1320 Autos One / Cooper Rolling Road Project

[Paul@1320]

At last we got back on the dyno today and tested Adam's Mini Mania exhaust 421 manifold, unfortunatley I haven't got the time to do all the comparisons but I can tell you that it out performed the 4-1 at rpm in theory it shouldn't off.

It made 139bhp at 6021 and 124 ft lb at 5089 (4-1 manifold made 135.2 at 6210 and 121ft lb at 5667)this was with the DNA exhaust sytem and a STOCK air filter, we actually lost horsepower with no panel filter in the stock housing and with no housing and airfilter.

This news flash is over for now and when I get 5 mins I'll give you more facts and figures.

[MINIMANIAUK]

Thanks to Paul and his continuing efforts well done!
the 4-2-1 made 10bhp over stock and 5 over the 4-1 , you may be puzzled why it out performed the 4-1 at high rpm also , but bear in mind the 4-1 is designed for the forced induction engine (cooper s) not the n/a cooper and one ,as I said previously the one /cooper do not like the larger diameter exhaust (cooper s size) either ,if you step down a small amount in exhaust diameter from the 21/2 cooper s size the power increases by 3-4 bhp and the peak torque point moves.
Now for something even stranger ..... the 4-2-1 out performs the 4-1 on the cooper S also!! even at the high rpms , I believe the cylinder head is such a poor design that even when the engine is supercharged it still requires an extractor manifold to aid the gas flow through the head and valves -despite the higher gas speeds of s/charging.
This is the reason that ported heads with cam and valves add so much power and torque -we have seen + 32 bhp on the S and + 16 on the cooper/one.
Paul keep the manifold and try it on your drag car,just match the exhaust flange holes to your head with a rotary file ,with a nice smooth radius,(The manifold you have is one of our older ones and the new batch are already done) and try on the strip -the clock never lies - I think you will gain a full 1/4 second
I really do wish someone would make a twin cam head for the Mini

[Paul@1320]

Thanks Adam that was going to be my next question whether we could take the rotary file to it

It would be nice if we can gain some torque from 3000 up because this will lower our 60ft.

I'm not sure if we'll have time to test it before Sat unless I do a couple of all nighters

[MiniPetrolHead]

Thanks for that 1320autos and MiniMania, have always wondered what the actual difference would be between the 4-1 and 4-2-1 manifolds.

So for the Mini One/Cooper does too larger pipe work on the exhaust manifold mean less power and torque?

The results given would sort of explain the reason why i pull away from my friends Mini? (due to manifold type even though she has had cylinder head work done?)

Alex

[Paul@1320]

I forgot to ask the other day Alex, what year is her Mini One??

[MiniPetrolHead]

Its an 03 plate and was dynod at 151bhp after the cylinder head and cam work was done with the new re map, why, would the year of the car have an affect on the performnace?

Alex

[Paul@1320]

Yes your Getrag box has a lot better ratios for accelleration but say over a 1/4 mile she would have one less gear change than you.

At 6000 rpm you are probably at 31 54 82
At 6000 rpm she is at 35 62 91

Also over a 1/4 mile every 100lb of extra weight slows you down a 1/10th so if she had every extra available and you had no extras there could be 200lbs difference.

Dont forget to overlay your torque / hp curve and where exactly is she gaining the extra 15 on you and is she loosing any anywhere??

[MINIMANIAUK]

The exhaust dimensions make a large difference to the one/cooper and move the peak torque position (always ignored) and usually increase the maximum bhp (always an attention getter) the one/cooper suffer a "hole in the torque" with peaks at 2500 ish and 5000 ish- this hole and the filling of is where the real gains can be made, the 421 manifold helps here ,but I believe a lot is to do also with the intake manifold (its length and volume ) will be set by design to have an rpm which it harmonises with the valves, giving best torque at these points. As there are no modified intakes available yet we are stuck with the existing one which has little room available between engine and radiator for a better design.this intake manifold also limits the effectivity of air filter/intake systems being replaced to better ones,I am sure Pauls efforts on the dyno will show this in due course.
similarly on the S the intake manifold is space limited but is designed to aid low down torque-
ultimately big bhp numbers impress , but high rpm bhp gains with torque dying a death dont really do much for performance.
cooper/one tuning has been pretty neglected in favour of the S for which there is an ever increasing list of items available and an easier option cost wise,but in time the one /cooper will have its day-they do outnumber the S in the UK

[Paul@1320]

In an ideal world you would have variable inlet and exhaust lengths for each rpm, so thats why everything is a compromise.

[MINIdriver85]

I'm very interested in this program of trying different solutions on the One/cooper! I'm wondering if and when the testing of different ported heads and different cams will start...I'm a bit confused on the matter and some comparisons could help me understand what's the best head+cam set, because head and cam should be chosen so that they work well together, and some heads might work better with some cams and worse with other ones...

[Paul@1320]

Unfortunatley the demand it seems is quite small and really we need to come up with a combo off parts that work well with a one / cooper and provide agood trq / bhp gainf for your hard earned pound spent.

We have another experimental cam to try shortly which will hopefully gain trq and bhp all over.

It would be nice to get our One to run into the 15s

[MINIdriver85]

Thanks for the reply...well, I hope in one year and a half time you'll be able to find something, as that will be the time I'll be looking for a ported head+cam combo for my one... I'm going to have a complete exhaust system + gruppe M + remap fitted this spring and your test with the minimania header was quite interesting for that, then I'll have to upgrade my gearbox to the S one...and then I'm going to be ready for the head+cam upgrade...so...take your time...but not too much!

[Innuendo]

i have some mods done to my mini one...
MTH Tuner file(98octanes fuel)
bmc cda
cooper S fuel pump
cooper S gear box
cooper S throttle body
decat

Its making around 130\140bhp..
next steps
Camshaft
and exhaust system...

After reading all this what is the ideal exhaust system for my car? SuperSprint? LARINI?
Other thing...

I have a cooper S engine at my disposal and i have been taking some parts...
i am going to switch my valves to the cooper s valves...
But i am thinking about "working" the cooper s head and put it in my car...

What do you recommend? port and polish to the intake?(someone said do me not to mess with the intake.....)

Other thing.. are there better intakes than the stock ones for our cars???

[Bhozar]

Mini Mania's manifold for the Cooper is supposed ot be quite good and show gains.

In the intake side, you could do independant throttle bodies.

[Innuendo]

the problem with itbs is that to fine tune them is a big problem... and my car isnt a track day car.. its my everyday car .. it has 134000km's and still rolling!!