24 replies to this topic

[Vipernoir]

ring gear will be about 20-24" but thats diameter not circumference, the gear would need to be 1/24th the circumference for the right rpm.

Errr....
Circumference is a derivative of diameter. The pulley will need to be 1/24th of whatever dimension you choose to measure on the flywheel.
Either way, the small pulley will only be about an inch across.

140,000 rpm at 7000rpm is pointless - you need to achieve max boost lower down the rev range or it will be a topend screaming monster that is nigh on undriveable.

[norwegianminiman]

norwegianminiman is correct...

yey someone agrees with me^^

did a wee bit of calculating:

assuming one wants the charger going at 140000RPM at 3500RPM, and that the flywheel if 20"diameter...

then having the flywheel (20") driving a 2" pully on the intermediate shaft, then a 4" pully on there driving a 1" pully on the charger...

then... 3500RPM*(20"/2")=35000RPM on the intermediate shaft, and 35000RPM*(4"/1")=140000RPM on the charger... my head hurts now, hate digging out knowlage I've only used once before

[davethemini1293]

ok thread dig up,
but did you ever get anywhere with this???
im collecting parts atm,
i've already got a t34 cossie turbo
and abilty to make pulley's etc,
i like the idea of running it direct from the flywheel,
any new thoughts?

[davethemini1293]

anyone??

[davethemini1293]

serious?
no body has any input atall????
this could be a Very cheap way to forced induction....
OR very expensive.....

[Shaz_mini_Beast]

no he's not gone down that road, i know as he's building my turbo engine atm and my mini is in his garage lol.

[mini.cooper998]

shaz is right i ended up going the roots way very similar to johnnysti on here. once i get shaz's turbo built up will be starting back on the track car build and the blow through eaton m45 setup. cant wait now

Andy

[Shaz_mini_Beast]

you'll be glad to kno andy ive ordered my boost pipes, megajolt, and filters proper big hit on it. sorry i never came round this weekend been a bit mad. ive got my poppers, lead replacement, pointless turbo module and boost controller sat in my bedroom ready to go on.

[Wil_h]

I think most of the problems with this idea are apparent in this thread and it's self expanitory why this project never went any further.

Basically of you want a belt driven centrifugal charger then buy a rotrex.

[NDT]

I think most of the problems with this idea are apparent in this thread and it's self expanitory why this project never went any further.

Basically of you want a belt driven centrifugal charger then buy a rotrex.

Agreed.
Belt driven centrifugal blowers are not a great idea - boost goes up non-linearly with speed.
The best way to engineer this would be to get compressor maps for the different compressors and work out the thermodynamics from there.
IIRC things like the turbo technics supercharger had an oversized compressor compared to a turbo, so that there was some meaningful boost at lower rpm.
Then to stop overboost at high rpm, rather than use a blow off valve (which would work but would waste a lot of energy), sized the inlet to the compressor to 'choke' the flow.

A positive displacement blower would be better - or a Messerschmidt style centrifugal blower with a slipping clutch... buth that's not easy to set up at home...