Forced induction 100cc

[Flettner]

No problem.

[Sketchy_Racer]

That's right all 15psi of it, nice efficient cool boost. Intake air temp was 35 degrees in the plenum Ran bike for 20min, no boost loss, if anything it got better. Still no idea on shaft RPM

I knew I would get there eventually

Now the concept is proven it's time to make the real deal! with a proper oil pump and proper rollers.

Might try the larger housing and impeller next, see if I can get more than 20psi. And also try one more gear step up to get more boost at lower RPM. It makes 5psi at 3000RPM and 15psi at 5000RPM and holds 15psi to 8000RPM (didn't take revs past that)

Surge does not seem to be an issue even when flow is chocked off so running larger impellers than turbos is possible it seems as the blower is no reliant on exhaust vs intake pressure ratios.

So happy it works!

[koba]

That's right all 15psi of it, nice efficient cool boost. Intake air temp was 35 degrees in the plenum Ran bike for 20min, no boost loss, if anything it got better. Still no idea on shaft RPM

I knew I would get there eventually

Now the concept is proven it's time to make the real deal! with a proper oil pump and proper rollers.

Might try the larger housing and impeller next, see if I can get more than 20psi. And also try one more gear step up to get more boost at lower RPM. It makes 5psi at 3000RPM and 15psi at 5000RPM and holds 15psi to 8000RPM (didn't take revs past that)

Surge does not seem to be an issue even when flow is chocked off so running larger impellers than turbos is possible it seems as the blower is no reliant on exhaust vs intake pressure ratios.

So happy it works!

Brilliant!

Was this from changing the fit of the rollers?

[Sketchy_Racer]

Brilliant!

Was this from changing the fit of the rollers?

Yep, a complete re-design on the outer ring and it's interference on the rollers. Seems to have worked a treat. I will run it up on the dyno for a few loaded power runs on the weekend then pull the charger apart to check wear. In theory there should be none.

[koba]

Yep, a complete re-design on the outer ring and it's interference on the rollers. Seems to have worked a treat. I will run it up on the dyno for a few loaded power runs on the weekend then pull the charger apart to check wear. In theory there should be none.

Cool, keep us posted; this is really interesting.

[Yow Ling]

well done Sketchy, I would have hidden it in a secret place in the shed by now, maybe even earlier

[Ocean1]

Nice!

Where's the video?

[husaberg]

Yep, a complete re-design on the outer ring and it's interference on the rollers. Seems to have worked a treat. I will run it up on the dyno for a few loaded power runs on the weekend then pull the charger apart to check wear. In theory there should be none.

well done Sketchy, I would have hidden it in a secret place in the shed by now, maybe even earlier

Impressed I wouldn't have got past the talking it up stage

But does it deserve a better motor to drive it now?

[Sketchy_Racer]

Thanks guys, yeah it has definitely tested the patiences but I knew it wasn't going to be easy or everyone would do it.

I will go into the details of the design on the weekend once I pull it down.

The best part is once the gearbox is sorted a RHB31 compressor housing is $10 USD and a impeller $15 USD so if I can manufacture the gearbox cheap enough I am hoping to be able to sell them for less than $500 as a complete unit that can be bolted onto anything 250cc or less.

In terms of manufacturing, once production processes are added there are not many parts and they are simple in shape, even cast materials could be used.

[ducatilover]

The best part is once the gearbox is sorted a RHB31 compressor housing is $10 USD and a impeller $15 USD so if I can manufacture the gearbox cheap enough I am hoping to be able to sell them for less than $500 as a complete unit that can be bolted onto anything 250cc or less.

I like this very much.
I'd love to have on on the DR motor, just for the penile extension factor

[Sketchy_Racer]

The *chhh chh ch ch ch* of surge when I shut the throttle nearly made me pass out with coolness. May sound even cooler once the blow off valve is connected

[ducatilover]

It's not compressor surge doing it is it? I'm not clued up on these set ups

[Sketchy_Racer]

It's not compressor surge doing it is it? I'm not clued up on these set ups

Yep, it's completely normal if the throttle is shut and there is no blow off valve to relive pressure, so it surges back down the compressor. It's not bad unless it is surging under load. (and is really only an issue for turbos, not superchargers)

[TZ350]

That's right all 15psi of it, nice efficient cool boost. Intake air temp was 35 degrees in the plenum Ran bike for 20min, no boost loss, if anything it got better. Still no idea on shaft RPM

I knew I would get there eventually

Congratulations ...... very impressed

PS I would like to try one, please let us know when you are ready to make one or two.

[ducatilover]

Yep, it's completely normal if the throttle is shut and there is no blow off valve to relive pressure, so it surges back down the compressor. It's not bad unless it is surging under load. (and is really only an issue for turbos, not superchargers)

Thought so, comp surge does sound great (memories of a Mazda BFMR with cruise control, would back off going down hills, pe-tow-tow)