Formula 5 question?

[Drew]

One of you homos already knows the rule. What is it, and has it been done? I have no inclination to trawl through MNZ's website trying to find rules.

[Moooools]

100cc forced induction 4 strokes are allowed.

[F5 Dave]

Ahh I forget (this is fun, like having a little brother to torment throwing his teddy between you & your sister. Sadly I was the youngest).

There have been a couple, actually supercharged, er hold on was Diesil's turbo or super charged- whatever.

but the short answer is none that have 1/2 way worked worth a dam that I have ever seen.

[F5 Dave]

ahh crap, spoilsport, we might have got him to cry.

[Moooools]

The impression I have gotten from talking to a few people is that you would need to run about 20-25 PSI of boost to get to a stage where it is worth it, and with 25-30 you would be looking at about 45-50hp. But to get to that level you wouldn't just be able to whack a turbo on and watch it go. You would be wanting to lower compression and put some stronger valves and a new cam in at the very least. And getting the bottom end to take the load wouldn't be easy. It really doesn't sound like a cheap exercise to build one.
It certainly wouldn't be cheap to keep it going.
It would be fun as fuck to ride.

[Moooools]

ahh crap, spoilsport, we might have got him to cry.

My apologies Dave. To make you feel better I will let you beat me in next year's F5 gp.

[jasonu]

The impression I have gotten from talking to a few people is that you would need to run about 20-25 PSI of boost to get to a stage where it is worth it, and with 25-30 you would be looking at about 45-50hp. But to get to that level you wouldn't just be able to whack a turbo on and watch it go. You would be wanting to lower compression and put some stronger valves and a new cam in at the very least. And getting the bottom end to take the load wouldn't be easy. It really doesn't sound like a cheap exercise to build one.
It certainly wouldn't be cheap to keep it going.
It would be fun as fuck to ride.

A good builder would get that done in an afternoon....

[Drew]

The impression I have gotten from talking to a few people is that you would need to run about 20-25 PSI of boost to get to a stage where it is worth it, and with 25-30 you would be looking at about 45-50hp. But to get to that level you wouldn't just be able to whack a turbo on and watch it go. You would be wanting to lower compression and put some stronger valves and a new cam in at the very least. And getting the bottom end to take the load wouldn't be easy. It really doesn't sound like a cheap exercise to build one.
It certainly wouldn't be cheap to keep it going.
It would be fun as fuck to ride.

100cc single isn't capable of driving a turbo or supercharger fast enough to create that sort of boost. It would need to run a turbo and blower. Start with an XL250 bottom end and you've got a bottom end capable of taking 40 horses.

There would be a lot of engineering, but there's no reason it can't be reliable.

[gav]

Your logic is that if I put an FXR engine into an rs 125 chassis thus making a purpose built race bike, the FXR engine becomes a competition engine. Which is wrong.

Same deal with the metrakit, putting a street engine into a race frame doesn't make it a race engine.

This is pretty damn clear cut!

Its not an individual doing the fitting, it's a factory/company. If Suzuki released a FXR150 in an alloy chassis that was set up exclusively for racing, on slicks etc, oh wait and with a bigger (30%) carb fitted, race pipe, also 20% more revs would that be ok would it?
The std GPR50 has a 14mm carb, max power at 10K revs, the Metra has a 19mm carb and 12K revs.
Im sure it starts as a std engine, but if the Forza 155 pit bike was considered unsuitable because its a competition engine/machine I find it hard to believe that this Metrakit bike can be considered legal. If someone bought a Metrakit rolling chassis and then fitted a Derbi 50 fitted thats fine, but thats not what has happened here is it? It's been bought as a purpose built race bike and is sold as such. What next? a TZ250 is ok for F3 because a TZR250 Kocinski rep is based on the same thing?

[Moooools]

Its not an individual doing the fitting, it's a factory/company. If Suzuki released a FXR150 in an alloy chassis that was set up exclusively for racing, on slicks etc, oh wait and with a bigger (30%) carb fitted, race pipe, also 20% more revs would that be ok would it?
The std GPR50 has a 14mm carb, max power at 10K revs, the Metra has a 19mm carb and 12K revs.
Im sure it starts as a std engine, but if the Forza 155 pit bike was considered unsuitable because its a competition engine/machine I find it hard to believe that this Metrakit bike can be considered legal. If someone bought a Metrakit rolling chassis and then fitted a Derbi 50 fitted thats fine, but thats not what has happened here is it? It's been bought as a purpose built race bike and is sold as such. What next? a TZ250 is ok for F3 because a TZR250 Kocinski rep is based on the same thing?

Stop being stupid.

If Suzuki brought out that bike it would be legal, and I would buy 10 of them.
Carbs are open. Ignition is open. Pipe is open.
The engine is tock internally in the metrakit.
It doesn't matter for shit who puts the two of them together, that is a road engine, with a race ignition, pipe and carb.


The Forza is an engine build from the ground up as a race engine. So it is obviously in a different category.

[Drew]

Fuckin hell, there's enough rule arguments on these things to keep Biggles happy for years.

Note to self, unsubscribe as soon as someone brings a rule into question...Even if it's me.

