hi
just wondering what are the benifits from having 1 of these gearboxes????
cheers steve
Errr, none unless your DEAF!!
WHAT
Straight cut gears are stronger than helical cut ones. This is because all of the tooth is in contact as against just part with helical. Most, if not all, race boxes are straight cut. There main drawback is they are "F" noisy. HTH Ray
thanks for the info i understand more now thanks
You know how noisy (whiney) reverse is on a lot of older cars? thats because most have straight cut reverse (cheaper).
Now imagine that times 2 or 3 (considering most people rarely use more than 1.4-2k revs when reversing)
In a 7 type car there is a good chance a straight cut gearbox will be loader than the exhaust.
Straight cut gears produce less friction ie reduce transmission power losses.
When I started with 7's back in the 80's if you wanted a nice set of ratios (with a usable first) strait cut was really the only option. Had
2, both were 4 speed which are quiet once you are in 4th, with a 5 speed its noise all the way (unless you use 4th as top).
Now there are several suppliers who manufacture helical cut close ratio boxes thus for road use there is really no need to buy a strait cut. I have a
BGH in the car but it was troublesome originally (sorted under warranty but it was a 400 mile round trip twice to sort) and I have since found out
that many parts used are not new e.g syncros, they should be in a £1200 box surely. Worried about reliability I decided to get a spare sorted, Steve
Perks at SPC built it for me from the front of a type 9 4x4 V6 box and the back of a dead diesel box plus his close first kit. It only cost me about
£300 since the alloy bellhousing off the V6 box sold for £200 on e-bay, box cost me £6 on e-bay. He also does a beautiful full helical close box if
you have a deep wallet, much better spec than BGH.
For racing I would probably still buy strait cut because they do release a few horsepower but for the road no way.
In my last kit i installed a trans-x straight cut box which was the best upgrade i ever made!
The ratios were so suited to the kit, long first gear (55mph in first) close ratio box, all ratios were just perfect (especially on track) and the
sound (to my ears) was just fantastic....
And it just added to the whole 7 experience!
I also have a tanx straight cut box in my car, and whilst it's obvious it is straight cut from the noise, it really isn't bad at all and far
better than most other makes that i've been in/used. It's quite easy to have a conversation with a passenger or listen to the radio
Perfect ratios for my car/engine too.
Ian
wow that took nine replies until skippad said why we use them! much better ratios keeping the power all the way to top and also as oddified said not that bad and is surely the reason why we have these cars!! performance.