61 replies to this topic

[Scott Collins]

the 951 in the video is not slow. and how hard was the GT-2 trying? if he was full on, then the 951 goes to the head of the class.

now back to the original topic - Cloud, you have the com....

[Cloud9...68]

I may have missed this, but I hear a lot about power and suspension. These should be secondary in a race/DE car to safety. If you want a car that will be mainly for track, you need a cage, seats and harnesses.

Agreed, safety is definitely a top consideration. Included in my list of mods should I end up keeping the 968 and using it primarily as a track car would be Flash's chassis brace (although last I heard, Flash wasn't planning to make any more of these, and while I fully understand his reasons, this would put a further damper on the keep-and-convert-the-968 option) with harness bar, racing seats, and a full harness.

[flash]

lol - i can be persuaded to do a lot of things - i'm definitely not doing any more batches though - they are just way too much work, and take too long when they are all lined up like that - it just overwhelms the welder i use, and the guy is so good that i don't want to go elsewhere

[Cloud9...68]

OK, thanks for keeping the door cracked open. We'll see my state of mind once I'm done replacing the fuel lines, belts, rear main seal, clutch, oil pan gasket (and probably the rod bearings while I'm in there), lower balance shaft seal, and re-sealing the power steering pump and steering rack. Heck, while I'm on a roll, I may go ahead and yank the head and have it rebuilt. My decision as to whether to keep and modify it vs. selling it might come down to the condition of the flywheel - if it needs to be replaced, I'm not sure I'd want to spring for a new DMF (if they're even available), and a single-mass flywheel may really limit resale, while enhancing its utility as a track car.

By the way, I remember discussions about compatibility of lightweight flywheels with the supercharger, but I don't remember the final conclusion. Can the supercharger be used with the 18 lb single-mass flywheel RS Barn sells?

Oh, and speaking of flywheels, has anybody ever used a lightweight flywheel with an aftermarket shift knob? My initial suspicion is that it would amplify the already annoying buzz, but given the complexity of all the harmonics of the linkage, who knows? Thanks.

[flash]

18 yes, but S2 harmonic balancer required - 12 no

[Cloud9...68]

Any bets as to what kind of shifter buzz will result from a car with an aftermarket shift knob (a very light aluminum one from a 996 GT3 in my case), 18 lb flywheel, S2 harmonic balancer, and the supercharger? Not that it would really matter, because such a beast would primarily be a track car, but I'm still curious...

[flash]

i don't think the buzz would be all that different - i did not notice any real change in shifter buzz when i went even to the 12lb unit - all of the rattle is in the rear - i don't know if that would transmit up front and increase the buzz in the shifter or not - of course, if you are going to track the car, you are probably going to want to go back to the stock shifter anyway, as almost all of the aftermarket shifters do not provide for proper shifting technique (fingers never touching the shifter, ball in the cup of your palm)

[bombfactory]

The best shift knob I ever had was a Titanium Cavallino - it was a solid billet sphere of polished titanium. It worked with the palm of your hand like a ball jointed socket, and had just enough heft to help smooth out the shifts on my short throw shifter (this was on my E30 M3). And since it was titanium, it didn't get too hot if it was baking in the sun. Sadly it appears the makers of it are no longer in business - they were based in Costa Mesa. Not sure if they ever made them for Porsches.

-Austin

[craigawoodman]

Back to the topic of a DE car.

THe challenge of the 968 over other cars is to be able to maintain corner speed and late braking. A 911 cannot brake and turn at the same time. It took me a while to learn where I could actually be quicker than a 911. I honestly think I would not be anywhere as quick a driver in a 911 compared to the 968 - the 968 is just so forgiving and well balanced. I have commented that by increasing the power of the car, I will have to learn throttle modulation - something I really don't have to do currently - with the rear tyres and R spec tyres - there is so much grip, just plant it and go.

THe balance of the car is what is impressive, this is why on twisty tracks the power difference disappears in terms of lap times. I can hold the car flat through corners where 911's are backing off or braking.

It also took some time to grow some cajones to drive to the limit of the car (and some spins - normally from carry too much corner speed - not power oversteer).

I think that as a car to learn your craft in - the 968 is exceptional.

By doing the mods little by little, you also get to appreciate how the mods affect the car. My budget is not unlimited and the car has progressed over the 4 years I have owned it, but like Flash, mine now owes me something in the region of $75k (but our cars have a much higher initial purchase price than yours).

