Tissot Porsche Rebuild


Stutt9art VIP
Cars owned: Multiple Porsches

Took this car in late 2017 and it has been back to the customer during 2018 but is being released this afternoon in final form in terms of the engine power.

The engine was built and tuned by someone else originally. The plan was to move the car to full latest Motec set up and maximise the power we could get, but providing safety in terms of protecting the engine.

Unfortunately, although in a good way in the end, it had quite a major engine oil leak as well as gearbox leaking etc. The car seemed to drive okay but had a lot of poor fueling on overrun and idle, didn't drive well on inclines and so on. We ended up stripping the engine down and making some revisions, fixing the oil leaks and so on.

Car felt quick but not what you would have expected. Unfortunately when it became clear that something was wrong with the Throttle bodies (TBs). The basic check you always do before tuning a car, is to make sure that when you put your foot 100% down, that the TBs are open 100%. Clearly that had not been done in the past, and when measured even at 100% pedal, TBs only opened 70%. So rebuilt the TBs and all the linkages only to find that the butterflies had been drilled (presumably to try and correct the idling) so replaced those as well. Tuning a car with the TBs opening only 70% is not exactly good practice.

Engine is essentially 3.6L with TB and different cams, valves etc. We have done full sensor implementation - for example you cannot rev the engine passed 3000rpm until oil temp is at a preset level and so on.

The owner took the car away some months ago (it made around 290whp) at that time which is pretty impressive but always seemed to be great some times and poor in others.

So here is where latest ECUs come in. With full diagnosis, we were able to identify an O2 sensor on one bank slightly out of range, a Throttle Position Sensor (original) that again was giving erratic voltages under certain loads. Once those replaced, when back to tuning and the car is a different animal - lots more power under the curve and a peak of 306whp. Given the transmission loss on the g50 box, certainly up the top rpm it will be close to 350ps (345hp). Won't be far away for sure.

The benefits of installing modern ECU like Motec is the ability to maximise return on engine builds whilst be able to protect engines better. Tuning engines which are a mixture of cams, intakes, compression ratios is so much easier (difficult to do on old ecu). The downside is the cost - approx 7k-10k for full installation, hardware tuning etc, but then again better than blowing an expensive engine.



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Tell this 'owner' his car is pretty f'ing awesome. I guess he's not a regular on here then? ;-)
Good work - car looks mega!

How are you with MFI / High Butterflies / nasty cams?
Good work - car looks mega!

How are you with MFI / High Butterflies / nasty cams?
everything covered now - have a guy with 25 years experience and with our diagnostic we have made great strides - could not have said that two years ago on the old cars with different sets up but would say 25% of traffic is pre 89.

Just stripped 2.2 for full build this week. have a queue now which is good.
No pressure on this engine today for first starting for customer - just base motec tune to get running - complete new engine after it has been blown because of poor tuning and no sensors to protect. Bored out now to 3.55l. AT high rise stacks , trick cams, lw rods, 9e pistons (high compression) , etc etc. Has complete custom fuel system by us , and then even has coils on each plug for full control.

This will sound and perform amazing once run in

Tell this 'owner' his car is pretty f'ing awesome. I guess he's not a regular on here then? ;-)

This belongs to the chap who brings multiple cars to your track days.
I’ve driven it a bit, can recommend ear defenders especially on the motorway 🤣