3 replies to this topic

[jonb_5]

Hi All,

I am planning to do a fairly decent 1275 engine build, tuned etc bored out to around 1360 cc. Looking around the 100bhp mark.

I have recently discovered I might be able to get my hands on a supercharger from a new mini cooper s.

Would like to know what sort of alterations would be needed to fit to the normally tuned engine, the way i understand it i would think very little??

Any idea what bhp gain there would be?

Thank you for your help,

Jon

[Sam Walters]

Its not easy

lets start externally

new manifolds for supercharger
modify supercharger
pully for supercharger
manifold for carb to supercharger
new fuel tank/modify existing one
electronic fuel pump

now internally inside the engine

Stright cut gearbox because the engine will now develop over 100 pound per foot of torque
stright cut drop gears
might aswell put on a lightened flywheel and back plate aswell as a grey diaphram clutch.
new radator
tapped oil gallery plugs (every engine build should have this done imo)
grinding out the chamber in the head to lower compression (while your at it might aswell put in bigger valves and have it ported)
crank work (tufrided, balenced, cross drilled through the mains)
rods stress relived and balenced (strangely if this was a 998 engine the standard rods are good for upto 160bhp)

probably missed a few things

and to be honest if your serious about it you wouldent be useing any of those kits as they all suck through the carb (carb on the inlet to the supercharger)

you want a blow through setup that way you can use a intercooler.

and you posibly wouldent be useing the eaton e45 super charger as its only efficient to 12psi.

[Wil_h]

There is a lot of sense in what you say flyingears, but a lot is unnecessary. The helical box and drops are good for way more than 100ftlb, the main limiting factor to the drive train is the diff, you'll need a 4-pin type (which isn't mentioned above).

You shouldn't need a new rad if you have a decent 3-core standard one.

Also, all the internals, like crank and rods will be fine in standard form, it's rpm that kills these bits, an SC engine will most likely have a limit of 6k, so no worries. You only need to mod the tank if using a blowthrough system, suckthrough needs no mods.

I agree that the kits available are not so good, and a blowthrough system is better though.

[Sam Walters]

im a peace of mind person!