Upgrading 1989 Porsche 930 RUF BTR Conversion

[donau]

Originally Posted by bmwrules

I'm looking forward to seeing the dyno report after all this work is done.

Thanks, same here. I will need to change my turbo again unfortunately since the one I have should be good only to about 550hp.

I will do the breaking in of the engine with the old turbo though. Just in case there's any loose stuff going thru...rather mess up the old one than a new one.
This time I will probably go with one of those ball bearing Garrett GT35Rs.

Glad to hear that the op went well and since you are posting again I am assuming that you are well on your way to getting back to normal

[bmwrules]

Originally Posted by donau

Glad to hear that the op went well and since you are posting again I am assuming that you are well on your way to getting back to normal

Thanks.

[donau]

OK, it's been a while since my last update so here's what's been happening since my last update:

Twin Plugging Work in Progress



In the process of porting to 42mm



Cams new (GT2 Evo) and old (Group B)




Engine with cylinders back on:


engine with 3.2 intake sitting on it - injectors: 72lb/hr Siemens - after this picture taken, the throttle body was rotated 180 degrees. Also the 3.2 intake just sitting there for the picture, they were short of a couple of spacers that were supposed to arrive this morning.



Turbo: Limit Engineering version of Garret GT3571 (oil cooled only)
This is one of those custom turbos that you can't really get much information on, but I do know something, although very little. We measured the
Turbine exducer and it was 64mm. I'm guessing the inducer would be about 74mm which would match approximately some P trim wheels. The "claim" is though that this is a clipped Q trim wheel. Apparently this is what my builder was told. They've had a business relationship working at races going back lots of years. The compressor inducer measured 62.66mm. The stamps on the housings show Compressor A/R of 0.70 and Turbine A/R of 0.82 although I was told a different number for the turbine A/R. So, bottom line: quite confusing and secretive but as long as it delivers as they say I should be happy.



GUARD TBD - I'm pretty excited about this one - TBD because my car is and will remain mainly a street car. The racers always get the LSDs.



And then best of all, M48 with continuous data logging and Advanced analysis options



I am cautiously optimistic about possibly getting my car back by the end of April. This is because the next race is a month away. Race builds and race support is their bread and butter work, therefore everything else always waits when there is a race coming up.

[bmwrules]

That sounds very exciting. I'm looking forward to going for a ride once it is all put back together.

[donau]

Here's a few more pictures of the later stage of finishing the rebuild.

Coils are on:



Odds and ends like throttle linkage and distributor wheel are in:



engine+transmission about to go back in the car:

[donau]

To conclude this phase of the thread, I had the car back for a week or so and my expectations were exceeded.

The car feels confident, aggressive and drivable. I even don't mind taking it into the heavier stop and go traffic. Naturally all the positive ingredients of the 930 rawness are still intact like the steering and breaking.

I was only doing engine break-in kind of driving with the boost set to 0.6 bar. That actually feels quite sufficient for the driving conditions that I have here. But I will turn it up to 0.8 once Speedwerks has finished with the additional tuning based on the data that was logged during the 675 miles that I drove the car.

There have been several initial pulls showing somewhat varying results, presumably due to the initial tuning process going on. The best 0.8 pull that I saw was 531rwhp which is the number I was targeting, only at about 1.0-1.1 bar, so that is why my expectations were exceeded. There was another pull that was done a notch higher that produced this graph:



I must hasten to add though that by increasing boost here will not get me any higher - maybe 10 - 15 hp, but that's about it. The reason is that my throttle body starts choking at these power levels. So, even though the boost may have been 0.9 here, 1.1 or 1.2 would not have gotten me any higher. In fact I have other charts where higher boost levels were used and the hp results were about 12 hp less than in the graph above, although the torque levels went up to 550rw lb-ft.

So, a few points: only initial tuning done so far, hitting the limit probably at around 550rwhp/550rwtq, car feels great to drive, very torquey. I am extremely happy about the EFI conversion. Best thing I've done to this car so far. That is until the following:

I have purchased two 6 speed transmissions from a member of the Rennlist board. The 6 speeds are a G64/51 that is the transmission used in the 993TT cars, and a sequential 6 speed that started out its' life as a G50/80 (993GT2Evo transmission) and was later modified by a company called GT Ltd which is now a part of the Ricardo organization. Here's a couple of pictures (taken at Speedwerks) of the sequential with the GT2 axles, the sports clutch assembly (the flywheel is a lightweight single mass fw) and the shifter:




I had planned on installing the sequential at this time but changed my mind about a week ago. I will have the 993TT transmission installed and will save the 6 speed sequential for a track project later on.
I will utilize the LWFW/Sports Clutch though.

Once the final tuning has been done and the 6-speed installed I may post again for updated numbers and driving impressions. But for now, the initial numbers using the chart above and converted to crank horsepower and torque by dividing by the factor of 0.85 (15% loss) are approximately 644hp/612lb-ft (or 830Nm)

[bmwrules]

That looks very exciting. I'm looking forward to taking a ride in it sometime.

[Bruce]

Interesting stuff, Olli. Thanks for the update.

I had no idea you'd end up getting so much power out of you're 930.

[donau]

Thanks guys!

The 930's are probably one of the easiest 911 Turbo cars to increase power. There's a guy on Rennlist whose 930 produces 844 crank hp. One of the Speedwerks co-owners has a 930 that's close to 800 hp and I have seen other dyno charts of 930's that are in the 800-900hp range.

What I have now will be plenty and I am in no hurry to do further modifications to get an extra 100-200 hp, but I do know how to get it done:
bigger throttle body, 95lb injectors (I've got 72lb now), twin turbos and a more efficient IC. In other words the engine would not even have to come out.

[bmwrules]

Do you know how much your car weighs? You're in Enzo territory for horsepower. I know that Enzo weighs around 3000 pounds but I'm pretty sure your car weighs less than that.