electric superchargers

[scott]

There is a thread over on CS about those £160 electric superchargers on ebay.
Basically everyone is saying they are a load of crap, i agree they do sound like a load of crap and i wouldnt waste my money on one but no one on CS has actually purchased one and used it on their car so how can they comment???
Surely all good ideas start somewhere dont they???
I dont understand engines enough to really comment, im sure GeorgeK or someone will be able to clear up the issue.

Thoughts???

 

[BenG]

Im pretty sure its a fan that is bolted to the inlet manifold, it is connected to and powered by the battery. The fan forces more air into the manifold resulting in an extra 1/2 psi (or so it claims). I guess if the ecu was mapped correctly after fitment it would be reliable and maybe even increase BHP, although I dont think it would gain much.

Personally I dont like the idea of forced induction on a n/a engine and im pretty sure thats what its all about ???

 

[scott]

Thats what i thought BenG, dont think it would give much gains if any but like i said im no expert. If it did work i dont think it would change the power delivery though? :?

 

[BenG]

I would imagen the fan would only force air in at lower revs, but I could be wrong, it would depend on the rpm rating of the fan. The engines natural intake force would spin the fan very fast and at some point this will be faster than the fans max rpm rating. (the rating in which the fan can spin using the 12V battery supply) after this is reached the engine will just continue to run as normal, without forced induction. This would give a power boost lower down in the rev range.
Thats the way I see it anyways, maybe someone could shed some light on the matter...

 

[nickboazracing]

I haven't actually seen one of these on eBay, but I would guess that for £160 it won't set the world alight.. or everyone would have one, surely?!

Bare in mind a turbocharger will spin upto 100,000rpm and a supercharger requires a significant amount of bhp to spin it up, (the classic quote refers to top fuel drag cars - 1000bhp to turn the supercharger at full speed, apparently) I think what I'm getting at is that you need a LOT of energy to force air into the engine when ou think about the mass of air it consumes, per revolution. Assume 75% volumetric efficency on a 2 litre engine, doing 6000 revolutions per minute... A lot of air.. I don't think a £160 bolt-on from eBay will do much.