Jeff N.

OK. Have a lot of seat time in my BMW at the track. We're old friends and we understand each other. I'm getting ready for my first DE event with the 951 and would like to understand from DE veterans how one should approach driving a 951. Couple lead off questions might help:

• How to best manage building boost as you move towards the apex? Are you rolling into the throttle earlier than with a NA car? Are you left foot braking? Essentially, how do you ensure that you have the boost you want when you need it?
  
• Are you having any weight transfer forward issues when you feather the throttle mid turn? I've noticed that sometimes I can generate a pretty good 'hiccup' in the boost if I manage to lift just the right amount at just the right time. Of course, this not good. (BTW, all the misc parts seem to check out).

I'd appreciate some ideas and tactics to get me started for both low speed turns and high speed sweepers.

gt37vgt

well i thing i noticed in my turbo beema and in my 951 is that with a modest power increase both cars need big riase in rear spring rate other wise they get exessive transfer to the rear while coming off the apex .
there are are few very cost effective ways to make the car less laggy the first is an in line pressure releif often refered to as a "boost inhancer " its a pressure relief put in the waste gate signal line that isolates the creeping leaky wastegate below a preset pressure like 12 or so psi it can also be used to up the boost a bit if you like . a good after market wastgate both these items are about 50 bucks each .
the other way to do a search here on rennlist for MSD then go spend 200 on one.
i think one other possible trick is that if you can trick the ecu in the current set up the ecu will cut all feal if it sees more than 2000 rpm and throttle closed . so if you were to put a switch or relay in the line . that you could activate at drive time this will disable the idle function of the car

Zero10

I think he was asking about driving tips, not about sketchy mods like a switch to disable the fuel cut with fully closed throttle?.....

That said, boost enhancer = good idea = ~$50 as mentioned
New wastegate = perhaps excessive = WAY more than $50 mentioned above, espcially for a good one.
No idea why he is reccomending an ignition box.... not going to make any measurable difference until you've gone with standalone engine management.

Some things I have done:
Left foot braking, learn how to do it, then get good at it, this will cut significant amounts of time off of your laps. This is almost a must when passing other cars.

As for cornering, I am rolling on the power sooner than in a N/A car. Perhaps braking and heading into the corner a little slower, but I get to roll on the power a lot sooner, and with some left foot braking I hit peak boost just as I straighten the wheel out.

gt37vgt

oops sorry i'm good at messing with cars and crap at driving and writing posts . as for wastgate ooops i meant Blow off valve thanks for that .
and as for the ignition box i said do a search here for MSD read the threads and you will understand . and stand alone engine management makes the MSD pretty much redundant so i'll be getting rid of my MSD

billthe3

For the record, I vote you learn the car before you start throwing upgrades at it.


The only driving suggestion I have is that full throttle in the turn isn't good. Even a stock 86 951 makes enough power without a lsd to get the car to go sideways a little - its easily catchable and preventable, but it can still do it if you completely floor it.

333pg333

I think you hit the nail on the head there Bill, lsd. No not the type you were warned off by your parents, a decent lsd is a huge plus at the track. In fact the stock 40% is not really designed for trackwork either so look at some aftermarket ones if you're serious. As for left foot braking, that can be a good and bad thing. If you trail brake into the corner and l.f.b. you can rotate the car into a wall pretty easily if you're not really used to it. Probably better to get the hang of it before trying it at high speed. Hey maybe you're already doing it in the BM, so excuse me if that's the case. Anyway lsd is paramount to good times.

DDP

Agreed.

gt37vgt

And once again i shake my head at the arsoles who paid more than a house cost in the eighties for thes lovely cars and didn't have the ***** or sense or spirt to tick the box "lsd".
come over here rich boy i have somthing for you

jerome951

Drive it like a point and shoot car. Overslow for the corner slightly so that before the apex you can plant your right foot without lifting. Feathering the throttle doesn't help as you aren't building boost. Hang on as you track out and the power builds. If you find you can track out without lifting, increase your entry speed slightly.

