1150 EF updating project

[Blower]

I change the plenum today and redegreeing the cams. Cams are now: in 18.5/59, ex 64/17.
After testride I check the spark plugs, #1 & #4 was light gray and #2 & #3 was light brown.
In steady speed it was better, but there was still some "jumping" between 2500 -3000 rpm. Engine pulls stronger, than before.
I try to get that problem zone better with fine tuning the efi ignition and fuel map.

[Blower]

Will you please just put BOTH the intake cam & exhaust cam in at 108 lobe centers! I GUARANTEE you will see improvement! Stop spreading the cams apart on a forced induction system. Ray.

The most of the supercharger cam specs I have found from different manufacturers have a 112 - 117 lsa.
If that plenum modification help or not to get the engine running smoothly in steady speed, I´m going to try that 108 lobe center. One "turbo guru" say: 110/110 would be good for forced induction.
It would be interested to know if anyone have ever made a real superchrager cams for GS 1100 or 1150 engine and the cam specs...

[rapidray]

I´we got cams now: in 15/61, ex 55/19. I´m going to try next: in 18/58, ex 64/10.
If that does not help, I need to made a new different shape plenum.

I try to look that link, but it does not work.

Will you please just put BOTH the intake cam & exhaust cam in at 108 lobe centers! I GUARANTEE you will see improvement! Stop spreading the cams apart on a forced induction system. Ray.

[Blower]

I start to make a new plenum. I redegreed the cams, but no help for the problem.

The new plenum is a WRC-type:

[Blower]

I didn't realise that the MR2 link is no longer active. That's a shame, as there was some good info on that site. I thought that I had saved that info, but somehow I overlooked doing that.

Do you mean that you have tried the 15/61-55/19 cams and you are still experiencing that surging effect when cruising? If that's so, then your plenum pressures must be causing your problems.

There's a school of thought that recommends fitting a turbine type SC instead of the gear positive pressure blower that you have chosen. Their logic is that you run stock NA cams and compressions so that the bottom end performance (up to 3000 rpm) mimics stock figures. From then on, the turbine takes affect, and you get the type of grunt you get from a turbo, but without the heat issues, or bottom end lag. The other advantages of this system are that you don't blow unburnt gases straight through the cylinder at lower rpm and the boost keeps rising with rpm increase, just as a turbine should!!

I can give you some more info on turbine type SC's if you decide to take that option.

Yes, I have now Yoshi stage 1 cams installed in15/61- ex55/19.
First thing I´m going to do is put a "damper" in the map sensor hose.
If that does not "smooth down" the problem zone, then the cam re degreeing and then a new plenum.

A centrifugal supercharger would be easier to tune, but I have chosen this "stone age" roots-type supercharger and going to try to live with it.
Maybe my next bike would be with centrifugal sc or turbo.

[49er]

I´we got cams now: in 15/61, ex 55/19. I´m going to try next: in 18/58, ex 64/10.
If that does not help, I need to made a new different shape plenum.

I try to look that link, but it does not work.

I didn't realise that the MR2 link is no longer active. That's a shame, as there was some good info on that site. I thought that I had saved that info, but somehow I overlooked doing that.

Do you mean that you have tried the 15/61-55/19 cams and you are still experiencing that surging effect when cruising? If that's so, then your plenum pressures must be causing your problems.

There's a school of thought that recommends fitting a turbine type SC instead of the gear positive pressure blower that you have chosen. Their logic is that you run stock NA cams and compressions so that the bottom end performance (up to 3000 rpm) mimics stock figures. From then on, the turbine takes affect, and you get the type of grunt you get from a turbo, but without the heat issues, or bottom end lag. The other advantages of this system are that you don't blow unburnt gases straight through the cylinder at lower rpm and the boost keeps rising with rpm increase, just as a turbine should!!

I can give you some more info on turbine type SC's if you decide to take that option.

[Blower]

I still believe that you have far too much valve overlap for a road going supercharged machine. You also did some pretty radical inlet porting from memory, which will be causing inlet pulses at lower flow rates. Usually a good seat radius job and some minor port reshaping is all that's required for SC mods.
SC Cams usually include a higher lift for the exhaust over stock.

Check out that supercharged cam timing link I gave you earlier on in this post.
You will notice that the overlaps are a lot less than what you are running at present.
Some of your problems could also be associated with the plenum design.

I´we got cams now: in 15/61, ex 55/19. I´m going to try next: in 18/58, ex 64/10.
If that does not help, I need to made a new different shape plenum.

I try to look that link, but it does not work.

[49er]

I have continued the EFI tuning, but it seems to be impossible to get it running good between 2000 and 3500 rpm in steady speed on highway riding.
Under a light acceleration it runs fine and under boost it really goes.
I check the spark plugs after a slow highway riding (2000 - 3500 rpm) and #1 & #2 was a light brown, #3 was black and #4 was light gray.
I have changed the injectors, the spark plugs and the spark plug cables, but no help.
It seems that there are some starange suction impulses in the plenum.

Next thing is to change the cam timing.

I still believe that you have far too much valve overlap for a road going supercharged machine. You also did some pretty radical inlet porting from memory, which will be causing inlet pulses at lower flow rates. Usually a good seat radius job and some minor port reshaping is all that's required for SC mods.
SC Cams usually include a higher lift for the exhaust over stock.

Check out that supercharged cam timing link I gave you earlier on in this post.
You will notice that the overlaps are a lot less than what you are running at present.
Some of your problems could also be associated with the plenum design.

wow

all i can say is right on man.... now thats how to make power!!!!
keep the photos coming im watching and saving cash right now....
got to have one.

[Blower]

I have continued the EFI tuning, but it seems to be impossible to get it running good between 2000 and 3500 rpm in steady speed on highway riding.
Under a light acceleration it runs fine and under boost it really goes.
I check the spark plugs after a slow highway riding (2000 - 3500 rpm) and #1 & #2 was a light brown, #3 was black and #4 was light gray.
I have changed the injectors, the spark plugs and the spark plug cables, but no help.
It seems that there are some starange suction impulses in the plenum.

Next thing is to change the cam timing.

[Blower]

Is that a motorcycle letterbox in the background??

Yes, it´s made from old russian IC.

[hillsy]

Is that a motorcycle letterbox in the background??

Blower,
I disagree with your assessment of the aluminum fairing. "Good enough" isn't quite 'good enough'...I think that fairing really caps off the silver/black theme that you have going on with this bike. Great fairing. Don't see one of them at the Sonic every Friday night.
-KR

that is one breathtaking machine

That is one sweeeeeet looking machine ! Cheers !