StephTell

Now I hear and see a lot about turboconversions here but hardly anything converted to run a supercharger?

How come?

When I see the vid's of racecars with SC's fitted I must say I love the shrieking whining sound (reminds me of the missus I guess) and they seem to go well...

Would it be overly hard or dear to convert a cossie to run a SC?

Stavros

A few Cossies have been done in the past.

The main reason it seems nobody does em is people dont understand em much in the UK, so all we ever see is high compression low boost jobs pushing out fairly low power, 150bhp per litre type things at best.

Overall a turbo is way better, but the instant response of a s/c can be a big big advantage.

Ive been in a 400bhp 2litre supercharged 306, and it was mega impressive, worked way way better than a 400bhp turbo on a FWD car, but that was as it had a centrifugal supercharger, so didnt have as much midrange as a turbo or positive displacment supercharger, meaning loads more traction.

StephTell

I remember I used to have a VW Corrado (I know I know....but it's been 10 years like...) wich had the charger fitted and it didn't feel special at all but it did feel like a small V8 if you know what I mean? Easy power all the way through the range.

If you look at vids of SC hillclimbcars you see the instant response when on the throttle...looks brutal enough, especially on shortish gearing....

Would be really interested to see a big power SC Cossie!

Mike1

Years ago when I was looking for an XR4i, I had a test drive of one that had been fitted with the Power Engineering Sprintex charger. That charger was originally off one of the XR4x4 conversions they did but he had bought all the kit and fitted it to the rwd V6.
Was a really nice car - I would have bought it if the guy who'd seen it an hour before hadn't had first refusal. They come up now and then for sale. I think it was about 230-240bhp.
Derek Bell, the racing driver, used to have the 4wd version and reckoned it was one of the best cross-country cars he ever had.
I've just got the wife's Cooper S to have a go in now - doesn't have the nice soundtrack of the V6 though

StephTell

IF I'd ever fork out for a SC I don't care wich one as long as it has the massive whine like the Lancia S4 hillclimbcar!

jammy86

the main reason that its not done much is that you need to take drive off the front end of the engine. It might be a possibility in the cossies with the engine orientation, but on the FWD stuff like RST's it would be much more difficult.

In theory a turbo charger is using otherwise wasted energy (thermal recovery from exhaust gas) and so increases thermodynamic efficency. Since a SC takes power directly out the crank its less efficient, but its advantage is that there is no lag.

I'd like to see it done more though.

JAmes.

ST_Mike

I have a supercharged Fiesta ST currently at 232bhp

It drives very well and I have no traction issues really, its a centrifugal Rotrex charger, so power is very linear.

It doesn't feel as fast as your doing, you dont get the big push of a turbo but the SC is a lot more drivable I guess.

StephTell

Been out in a MKII VW golf with a 230 BHP supercharged lump, felt fast alright!!

ST_Mike

MKII golf would have weight on its side aswell though I guess, for a small car the Fiesta ST is quite heavy

StephTell

I think it felt fast because of weight and also because it felt rather frantic if that makes sense...torquesteering all over the place

Charlie Chalk

iTrader: (1)

My mates Swift.

https://passionford.com/forum/showth...ighlight=swift

Mike1

My friend's Pretty Rapid as well - not up to the standard of that Jamaican chap Bolt though.....

pa_sjo

I contemplated it on a cossie, but Rotrex dont do a s/c versatile enough for a high power small displacement engine (they recommended using 2 superchargers to achieve 500bhp on a 2L).. Also the nose of a cossie crank isn't exactly super strong, so not sure turning a s/c is a great idea

Stavros

I thought their biggest one was rated to 600?

Fuck them anyhow, if you want big power and a centrifugal charger rather than positive displacment, then...
http://www.procharger.com/models.shtml

Or if want a decent Lysholm jobber for instant boost, then Keene Bell ones dont cost much condidering what they are...
http://www.kennebell.net/pricelist/SC-PRICELIST.pdf

dunketh

The yanks seem to do it a lot on everything.
The classic brigade do it in the UK a lot too - its just no-one seems to do it on Fords in this country.

I always find this Minor build inspirational:
http://www.morrisminoroc.co.uk/index...wtopic&t=18683
CHeck out the mini & MG forums too.

Stavros

It happens a lot in the UK, but just like that Minor in your link, not to big power, like said at the start, rarely ever even 150bhp per litre, and that Minor is even less so.

Plenty of supercharged Zetecs on this forum with 200-300bhp. But thats not much in the grand scheme of things.

Mike Rainbird

iTrader: (3)

What about one of these?:

http://www.worldcarfans.com/7060505....d-supercharger

Has anything happened with them, as since the launch, it has gone quiet? Would love to try one on a Cossie .

RWD_cossie_wil

iTrader: (9)

I was only thinking about this last night actually, would LOVE to make a twin charged cossie, GT35 for the top end and a low end charger geared up to make big boost low down, then drop out at say 4000+rpm as the turbo comes in.

Would you run the charger through the turbo, or run them in parallel?

Mike Rainbird

iTrader: (3)

The trouble is finding a supercharger that is of a suitable size (flow and physical dimensions) to fit:



This was too small to be of any real benefit, you really needed the one in the link I posted above, but this wasn't (isn't still?) commercially available.

Stavros

Will- Cutting it out is a shit idea IMO, and should run the turbo thru the charger, as long as the chargers a posi displacment one. Pointless with centrifugal one.

