Turbo build... Experience needed
Turbo Mini Forums

Pretty new to the turbo scene.

Looking to turbo my clubman Gt

I would like people's opinions on any changes they might consider and also anything I might have missed

Here are my specs at present

35.6 x 29 head
1293 block
Omega 10cc cast Pistons
Intercollegiate (maybe mr2)
Mega jolt
Standard controls ( is it worthwhile getting these balanced)
Arp rod bolts
Kent kc500 cam
Rts clutch
Gt1752 turbo

Would I need any bulkhead changes to my clubman?
What gearbox would you recommend

Thanks in advance for your help

You don't need to created power with high RPM, so no need for balanced conrods or ARP rod bolts. Use standard A+ rods and get the clutch balanced though.

Cross pin differential is a must. The rest of the gearbox should be good for roughly 130 hp, if it's in good condition and you're kind to it.

The rest of the list looks sensible, but you now need to pick a power figure, estimate your boost, decide on compression ratio then build your spec to this.

Edited by PhilR on 4th Mar, 2016.

Thanks Phil

I was hoping for around 150bhp.. How do I work out my boost and compression ratio from this?

Looks like a decent spec for 150hp and a bit more,

as phil says, dont need to wory about the balancing, although personally I do like to fit the ARP's as they are pretty much fit and forget for future rebuilds.

compression wise, you'll need about 28cc in the head, that will give about 8.8:1, might pay to runn the pistons down the bore slightly ( ie not get the block decked) to get a little less CR so you can run a bit more boost if you want to.

oh 28cc is about the most you can go to in the head easily, although it is possible to get some more out. also might be worth going for a 31mm exhaust, Benross and TurboPhil on here both do good head work and would be able to advise better.

gearbox wise, definatly fit a Minispare Xpin diff. at 150 your on the edge of what the std gearkit will handle, some get away with it some dont ( probably down to driving style.) I would sugest going for the minispares evo gear kit, its what most people here run and is good for over 200hp. drop gear wise, you will be ok with the std helicals which will give you a quiet 4th gear.

Edited by Joe C on 5th Mar, 2016.

BHP: estimate the power you'd get if your engine was NA - I'd guess around 90. You'd have to multiply that number up by another 66% to get 150, so you'll need 66% more air. An NA engine consumes air at an atmospheric pressure of 1Bar so boost needs to provide the extra 66%... So thats 0.66Bar (or 10 psi).

For several reasons, that's only an estimate. I'd imagine 9 to 12 psi should get you close.

If your intercooler does its job and your MegaJolt and fueling are set up well, 9.8:1 8.8:1 CR sounds good to me. I'd personally make a habit of only using higher octane petrol.

Edited by PhilR on 5th Mar, 2016.

do you mean 9.8:1 phil ?

Medusa + injection = too much torque for the dyno ..https://youtu.be/qg5o0_tJxYM

Blimey, no! (Was thinking about 98RON while typing)
Edited, changed to 8.8:1 CR

Edited by PhilR on 5th Mar, 2016.

Sweet baby Jesus... That has just filled with even more dread...lol

As above but if you want a very smooth engine its well worth getting. The whole rotating assembley balanced I.e. flywheel ,clutch back plate and crank pulley, crankshaft, its a pleasure to drive sutch a smooth powerful Engine

Edited by BENROSS on 5th Mar, 2016.