Low compression engine & Supercharger

[jackb_ms]

I have been reading some very interesting books on blowers.

I at the stage of choosing which engine i will use.

I don't think i would like to use a K engine due to its high compression ratio and it's fragility passed 250bhp

Which engine should i use? a Ford or Vauxhall? any other idea

 

Jack

[AMMO]

Duratec. Lighter than a VX. A friend wants to turbocharge one. Personally I would think a supercharger would be nicer. Look at Eaton superchargers. They have their own oil sump and now incorporate a system which means the boost only comes on when the engine is under load. The other option is the Swedish made Opcon Autorotor.

 

AMMO

[scooby dooby doo]

the "fragility" of the K passed 250 bhp is because its generally doing about 9000 rpm to get that much power, most engines get uncomfortable at that speed ❗

 

That said, if you want huge power I suspect an Iron block may well be a better idea - although plenty of supercharged K's have been built into Elises etc..

 

HOOPY

R706KGU Hoopylight R

[jackb_ms]

Cheers AMMO

 

The layout i'm interested in is it's the blower being fitted after the TB. According to my reading the mixure air/fuel should cool down the air enough to not have to use an air cooler.

 

It's look like the Roots units are a better unit fitted with small-ish capacity engines. I believe the Eaton unit is a Root.

Do you have a name for this Eaton unit?

 

Jack

[AMMO]

Jack

 

I've just been rumaging in my garage where I keep a filing cabinet full of files relating to old / abandoned projects. I found a file called "Superchargers" dated Septemeber 2000. I don't know if this information is still current.

 

The Eaton Supercharger you will probably need is the M45 for 2.0 L to 3.0 L. passenger cars. The company that I was talking to at the time is Supercharger UK in Andover on 01264 334277.

 

Hope this helps.

 

AMMO

[jackb_ms]

I've called them this afternoon.

Very helpfull people. they redirected me on www.magnusonproducts.com

Did you heard about Mr Corki Bell? He suppose to have written a book on supercharger.

Do you have any info in your "superchargers" folder by any chance?

 

Other little question, can i fit a supercharger without lowering the compression ratio first? If yes how?

 

Jack

[Bill Shurvinton]

I've got a copy of the book if anyone you know is ever lurking in the fleet area and wants to come up to my hampshire hill and pick it up.

 

For a 7 a screw compressor is not the best choice. Centrifugals are

-lighter

-smaller

-more efficient

- easy to package

-allow you to keep the stock intake (including throbble botties)

 

BUT have a different boost pattern. The boost curve is exponential, so you get a little at low revs and a lot at high revs. Now to me this is what a se7en needs, not a unit that pulls 2PSI boost at idle and makes your car behave like it has a V8.

 

Now in all things you pays yer money etc. Ideally you still want a car that revs and revs, but you want 50% more power at the high revs, not 50% more at low revs and 1000RPM cut of the limit (NB extreme example).

 

In terms of CR, if you have mappable ignition you should be able to run 6PSI or more without dropping the compression at all. More with water injection. More than that and you should start thinking about less (unless your engine was 9:1 to begin with.

 

Hope this helps

 

Bill

[Mr Locust]

here

 

get the info and see if it can be repackaged??

 

Ian

 

Green and Silver Roadsport 😬

[jackb_ms]

Bill

Can i take on your offer?

My 21 will need to get some exercise after a week of doing nothing.

What about saturday?

 

You don't have a blower hidding in your garage by any chance, which i could study?

 

I do like the V8 feeling, lots of low down torque and plenty of power higher in the revs. It's what my VVC is doing now.

 

The turbotechnic option is too expensive for what it is, at £7.5K. The only bespoke parts is a second injector.

The plenum they use is pretty but i can have one made for £400 and a set of low compression piston are not this expensive. They must do a least 50% pure profit on this installation.

And i would like to fit the blower after the tb not before, to use the petrol as an air cooler.

I still would like to see an installation. If someone know about an Elise with a TT installation.

 

Jack

[Bare]

It's been my observation that Turbocharged cars almost always outperform Supercharged ones .. at the drag strip and 'ahem' on the street.

Barring of course the High specification, extreme cost purpose designed Machinery.

Turbos provide the power faster and earlier.. asuming equal competence of the setup.

Boost power 'rule of thumb' indicates that 1psi = 5hp.. and this seemingly holds true below about 2 bar.

Theoretically you could run 15psi (pressure system of yer choice ;-) BUT to do so you will need electronic Boost management, Ignition retard, and Water injection.. at a bare minimum. We won't even mention Sodiom or Ni90 valves, Forged Pistons/Rods/Crank, or oil sray jets for the piston crowns.

For this you will get 'Heart Attack' acceleration.. beginning at about 3 k and growing rapidly up to 5.5 k.. unless 'pupose designed Turbo'ed engines seem to max out efficiency wise below 6k.. just no apparent advantage in spinning it faster.

Thrilling:-).. but having been 'foo;ing' with my Turbo Saabs since '84 I really would not want it a 7.. Power is simply too unsubtle, and tricky to control precisely (for me it's all one can do to keep my Saab (9000)in a straight line under Boost.. and it weighs in excess of 3000lbs!).. a marked contrast to the light precise nature of my 7.. kinda like putting on heavy work boots after being barefoot.

But as always 'yer Mileage May Vary'.. just be carefull what you wish for ;-)

[Anthony]

Hi Bare, apologies for the hi-jack, but any suggestions on 900 turbo upgrades, before I go down the Abbott hybrid turbo route ( call late 97 2.0 HOT )

[Bill Shurvinton]

Jack,

 

Saturday looks good. E-mail me on bill@shurvinton. fsworld.co.uk and I'll send directions and the like. Don't have a blower on me, but look under the bonnet of any merc 'Kompressor' for a good idea. You can get M60s on ebay all the time as the american market use them quite a lot.

 

Bare: you are right that a turbo is more efficient and therefore,all things being equal will give more power. The only reason top fuel dragsters use them is that turbos are banned. You can get turbos to work very well in a se7en, but it takes careful tuning and sizing of everything to get the right power delivery.

 

[normalbloke.29]

My Caterham is turbocharged(and fitted with a YB lump) Can vouch that it works VERY well ta.