Mike- Its not the size thing thats the issue there (tho thats tiny), its the fact you used a type of supercharger thats TOTALLY pointless for a twincharged application
Why use a charger that only gives maximum boost at maximum rpm for something to give you more low down power?
You need a positive displacment charger to make any twincharged setup work.

RWD_cossie_wil

iTrader: (9)

Ideally you would want to keep it in, but you run into some major problems of compressor overspeed, and basically having a negative pressure behind it, the supercharger will always be the restricion. Somthing like a down geared roots blower would be ideal, to give lots of boost at low engine RPM, but you would have to slow it down somehow or disconnect it via a clutch ( like an aircon clutch), as the vanes would just explode at 8000 RPM (engine speed) and would possibly cause a big restriction meaning the turbo could notget enough air in.

Way I would do it is run the charger into the turbo inlet, but have a Y pipe with a non-return valve and a auxilley air feed, so as the charger runs out of puff, the NRV would open and allow extra air to be drawn into the turbo, with an RPM switch to disengage the charger at say 4000Rpm. . Space is the big problem, as is finding an electro-magnetic clutch man enough to hold a supercharger.

Any idea how much power a eaton blower off a mini cooper would take to drive at max airflow? I am told it would take about 20-30hp which is a hell of a lot for an aircon clutch to hold onto.

Stavros

Why the fuck would you run in to compressor overspeed? Youd only do that if you specced it all wrong, and only time youd ever spec it so its that bad is if you used a centrifugal supercharger as they give fuck all low down, and anyone who knew what they was doing (see above for examples of not ) would never do that.

ALL sucsessful twincharged engines use a positive displacment charger for this reason, and geared in a normal way like it was running alone right thru the revs.
How hard you push it will depend how you want the car to drive etc.

Wat you are suggesting is complex and not all that good, esp as you miss the main plus points of twincharging doing it that way.

I know people and companies that have sucessfully done it, and also tested it cutting out with an electromagnetic clutch etc, and the way I say is the best way by miles still.

Im not guessing, im going from real world proven stuff.

yellowsierra

Who needs words,

http://www.youtube.com/watch?v=WB0cu...eature=related




http://www.youtube.com/watch?v=2lQX3cOAbes

RWD_cossie_wil

iTrader: (9)

Fair enough, as I said, I don't really know a great deal about it. I was thinking have a down-geared roots blower for the bottom end, would be nice to have v8 torque from a 4 pot. Have you got any links/pics of some twin charged engines?

So, ideally you would have a roots type charger' blowing through the turbo?

Stavros

No, dont need to downgear anything, you just run the right supercharger at the right revs so you get the airflow you want and not overspeed it at the top end.
And its the other way round, always blow turbo through supercharger, as per delta s4.

And you get better than v8 power delivery, way better, brings in the turbo out of nothing, so dont really need to go too bananas with the supercharger really, depends on the spec and how you want the power delivery.

If you spec it right you also get mentally low pre-turbo backpressure, meaning you can run rediculous amounts of ignition without det.

Only thing you have to take care of, barring the amount of room, which makes it a near on no-go on most cars, is the charge temps, which are much higher, hence why the S4 used 2 massive intercoolers, rather than the 1 of that size that most car sof that power would use.

Supercharger bypass was only used (IIRC, and contrary to popular internet bullshit) off and for light throttle on that car as engines seem to behave quite strangely when letting off the throttle without it it seems from what testing ive seen people do.

Main problem with any setup like this is when it comes down to it, it soon becomes more bother than its worth, mostly due to lack of room and amount of custom fabrication needed.
I mean, why try and make your turbo 4pot behave like a V8 when itd be cheaper and easier and more reliable to just V8 it anyhow. Or even run ALS.

RWD_cossie_wil

iTrader: (9)

I was looking at it from a cheap conversion point of view, as a mini cooper blower is around £100, and I recon there is enough space down the inlet side of a cossie engine to mount it, as per mikes pic, as the later 4x4 belts the power steering pump is on the exhaust side.

Stavros

Its 2 to 3 times the length of Mikes one, but would work better, as using a centrifugal one like Mike did is an utterly retarded idea, and if Harvey did that than his cleverness has gone way down in my expectations.

An M45 geared up but without overspeeding too bad at the redline would just about work, but an M62 would work far better.

Even if it did fit itd be a horribly conplex pipe run tho if you plan to run it before the intercooler.
Certainly dont fit on an S13 without using it as part of the inlet manifold as i tried, and then would need some serious water injection to take care of the temps.

RWD_cossie_wil

iTrader: (9)

M45 is off a Mini isn't it? Whats an M62 come on, and can you get them cheap enough?

Thats why I was thinking roots type, purley for the low end. Pipe work wise, I can't see it being too bad, turbo compressor to charger' inlet, charger' to intercooler, intercooler to throttle body. Would be a lot simpler using a twin pass intercooler so the pipes are both on the inlet side of the engine.

Elwood

http://www.youtube.com/watch?v=ShE-77U2VGI

Nice

Stavros

Will- Some smallish Mercs ran M62, the smallest ones ran M45s tho.
And trust me, plumbing would be a mare.
Supercharger outlet would be facing the bulkhead, and almost touching it, which would be the worst. The rest is simpler in directions, but still cramped as a bastard.

Daviet

my mates just supercharged his s2000 at the weekend,not been in it yet as hes waiting to get it live mapped but still goes well just now and sounds qaulity imo.

RWD_cossie_wil

iTrader: (9)

The roots blowers have thier own internal oil pump etc don't they? Does it matter which way up they are mounted?