Advice about supercharging a 998.
Turbo Mini Forums

So having mostly lurked about here for a while and reading various build threads, I've pretty much settled on supercharging the existing 998 engine I have in my Mini, but I do have some questions:

Firstly and I suppose most importantly, the supercharger itself: The Eaton M45 seems to be the most popular unit to use, though people seem to have better things to say about the SC12. The question is: Are there any other superchargers I should be looking at as an alternative to these units?

Secondly: Blow-through or suck-through? I've done a fair bit of searching around the forum about this and I've not really been able to get a decent feel for the pros and cons of each. Suck-through seems to mean you can do what you like with the carb, but I'm unsure about putting fuel/air mix through the charger itself.

Thirdly: The carb. I'm assuming that even on a lowly 998 I'm going to need to move to a 1.75" unit of some kind?

Finally: Exhaust. I'm currently running a regular stage 1 kit, so the freeflow manifold and RC40 twin box unit. Is that going to be sufficient or am I going to need to move to an LCB, (or god-forbid three-into-one) setup?

As a note, I'll be doing this project in conjuntion with a complete strip and rebuild of the engine and some long needed bodywork repair. This is not going to be a rush job of any kind, (if only because there's no way I'm going to be able to afford to buy all the parts anything other than piecemeal) so if anyone has good suggestions that might otherwise seem inconveniently time/effort consuming then I'm all ears.

Thanks!

What is your objective?

Lots of power?
Good drievability?
Decent MPG?
Something to show off?

In generat the M45 is not an ideal SC for a 998, net even a 1275 either really. The SC12 is better, but there are no install kits available so you're on your own.

Suck-thru is easier and when considering everythin, probably the best solution for an SC.

The honest opinion you'll get on here is just turbo instead.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

Save yourself the hassle of being branded the biggest gay in the village and go turbo!

You will most likely get more power, more fuel economy, better drivability (if you size your turbo appropriately) and a lovely wooshy noise if you fit a dump valve

Also mapped ignition would be a good idea :)

Welcome to TM BTW!

If something is worth doing, it's worth doing half of.

You can buy a kit for the sc12 from aus. I can put you in touch with the chap that makes them. They top out at 12psi. I doubt you would make 100bhp on a 998.

Have a look at my build thread to see the sc12 kit etc (search for 1275gts)

On 5th Jul, 2013 Tremayne said:


Showing off is always nice! There is also just something about the *sound* of a supercharger.

Reading up on RTS Clutches

Edited by Tremayne on 5th Jul, 2013.

There was on in the for sale section recently. I think mine came from new zealand. It cost me about £750 in total I think (kit and charger), so better value than eaton chargers and kits.

I have an Eaton M24 for sale.

Perfect size for a 998.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

That might be a good option if you are comfortable with your fabrication.

i recon at 77 bhp ATW my sc12 998 was about 100 at the fly.

Edited by gr4h4m on 5th Jul, 2013.

I run a supercharger and I don't care the TB is on the wrong side.
VEMS + 12 PSI + Liquid Intercooler = Small Bore FUN!

Regarding the blow-through / suck-through choice, are there any problems associated with having the air/fuel mix going through the SC and intercooler rather than just air?

Suck-through seems to make life very easy, so I'm wondering what the downsides are.

yeah, you dont want fuel and air going through the intercooler,

I saw a suck through turbo'd beetle at pod a few years ago that had a chargecooler after the turbo, it had a backfire or somthing and the charge cooler exploded....