My suggestion, keep using yours to hone your skills and wait for a well sorted 968 track car to come up for sale and then jump on it.

[Cloud9...68]

Craig,

You make a lot of good points - definitely some food for thought. You're basically comparing the characteristics of a car with a high polar moment of inertia (the 968), to one with a lower one (the 911). I can see how a car set up like the 968 can inspire confidence to carry more speed through the turns. But on the other hand, a low polar moment inertia, such as in a mid-engined car (like the MR2, for example) has a lot of advantages, too, as evidenced by the fact that every major racing category where it's allowed, goes with a mid-engine configuration. But I can see that such a configuration is less forgiving, and maybe not as easy to learn on.

But if I keep the 968, I definitely need to do some things to it to make it more capable - it's just plain slow as it is now, even on the tight, twisty track I've done most of my driving on. If a guy who ended his driving career in a factory-sponsored Ferrari 333SP prototype can't turn in a lap within the same zip code as some of the faster cars that normally frequent the track, nobody can. And I'm not talking about Ferraris and high dollar Porsches; my 968 can't keep up with the likes of Mitsubishi Evo's, Honda S2000s, a variety of fairly run-of-the-mill BMWs, etc.

You seem to be leaning toward continuing to improve the grip, through things like coilovers, better tires, maybe bigger sway bars (although I have M030s now), etc. I know you base that on experience that clearly speaks for itself, but I'm stumped over the fact that my suspension is already fairly well tweaked, and that there doesn't seem to be a huge amount left on the table, but I could be dead wrong about that. I guess what I have to do is compare, dollar-for-dollar, what it would take to really turn my 968 into a fun and capable track car, to the type of MR2 I have in mind. Seeing as I'd want a stroker 2.3 liter motor (to enhance the low-end torque), my dream "cheap" MR2 may end up being a lot more pricey than I've been fantasizing..

[craigawoodman]

One of the biggest improvements you will get is with the tyres. Are you running R-Spec or better tyres?

On our short tracks, moving from a road tyre to an R-Spec tyre will normally give you around 2 to 3 seconds a lap.

How much time difference is there between your times and the other car's times?

Also, are you comparing apples to apples - what do the other cars weigh and how much power are they putting out.

At a long track, with very long straights, my 968 was around 18 seconds a lap slower than a 911 GT3 RSR, so it is all relative. It was quicker however thna most Cayman S and quicker than all Boxsters. It was also quicker than a lot of GT3's - even though I give away around 200hp.

Cars are subjective, as per my last post - I do not delude myself that I could get into a 911 and drive one quickly - the driving style would simply be too different and I would have to learn how to drive one. Whilst most instructors are quick regardless of car - it still takes time to learn the car itself to be very quick in it.

Another example of relative times. A car magazine ran Audi R8's around Lakeside over here (in road spec). My 968 was 1.5 sec a lap quicker than the V8 and around the same time as the V10. Not sure how hard they were trying, but this is a car that costs around 10x what a 968 does.

I also look at the times that run around Wakefield Park in NSW. I managed a low 1:09 (there is a clip on Youtube - 968 vs GT3). The GT3 smokes me on the straight, but I catch him in the braking zone for the first corner and then get held up everywhere.

Do not under-estimate suspension set-up. Having a car that stays flat and planted will not only allow you to carry more speed, but to also accelerate earlier. The bigger brakes also allow you to carry speed longer prior to braking. All of these little things add up to a big improvement in lap times.

As per previous posts, regardless of the car you have, you will have to tinker with it to get the best out of it. Depending on track, this could be as simply as pressures and alignment/camber, etc, through to major changes to the car. Once the bug bites, it bites hard. But tinkering and looking for the next opportunity to go faster is part of the challenge.

It was even enough of a challenge for me to now start looking at the driver and trying to reduce the weight that this add to the vehicle (which in my case is considerable).

There is no silver bullet here - ever car will have its own unique challenges and issues.

I have seen EVO's throw rods and have a smelly mess on the ground as well. But on most tracks I would be faster than an EVO (not sure about a massive HP version - but a stocker or slightly modified one I would be quicker).

Last time the car was dyno'd it was making 186hp at the wheels - so my car is now power house as well.

You should be able to see lap times from events at the Queensland Porsche Club website for comparisons.

