Need advice on..

[bluesman]

OK guys, I've just bought turbocharger from Fiat Punti 1.3 liter.
Idea is not to turbocharge, but to supercharge Storm - obviously couple of years project.
Here is some trick: thereis few types of supecrhager, one of the centrifugal. It is EXACTLY like charging part of turbocharger. So, if you unbolt supercharger part from turbocharger you have it.
Centrifugal chargers known for not being much help at low rpm's, but still do not have turbolag like turbochargers. So, since Storm makes more than enough Nm in low rpms I think centrifugal charger is perfect for Storm.

Now comes the question. Anybody have any idea where to drive supercharger from? Anybody knows how to make cranckshaft exptension or any other variant?

I want to supercharge Storm with mild level of boost, reaching about 150 bhp rear wheel. I know I will have to replace CV carbs with Mikluni's HSRs, but since thos easily availible off ebay (Harley's using those) I can get it all sorted. It is only CNC machinig of new engine case cover and gearing charger off engine that keeps me thinking...

[kevg]

I'd imagine with the crank running accross the bike you are looking at a drive chain to where you want to mount the supercharger, at the end if the crank is a bit impractical, i'd be sticking out the side of the bike.
i suppose you could put a bearing and seal in the crank case and a cog or pully on the end of the shaft extension, with a chain or belt directly driven from there to the charger.

[alan]

[Stormin Ben]

Bluesman,
Have a look at this thread, had some useful info in
http://www.vtr1000.org/phpBB2/viewtopic.php?t=6585


Including this beauty!!

[Max]

Right I have been pondering over this for a bit and have the following points/questions

1 from what I can remember centrifugal type superchargers require little or no mods to pistons, compression ratio etc due to the smooth delivery
2 centrifugal relatively efficient for supercharger
3 Dont give much boost at low revs (not really a problem on a bike)
4 using a converted turbocharger do you plan to use an extra gearbox as most turbos spin somewhere between 80,000 and 200,000 rpm and a direct belt drive would have one v small cog and one v large cog ?
5 Are the bearings in the turbine suitable for taking the sideways load of a pulley/gear ??
6 With the gearing problems etc, this is going to use a lot of power to turn itself, will it produce enough extra power to give a decent power gain.

Please don't take these as negative comments, its just things that have occured to me thinking about this project. Its an interesting idea as small turbos are probably easily obtained these days compered to superchargers.

[tony.wilde1]

bloody hell ben,thats outrageous!!

[beenz]

I have to agree with Max that a turbo needs to run at far higher speeds than a supercharger and the bearings in a turbo are often the plain type and are not subject to any load at all. A turbo in effect just spins freely in it's bearings.

[bluesman]

First of all - guys, thanks for advice and comments, it is really encuraging (yes, it is!).

Let me try to answer some very well pointed out things ( just need to convince myself )

About bearings - this is absolutely spot on, I had this feelings I forgot something... I know bearings in this turbo is not "floating" type, so they can take some load. If I drive charger chaft by straight-cog gears it shoul minimise load, so that main load will be on other shafts which will spin at much less rpms. Then - I will be machining kind of blanking plate to be bolted onto casing of charger instead of turbo part anyway. So, this should allow me to make place for additional charger shaft bearing to hold load caused by gears. Obviously, as you are 100% right about spin speed (up to 150 000 rpm) question about bearings is tricky. I hope that with help of my friends back in Kiev I can get hold of special high-speed bearing used in aircrafts made in Kiev. You know - AN makes not only world largest cargo planes but small commercial planes with lots of small parts too

I prefer to use puleys and belt, but then I have to do ratio of at least 1:40, and that not going to be possible with belt, so - gears for sure, preferred planetary gears system.

About taking bhp to drive charger - fair point, but centrifugal chargers take way less bhp than roots or screw chargers. I know that pictured above Storm with roots charger makes in excess of 200 bhp, but obviously it eats way too much fuel and half of engine components must be aftermarket/specials. This is why I prefer centrifugal - I really need cure of Storm running out of breath in higher rpms, as I think low-middle grunt is more than enough as it is.

So, here is my backup plan: if I fail to make it into charger I'll try it as turbo and see what's up about turbolag. They say with smaller turbo's lag is minimal. I still have not seen part I bought yet, as I had to have it sent to my friend in UK in Brooklands, so when he will be here next time he'll tak turbo with him. Airport lockdown stopped me from asking my other friend to take turbo with him on the plane....


Thanks again for your advices and comments! I definitely going for it, it's just I'll have to make it slow project - our third baby was born last friday, so budget for bike took anther cut and obviously I should not even open my mouth about bike for few weeks or my wife will be really unhappy!

[sirch345]

Bluesman 'Congratulations' on the new born

Chris.

[bluesman]

thank you!

I must admit - it's our third and I still feel "not ready to be father"

[sirch345]

thank you!

I must admit - it's our third and I still feel "not ready to be father"

That's interesting