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cams
25-06-2008, 01:00 PM
Howdy,

Does anyone know if there are lower ratios made for the manual Legnums? Just realising that cruising at 100 on the motorway, I'm doing about 2750rpm. I'd kinda like to bring that back down to 2000. (in the interest of keeping the Legnum in these days of astronomical fuel prices)

Alternatively, is a 6spd option out there without going to the extremes of spending 10g and getting one made up?

And is the Evo 5 Lancer gbox the same as the Legnum VR4 box? Just something I've heard before . . .

Cheers
Cam

Nutter_John
25-06-2008, 01:03 PM
Yeah there is the option of a 3.73 final drive , this costs around £500 uk pounds , have a search on here as it has been mentioned a few time

bradc
25-06-2008, 10:53 PM
coordsport in the UK do a 3.9 final drive (stock is 4.111) and teamrip in the USA do a 3.73 final drive.

6 speeds aren't an easy option, you're looking at 5k plus and while all evo 4-9 5 speed manual gearsets fit, they all have shorter final drives than stock. The 7-8 5 speeds do have a 0.720 5th gear instead of 0.761 which is what our cars have.

cams
30-06-2008, 11:34 AM
Thanks for your help. I may look into it

Nick Mann
01-07-2008, 01:26 PM
coordsport in the UK do a 3.9 final drive.
But to get this you need to buy a whole gearbox with that as an option. It is not a gear that fits in a standard box.

bradc
01-07-2008, 08:41 PM
ohh, so you've been in contact with them Nick? Interesting to hear!

Nick Mann
01-07-2008, 09:15 PM
Yes I have Brad. Nothing particularly useful though. Many of the options on their Evo Gearbox sheet are for custom build only. The boxes are not internaly compatible with the Mitsy box. IIRC the clue is that if it is no good for group N rallying, then it is not a direct swap. Group N rallying stuff is made to OE specs and is compatible.

Nick Mann
01-07-2008, 09:18 PM
They can do a slightly longer final drive though. IIRC the stock final drive is 70 teeth to 17. They can offer a 69 tooth that slots in to the stock 17 tooth gear. That gives 4.06 rather than 4.11

TBH that's not worth taking the box apart IMO.

bradc
01-07-2008, 10:43 PM
Yeah, 4.055 is the stock ratio I have in the ST-R. They aren't willing to make up a batch of 3.7-3.8 gears?

Kenneth
02-07-2008, 01:24 AM
Er, hate to say it but I reckon you are wasting your time.

speed takes power, you need to use a certain amount of power to overcome the air resistance. The gear you are in doesn't affect this, but it does affect how hard the engine has to work (load) to keep up this speed. (as the gearbox multiplies the torque based on gear).

higher gear means less rpm but more load.
The benefit of running more rpm is that when you change the throttle there is less time moving between load points (both faster throttle response and less change in TPS) and therefore less time is spent injecting excess fuel into the cylinders.

Of course the downside is that there is more likely to be more noise and vibration.

bradc
02-07-2008, 04:24 AM
Kenneth - you are right, but in the Monaro for example which has very high gears, 4th is about the same as 5th in a VR-4, 5th is even higher and 6th is 1500rpm at 100kmh, changing into 4th or 5th uses quite a bit more fuel when driving on a level surface with the cruise control on compared to 6th gear. The instantaneous fuel usage goes from about 8l/100km to 9l/100km going from 6th to 5th and up to about 9.5 when in 4th

Kenneth
02-07-2008, 04:31 AM
I think the important thing you have mentioned is the cruise control. Cruise control is known for being able to make minor adjustments to throttle to improve fuel economy, however in a VR-4 without cruise control I suspect you would go the other way due to the foot not being quite so accurate.

Not to mention the times when you decide to plant it and see what happens. For some reason no matter how sedate I decide to drive, there always comes times when I floor it :P

Also, I would be interested in what happens to the Monaros fuel usage when you hit an incline. Level is great, except there are not many places in NZ where that is the case. (bugger all in the north island)

bradc
02-07-2008, 07:42 AM
Going up the Bombay's it was using around 20l/100km in either 5th or 6th. The problem is that it isn't the same incline the whole way up so rather hard to test. Not sure what it would be overall on a long journey but perhaps someone could try driving in 4th everywhere for a day and not using 5th at all and seeing what the difference is like.

Nick Mann
02-07-2008, 09:38 AM
They aren't willing to make up a batch of 3.7-3.8 gears?

They don't make anything. They sell other peoples products.

And Ken, I appreciate all you points and I'm sure many of them are right. But I want a car that revs at a sensible amount on the motorway. Many people drive on UK motorways at 90 mph, this equates to a 4000 rpm engine speed. In MANY other cars I have driven, all with less power, the engine speed is closer to 3500 or less. i.e. a 10-15% longer gear. I can't see that this would have many detrimental effects, except that each gear will accelerate less than with a shorter final drive. The advantage is that you can stay in each gear longer, so for example 0-60mph will involve one gear change, not two.

bradc
02-07-2008, 09:41 AM
ohh. So who makes the final's for them then?

pezza
02-07-2008, 05:26 PM
I figured the final drive in VR4 was high but did not realise is was >4

I wonder how much slower and more sluggish a 1bar'd VR4 would feel with a lower FD ratio then... say 3.8 and whether it would have enough torque to still *entertain* in 5th....( I guess this is where the V8 cruisers and TDi's have an advantage)

I seem to remember hearing that the guy with the 6 speed evo 8 box in his 8G VR ran a HKS gearset with 3.84 FD (before the evo engine went in) but do not know how it behaved in 5th 6th. his car was far from standard tho. I can ask the guys who worked on it and took it for a thrashing...

bradc
02-07-2008, 09:13 PM
Over on EvolutionM there have been people running 4.111 and 3.73 finals. Their stock is 4.582 and some people have been happy with them, others haven't. The main thing over there is that the longer final lets them stay in 4th gear down the drag strip rather than changing into 5th.