also add a layer of physicality to the steering which I think will be a welcoming factor to the driver as it adds a layer of security reminding him that the onset of understeer is some way away and there is plenty in the bank for avoidance should it be needed. There is no need to describe the behaviour of the chasis on turn in, apex or exit because at road speeds the car has so much grip and is so far away from it's limits that only a complete idiot would get anywhere near the point at which the chasis even began to start to do it's thing. Instead it just keeps on telegraphing everything that is going on under each wheel with such clarity that it becomes almost intoxicating. The nose still snuffles along reminding the driver that he is driving a 911 but the higher spring rates and sharper geometry combined with the huge grip levels of the tyres make the car feel almost mid engined at road speed levels. Even with the huge grip levels, the engine and greabox do not feel overwhelmed. The single mass flywheel makes a big difference here and is definately a modification that this set up would miss. I have not weighed the car but ditching much of the heavy interior definately unlocks more performance and makes the car feel genuinely fast on the road.

The thing that most comes across when driving the car on the road is that although it provides a level of interaction that is lacking in modern 911's, it chasis has a level of compitence that would fool any driver into thinking that it was indeed a brand new car. It is not an old car that feels like it is punching above its weight, it feels like a new car with new car levels of grip and braking whilst still managing to provide a level of feel and interaction which just isn't there any more. The stiffer spring rates and roll rates combined with decent modern damping have unlocked in this little chasis someting realy special and shows what an amazing car this realy is. If it had benefitted form modern damping technology in 1990 it would have taken the game forward light years.

The next big test is the circuit. The set up will show it's real character and - I suspect - where the flaws in the balance are. Track set ups are rarely bang on straight out of the box and I am expecting some nipping and tucking.

To you guys thinking of building something similar, a few things to note;

The front brake calipers are very big by 1990 standards and will need careful wheel choice to prevent the calipers from binding of the front wheels- see attached pic. Make sure that the design of your wheels will accomodate the front calipers before you source them.

Secondly, tyre choice is a key component in the balance of the build, I found that there was more choice of available tyres in 18" than 17". Again, this may effect your wheel choice.

Finally, the shoulder of the cup 2 tyre is very square and with the low set up of the car can lead to them not fitting unless the correct wheel offsets are chosen since they sit well under the wheel arches. I was very lucky - There is a 2mm gap between my rear arches and the tyres that sit under them. Very close! I will post up the offsets after Ive checked them. You can use these as the max offset possible to use. Another option would be to use 255 section rear tyres. I could not find a 255/18 in the Cup 2 but they may be available.

Thats it.

Will post up next after the track test.

[Steve Rance]

ras62 said:

That is a nice summary Steve and it sounds like you are 90% there with what you set out to achieve. I would be interested to hear your thoughts on spending some time in a 964 with a setup slightly less extreme, especially the ride height and on more road friendly dampers/springs.

I'd love to drive a car with a mild set up. The car I drove at Siverstone was reasonably mildly damped with stock bars but it had a pretty extreme diff and brake set up.

Edited by Steve Rance on Monday 3rd August 20:19

[Steve Rance]

SignalGruen said:

Yeah I noticed this too albeit I'm running 295/30 on an 11J rim at the rear. Much less breathing room when switching from R888 to Cups 2's although the Cups look much better from an aesthetics point of view Aside from ride height are you running RS geo ? Your spec is very similar to mine although I have a few extra bits and pieces and wider rubber as it's a widebody - if we're ever at the same track day I would be interested to get your thoughts on how mine drives in comparison.

Basically we took the RS geo and added to it. Ie more camber and caster and less ride height. I would love to drive your car. It sounds an intreging vehicle

[Steve Rance]

anonymous said:

[redacted]

I cant really answer that one for you. It may be worth setting a low budget and seeing what you get at the end of it. 964 and 993 C2's in coupe and manual are difficult to find and not cheap these days so I'd definately consider working some magic into the cayman. If it were me, I'd change the spring/damper combo, add some adjustable top mounts and lower control arms, increase the roll resistance and fit a single mass flywheel. Get a sharper geo and drop the ride height. go as sharp or as blunt as you like on set up. An airbag free steering wheel will give you a lot more steering feel and along with the sharper damping and geo, the car will definately feel more alive. I'd leave the engine alone, although i'd consider a Slippy diff - they arn't that expensive. If you fit Cup 2's and you want to track regularly, a baffled sump would be worth considering.

