Straight cut drops and ear defenders..
Turbo Mini Forums

Guys, I am in need of your experiences. I have only ever used either all helical or all straight cut transmissions but am now faced with a dilema.

I would like to go straight cut drops in the build I am doing to help with reliability (aiming at around 120-140BHP) but we have already bought two sets of sound proofing, twin box exhaust, electric windows and arranged for the full leather retrim. This car is not a stripped out racer.

My concern is that the drops will be too noisy and I will be taking them out after about half a mile, not noted for her patience my good lady!!!!!!

My question is this, I know full straight cut makes a lot of (loverly) noise but would 1:1 straight cut drops be much noiser than helicial ones when used with a standard helical gear set in the box?

Anybody who has used this combination please post your thoughts. If possible why not post an audio file ..... :)

I don't want to be taking the engine out the same day as the MOT LOL....

Every day is a school day ...........

How fast and how expensive ...... the same question...

If sound is a concern, I wouldn't fit them.

They are probably too loud for a daily driver IMO.

I use my car as a weekend toy, but don't think I could manage long distances in it.

If the cars not being continualy thrashed helicial should be OK as long as you set the clearences correctly.

In my experience, the gearbox will break long before the drop gears ( ive only used A+ stuff )
Even when I had the tran-X gear set, I managed to break 2nd gear, and the std drop gears were fine.

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

noisey drops can be helped by using a thinner block/box gasket to get the clearance correct

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

Ok, as I thought.

If people aren't having problems then why are so many using the straight cut drops with a helical box?????

Confussed.

I have run a 155-160BHP turbo on standard, but careful built, set up and never had a problem. Then again I grew out of the traffic light GP before I had a car licence.......

Every day is a school day ...........

How fast and how expensive ...... the same question...

If you fit straght cut drops you can bin the radio

1293 Turbo mini

i used ear defenders when i went to oxford last week, could have not bothered and been ok but my car has no sound deadning at all so you hear all the rattles and bangs ect

Mine has s/c drops and box don't sound too bad when cruising along.
Did have s/c box and helical drops which was as quite as normal in top gear

Metro turbo weekend driver,Mini turbo in the making again!

yep have to agree there in top its no worse than a normal mini

I think in the vizard book it mentions machining (.010")? of the tips of the teeth to reduce noise,but this will prob weaken them too.

Timken idler is quiter too,less chatter

Edited by Dangerous on 26th Nov, 2006.

Metro turbo weekend driver,Mini turbo in the making again!

i have been told my engine sounds "unhealthy" lol

having had an idler chew up a transfer casing on a std 1275 engine, id say it was deffo the weak link, but never really had the power to shred teeth off a g/box so....?

"Turbo's make torque, and torque makes fun"

"did you know you can toast potato waffles?"

A friend of mine doesnt use sc drops but has a sc box which keeps 4th helical, it makes quite a big difference imo, lot nicer on the motorway :)

strictly speaking...there is no 4th gear....it just locks the mainshaft solid.

Which is handy when ya strip the teeth of the input shaft lol, at least ya can still get home.

I was always tempted to try some A series drop gears, as the teeth did look chunkier, but as the A+ never gave any trouble, I didnt.

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

Isn't The Frog a daily drive and using helical drops and gears?

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."

Yep, and has done a fair few miles now with 140-odd bananas and no ill effects as yet, even with a standard diff too.

It will be interesting to see how long the gearbox will put up with it, and see who chickens out first, the drop gears, or Alex!

Well, my research into this concluded that if you rebuild the gearbox to exact standards using all new bearings, fit a good layshaft, torrington idler bearings and a 4 pin diff it should be OK for 120hp as long as you don't go round spinning the wheels everywhere.

You also need to set the primary gear and idler endfloat at bottom tolerance.

Maybe, I should make that 140hp!

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."

Well i was going to get SC drops for my engine, wont be turbo but i do like the sound of them but dont want them too loud .

The car will have carpets and dynamat (or equivelent) for soundproofing, two layers near the engine back, roof, floor etc, make it as quiet as possible.

Will the gears still be loud after that or will it be try it and find out sort of thing?

Manchester Minis

mines got s/c drops and box, and it whines most when slowing down. cruising its not too bad. i have the radio loud though!

i have the timkin idler in my box and its not as noisey.

i would go for this available from MED or minispares

who wants to soundproof a mini at all? the noises are like music to the ear

Somebody who wants to use it as their everyday car!!!!

Especially if that person is coming over from a modern, air-conditioned, leather interiored multi-valve GTi....... Even more so if that person happend to be female and would rather listern to music on the radio than gearsets!!!!

I've had both plush and stripped out Minis, both are great but in different ways. My road car would be stuff all use on the track and my track car would quickly become physically painful on the road........

Every day is a school day ...........

How fast and how expensive ...... the same question...

My car is going to be driven daily, going to take me to alot of events next year and driven around alot, dont want to be deaf by the end of it. Also i dont think a woman will want to hear the gearbox all the time when they are trying to speak or listen to music.

Soundproofing will be a must for me, keep noise levels down for serious amounts of driving (IMM is a good example)

Manchester Minis

mine is to b my every day car...the coopersport im driving now is going..