Gearbox - std vs st8 cut
Turbo Mini Forums

Hi guys,

I thought it was time we had a bit more of a debate on this topic... just becasue I was thinking today about how many miles I've managed on track this year.

I've managed about 150 miles this year and all on a std gearbox with std drop gears. The only mods are a central oil pick up pipe (nowt to do with the box I know but some disassembly required o fit it and I checked a few bits for wear while it was apart) and a x-pin diff.

150 miles might not sound like much but its all been flat out "race" miles.

Not bad for dealing with around 120bhp and 150 lb/ft I didnt think...

Your views gentlemen!

Alex

AlexF

I ran a 1310 Turbo with 112BHP at the wheels as my daily drive for 2 years on a completely standard box and drops.
Must have done about 15000 Miles
Not race miles I know, but I did enjoy booting at any opportunity

I was just waiting for something to brake though, but I never held back on the WAAA pedal

How much longer much longer It'll last is anybody?s guess. Now in the hands of a new owner (hope it does last him though)

I am planning on Str8 cut gears, drops and a different diff (possibly an LSD if not a least a different diff pin) for my next project though.

Think Dave?s the Gearbox Guru isn?t he.

I?d really like to know what he think is really necessary.
For my next project I really want to start from the bottom up making the box diff and block as solid as possible
So when I want to add more power by developing the top end of the engine and turning up the boost I don?t need to go back and redo stuff in the bottom end of the engine.

I?ve seen Vmax does a 5 Speed box with 4 Str8 cut and the 5th helical. 4 for the 1/4 and track and 5th for the motorway, as my project will primarily be a road car.
Anybody any thoughts/opinions on this?

My JK gearbox is damaged

The diff pin broke ripping though the casing so bad the diff bit fell off its chipped a tooth on one of the gears to

Dave do you fancy cheking out my gear set and seeing if its repairable? i would like to get another sccr box built up as ive got the standard one in the car at the moment

If Dave can't help mate I can and I'm only down the road!

alex

AlexF

I am running A+ standard everything at the moment. I think I am going to go with a 4 syncro Mini Sport kit and drop gears.

Personally, I reckon it would be nice for someone to manufacture a closer ratio gearbox to cater for wider power bands and taller final drives. I'm finding that my idea of running a 2.76 final drive with a 2.54 SC first will be like a normal second. I would ideally like my gears to be like this compared with a A+ box running 3.44 on 10" wheels.

1st= 1.4th 2nd=2.7th 3rd=3.9th 4th=5th

If you know what I mean.

I might actually try a rebuilt helical box first.

Bugger off, I'm getting there.

Why not use a standard S/GT set?? A bit closer than standard but not as close as the SC ones.

Alex but you drive like a Sunday driver!!

"Guru describes a spiritual teacher or master. A Guru has the power and wisdom to dissolve spiritual ignorance in a disciple. A true Guru has attained a extreme high degree of spiritual development before acting as a Guru. A traditional Guru has achieved God-realization before starting to teach. Exceptions are, when a Guru starts to teach while his Guru has still a physical body and spiritually supervises and guides him. In this case he often refers to his Guru when teaching to his disciples. A fully realized Guru having attained God-Union during the present incarnation has no need to refer to anyone else but God, as God is his true Guru and supervisor during his activities while teaching. He acts on behalf of God, never on behave of his personality. "



Does that sound like me???

I do know a little abotu transmissions, and have always maintained the A+ helical box (right until the metro ended production and quality fell sharply) is a good, strong unit that if rebuilt properly will last for many thousands of miles.
Problems occur when they're rebuilt badly, or not at all!
I can't comment personally on the Pre A+ boxes, but I respect and believe EVERYTHING that Jukka says, and he believes these are at least as good, if not better than the A+ metro gearsets.

Race miles... So that's just 4th, and 3rd gears in main use, maybe a little of 2nd... Hardly a lot of work for any gearbox... Try hill-climbing - lots of 1st and 2nd gear work and you'll soon see where the damage is done!

Wolfie - I'm outa here on the 6th, and am upto my eyeballs before then! Sorry! Describe to me why it's broken, and damage/ pitting / ghosting to any of the remaining intact gears.

Edited by turbodave16v on 24th Nov, 2004.

ill get pics

I'm aiming to hillclimb/sprint mine. Cornwall has some cracking tracks/country house drives.

S-GT boxes are getting rare now. I have an A+ one which is tight. Will see what I can do with that first.

Bugger off, I'm getting there.

most of us only have S/C boxes for the 1st gear ratio , a helical box with s/c drops is as strong as anything and a 1275 gt box is better, except for 1/4 mileing.

been there done that now have a S/C box only for getting better starts , well that`s the theory.

Everyone knows that instructions only have to be read if the thing doesn't work....

ps
if c/r 1275 are getting rare might have to put one of mine on ebay and see how rare there getting....

Everyone knows that instructions only have to be read if the thing doesn't work....

Arnt race miles harder than road miles?

Even sunday driver ones like me!

Alex

AlexF

Arnt race miles harder than road miles?

depends on your point of view , not many of us actually race , were by you do anything to win ,

Everyone knows that instructions only have to be read if the thing doesn't work....

true... but you hadly cruise along at 60-70 on track do ya!

And you certainly dont hang around chaning gear or accelerate gentley out of corners!

Well at least you dont in your video's and I try not to on track either LOL.

Alex

AlexF

if your doing mainly road miles the a+ box with comp diff pin is more than adequate and quieter.

i ebeliev i have a 1300 gt gearbox, how can i identify it, (its not on the car, but is attached to the block.

thanks
Dave

a 1300gt box will be remote and not rod change

But, the internals of a GT box can be fitted in a Rod-box, also there was something called the 1275GT which also had the "1300GT" box which was rod change from spring 73 :)

Oh, and you cannot identify it from the outside.

Edited by Vegard on 25th Nov, 2004.

this is race miles

listen to the gear changes, thats a hard life!!!

Edited by Jimster on 26th Nov, 2004.

Team Racing

link doesnt work matey :)

alex

AlexF

sorry guys, I should learn to type, it's up there now, try again!

Team Racing

but the straight cut gears sound ace!!

stuart doesnt recommend his 5 speed gearboxes for a turbo because they arent strong enough, i was trying to get one but he wasnt letting me have it

it might be my pc... but I cant hear much other than random noise!!!!

alex

AlexF