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Turbo Help


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#1 A1111j

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Posted 04 December 2021 - 05:05 PM

Hi everyone I am doing a full restoration on my mini and I am the point of doing the engine and gearbox. I have a couple question about turboing it.

This is my spec so far
1330 block (at the machine shop getting rebored)
Kent 266 cam kit
Pre verto clutch with X pin
Minispares mse6 head

1. What sort of bhp/torque can you run for the gearbox to be reliable? This car is going to be my daily drive I don't want to have to rebuild the box regularly. I don't really want to have to go sc drops as they are too noisy.

2.What pistons would you recommend? And are 12g441 conrods good enough for the job?

Any help would be much appreciated
AJ

#2 nicklouse

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Posted 04 December 2021 - 08:30 PM

Pistons depend on what you need to get the compression ratio to why you need.

 

your gearbox and drops will be fine if they are in good condition. Either check everything your self or send it away for a check and overhaul.



#3 Ethel

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Posted 05 December 2021 - 12:08 AM

Plenty, it's not so much set figures as how you get them. Driving like a total loon will take a toll. Not dropping the clutch or smacking gears in at revs way beyond where there's any point should avoid bits letting go. It really is worth paying attention to wear & tolerances, it'll accelerate faster than the car.

 

Reasonable oil, regular changes, centre oil pick up, maybe an uprated layshaft, and you can expect to lose your driving licence before your gearbox, if it's for the road.

 

Mokespider's posts on transfer gear idler alignment are worth a read. I think we still have others on oil feeds & pinning idler thrusts, though debatable if they're necessary.



#4 A1111j

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Posted 13 December 2021 - 07:38 PM

Ok thank you for all the help. I know what have to do to the box and what pistons. Do you know what sort of compression ratio I should be running for 120bhp and what boost I need?

#5 Ethel

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Posted 14 December 2021 - 12:45 PM

I'd think that would be achievable with a stock engine & intercooler. The ERA Min  is supposed to have cranked out 95hp with a CR of 9.4.  It was a plain Metty Turbo minus the boost control, so 7psi IIRC. That'll have been on full fat petrol though.



#6 A1111j

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Posted 26 December 2021 - 01:00 PM

I am going to aim for 8:5.1 just to be safe. Anything else you guys recommend? I am thinking of getting clubman gear set with helical drops hopefully it wont be too noisy.

#7 Steve220

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Posted 28 December 2021 - 12:50 PM

I am going to aim for 8:5.1 just to be safe. Anything else you guys recommend? I am thinking of getting clubman gear set with helical drops hopefully it wont be too noisy.

It'll be fine once in 4th, there's barely any noise then. The MSE6 head isn't ideally suited for turbo, it's not using stainless valves to handle the heat and the porting won't be ideal for boost. You need to match the chamber size to piston dish size to work out the ratio you're ideally after. You need those figures first. A lot more planning is needed here.

 

The 266 cam is quite a nice one for driveability.



#8 mini13

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Posted 30 December 2021 - 11:35 AM

General rule of thumb is as long as you have an x pin diff, the rest if the box will be ok until around 140-150hp as long as you have some mechanical sympathy. The turbo clutch will start slipping by then,




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