If you still have a hankering for an air cooled, You are welcome to drive my 964 to see where a standard C2 can be taken with a few bolt on bits. You may find it interesting to compare it's character to the lovely original C2 that you drove recently. The spectrum that these cars can be created to cover is very broard. I think that is the main joy of the aircooled cars, you can change the character of them very easily by bolting on bits from the tried and tested Porsche motor sport parts bin and turn just about anything into a track weapon. That is the unique nature of early 911s. They've all been raced extensively and parts and tuning routes are so readily available that It's realively easy to turn them into something that gives most of the feel and experience of a an RS or even a full on historic racer.

[Steve Rance]

The cayman has a lovely chasis and a lot of car for its current money. All the basics are already there. My only advice is to be very clear on exactly what you want from the car and stick to that - or it's a very slippery slide. The first thing to do would be to make sure that as much of the chasis is adjustable as possible. Then set the spring rates and make sure that they marry to the damping rate. That will give you the all of the freedom that you need to set the geo that suits you and control the wheel movement the way you want it. It is amaing how much a geo makes to the feel of a car and the feed back that it gives you. The valving of many modern dampers will give you almost the best of both worlds with high speed and low speed control.

[Steve Rance]

Hi Neil

Apologies. Just spotted your post. Your data project sounds very interesting. I will give you some feedback as soon as I can. The softer helper springs are always tempting. I'm a big fan of using them - especially on road/track cars. With the 964 I am mindful of the /bump steer issue across the font axle so don't want to encourage any more movement than necessary. To be honest, the Clubsport kit is very well judged and does not feel stiff at all. On the current valving set up, id say it needs a tad more fast bump for track work but the proof of the pudding and all that. Off the top of my head, the spring rates are 300-350 front and 700 rear which is cup territory. Feels absolutely spot on. I'd have been dissapointed going B10 as that is substantially softer and would definitely bring the bump steer factor more into play.

[Steve Rance]

The Momo wheel is over 40% lighter than the standard 964 wheel and has a similar effect on the steering as a light weight flywheel has on throttle reponse. There is far less inertia to overcome so it is a lot more sensitive -but it also gives more kickback (sepecially on cup 2's). some drivers like that, some don't. I prefer to have as much as feedback possible and just filter out the kickback. Secondly, it is 10cm closer to the driver which is important to me as I prefer to sit close to the steering wheel. Most racing drivers do. Again, some drivers like to sit further back from the wheel - relative to the pedals - so may prefer the normal wheel location. Thirdly, the Momo has a smaller diameter than the original wheel which again I prefer as I find the rack a little slow - often a driver needs to take more lock after crossing his arms - and this helps speed it a little so that in most situations, crossed arms is adiquate. To a large extent, it also negates the effect of the powered steering - which is quite subtle on the 964 - and almost gives the feel of an unassisted rack. Which again I prefer.

The airbag issue is a bit of a red herring as 964's - at least the cars that i've driven - dont have them.

[Steve Rance]

All of the 964's that I have driven have had the sport wheel. The wheel in the first pic. The RS wheel is the same but with RS script. These wheels are non airbag. The airbag wheel - the second picture - is a whole lot heavier still.

It was only when I weighed my steering wheel that I realised that it wasnt airbag - hence the red herring comment!

it could be that a lot of 964 owners assume that their cars have airbags when in fact they dont.

[Steve Rance]

ras62 said:

You can get a cat bypass muffler that is slightly louder than standard but tbh running with the other two silencers in place the car will not be that noisy, especially from the drivers seat.

Would you have any recomendations on manufactures for one? Also, how would you best improve the exhaust on a 964 whilst minimising the increase in noise?

Thanks in advance

[Steve Rance]

Sorry. To be clear, I am not looking for noise improvement at all. I suffer from tinitus. I am looking to have an efficient system which is not too noisy in the car or ut of the car - Must be track day friendly.