Suorahampaisia löytyy useampaa eri mallia mutta tosiaan se ääni on aika kammottava jos pitää kauppaan lähteä ja kikkailla parkkipaikalla
2WD:stä en tosin ole varma mutta löytyy 4WD Quife-ratassarja (ilmeisesti ei kovin hyvä , hampaita murtuu) sekä tottakai motorsportin suorakytkentää 5-ja 7 vaihteista , takavetoisista ainakin sama mitä käyttivät rallissa ja RS500-radalla . Luonnollisesti vaatii jonkinverran €€€€ .
Lainattu suoraan WRC-cosworth.com:sta :
Possible gearbox upgrades
* Pete Doughty's DPE boxes: There was a lot of problems at first with these, but they are all fixed now with one car with 552hp having no problems even after a lot of full throttle launches.
You must deliver your standard gearbox to him and he does either a second and 3rd gear conversion or the second gear, 3rd gear and main shaft. The gearbox will be very noisy in second and third with the first option and in all gears except 4th with the second option due to the mentioned gears being straight cut.
The prices are £1800 + vat for 2nd & 3rd. £2200 + vat for 2nd, 3rd & main shaft.
Pete Doughty, Nothingham, England. Phone: 01159 262073
* DOME gearkit: This is a helically cut synchro gear kit produced by a Swedish company that also produces the gears for the McLaren F1 cars. Very strong (they have never had a gear brake) and uses the standard ratios. There are a number of different so called "Swedish" gearkits which are not all the same. Sweden has a number of engineering companies producing gear kits with varying degrees of quality.
* Quaife Uprated gearkit: This is quite like the DOME kit,but the gears are only slightly bigger than the standard gears. They are however heat treated and shot peened to increase strength.
* Quaife Big Tooth uprated gearkit: As above but with bigger teeth (stronger and noisier).
* R&D gearkit - has straight cut 1st, 2nd, + 3rd gears (all standard ratios). Cost is around £2200
* R&D 6 Speed Straight cut Dog engagement gearbox: This gearbox uses straight cut big tooth gears to dramatically increase strength. The design of straight cut gears actually forces them together so unlike helically cut gears. The engagement is by dog ring and not synchro, this allows a phenomenally fast change, basically only limited by how fast your hand can move the lever, you also don't need to use the clutch when gearing up, thus increasing the speed of the change even more. There is an excellent choice of ratios. Modificationsneeded to fit the box are: Clutch actuation must be hydraulic and by a center push bearing and the hole where the gearlever comes into the car needs to be made slightly bigger. The cost for the complete built gearbox is £4,750 + VAT. It is very loud due to the straight cut gears, but very strong.
* Fixit gearkit - from sweden.
* Quaife group A gearkit costs around £5000. It has different ratios (for rally), so limit's topspeed to something like 130-140 mph.
* Quaife group A gearbox, basically an MT75 with their gearkit already fitted, costs £7000.
* Quaife 6spd sequential gearbox - This is the ultimate gearbox upgrade from a performance standpoint of view. It is very very strong, doesn't need to be clutched and ratios can be had exactly as you want them.
As with everything really serious (solid) there are downsides:
1. The cost: £10.000+.
2. Driving it in the city and traffic can be a pain.
3. The dog-rings wears a lot faster than the synchro rings on a normal synchro-box. They may last 10.000km in road use, then it's out with the box and change the dog-rings.
4. Requires modifications to the tunnel, front diff and propshaft. Also requires modification to the clutch actuation.
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