Im waiting to see this S&S cam. Also I think you have the cam spec wrong its 635 they don't make 535.
I don't see how this 635 cam is going to work it has (57d over lap) If we are taking about the same cam.
Thanks FD

 

Sorry Frank it was a type on my part that I thought I corrected. it's the 585 cam that was recommended but I don't see it as much than your cam. I'm not sure if Dave or Aerocharger chatted with you on this.

Thanks.

http://www.sscycle.com/tech-info/cam...and-cam-specs/

 

That's still an odd cam selection for a turbo. In the automotive industry, most turbo specific cams have very little overlap, late intake valve openings and have exhaust durations that are less or equal to the intake duration.

For example, here are the Specs for a Subaru Sti turbo race cam by Brian Crower..

Duration 234 / 234
Intake Opening 7 BTDC / 47 ABDC
Exhaust Opening 55 BBDC / 1ATDC
Overlap 8

Note, this is a race cam and it only has 234 deg duration. You have a turbo so don't get hung up on LONG duration. Usually (I'm sure there are exceptions) Turbos benefit from SHORTER exhaust duration compared to supercharged engines. It increases exhaust velocity and helps spool the turbo quicker.

Minimizing overlap is more important. Even with todays more efficient turbos, the exhaust back pressure is higher than the intake charge so excess overlap will/can result in reversion.

Not alot of harley cams out there that work well with turbos.

The Andrews 32 looks ok...

Duration 236/ 240
Intake Opening 10 BTDC / 46 ABDC
Exhaust Opening 52 BBDC / 8ATDC
Overlap 18

 

That Andrews 32 looks to be the same specs as the EV31 Blower cam they make. I run an EV31 in my old FXR and its got a nice smooth power delivery. The specs for that 585 cam do not smell right for a blower engine as it looks to have about 40 degrees overlap.

I tried an EV35 in the FXR turbo originally (its a high overlap cam) and man the bike took off like a two stroke over 3000rpm, but was flat low down.

 

OK, the work begins today. I am going to try the cam recommended by Aerocharger, if not perhaps one more crack with a cam with less overlap, if not, I'm going to remove it and go with a Procharger. My VE is pretty low so even the SC should give me better numbers with smoother power delivery than the charger. Let's see what happens and happy winter everyone.

 

What cam do they recommend?

 

They recommend the S&S 585 which I don't think is going to work. I was thinking Andrews TW32HG or TW31s. I think I can use the higher lift cams because of the engine mods and it still has similar overlap to the 31 which is way less than the cam I have now.

I'm open to hear thoughts.

If I can't get better efficiency I'll switch FI units to a different turbo or a pro charger.

 

I'm going to be switching out the turbo, it appears to be too small. I put a boost gauge on the exhaust header and it's running twice the pressure as the boost side. I've been told it should be equal or less.

I'm probably going to switch to the super charger. I'm concerned about the belt but it seems that a lot of folks are having good experience with them. I have a bit of time to think it over as I stare at the snow.

 

Frank has a used Procharger (complete set-up} sitting on a shelf that he just took off.There is nothing wrong with it.It just needs to be polished.You could probably pick it up for a good buck.

 

I'll check it out. I'd have to have it powder coated. Engine and primaries are black.

Thanks for the heads up.