What is interesting as well is that there was another 968 that was stripped and had a cage in it competing in previous years. We used to run in different classes (as his car was some 200kg lighter than mine), but I could normaly just pip him for lap times. To this day not sure what the reason was (18' rims and wider tyres on my car, wheel spacers, etc, etc). But there are differences even between the same car and driver.

I am going to do a Driver Ed day to see just how much lap time is left and whether or not I am going as fast as possible - but until a real race driver has a punt, I am assuming that there has to be a couple of tenths left somewhere.

Another thing in favour of the 968 - we share our ideas freely.

[craigawoodman]

sorry, another point, mid engine is normally used in preference to a front engine and gearbox design from a weight distribution point of view. The benefit of the 968 with its transaxle design is that it achieves a 50/50 weight distribution without having to be mid-engined. By having the transaxle design, it is far more progressive when it appreoaches the limit of adhesion and easier to catch when beyond it. I think it is also less susceptable to bumps and pitching than a mid-engined car.

If you have grown up with a normal (front engine/gearbox car), the driving style to get the most out of the car seems to be more aligned to the 968 than a mid-engined car.

My car after corner weighting and accounting for driver is almost 50/50 front rear and 50/50 left right. It pisses the 911 crowd off in a huge fashion.

Some more food for thought.

Craig

[flash]

cloud - you said the suspension was "fairly tweaked" - please elaborate - i don't see any description of spring changes or shock/strut changes - if you're still on stock stuff, there is a lot of room for improvement there - every 2 miles per hour you can increase your exit speed cuts about a tenth of a second off of each lap at most tracks - it may not seem like much, but it adds up

also, unless you balanced the rear braking to match the big reds up front, those brakes are probably costing you time - they are quite heavy, which costs you power, and without balancing them, they cause the car to nose dive, and while you might "think" that is better, it actually upsets the balance of the car which costs you speed

i used to regularly stomp all over cars with a lot more power in my little mgb - it was all about being able to stay flat out through the turns

[Cloud9...68]

You guys are taking my concept of what I plan to do, and are completely blowing it out of the water

Flash, let me start by partially answering your question. I can't give you a complete answer, because I'm not near my documentation. The previous owner installed 250 lb/in front springs, and some sort of adjustable red Koni sport shocks. I can't read their model number, but once I have the front suspension off the car to remove my oil pan, I'll be able to. He also said they lower the car about 1". In the back I have yellow Bilstein sport shocks, and of course the stock torsion bars. I recently read the shocks' model number, but I don't have it with me. It has M030 sway bars (31 mm in the front, 19 mm adjustable in the back, iirc). It has enormous four-piston calipers front and back from an '88 944 Turbo S, Zimmerman cross-drilled rotors (not sure of the diameter), and it has the Turbo Cup brake bias valve, which I bought from RS Barn. It's been corner balanced by a reputable shop (again, I don't have the figures on me), and the same shop did the alignment at the same time. He said it was an "intermediate" alignment - definitely not full track, but more aggressive than the standard street setting. I don't think it has excessive camber. It has upper and lower front braces, and it has a Guard torque biasing differential.

I've only driven one other 968, a stock one, and I'm sorry if I offend anyone, but I was so appalled at how mushy and un-sportscar-like it was, that it almost made me decide against getting a 968. In comparison, mine is definitely firmer, but not punishing, and the handling is in a different league. Others who have driven my car have said the same thing, and Bill Dollahite, the retired race driver who owns Driveway Austin, also commented at how sweetly set up it is (and this was twenty minutes after he hopped out of a Ferrari Enzo he had just taken for a few hot laps).

Having said all that, I'm sure there is a ton left on the table to make it corner significantly better. I've just been under the impression that in terms of the degree of incremental improvement potential, there's a lot more to be had from increasing the power (per the comment Bill made after driving my car) than from further tweaking the suspension, but after reading Craig and Flash's comments, I'm seriously re-thinking that conclusion. It sounds like I need to contact Pete for some specific recommendations as far as a suspension set-up that will meet my needs, but in the meantime, I'd be interested in comments on my current set-up, and opportunities for improvement that would give the greatest bang for the buck. Thanks; this is fun stuff, and I hope others are getting some useful info from it as well.

