BMW K1200RS - Possible supercharger conversion
Turbo Mini Forums

This is mine. I'd do it slightly differently next time round though.

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Just as a thought, will short runners hurt the Rpm potential of these engines, or is that mainly dictated by turbo choice and cams.

I'm planning on using a Jim style one.

Edited by nky_84 on 29th Jan, 2014.

not very clear, but check page 2 here

http://www.turbominis.co.uk/forums/index.p...tid=10176&fr=50

page 6 onwards...

http://www.turbominis.co.uk/forums/index.p...d=169346&fr=125

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=199607

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=228651

http://www.turbominis.co.uk/forums/index.php?p=vt&tid=488368

That manifold I made 5-6 years ago I've now remade, I'll dig out some photos of the new manifold I made

Edited by Jimster on 29th Jan, 2014.

Team www.sheepspeed.com Racing

Joe -No combination of 16v and turbo variations managed to uncover those specific threads, so thanks very much!!

Jimster - that would be great to see.

Have ordered new shells and thrust washers for the winter refresh (clutch had absolutely destroyed the thrust washer, so looks like i'll be replacing that on a fairly regular basis next season..). Once thats built back up, i can position the engine and properly work out whats going where etc.

One thing i'm a bit concverned about is how to secure the turbo, other than relying on just the manifold. I'm going to be some way away from the block, so is causing me some headaches just now...

A few updates. Have cut and welded the manifold (just need to cut down to size. Wedling is not pretty, but is plenty strong i hope!



Have also fabricated the downpipe using Saab elbow and some SS bends.



Next task is to split the pistons and rods and go about increasing the dish to get compression down. Then work out dumpvalve, plenum, intercooler pipework and finally rebuild the engine!

Looking good.

Bit more progress today. Manifold cut to size, flanges attached and bolted up to the head, it fits!
Also, Weber box chopped out and extended for cold air box. No going back now!

Nice. I was wondering how you where going to clear the master cylinders with the inlet hose...

Bit more progress last week. Intercooler secured, pipework sorted and turbo plumbed in. Exhaust fabrication finished and fitted. Radiator fitted and plumbed in. DIY plenum made and fitted (still to be determined if this will hold much boost, but should get me up and running at least.



Started it at the weekend on the old NA map and it idles really nicely, but with the boost pipe disconnected (NA mode) its very stuttery through the rev range, which im guessing is due to differences in inlet, airtemp/map sensor and exhaust manifold back pressures?!

Have bought some 440cc injectors, so once they arrive, i'll get them fitted and hook up the turbo and see if i can play around with a turbo base map to get it running. Once im happy with that, will plumb in an N75 to up the boost and get it on the rolling road.

I'm running RS cams on 2.4m lift as per specialist components book, i've heard its better to drop the lift a few mm for turbos, anyone have any views on that?

Finally, anyone see anything drastically wrong with the above plan or in the pic?

Nearly there i hope!!!

Cheers,
Nick

Edited by nky_84 on 7th Apr, 2014.

see how it drives. if you want it to come on cam earlier drop a set of lt cams in there. what turbo is it?

yeah, not being road legal, i dont like taking out round the block very often, but i dont have much choice! Its a GT1752. Are LT cams readily available? Whats the going rate and are they a straight swap for RS?

I dont think it will be off cam very long with the 4.5 diff fitted!!

Most of the cams were of the LT variety, so are easy to come by. RS ones are a bit more scarce.

Any chance of a video of it at idle? must sound quite nice with the large cams in.

yup. will pop into the garage after work tomorrow and take a quick vid.

It idles about 1600rpm when its cold.

After that vid, i swapped in the 440cc injectors and a turbo base map and it started ok but only idled about 900rpm and was very lumpy! Will scale the sensors etc at wknd and connect the lamda, which should get me up and running and and able to test with turbo hooked up.

Small update. Took the car to the rolling road today and to cut a very long saga/ story short it made 137bhp at 0.4bar and 170bhp at 0.6bar. It went and died on us just before things were about to get interesting and the boost upped!!

Car was running perfectly up until It cut out mid way through a power run with no warning. It wouldnt start after that so we called it a day.

Lots of progress and shown glimmers of the time and effort all being worthwhile!!

Back to the drawing board as to why it died and why it now wont start but I dont think its mechanical failure.

There some very healthy figures. Any graphs? Curious about where max power occurred then tailed off.

Edited by minimole23 on 25th Apr, 2014.

well that promising numbers,

fingers crossed that the issue is nothing too serious.

Only got one graph pic. Will post in morning. Will try to dig out the na graph too. Huge increase in low down grunt I think.

Plan to get some decent ones when I go back for final map.

It made the 170 at 6500 iirc too. Will be pushing it to 7500 if its still making power then.

with those cams it should make power to 8k

yeah, it regularly went over 8k in NA mode, just need to find out if its worth doing that on the turbo side of things. It only went up to 7500 once on the rollers. Its amazing how much more mechanical sympathy you have when you are not inside car and chasing a laptime!

On the rollers:


NA Printout:



Turbo printout of run when it died:


Was a shame as i think it was well on its way to smashing the previous best of 170. Notice the boost did something pretty odd when it died. i'm hoping its something simple like a fuse but should hopefully find out today.

what did the boost do?

when i bent an exhaust valve the boost went all fluttery,

Boost is in the graph, secondary axis.

Compression test;
1-130psi
2-130psi
3-160psi
4-160psi

Would a blown head gasket achieve 130psi? Would it also prevent it starting at all?
Going to whip the head off as ive checked everything else I can think of

hmm, I would say there would need to be a lot less compression than that to cause it not to start due to a gasket.

could the belt have jumped a tooth? without looking into it I dont know, but could that skew the valve tining on the cylinders so two gain compression and two lose it...