Upgrading 1989 Porsche 930 RUF BTR Conversion

[Bruce]

I had an oil change done to my car and once I got my car back the compression was gone and the car drove poorly. I do not want to PUBLICLY express my suspicions as to what happened so let's just take it from here.

That doesn't sound to good... and I would imagine this whole operation isn't too good on your pockets either..

Anyways..thanks for the update Hope all goes well

 

[donau]

That's a lot of good work being done there. I know you haven't felt comfortable using all that power the car has. I can't remember, was it somewhere between 450hp - 500hp? Now with this engine rebuild you should feel comfortable putting the hammer down. I hope you get a chance to take it to Virginia International Raceway and get some good laps put down.

The good news is I'll get the same power with a lot less boost After this work I will be looking forward to some time at VIR. For dialing some more power, I think I'll do the EFI conversion first to be safe on getting enough fuel always at the right times. The CIS system has its' limitations.

 

[donau]

Sad about the sudden failure and I hope David does a good work with rebuilding the engine.

Thanks Luwalira! I have a good feeling about
his work knowing a little about their racing successes, and a some about his background in the racing and engine building world

 

[donau]

That doesn't sound to good... and I would imagine this whole operation isn't too good on your pockets either..

Anyways..thanks for the update Hope all goes well

Thanks Bruce! Yeah, it would have been nice to use this money for the EFI conversion (Motec M48 would be about $8,000). Since I am giving my old crank as a trade in for the new one, the parts cost is only around ~$4,000 (which is what I paid already). I guess the labor would be another ~4,000.

Of course then it's again a totally different story price-wise if I give in to all kinds of temptations and want the M600 instead of M48.

 

[Bruce]

Thanks Bruce! Yeah, it would have been nice to use this money for the EFI conversion. Since I am giving my old crank as a trade in for the new one, the parts cost is only around ~$4,000. I guess the labor would be another ~4,000.

Ouch


btw, Olli, have a great Christmas & happy new year

 

[donau]

Ouch


btw, Olli, have a great Christmas & happy new year

Thanks Bruce and Merry Christmas and a Happy New Year to you too

BTW a little OT: Congratulations on your statistics on this forum, they are simply mind boggling.

 

[donau]

That's a lot of good work being done there. I know you haven't felt comfortable using all that power the car has. I can't remember, was it somewhere between 450hp - 500hp? Now with this engine rebuild you should feel comfortable putting the hammer down......

Just gave SpeedWerks the go ahead with the Motec EFI conversion, starting with M48 and will see in the future if upgrades to M600 necessary, or desirable.

So, regarding your comment about power: Yes, I should feel comfortable taking the car to the limits from the perspective of the engine holding up. But from the perspective of staying alive, we'll have to see, especially now that there will be a lot more power too.

 

[donau]

Parts are starting to arrive. Here are the cranks side by side. The left one is the new 3.6 RS crank that has 2mm extra length from the center of the shaft to the center of the journal. Hence the 2mm longer stroke.

You can also see that the throws/counterbalances to which the journals are attached to are much smaller on the new one (next pic). This accounts for approximately 6-7 lb weight reduction compared to the old (2nd pic below). Hence less effort required to turn this thing around. Please also note how some of the throws/counterbalances have grinding clearly visible for perfect balance.

Carrillo Rods:

The Carrillos are an H-Beam design while the old turbo rod is an I-Beam design. The weak point in the old turbo rod obviously the narrow part at the top. The next two pictures show the difference:

In the next picture the Carrillo Rod bolt is the one closer to the rod in the picture and the regular turbo rod bolt is the longer bolt. I don't know how clear it is from the picture but the old turbo rod bolt just gets pushed through the whole and there is a little bit of thread at the end for a nut to lock it in. The Carrillo rod bolt is threaded into the whole and no nut needed.

Oh yeah, and those are my shoes at the bottom too....

The GT2 Evo cams should arrive next week. Also, the machining of the cylinder heads for 41.3 mm has been done.

Since my previous posts I have also decided that twinplugging should be done at this time while everything is out. That will be done.

Originally I thought of saving some money and not do that since the Mahle piston tops are flat and the cylinder head is hemi. In theory one spark should be just fine. But upon further research into this I have discovered that having two sparks will decrease the chances of detonation and driving with 93 octane street gas becomes a less risky thing to do. Not to mention that it does improve performance as well somewhat.

I don't remember if I mentioned this but now with the Motec M48 sequential EFI, I will also do away with distributors and use Motec supplied Denso coils (MDEN-580) on the plugs.

 

[Bruce]

Nice update Olli.

Hope all goes as planned

 

[bmwrules]

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

 

[donau]

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]

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.