darth g-f

X50 UWM reflash and 1.0bar wastegate here. Been running that set up for two years on the stock clutch...

Well after Kevin's input I'm starting to believe that I have an aftermarket clutch. The car previously had a reflash (not Kevin's) so maybe it had an aftermarket clutch too.

When the dealer did the tranny repair for my 2nd gear popout, I asked them to check my clutch. They said in nice shape with lots of life left...

Mercedesben

Stock clutch got weak at 36k miles.
I got Kevin's upgraded clutch with rs 4.0 flywheel. Clutch holds great and my only disappointment is the flywheel rattles at a stop without the clutch engaged.

Kevin

Minor side note.. I haven't sold a 4.0 liter RS flywheel for a street driven turbo.. You would have the 964 RS flywheel (99.9% sold/supplied) with the GT3 sprung disk (not the 4.0 liter disk)..

Mercedesben

Okay I stand corrected about the clutch it works great! Just the rattle at idle is a little annoying at times. I thought you told me had something from the RS 4.0 in the clutch kit. Overall I'm really happy and if I want rattle stop I just push the clutch in.

Kevin

The 4.0 liter flywheel is roughly 2.8 lbs lighter than the 964 RS flywheel. The backside of the flywheel DME trigger teeth are machined (where the weight is taken from). The turbo engine does not need a lighter flywheel, it doesn't see the high RPM's as the GT3's.. Every other component from the Sachs 764 pressure plate, ring gear, T/O bearing, pilot bearing, guide tube, and bolts are the same in both kits. The other difference is the clutch disk. The 4.0 liter disk pricing has been out of reach till recently. The previous GT3 disk has be discontinued by Sachs. The new replacement disk is similar to the 4.0 disk. The organic/metal sintered lining is the same. However it is the sprung hub and springs that are different between the two clutch disks. This explanation is to help describe what is available with the factory 964 RS, 993RS 996GT3, 996GT2, 996 turbo and 997GT3, 3 and RS.. Cheers...

jumper5836

Great info Kevin

powdrhound

There is basically zero noise with the 4.0 disc combined with the 964RS flywheel and 999.764PP. You can only hear some rattle when the A/C is on when the gearbox is hot. Otherwise it's quiet. Great clutch

Kinesis 996

curious usually how many % is the drive train loss?

Kevinmacd

Think rule of thumb is 15%

powdrhound

We are going to dyno my car (Rturbo with recently added Kevin's k16/997GT2 ZC turbos, injectors, and ECU) my friends stock k16 996tt with just Kevin's flash, and a friends 997TT with an EVOMS flash/Europipe. The plan is for us to do it on the same dyno, day, and time to get a good apples to apples comparison. I'll post up the numbers.

996tnz

Super stuff - look forward to the results. Bonus points awarded for advising what fuel they ran, and whether manual or tip.

Do you have any Gtech/ dynolicious/ Vbox or dragstrip performance figures on your Rturbo? Very nice car BTW - one of the few I'd swap mine for as a daily driver. Is yours wide or narrow, 2WD or AWD?

That said, I'm well satisfied with my UMW K16 car already. Most high hp cars have trouble getting within 0.2 to 0.5 sec of their paper performance specs on our coarse chip roads here in New Zealand, as magazine tests confirm. With Veyrons, Enzos, F1s and late model Zondas etc light on the ground it is really only 991 Turbos, perhaps the very latest GTRs, a few other tuned or limited edition exotics, and a handful of heavily modified japanese cars I'm otherwise likely to meet that might be noticeably faster in real life - though not as daily drivable. The only stock car I've ever actually seen out on the road here that I thought would be significantly quicker than mine to 60mph/100kph was a McLaren MP4/12C - if the rear wheel drive doesn't hamper grip on our chipseal. With much of the performance world now turning to turbocharged AWDs things will likely heat up soon (but thanks again for the fast ride Kevin).

Looking forward to seeing those dyno runs, Powdrhound.