[husaberg]

100cc single isn't capable of driving a turbo or supercharger fast enough to create that sort of boost. It would need to run a turbo and blower. Start with an XL250 bottom end and you've got a bottom end capable of taking 40 horses.

There would be a lot of engineering, but there's no reason it can't be reliable.

Yes it is but in the case of a Supercharger the real problem with supercharging a single is the fact the bangs are 720 degrees apart that bit can be got around with a suitable plenum chamber or suitable volume the other problem is the intermittent firing plays havoc with the drive system with is why supercharged singles are not that common. RS engineering in the UK did a Yamaha 660 five valve (Tramonta) if memory serves me right that was one of the few real successes of the concept (70hp) there was a bit of pre and post war stuff as well but the ban on supercharging ended them. I can remember a copper Manx norton the intake pipe was around 6 foot long. Of course a 100cc twin esp with a 360 crank would not have these problems to the same extent. but as Dave mentioned it is no a simple procedure the major hurdle is the expense of the beefed up custom parts required as well as the programmable ignition the inter cooler a the water injection the riding rate pressure regulator if using carbs (possible with a pitot tube and suitable CV carbs and mods) but preferable fuel injection special valves it start to get super expensive.. My one stalled when I could find a suitable forged piston and i figure how much the destroking and the primary drive pinion mods was going to cost.

The xl250 is not a goer in my eyes as it would need a new crank (stroke) and the bore is way to big.

I would start with a Aisin amr 300 super charger off a 660 kei class car there is a few about.

the turbo is not really a going for circuit racing or is any centrifugal supercharger as the bottom end is shit and as they are made for a motor 6x the size. The beauty of the roots blower is it can be geared for max boost and will work at all revs not the most efficient blower (screw) is better for the application we would use but available and capable of being downsized if required (not Nes in this Ap just drive a Half speed for around 22psi)


A wee bit of light reading below.

http://www.x386.net/TTR/tech/cgi-bin/charger.cgi
http://victorylibrary.com/supercharger/super-drive4.htm
http://webcache.googleusercontent.com/search?q=cache:ie5FgkvVv7gJ:geometroforum.com/topic/3691319/1/+TURBO+IHI+RHB31+COMPRESSOR+MM&cd=1&hl=en&
ct=clnk&gl=nz&source=www.google.co.nz
http://www.dune-buggy.com/turbo/fuelsystem.htm
http://autospeed.com/cms/title_Super...4/article.html
http://superchargersunlimited.com/specs.html
http://autospeed.com/cms/A_1931/article.html
http://www.elsberg-tuning.dk/supercharging.html
http://forums.nasioc.com/forums/showthread.php?t=570978
http://www.diygokarts.com/vb/showthread.php?t=9460
http://www.vespalabs.org/User:Intern..._Turbo_Charger
http://www.triumphexperience.com/art...ugh-an-su.html
http://autospeed.com/cms/title_The-C...0/article.html
http://www.turbomirage.com/water-alc...ion-links.html
http://www.nicoclub.com/archives/alc...he-basics.html
http://www.injectacarb.com.au/fuel-p...d=7f20a539b789
http://www.dragbike.com.au/forum/viewtopic.php%3Ff%3D6%26t%3D23+blow+through+cv+car b&
http://www.summitracing.com/parts/MAA-4309/
http://www.turbogemini.com/Turbo Accessories.htm
http://feralinjection.com/cbr.html
http://www.rbracing-rsr.com/waterinjection.html
http://www.ty4stroke.com/viewtopic.php?t=29536
http://victorylibrary.com/supercharger/super-carb6.htm
http://www.thefang.co.uk/news2008.htm
http://www.superchargersonline.com/h...r.asp?submit=1
http://www.caferacer.net/forum/topic...06&whichpage=2
http://www.chinese-parts-canada.com/...injection.html
http://www.streettuned.com.au/index....productId=1494
http://www.megasquirt.info/
http://autospeed.com/cms/title_The-N...6/article.html
http://www.siliconchip.com.au/cms/A_103609/article.html
http://mastercircuits.blogspot.com/2...rsion-kit.html
http://forums.evolutionm.net/other-c...nything-6.html

[koba]

I rection one could also find the smallest turbo available (I've seen a tiny one on a diesel generator) and turn down the turbine and impeller. One could then make inserts to go in the housing and make it all match up again.

Bah, May work, may not. All just un-academic musings until someone wastes a whole pile of coin on it that would probably be better spent elsewhere.

Watch for some interesting developments if I ever win lotto.

[Moooools]

Turbo would be good if you were prepared to burn some coin on a boost controller and an anti-lag computer.
After that it wouldn't be much worse to ride than those pesky 2 strokes.

[Drew]

Turbo would be good if you were prepared to burn some coin on a boost controller and an anti-lag computer.
After that it wouldn't be much worse to ride than those pesky 2 strokes.

No need for fancy computers, anti lag can be made with an small fuel pump, a diesel injector, and a micro switch on your clutch lever. If ya wanted to get fancy you could put a timer on it so it only pulses a certain amount of time each pull of the clutch, to save having a foot long flame out the pipe when your waiting for the flag.

Boost control is easily controlled with a pneumatic waste gate actuator, and just as easily made to be adjustable.