2001 Porsche 996 LS1 Conversion Thread by 1dirtyZ

6 minute(s) of a 276 minute read

thanks buddy ,


well I got it all wired up and done , the car works great and I started messing with tuning it while I'm driving it around. there is one small issue that is giving me a hard time ; the car has a very hard lean stumble a hair of idle . if you lightly touch the gas pedal ( about 1% throttle) the car will go super lean according to the scanner and the rpm will actually drop just before dying. this is making the car a bit hard to drive from a stand still.
I tried everything in the software to correct this but there is no change , so this is leading my to the next possible culprit ; a faulty map sensor or O2 sensor. reason I say that is because the map sensor is old plus it reads off the log manifold I have ( I tried changing where it reads) ,,,, and the wideband I installed on the Porsche is just as old and is off my Camaro ,,,, which is old and abused

so to address this I will swap the NTK sensor I have on there today to a bosch new unit , and I already ordered a zr1 3 bar map so I can install it in the original location next to the throttle body .

other than that the car pulls hard and hooks good ,,,, right now its just under 8 psi of boost , i plan on raising that back to the 18 psi soon and see how much the new tires will like that

plus there is a test and tune session this Friday at the local track , and i plan on attending it to see how it does

wish me luck !

7-12-2016

quick update ,

I swapped the map sensor to a ZR1 map sensor and it seems to have done the job.
I drove the car to the shop and it seems to drive fine and the dead spot just at tip in seems to be all but gone.

I still need to redo the vacuum lines and properly position the sensor , but so far it seems ok.

9-17-2016

well i'm finally back home

I did get the bushings in the car a while back and did a four wheel alignment and the car drives and tracks sooo much better now.

here is how the old bushings looked like :

and this is how it looks after they were installed :



and i guess this explains why the car was all over the place :



i also swapped out all the valve seals to see if it would help with slight smoke i get every now and then.

and since the last time i dynoed the car there has been two issues that have been giving me a hard time; the first one is an issue with the boost reading of this thing; on the dyno it made something around 18 psi on the wastegate actuators it had on it ,,, which did not make sense at the time but i was happy so i didn't care

after a while the car stopped making the 18 psi like on the dyno and now would not go past 8 psi . i tried adding preload tot he waste gate actuators to try to eek out a few more psi but no luck. so i assumed there was something wrong with the actuators before and then they got to work properly later since they were rated to 8 psi. i did check all the wastegate lines and everything was in order. so got a new pair of wastegate actuators that are the 17-18 psi version and just installed them to see if they fix the boost issue .


the other issue i was getting was a missfire under WOT after 4500 rpm where the carwould buck violently under WOT . i tried swapping plugs from TR8 to TR6 , swapped plug wires , and coils with new ones but with no luck.

so i took the car out this weekend to a local race spot , and did a few passes to see if i fixed anything ,,, and oddly the bost is still at 8 psi ( and since i did nothing to the missfire it was still there )

the logs show that the boost hits 8 psi and flattens out , and you can see the AFR spikes when the missfires happen . the fuel pressure is rising with boost and holding steady for the most part.

i'm not really sure why this is happening , but i think there might be one of two possible reasons ; the first being that the air filters are restricting the air going into the turbos , and the other is that the BOV's i'm using are opening under boost .

as for the misfire ,,,,, i'm still scratching my head ,,, i'll try a new set of coils to see if that helps . i'll aso see if i can clean the filters to see if it makes any difference , or maybe run the car without them or install a better set.


other than that , i'm taking the car to have the AC carged so i can have a nice cold AC ( just in time for winter )