996tnz

Sorry, just saw your comprehensive signature has you down as 2WD. About the only thing missing is the wide/narrow body spec. Won't affect the dyno of course but potentially the 60-130 and particularly beyond those speeds - standing km/mile etc.

powdrhound

I've never had my car to a drag strip and never done any a box data. All 3 cars are manual and running 91 tunes. My car is a wide body. Kevin is still in the process of fine tuning the programming for my application. At the track we run a 50/50 mix of 91/100 fuel for better margins. The stock 996tt with UMW tune has run a 2:12, the 997tt Evoms car a 2:06, and my car a 1:57. I am on Nitto NT01s, the other cars on street tires. With regards to engine output, comparing lap times is meaningless since you are dealing with different cars, drivers, etc. My lap times right now are identical to what I ran with my RUF turbos / UCU but the UMW power delivery is totally linear just like a normally aspirated motor which makes throttle modulation mid corner a breeze. Really works beautifully. Power ramps up so smoothly and progressively that it almost makes the car feel slower because you don't have that strong shove in your back right around 4K or so. That was a lot of fun on the street but not so much mid turn in a high G corner. Kevin has my tune set pretty conservative because I'm on stock internals but we have room to open it up once I rebuild at the end of this season as I'll be at close to 100 track hours on the motor at that point. The beauty of Kevin's programming is the fact that you don't just get a canned tune but rather the option to have your tune tailored to your application based on your catalogs. It goes without saying, Kevin's after sale support has been superb.

I ran my car at the track last year against a McLaren MP4C and both cars were dead even at the end of the straightaway at our track at about 145mph. This was with my old RUF K24hybrids. I could out brake the McLaren though and had about 2 seconds per lap on him. I rode as a passenger in the McLaren and it was a very very sweet car. Almost video game like with its torque vectoring and all the computers working behind the scenes.. I recently ran with a 991TTS. It was surprisingly slow. That car puts down great numbers on paper but that is clearly due to launch control and the PDK box. Once moving its a bit of a pig. Same goes for a GTR, it's a heavy pig and you just can't get around the laws of physics.

996tnz

Thanks for sharing. Track is a better indication of allround ability anyway. The Nittos are only probably worth about 4s or so I'd think, leaving power and suspension (and weight?) to make up most of balance.

Great feedback. I've run my UMW tune on track and closed road courses and love it too - though I'm still re-adjusting my track braking to match the upgraded speeds.

Interested to see what you'll do in there. Are you going as far as adding additional oil squirters and pickups?

Nice info thanks and a lot of fun I'll bet. It still blows me away how well our 15 year old design runs against newer gear once breathed upon, and you must be pedalling it well too.

Advanced torque vectoring/proper launch control and PDK together look to be worth something like 0.3 to 0.5s in the 0-60mph stakes at high hp. Similar systems in the original R35 GTR helped it bat above its league on that metric before getting a bit wheezy. Even so, one from an update or two back with a 3.6 sec paper 0-100kph could only be made to run a 4.1 on our chipseal by NZ Autocar magazine - a figure mine typically shades out on the same surface with lesser tires (only done 3 metered runs but gone sub 4 to 100). Even racing on track - while still stock - the two times I lined up on P2 against a pole 2008 GTR I made turn 1 first so I don't really have faith in some manufacturer's figures.

Any downside to your Guards diff on the street? Extra maintenance requirements? It's one weakness I wouldn't mind addressing still.

powdrhound

Nittos are worth about 2 seconds over street tires at our track. Hoosiers or slicks another 2 seconds quicker than Nittos. As far as the rebuild, it' s not going to be anything crazy. I already have a GT3RSR crankshaft and oil pump that will go in along with Carillo rods and probably Mahle 3.8 pistons/liners. Maybe some head work to see if we can get the engine to savely rev up to 7500 or so. That's about it. The Guard diff has been flawless. Zero noise, zero issues. It just plain works. RUF used to get their diffs from Guard until 2005 when they switched to Porsche Motorsport diffs.

I've been real happy with how the engine has been runnning with Kevins Turbo package. No issues whatsoever. Obviously part of the UMW package is Kevin's superb after sale 24/7 support which is second to none and hard to put a value on. Many people don't realize that. The rest of the car is pretty much dialed in. My near term changes are a swap out of springs on my suspension next week and then a 997 GT3 vacuum pump retrofit on the engine along with a Motec or Aim datalogger wired into the car in the next month or so.