10 replies to this topic

[pakgorgor]

I'm pulling the motor out to rebuild the gearbox. Plan on changing to central oil pickup at the same time. Wondering if it's worth changing some other bits while I'm at it:

 

- MED ST1 flywheel/clutch? Or just change the clutch plate?

- Rebuild diff? Or cross pin diff?

 

The car is driven on public roads only (no track and no plans to track it). It's got a K&N filter, LCB, and playmini cat back. I'd like to improve acceleration so that's why I'm considering a lighter flywheel. Also thought of changing to 1.5 rockers but have heard mixed reviews for an SPi.

 

Please share your thoughts.

 

[Bobbins]

I've recently fitted a MED ST1 kit to my JDM (Spi/Mpi) and it's worth it just for the smoother running due to the balancing. Pickup is better as well, noticeable in mid-upper rpm but it's the balance I really noticed.

[Wiggy]

If you have the pennies, changing the head for a more performance orientated one will net you the most gains. Plus unlocking more of the potential from other mods.

Or lightening the car would help.

If your running 13" wheels, they tend to be very heavy (for a Mini).

[imack]

I'd fit a minispares cross pin diff for reliability.

[pakgorgor]

I've recently fitted a MED ST1 kit to my JDM (Spi/Mpi) and it's worth it just for the smoother running due to the balancing. Pickup is better as well, noticeable in mid-upper rpm but it's the balance I really noticed.

How firm is the pressure plate compared to stock?

[Bobbins]

Doesn't feel any different

[viz139]

You havn't stated which model of SPi you have so if its a low compression one you could fit high compression pistons and a better cam.

[brivinci]

If you have the motor out, and are going to be going down the more-power route, it would be a good time to change the cam for something a bit hotter. Swiftune, MED, Piper, etc all have injection specific cams. Its is a motor out job so makes sense to do it now. You will not see much in the way of overall HP but you will see an improvement in drivability and more torque down low. As stated above, the only real way to see/feel a nice bump in performance is a proper head. Cam, headers, exhaust, lifters, all add a little here and there but when combined with a proper head, it all comes together...with the ceiling being around the 85hp mark for injection cars.

 

Central oil pickup is a good idea to do, as is a cross-pin diff for added strength. That will not add anything more then piece of mind though. If outright acceleration is what you want, switching to a 3.44 final drive will give you some added zip off the line...but you will sacrifice top speed/RPMs on the other of the needle. 

[pakgorgor]

Thanks for all the suggestions! I will look into all the options and see which fits my budget.

[dmandan]

I've got a 94 spi cooper, had the head done by a pal bigger inlet valves ect ect, 1.5.1 rockers and contrary to expectation it sailed through emissions, i've got st1 kit and k&n induction (k&n made a massive difference by the way and you can get from demon tweaks for 50-60 quid) over 4k rpm it goes like stink now. i've got low compression on cylinder 2 so the engine coming out shortly but it's still putting out 71.5hp at the flywheel.

 

I'm going to do slight rebore and a cam so fingers crossed we'll have more horses next year.

 

If anyone's got recommendations on a cam I'm all ears.....

[dmandan]

https://www.demon-tw...kit-k-n57-0082/

 

thi is the link for K&N induction kit it's a shade under £100 from minisport takes 5 mins to fit and will never take mine off now....