100cc forced induction F4 bucket. Anyone keen to have a real go?

**pete376403** · 11th July 2012, 21:12

Originally Posted by TZ350

It has been talked about but its not within the rules so no real incentive but there is a F5 2-stroke running nitrous up here, just for fun mind ...

If we were going to run a supercharged or turbo 4 stroke we would look at having a motive force (engine) just to drive the compressor as the rules don't say it must be turned by the prime mover. For a turbo we could look at cng/air for driving the exhaust impellor.

Blowing a 4 or 2 stroke with either compressor style we could use an inter cooler and pump up a large plenum to say 15psi and have it blow through a fuel injector body on the inlet.

Are you allowed more than one engine per bike, ie what you are describing is a second engine to drive the compressor.
Tyrell tried to have turbos banned in Formula 1 by claiming the exhaust side of the turbocharger was really a second engine ie a gas turbine - that claim failed because the turbo could not run independantly of the main engine, however what you describe could run independantly.

**Ocean1** · 11th July 2012, 21:36

Originally Posted by pete376403

Are you allowed more than one engine per bike, ie what you are describing is a second engine to drive the compressor.
Tyrell tried to have turbos banned in Formula 1 by claiming the exhaust side of the turbocharger was really a second engine ie a gas turbine - that claim failed because the turbo could not run independantly of the main engine, however what you describe could run independantly.

As McLaren tried, (successfully) to ban the Chaparrel J2 because of it's twin 2T suckymotors.

And while neither F1 or Can-Am rules apply in this instance the lesson is clear: Win with anything too far out in left field and the hoards will clarify the reg's and arsehole you outa there.

**Ocean1** · 11th July 2012, 21:40

Originally Posted by TZ350

If we were going to run a supercharged or turbo 4 stroke we would look at having a motive force (engine) just to drive the compressor as the rules don't say it must be turned by the prime mover. For a turbo we could look at cng/air for driving the exhaust impellor.

Good ideas, but unless the crank or pistons are absolutely on the limit why wouldn't you just drive it off the main engine and wind the gate up another half lb?

**koba** · 11th July 2012, 21:41

Originally Posted by Ocean1

As McLaren tried, (successfully) to ban the Chaparrel J2 because of it's twin 2T suckymotors.

And while neither F1 or Can-Am rules apply in this instance the lesson is clear: Win with anything too far out in left field and the hoards will clarify the reg's and arsehole you outa there.

I've probably said it before but you should really have a good look at coming to play with buckets.

From what you post I'm sure you'd love it.

**Ocean1** · 11th July 2012, 21:45

Originally Posted by husaberg

Arh yes... but you should start with a s few compromises as posible in my opinion anyway

Yeah, I hate some of the manifold abominations you see on blown gear too, but the fact is outside of oversized headers it's just not that important in terms of output. Asthetics, yes.

**Ocean1** · 11th July 2012, 21:50

Originally Posted by koba

I've probably said it before but you should really have a good look at coming to play with buckets.

From what you post I'm sure you'd love it.

I would. At least the build part. 'Cause I don't bounce well anymore.

But for now I have about enough time to drop in to watch once in a while.

Maybe next year, when my clients pay me enough I can put aside some playtime.

**koba** · 11th July 2012, 21:55

Originally Posted by Ocean1

I would. At least the build part. 'Cause I don't bounce well anymore.

But for now I have about enough time to drop in to watch once in a while.

Maybe next year, when my clients pay me enough I can put aside some playtime.

Cool, it would be good to see.

**husaberg** · 11th July 2012, 22:09

I have posted this before but for those that missed it.

**jasonu** · 12th July 2012, 05:01

[QUOTE=speedpro;1130355496] It did wheelie in "any" gear though. QUOTE]

Yep seen that at Pukekohe back straight. Wheelieing past an Aussie TZ750 like it was going backwards.

**FastFred** · 12th July 2012, 07:50

Originally Posted by Ocean1

Good ideas, but unless the crank or pistons are absolutely on the limit why wouldn't you just drive it off the main engine and wind the gate up another half lb?

TeeZee has talked about that before, the idea was that with a 1000cc who cares but with a supercharged 100cc 4-stroke motor on Av Gas (F4 rules) could not make all that much power. And by driving the supercharger independently mitigated the losses in turning the compressor. So pretty much everything the 100cc motor could produce was available for driving the rear wheel.

**Grumph** · 12th July 2012, 07:54

Speedpro - boost is addictive. Pity the postie rules exclude reliving the fun bits....

the tramontana thing - yes, seen it before and there's one thing there I must warn about.
blower drives....for road and drag use by all means use toothed belts but fercrissake don't use them for roadrace applications - or speedway for that matter either.
There's got to be a certain amount of slippage in the drive. Back off at high revs with a blower spinning on the end of a rigid drive system and something will give. I've seen crank ends come off speedway motors and they have less violent load reversals than roadrace motors.
On another thread on here someone quoted seeing a MR2 crank end come off too - it's not hard to do.
The last successful mechanically blown motor on speedway - Glen Smith's TQ - used a polyvee drive setup cos a friend of the engine builder had seen our roadrace setup and knew it worked