[flash]

no worries - it's all good

obviously we don't want to see you make a decision you might regret - that being said, maybe this car will never make you happy on the track - i am dealing with that very issue myself

definitely take some time and talk to others who have gone the whole route - it sounds like your suspension is essentially a +2 setup, which leaves a lot more room on the table for a better handling car which would allow you to go onto and come out of the turns a lot faster, which is the key to low lap times - the straights, where you could use power, don't usually represent the same kinds of big changes in lap times - you might gain a car length or two over a long straight by adding 100hp, but that's only a tenth of a second, and if you then have to scrub off all that speed going into the corner, you could easily add back the time you gained

i'd see if you could get a ride in or drive somebody else's car that is set up, and then see what you think

[Cloud9...68]

Craig, on to you,

First of all, I hope you and yours are OK following the devastating cyclone in Queensland, which according to your profile is the state you live in. I know nothing about Australian geography, but I can only hope the your area was spared. The fact that you're posting here is a good sign.

What an amazing and paradigm-shifting post. To answer your questions about my car beyond what I said in my last post, I'm on street tires - Sumitomo HTRZIII's. I've never driven on racing tires, although it sounds like that should be my next move. I just replaced the fronts, so I think I'll want to wear them out first, though.

Most of my recent track driving has been on flat, hightly technical 0.7 mile track. A fast car and a good driver can lap it in 36 sec.; 35 sec is exceptional. After completing the beginning course at the track (Driveway Austin), my times were in the woefully pathetic 44 sec range, but at least I was consistent. After about eight 20-minute follow-up sessions, I'd figured out the importance of keeping the speed up through the turns, and my times started dropping precipitously, down to 42s, then just over 40s, and finally down to my best time of 39.4 sec. The track owner, a retired racer, lapped the track in my car in 39.2 sec, although that was admittedly with me in the passenger seat. So, my guess is that 38.5 sec is probably the absolute fastest it's possible to lap the track in my car, at least with street tires. This isn't drastically off the pace of the faster cars, and I'm pretty well mid-pack compared to the other cars that come out to the track, which are a mixture of everything under the sun, from Miatas to Ferraris, and everything in between. But my worry is that when I move to the intermediate course (I've passed the test allowing me to do so), which opens up a larger part of the track, with serious elevation changes, I will be left in the dust.

Your experience with your car is amazing and inspiring. One data point I have that supports your results is that some of the fastest times at Driveway Austin have been in Spec Miatas, which don't have a better power-to-weight ratio than a 968.

So, now that you guys have convinced me a 968 can be made into a great track car after all, my next decision point is whether this is what I want to do that to this car. Here's my dilemma - I insist on keeping the 968 garaged, especially here in blistering central Texas. I don't want my hatch de-laminating any more than it already has, thank you very much. But I need a car to drive me 4 miles each way every other day to my vanpool pick-up point (I share driving duties with a guy who lives up the street from me who rides in the same vanpool). This means that I need to keep another car, in our case a 2003 Chrysler Minivan, just for that one purpose, which is a waste. If I sell the 968, I'd buy a car that isn't nearly as "nice", and convert into a track car, but keep it just streetable enough to drive to and from the vanpool pick-up point (although my co-rider won't like the bone-jarring ride). This would be a car I wouldn't care about leaving outside, so I could sell the Minivan, the proceeds of which could go toward more goodies for the track car.

If somebody could help me figure a way out of this quandary, I'm all ears. Thanks.

[Cloud9...68]

Flash,

Unfortunately, this is Austin, The Land Barren Of 968s, so I don't think there is one anywhere near me that has been set up for track duty.

[StephenHallman]

I've seen cars sell for hundreds of dollars. 4 miles each way and one of those cheapies might be able to do that. Of course there is the more extreme case of where you could get some exercise Could help you go faster around the track too. Biking, or running if you so choose. Just a thought.

[Rap]

Guys it is interesting to listen to the discussion here and the various responses. Here I am a newbie to all of this and merely considering which if any mods I could make on a newly purchased mint 92 coupe. Cloud is your decision over selling the 968 and buying a track car while also selling the minivan and using the proceeds to further improve the track car? So you end up with one vehicle? Or did I misread 2 out of the last three sentences? Seems to me that one might start at the end goal and walk back and figure how to accomplish it. Easier said than done I know. The fly in the ointment is the Texas sun. Perhaps that is the determining factor.

[Cloud9...68]

Yes, one of my goals is to reduce our stable by one car. This would mean that whatever ends up as the track car is also the car I drive to the vanpool pick-up point every other day. As far as buying a cheapie car to drive to the vanpool, my heartburn over that is that I still have to pay insurance on it, plus store it at my house. My solution needs to include a net reduction of one car.