998cc turbo advice/help needed
Turbo Mini Forums

Hey guys, im new to the forum, had a few minis in my time but its my first turbo one so thought id join to get advice and meet fellow enthusiast! 😊

Just bought a 998 turbo mini project off a friend of mine, doesnt need alot of work to get it on the road, needs radiator fitting, new battery, welded or new passenger step and some welding behing the dash, probably a good tune up aswell, but as its off the road anyways i was wondering if i could get advice on a couple of mods? Maybe a little bit of extra bhp with safe psi so i dont melt it. Just bought a fletcher twin core rad to go in, been told the cooper s head (12g295) on a 998 turbo is best way to go to increase cyliner volume? And possibly some 1.5 rockers aswell. But what would or have you lot done?

Current spec:

Engine-

998cc engine and head standard.
Metro turbo, manifold and carb.
Cone air filter.
Fuel pressure regulator.
Electric fuel pump in boot.
1275 gearbox.
Rc40 exhaust.

Brakes/suspension-

Vented discs.
Green stuff pads.
Gmax shocks.
Hi-lo suspension.

Other mods-

Wide arches.
13x7 wheels.
Bucket seats.

Lose the 13 inch wheels to start with

Check out Paul s project he's the 998 guru

Wil_h has a epic 998 turbo aswell

My thread has a few bits but I'm supercharging mine

The two builds Chalkie mentions are very good reads, there's lots of info in there.

For a more basic 998 build have a look at Shauna's build thread in the 'Show us Yours' section.

If the engine is standard then the compression ratio will probably be a little high, you're right in that a 295 head is the best/easiest way to go but they are expensive and are all very old so likely to need new valves, guides etc. Other options you have are get the chambers on the standard head modified or fit a modified 1275 head. Info on both available through a search.

The T3 off the metro turbo is a little large for the 998 I think, might be a little laggy on the road but would probably give you a good kick when it comes on boost!

Don't know whether the 1.5 rockers would give you much improvement, 1.3s would be better I believe. The best performance jncrease would be found with a 295 head and a different cam shaft.

All in all the spec sounds fine, just make sure that the compression ratio is right for the boost you want to run.

Edited by Mike-998 on 16th Dec, 2015.

http://www.turbominis.co.uk/forums/index.p...tid=469104&fr=0

Whats wrong with the wheels lol id love to have 10's but that means converting the brakes and atm i wanna focus on the engine. Im lookin through a few threads and gettin bits of ideas here and there but figured itd be easier making my own thread and gettin advice based on what i have and want 😊

Ah cheers mike, thats helpful, yeh ive noticed the heads are rare/expensive, wasnt sure if i had other options but i might look into getting mine modified if it works out cheaper/better! But yeh just a basic set up thats nippy but is t gonna blow up is all im after, ill be buying a bigger engine and tuning that 1 over a long period whilst i run the engine thats already in.

In which case just do a little bit of maths and get the head modified to make the compression ratio somewhere between 8.5-9 and run boost between 4-7 psi as the metro turbo did. Will probably do you fine until you have built up the other engine.

http://www.turbominis.co.uk/forums/index.p...tid=469104&fr=0

You could always look at using Megajolt. One of the things you need to get under control for a reliable turbo is the ignition timing so although it might not look like its going to give you massive BHP increases it probably would allow you to run more boost safely.

If you upgrade the engine in the future its easy to swap it over too.

Ive been looking into mega jolt, but its not something im familiar with or have worked with before so dont really know what im doing or how it works, id need help when it comes to stuff like that.

On top of the above I would say fit intercooler.
And remember if you want to fit a 12G940 you best also pocket the block.

Dazed and Confused....

I think I've got a list of my engine spec on the first page of my thread. Depending on what sort of power you want you don't need to have an intercooler, I've ran mine for over a year daily safely on 8 then 10psi. A 295 needs to unskimmed really or you could put a 940 and pocket the block to get the right compression

Edited by Shauna on 16th Dec, 2015.

They don't die, they just get faster!