I just installed a Sachs 2.5 Clutch and a LW FW(Stock was toast). Im trying to get the hang of the LW FW still. Very Different! New Clutch grabs really good. Boosting it in 6th gear the car does not slip like before. But In 3rd-4th-5th it starts Shuttering Real bad after about 4,000 rpm. Its almost that if I am running with a tank of 87 Octane. Could it be a bad/faulty tune? I am thinking that it hasnt switched back to regular 93 Octance, since the last tank of 110. I have heard about the car going into Limp Mode after 4k rpm. Is this true?

More History about my car: (Tubi Race Exhuast, Evo600 tune): I ran 110 Leaded in it about a year ago at the track. The problems of the car shuttering/slipping almost tend to overlap after I fuel up with 110. Could I have ruined my plugs & O2 sensors from the leaded fuel???? Or Do I just need to get the car out of Limp mode? Before I installed the clutch the shop scanned it and No CEL or faults were found.

 

it should take significantly less than 50 miles of driving for the car to adapt from 110 octane back to 93.

it could very well be sparkplugs or coilpacks.

you should also clean off your MAF sensors, i cleaned mine and the car was much smoother after.

 

If you ran leaded fuel at the track, then your O2 sensors is a good place to start looking for problems.

 

Where are the MAF sensors located?

 

is that shuttering feeling you get perhaps the PTM cutting in? Try with PSM off.
I have a LWFW ,764PP and sprung clutch combo on mine and it is great.

 

Thanks for the help. I will try with PSM off. But I know for sure im not lossing traction. I have been in a situation where PTM kicks in and its a instant cut in fuel, not the same sound/shuttering im having now.

With your LWFW do you get a high pitch chatter in low rpm's? for Example: 6th gear about 1,500-1,800rpm. Just barely applying some throttle..If it makes sense.

 

I have had the PSM cut in when I really get on it in the higher gears, surprised the first few times it happened.
Felt like misfire/juddering, realized it was the PSM cutting in with PSM in standby it dosent happen.

If you mean rattle? in high gear very low speed yes

 

You have the flywheel turned? or replaced when you did the clutch?

If it was not turned or replaced it can shutter,

 

Also. Best to bed it in nice and easy for the first couple of hundred K's. If she aint bed in nice then that may be causing a judder.

 

This does not sound like a clutch issue. If you have a Durametric cable, post a datalog.

bob

 

at this point it isn't a clutch issue. LW FW & Sachs 2.5 is Brand New. I replaced the clutch becuase it was slipping at first then started shuttering/cutting out after a few weeks. It might have started acting up after I put in race fuel.

At this point that car is some form of a Guardian(limp) mode. Motor runs strong up 4k rpm(under full throttle/boosted). Once it passes 4k it starts cutting out and the while car starts jerking/shuttering. If I gradually take the rpms up to red line it will not happen, Only under a WOT run or heavily under boost past 4k rpms. As of right now I'm leaning on changing the plugs. But before I start throwing more money into it I was hoping if anyone has noticed or heard of any symptoms that are similar to mine. Thanks

 

Power cutting off under WOT. My vote is the plugs particularly in light of your tune.

 

leaded fuel cause sensors on the 997 to fail fast..

 

Lead fuel for sure hurt something...sensors, injectors, o2, fuel filter, don't remember exactly which one it gets quickly!

Ah your cats may be plugged or damaged!

 

+++1 all of the above(o2, MAFs, coil packs, plugs, and, sadly cats). Have indie shop use exhaust probe/wide band sensor. Leaded fuel WILL screw up any/all of these parts, or at least cause their early demise. LWFW may just be making the problem a bit more apparent, kind of like shaking hands with and without gloves on, if that makes any sense. Good luck.