helical drops revue on 190 bhp +
Turbo Mini Forums

well , looking for the noise in my transmission , i started with the drop gears, and so hoicked off the side case ..

as you can see ,they look pretty much just as they were a few years ago when they went together ! most interesting .










now,bhp and torque wise ,what have they had to put up with ?

well, its had 188 bhp and 184 lbs ft at the shootout ,16 psi boost .

its since run a steady 19.5 psi at avon ,and peaked on the gearchange at 23 psi boost .(and thats with a nice flow of air through the ic ,something it did not have at the rr )
so i think its safe to say over 200 lbs/ft and 200 bhp ?


regards
robert (still looking for the noise ;()

Edited by robert on 5th Sep, 2010.

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

What endfloat have the idlers been assembled with?

Edited by minimole23 on 5th Sep, 2010.

cant remember moley , id imagine whatever is in the book for them .it was 1998 when i built it .lol

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

I ran my std drops for some 60k and never had any problems.

What exactly was the noise like, and when did it occur ?

What clutch ?

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

Ha fair enough.

I was just looking for reasons why yours has held together whereas so many others have failed.

12 years is bloody good going not have had to rip the engine apart for a rebuild. (by a previous thread the gearbox clearly ripped itself apart so doesn't count!)

Is your transfer case cracked where the idler gear sits? Looks like it's got a spider sat in it...

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

Thats impressive Robert. How many miles have they seen?

If something is worth doing, it's worth doing half of.

I've said it before, the earlier smaller idler bearings were prone to failure, and drop gears have built up a reputation from failures of these.

The later, larger, idler bearings are much better. I have found them totally reliable.

Fastest 998 mini in the world? 13.05 1/4 mile 106mph

www.twin-turbo.co.uk

Thanks for the info....very good to know as my straight drops just about send me insane after 20 minutes or so....

I did munch all of the teeth from my laygear recently, so I installed the clubman straight set, but I may switch back to the helical drops given your info as I am only N/A 1380 right now with boost in the works...

PS....Vegard, you don't have to say I told you so!

Eric
my pics.... http://www.fototime.com/inv/7AAF37CF3EFA956

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

good point steve ,ill check them tomorrow.

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

very intresting robert, iam i correct in saying you ran the helical drops with a SC gearset ?

the milage would be intresting ...... ?

is there any wear on the 1st motion shaft bearing ? and the gear and head set ?

yes steve , the staight cut clubman set from min-its , trannex i think .
no wear on the bearings i can find . mileage id guess at around 5k miles in two years .mostly at 175 bhp ,but raced at well over 190 bhp .

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

well pleased with your results robert top man.
one thing is that no more SC drps screaming if you dont want it

Robert It is fantastic that you have final put an end to this Drop Gear Myth I have been runing a set of hel's in a customers Racer for 3 years at 120 HP and well over the 100 in torque and like you we have never seen a problem,
well done that man.

Robert, its brilliant news and shocked most people i think , but i do think i have found the reason why they have lasted ??

Your just not driving it hard enough. lol

Rick

its so true lol

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

I agree.....

Combe this year???

bit more info..
cleaned up the gears ,here are some pictures of them ,they look fine ..







found i didnt have the right washers to do the end float on the idler ,so selected another idler that was .3mm thicker ,,

but have a look..

it doesnt look as well finished ,and the teeth on the turbo one are rounded on the tops ,,was there a better idler fitted to the turbo cars ?

notice its machined on the sides not rough cast like the other ..

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

9.85 @ 145mph
202mph standing mile
speed didn't kill me, but taxation probably will

allegedly there was something about the MPI drops that was uprated.

Saul Bellow - "A great deal of intelligence can be invested in ignorance when the need for illusion is deep."
Stephen Hawking - "The greatest enemy of knowledge is not ignorance, it is the illusion of knowledge."

this is definately an original 1987 turbo one .( i mean the gear,not the bearing )

Edited by robert on 8th Sep, 2010.

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

thats it!

I remember the article where Calver was banging on about it now...