rs10

A lot of interesting posts! I'm not sure what to make of it all yet. Some say don't worry, others say change everything. But I've heard too many cautionary tales to go and do 15 laps without worrying. I've no interest in doing laps on street tires, by the way. And I'm likely to go with coilovers soon and am tempted to add sway bars later. So that puts me in the higher risk group.

I'm still hoping that basic precautions (new coolant and oil - maybe 5W-50) and doing a cool-down lap every X fast laps (e.g. every 3) will nonetheless keep me safe - though I'm not yet convinced from what I've read so far.

If I don't get convinced, then there's another question. As I read more and follow links, I hear more and more about oil starvation, and not so much about overheating. Is this a significant seperate problem on it's own, or only a contributing factor to oil starvation. Or more practically, if I make sufficient mods to protect against oil starvation, should I still worry about keeping the heat down?

rs10

Also, a couple of people have said "watch the temperature". What should I watch for? At what temperature should one back off?

rs10

I think no one has supported a couple particular mods which I mentioned in the original post: changing the bumpers. So I guess it's not the first thing one would do to protect one's engine from the track. But I'm still wondering if it helps.

I've been thinking of starting a thread such as this one since hearing people say "don't use 996s on track". But the reason I finally started it now is that I now need to to do one of the mods mentioned in the original post anyway - I need to replace the front bumper (or to be preceise, the front bumper cover). And I wanted to know if the cooling advantages of the C4S/40AE/Turbo style bumper are great enough to outweigh the disadvantages (extra drag, I presume), given the other ways one can address engine temperature issues.

I'm still confused about this. Can anyone confirm that there is/isn't a significant cooling benefit to the C4S/40 AE/Turbo front bumper, or is there only a benefit it one goes for Turbo radiators, as on the C4S? And if there is a significant cooling benefit, is it great enough that one an skip some other precautionary messure, e.g. upgrading the oil sump?

Triple Black

Interesting read. Thanks for pointing that out.

Triple Black

If you will be running slicks then I'd suggest doing a mod to prevent oil starvation.

Schnell Gelb

Great - an intelligent thread and balanced.
1. "watch the temperature"
- if you've followed other threads there is a debate about where/how to accurately measure temperature if you are trying to respond instantly to a sudden, rapid rise in engine temperature. And the stock temp.sender location seems to be a sub-optimal choice. Some Rennlisters say we get a lagging/low reading from the stock temp sensor location .

2."oil starvation" - and foaming.
Whatever you modify and however you drive, the oil pickup must stay submerged to prevent bearing issues. That is easy to say .There are several different products for this issue.Few mention in what specific,extreme their baffles/deep sump work. For example ,one product claims to work on turn 17 at Sebring with sticky tires. That is nice but may be too anecdotal for a serious Track enthusiast.
I labor these two points because the cost of failure is so high .Relocating(but where/how?) a temp. sender and fitting an effective sump+baffle is cheap.

SWK6Cup

@Mikeborden:
Hopefully, this works, because you asked for it.

This was taken in September @ Mont Tremblant. It will take about 30 seconds before you see my car, as it was shot from inside a friend's Cayman S. I hope you enjoy it.

More to come next week?

Ernie J

Mantissport is the orginal oil sump manufacturer which has posted oil pressure trace data from actual race data to back up claims. Posted on Rennlist forums.

Bobster996

I've tracked my c4s several times with no issues. If you are going for sticky tyres, and intend to drive it hard, then there may be other things to think about. Will you need better seats and full harness belts? 911's corner really well, also , will you need to cool your brakes better?.
Mechanically, leave it stock until you've tried it, change the oil regularly, I'd use normal oil, but change it after 3000 miles. Leave the front bumper, it's designed to run with the radiators you have, the Turbo and 4S have bigger rads fitted, so if you swap the bumper, you'll need to also swap the rads and ducting to get the best effect.Also, I'd leave the sump standard, it's been designed to be driven very quickly, it can cope with a handful of track excursions. Remember, the Germans love speed, and build amazing fast cars.Yours will cope.
If you really want to turn it into a full on track slag, then it's your choice. I'm sure a decent race shop will recommend and fit all the goodies you'd need. it's a very slippery slope once you start.

Schnell Gelb

Here is the link to the Mantis Sport Deep Sump Data:
https://rennlist.com/forums/997-foru...baffles-3.html

KrazyK

What Mac said in the first line of his response. To add to it, the M96 NA was not intended for nor ever will be good for track use. The inherent flaws of the original design prevent this.

All I can add is OMG and clueless.

vandersmith

I DD my C4S and track it a few times a month. Victory loves preparation and I'd recommend you either do nothing or everything. Not committing across the board (brakes/suspension/cooling/etc.) leads to vulnerabilities. The car stock will handle the track beautifully without overdoing it. Improving any one aspect can lead to issues with others.

Here's my list:



Engine:
LN Dual Row IMS Upgrade
LN X51 Deep Oil Sump, Baffle and Pan
LN Spin-On Oil Filter Adapter and Magnet Sleeve
RMS
AOS
MAF Sensor and K&N Intake
Water Pump
Low Temp Thermostat
Coils/Plugs/Tubes
Alternator
Underdrive Pulley and New Belt
Function First Motor Mounts
GT3 Throttle Body
IPD Plenum
EVOMS Intake
Custom Headers/X-Pipes/Mufflers
New Coolant & Lines

Drivetrain:
New Clutch and Pressure Plate
997 Short Shifter
Guibo
Agency Power Shift Linkage
Reinforced Transmission Mount

Brakes
EBC Yellow Front Pads
EBC Red Rear Pads
Zimmerman Front and Rear Rotors
Motul6 Super Gold Brake Fluid
SS Brake Lines

Suspension
KW V3 Coilovers
Eibach Sway Bars F/R
Tarret Endlinks F/R
Tarret Monoball Camber Plates
GT3 Front Control Arms
OEM Tie Rods
Adjustable Rear Dogbones and Toe Links
Powerflex Bushings All Around F/R
Upgraded Thrust Arms F/R

Interior
Agency Power Roll Cage
Recaro SPG XL
Recaro Side Mounts
Planted Seat Mounts
Racequip 6 PT Harnesses
Extended Throttle Pedal
Momo Monte Carlo Steering Wheel – 350mm
Rennsport Hub & Quick Release
Valentine One
Dension Bluetooth Gateway
Cabin Filter
Track Mats
Radio and AC Trim
Bluetooth Adapter

Exterior
New Front Bumper and Lip
Rolled Rear Fenders

Tools
-Atlas 7000 Scissor Lift installed. Perfect setup for 911s.*

This is the LN sump/baffle you want:

KrazyK

That is indeed a nice list of mods. The cost to get a M96 NA proper for track use is hard to swallow for most owners. Looks like your doing it though.

9964runner

....GT3

Byprodriver

200 degrees is where I stop "pushing it" & go to 8/10ths.