Problems fitting K27 turbo

[Tom F2]

I posted this on Rennlist, but I would be curious whether any of the people who go to this board would have something to say:

I have finally got my 3.0 fully assembled, and I'm ready to put it in the car this weekend. Sort of.

The engine is stock, except '86 exhaust, Euro muffler, SC cams and the K27. I am writing this long post because I did not find the K27 to be a simple bolt on, and I am surprised that no one else seems to have mentioned it. I initially had trouble with the exhaust collector pipe(several posts here a couple of months back until I realized what the problem was), but that turned out to be a bent pipe that I purchased used. An undamaged pipe was located and installed, but the turbo bracket didn't line up. I cut and rewelded the turbo bracket, so the turbo was correctly supported on the exhaust flange and at the rear console. That took care of the hot side.

But the cold side inlet doesn't line up (the short hoses on the multiply bent pipe compensate to some degree, however, I feel that the offset at the turbo inlet will be a problem for air flow) and I had to relocate the holes in the rear shelf to get a neat fit on the cold side outlet.

None of this seems surprising, because the K27 is clearly wider than the LDZ it's replacing (unfortunately, I don't have my LDZ to place alongside my K27 for comparison, because this all started when UPS lost it), however, I'm surprised that there are no comments on any of the internet boards about the details needed to fit the K27. Do others shorten the steel pipe where it mates up against the cold side inlet? Is there some other trick? I can see that the very small distance between the engine mount bracket in the car and the cold side inlet pipe will be even smaller, when I finally install the engine.

Can anyone chime in with their own experience, please?

[PJMARKOW]

I don't know how relevant my experience is because I installed a K27 on my 1977 930 (3 litre turbo). Now I did have problems aligning everything, but a little rebending of the bracket that supports the turbo so that the GHL extracors lined up correctly and everything else was pretty spot on. The K27 is larger that the old turbo, but I just test mounted the rear tin work and with the extractors installed I could see pretty well where the turbo had to end up. When I finally installed it, I made sure the extractors where tight, then I loosely fitted the turbo, bracket and the connection to the headers. Then I gradually tightened everything up. Worked out pretty neat.

Cheers

[Tinker]

Paul,

Give us your thoughts / impressions of the K27 vs. the LDZ. Whick K27 did you purchase?

I also have a 77 and think my days on the stock turbo are numbered.

Tinker

[PJMARKOW]

I have the K27 High Flow. I t comes on about 2500 and then keeps pulling right through to 7000. Not as laggy as the old turbo.

Cheers

[rotorhead]

I have a K27 7200, boost comes on around 2700 doesn't hit as strong as the 3DLZ did at 3000 but pulls stronger through 4000 and dies off about 5500

[78P930]

Tom, I saw 930 that someone on a previous thread had ordered a bracket specifically for mounting a K27, although it was on a 3.3L. Part # 930 123 921 05.

PJ, Do you have a dyno sheet on your engine and what other modifications have you made? I have a K27-7200 with 0.9 bar spring and SC cams and it does exactly what Steve describes.

Pat

[john walker's workshop]

you bolt the turbo to it's flange and then figure out what you need to do to make everything else fit. welder, hacksaw, tinsnips, die grinder etc. normal K27 procedure.

[Tom F2]

John, as usual, you hit the nail on the head. The only thing you forgot was the cutoff wheel.

78P930, I take it that your car is running fine. My car is running well, now, under all conditions except idle and just off idle (the latter only when cold). I suspect a bad injector or two. The main problem I had debugging this car, after the learning experience on mounting the K27 was that it had a warm up regulator for a 3.3 Turbo. Luckily, it is not hard to readjust the WUR to match the control pressures for the 3.0. My modifications are SC cams, K27-7200, 86 exhaust and Euro muffler.

I hope to put it on a dyno after I change from the Castrol GTX 20W-50 that I'm using for break in, to an Amsoil TRO 20W-50.

I noticed that the opening pressure for the injectors went from 2.1 bar to 2.7 bar, going from the 3.0 to the later 3.3s. The only replacement seems to be the 2.7. Does anyone know whether this was an upgrade to cure a leaky injector problem, which is what seems to be happening to mine?

[Ken911]

a lot of people just chuck the turbo bracket , also with the inlet on the air side being different size you have to double hose the pipe side.

[john walker's workshop]

yeah, no bracket on my 3.0 turbo. the muffler support bracket seems to get the job done.