20 replies to this topic

[minicooper1.3i]

Hi

Having driven an 1993 SPI Cooper for many years and now I've just picked up an 1997 MPI Cooper (non-sports) with 83K on the clock (a lot of miles i know, but quite a bargain ) However, the performance in 4th is, well, C**p! There just doesn't seem to be any oomf above 3000 revs in top and getting above 70 takes for ages. My old SPI Cooper would do over 100 , eventually, but without complaint.


Has anyone experienced similar poor top end power on MPI's that have been around a bit?
If so, how did you rectify it?
I've already changed leads and plugs and fitted a K&N air filter to let it breathe more easily.

Any help will be gratefully received!

Thanks one and all!

[CooperTrooper]

change the diff to 3.1 or 3.44, you will lose a little top end but get greater accelaration through the gears, made a huge difference to my mpi.

Edited by CooperTrooper, 03 September 2007 - 09:06 AM.

[minicooper1.3i]

Cheers

Diffs are about the only thing I don't know anything about on minis.

Would it be easier to swap gearboxes from my SPi to MPi, or are they both the same? They're both driving 12" rims.
How on earth do you find out what is alredy there?

Thanks!

[CooperTrooper]

I think all later mpi's were installed with a 2.7 final drive which is way too tall for the car (unless your doing long miles daily for which you will get more mpg) just buya new final drive and take the old 2.7 one out...

[miniboo]

and i will give you money for the 2.7 FD

[redhotmini]

dunno why but mine seems to be hellishly quick compared to others, but cant see any reason why as its bog standard. i do give it a good spanking every now and then... unless someone fitted a different diff in mine but it seems to be really relaxed at 70mph, but i suppose that because i had a 3.7 or something stupid in my last mini

[Mini_Magic]

Mine has a standard 2.7 diff, still pretty quick and responsive in 4th at 70mph. It doers around 2500rpm at 60mph and it's pretty quiet and smooth at those speeds, for a Mini.

[redhotmini]

mine isnt quiet at all but then the downpipe is completely ******* because of a brick in the road.

[a_mini_thing]

Mine is pretty quick and the exhaust is blowing. dont know if it makes a difference thou. anyone else finding the exhaust catching the top of speed bumps at low speeds? go over at 5mph and it scrapes.

[Mini_Magic]

anyone else finding the exhaust catching the top of speed bumps at low speeds? go over at 5mph and it scrapes.

Nope, even though my cat is hanging a bit low!

Edited by Mini_Magic, 03 September 2007 - 07:59 PM.

[minicooper1.3i]

Had a hellish time today driving back from London, lost #1 & 3 cylinders so had to limp home along the A1 in rush hour traffic with just 2 cylinders doing a pathetic 30mph uphill and a old-fartish 50 down. Apologies to all, but I didn't do the Mini reputation any good today !

Found the fault though. Fitted new sparks and HT leads yesterday, and, although they were from Mini Spares, the rubber sleeving which covers the spark plug was two long on some leads, so that after a while of being squashed against the cylinder head, they pushed themselves off. A little attention with a Stanley and firing on all 4 again.

Still, performance is nowhere near what I used to get from my old spi, which would pull uphill from 70 with just a deeping in exhaust noise. And that was bulk standard too. Although I did hear rumour once that Rover's first launch of the SPI was more powerful than the later releases. Dunno if that's true or not.

Back to the MPI then, I ragged the a**e off it on the test drive, more out of frustration than anything else, and by taking 3rd to 70 I managed to get 85 out of fourth. But it was a fight and it wouldn't give anymore. Even downhill. It definately needs a new clutch, but I can't believe that would hold it back at the top end.

Anyone got any speed records from their standard MPI's? I'm not condoning speeding, naturally, but its nice to know there's power in reserve for when its needed. Might as well have my old 998 City E back again otherwise!

My best was 105mph with two of us in and loaded with holiday luggage on the French motorway! But that was the SPi.

[Sprocket]

If the MPi is running well at high revs and at low revs, the injection system is working well.

The 2.7:1 final drive really does make these cars sluggish. You need to take the RPM and the road speed then using a gearbox ratio calculator, you can then work out the final drive ratio. Expect there to be up to a 10% difference at 30mph and a 5% difference at 70mph, in the indicated road speeds.

If its the boggo, or near boggo standard 1275 MPi with 63bhp and the 2.7:final drive, then thats how it is, nothing wrong with it. One reason I recon MPi's have lots of trouble with the gearbox, the 2.7: FD just strains the gearbox so much more in fourth.

As for one of your statements, be aware that the max torque of these engines is in the region of 2600 to 2900 rpm so anything over that the engine is not producing max torque, and it will appear worse in top gear with the 2.7:1 final drive. Simple answer is to drive the car properly and change down a gear

Edited by Mini Sprocket, 03 September 2007 - 10:37 PM.

[Elisha-The-Cooper]

mines pretty cherpy but as chirpy as id like, mine is superb on the motorway, it can run a canstant 100-110 with no problems, but thats my maximum, any 1s mpi got fater than 110? as if my foots to the floor even downhill thats all ill gt out of her, hmmmm


x

[Elisha-The-Cooper]

lol and everytime i see coopertroopers name i sing "super trooper lights are gonna blind me, do do do do doooooo" dont know the words but its abba. x

[minicooper1.3i]

If the MPi is running well at high revs and at low revs, the injection system is working well.

The 2.7:1 final drive really does make these cars sluggish. You need to take the RPM and the road speed then using a gearbox ratio calculator, you can then work out the final drive ratio. Expect there to be up to a 10% difference at 30mph and a 5% difference at 70mph, in the indicated road speeds.

If its the boggo, or near boggo standard 1275 MPi with 63bhp and the 2.7:final drive, then thats how it is, nothing wrong with it. One reason I recon MPi's have lots of trouble with the gearbox, the 2.7: FD just strains the gearbox so much more in fourth.

As for one of your statements, be aware that the max torque of these engines is in the region of 2600 to 2900 rpm so anything over that the engine is not producing max torque, and it will appear worse in top gear with the 2.7:1 final drive. Simple answer is to drive the car properly and change down a gear

Sorry. But changing down to 3rd at 70 and expecting it to accelerate is asking a bit much isn't it? Anyways, after yesterday's fun with the sparks and leads and subsequent thrashing, its perfoming much much better this morning on the motorway. Nice a lively up to 70 in all gears and still pulled reasonably well from 70 up to 80. Couldn't go above that because of too much traffic. Still, promosing result. Think I'l leave it at that, change the clutch, and see about and S conversion next year.

By the by, does anyone now if MPi's need rolling road tuning, or is it all ECU controlled?