13 replies to this topic

[danrock101]

What's the cheapest you can make a DIY supercharger kit for? I've seen Bini superchargers on ebay cheap, I was just wondering why the cheapest kit I can find is a well over £1000
damn wrong section

Edited by danrock101, 26 April 2009 - 09:29 PM.

[Prawn]

All the kits you can buy at the moment use the bini eaton M45 supercharger too.

You're looking at £100+ to get one on ebay.

You'll also need to get the manifolds custom made, unless you can find some on ebay which seem to pop up now and again. how about this for a laugh? www.comedy ebay manifold.com

then you need to sort out some kind of lower pulley capable of running a belt to drive the charger, a suitable length belt, and a method of tensioning it too.

With all that done, you'll need to make sure you're CR is low enough, which will either require a nasty decomp plate, or having your head chambers taken out to lower the CR.

Is the rest of your car up to it as well? taking a mini instantly up to 130bhp+ is a huge jump, and if you're still on standard brakes and suspension it'd be pretty foolish too I reckon.

Fast, cheap, reliable. You can only pick two.....

[1987_ParkLane]

How about this for a laugh? www.comedy ebay manifold.com

I quite like the look of that, but just not the part where it has to come through your bonnet .

[danrock101]

All the kits you can buy at the moment use the bini eaton M45 supercharger too.

You're looking at £100+ to get one on ebay.

You'll also need to get the manifolds custom made, unless you can find some on ebay which seem to pop up now and again. how about this for a laugh? www.comedy ebay manifold.com

then you need to sort out some kind of lower pulley capable of running a belt to drive the charger, a suitable length belt, and a method of tensioning it too.

With all that done, you'll need to make sure you're CR is low enough, which will either require a nasty decomp plate, or having your head chambers taken out to lower the CR.

Is the rest of your car up to it as well? taking a mini instantly up to 130bhp+ is a huge jump, and if you're still on standard brakes and suspension it'd be pretty foolish too I reckon.

Fast, cheap, reliable. You can only pick two.....

nice one cheers, it looks cheaper than I thought then , yeah I'd do brakes and suspension first, minifins and metro turbo brakes. I've been looking at the turbos too but I'd get more benifit out of a supercharger because I don't like to rev too much

[Prawn]

I think you might want to reconsider your options then mate.....

Whilst a super charger gives you some low down boost, it's only proportional to the engine speed, so at low revs, there's very low boost.

The supercharger power delivery is more linear, and it keeps many of the n/a characteristics of the engine, as boost increases with engine speed, max power is made high up in the rev range.

Most typical turbo's don't have very high rev limits. The T3 spools up around 3k, and from what I've read, most people don't usually go much above 6k revs, as the speed is in riding the torque, so you don't need to use the revs so much....

[danrock101]

yeah I know what your saying, but at 3000 revs would I be getting decent power from a supercharger? I'm not sure because I've never driven anything supercharged Turbo I have and I if I wanted to get anywhere fast it would need high revs, but 3000 does sound good, I'm sure the car I drove kicked in about same but you didn't really feel it untill 4000 might be just me lol

Edited by danrock101, 27 April 2009 - 12:54 PM.

[Wil_h]

I think you might want to reconsider your options then mate.....

Whilst a super charger gives you some low down boost, it's only proportional to the engine speed, so at low revs, there's very low boost.

The supercharger power delivery is more linear, and it keeps many of the n/a characteristics of the engine, as boost increases with engine speed, max power is made high up in the rev range.

Most typical turbo's don't have very high rev limits. The T3 spools up around 3k, and from what I've read, most people don't usually go much above 6k revs, as the speed is in riding the torque, so you don't need to use the revs so much....

Interesting, I need to think about this and do some maths. But I always presumed that with an SC, as it is a pump that pumps 'x' amount of air per revolution, then you should have a pretty flat boost curve. The pressure is generated by the pump pumping into a fixed volume. The amount of air is the same every revolution, the volume is the same every revolution, ergo, the boost is the same. I thought this was the whole advantage to an SC.

[Prawn]

Interesting Will, I can see exactly where you're comming from, and I'm trying to think of ways to disprove it. I can't think of a mathematical reason, but I'm certain boost increases constantly with revs all the way to the redline. it could be to do with efficiency, but if your thoughts were correct, then surely the SC would be running as it's given pre defined boost level at idle even?

I think, that due to the charger spinning at very roughly twice the speed, that boost somehow rises exponentially or something along those lines.....

I've confused myself now.

[Prawn]

A little bit of research online and I've found a few things.

A positive displacement charger works exactly as you said, and provides an apparently constant boost level regardless of engine speed.

A centrifugal type charger provides boost which increases with the square of engine speed. much like a turbo.

I think the eaton M45 is a roots type positive displacement charger isn't it?

[BMC1380]

What's the cheapest you can make a DIY supercharger kit for? I've seen Bini superchargers on ebay cheap, I was just wondering why the cheapest kit I can find is a well over £1000
damn wrong section

Roofless - what happened to the brakes/Stefan

[BMC1380]

What's the cheapest you can make a DIY supercharger kit for? I've seen Bini superchargers on ebay cheap, I was just wondering why the cheapest kit I can find is a well over £1000
damn wrong section

Roofless - what happened to the brakes/Stefan

[roofless]

wrong place - but check your phone messages.

[BMC1380]

wrong place - but check your phone messages.

No phone to check, post pm instead, haven´t got hold of you in the right place, sorry for the hi-jack../Stefan

[danrock101]

wrong place - but check your phone messages.

No phone to check, post pm instead, haven´t got hold of you in the right place, sorry for the hi-jack../Stefan

I will let you off just this once >



:)