LSD certainly helps. With it, assuming you have sticky-ish tires on the rear, power-on-oversteer should only be a problem in the slower corners. I never lift when I get rear wheel spin (why kill boost?) unless the car get sideways.

333pg333

There's something not quite right with you, but you are funny at times.
Too much Melbourne Bitter methinks?

RKD in OKC

Slow in fast out is great advice for a rear weight biased 911 Turbo type car.
These cars have a much more neutral balance and don't have the rear bias to handle the extra power as the turbo hits unless you are already pointed straight, then it's too late.

First off, I would say that left foot braking is great, but I have never been able to master it while downshifting for a corner. My left foot is an all or nothing effort from years of operating the clutch pedal and only gets me in trouble.

Part of going fast in a 944 Turbo is throttle management accelerating out of a corner, but even more is using the near perfect 50/50 balance and slow rotation to carry in and maintain your speed into and through the corner.

With adjustable ride height and adjustable sway bars, tune the suspension so the car breaks loose all four adding throttle in a turn. I do this by finding a large enough area that I can slowly increase speed driving in circles about the average radius of a typical turn. At the limit all four should break loose at the same time accelerating at the same turn radius. At that limit the nose should tuck in when you lift, or push with more throttle. This sets up the car to be balanced slowly increasing speed though the middle of the corner. The other mod I recommend is to increase the rear brake bias to the next up bias valve. This helps initiate rotation on turn in so you can get off the trail braking sooner and start applying throttle.

With this setup made you brake late into the corner. As you turn in start releasing the brakes initiating rear rotation of the car into the corner. Lift completely off the brake and start applying throttle as soon as the rear starts rotating. This should put you in a slight 4 wheel drift with the rear rotating. As the car points into the apex apply more throttle just enough to stop the rotation, but not so much that the turbo hitting will loosen the rear as you apex. At this point you should be at the limit with a slight drift going into the apex with just enough throttle to maintain the drift. Add corner exit throttle a little earlier than you would in an NA as you apex carrying the drift out through the exit of the corner.

When cornering at the limit like this there should be enough power without the turbo to maintain apex speed. The trick is learning how early to go full throttle without powering the slight drift into simple oversteer.

Takes a lot of practice but very rewarding. You will be passing those slow in fast out 911 guys like crazy.

billindenver

While some of the above is great advice, a great deal of it depends on your driving style. Setting a car up based on how someone else drives a car that is similar (but by no means identical) is simply asking for trouble. I would take the car to the event as it is...drive it and see how she acts under your driving style. Adjust/modify from there. These cars are fantastic in their balance and you will find that even stock they run around the track pretty well.

jerome951

If you can LFB while downshifting my hat is off to you. I only use it when I need to transfer from braking to back on the gas quickly without downshifting.

It has it's applications, but setting up for a high-speed corner where you delay throttle application (and corner entry speed is critical) isn't one of them.

I'll slightly disagree on your comment about not flooring the throttle w/ the car turned because of power oversteer. Even when running Toyo RA1s (not all that sticky), I've only experienced power oversteer when in 2nd gear and never in 3rd or 4th. I have LSD, but even w/ my firm suspension (i.e. minimal weight transfer) it isn't a problem. In your hi-hp beast, I could see this being a problem, but not in a stock car.

Trucho-951

Turbo lag with a k26/6? At the track you'll be above 3500 rpm most of the time anyway, if not you'll need a downshift. LFB is not necessary, I use it only to help point the nose on long sweepers (sometimes). For your first DE in the 951, I agree with Billindenver, take the car to the DE as is, and Have fun, the 951 is very forgiving. The hiccup thing doesn't sound right, I'd get it checked out by someone experienced with 951's, or perhaps you're lifting too much!

Jeff N.

Thanks all - the suggestions are great. I know it's not a 'one size fits all' type answer.

Hearing what people are doing or not doing is really helpful in assembling a bag of tools. Also, I'm not focused on mods at all. The car currently is what it is (yes - there are some mods). I'm really interested in tactics used to get the car around the track in a composed manner given the unique nature of the 951.