4-speed or 5-speed?

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blownvn
Posts: 182
Joined: Fri Jun 04, 2004 5:57 pm

4-speed or 5-speed?

Post by blownvn »

Ok, I've been thinking this over a little bit lately and wondering whether or not I should go for a 4-speed manual box or a 5-speed manual.

I'm thinking 5-speed at the moment and the box I'm considering has a 0.85 5th gear which isn't too high. I figure I can always run the car in 4th gear if 5th gear proves too high but if I only have a 4-speed and run out of revs in the top end then I'm pretty much stuck with the 4-speed until the next year.

What do most of you sedan guys run in the gearbox department?
Stovebolt
Posts: 48
Joined: Fri Feb 28, 2003 11:09 pm
Location: Melbourne. Australia

Post by Stovebolt »

This question has come up on the "Landracing" web site, and the guys there advise use 1:1 final ratio, due to the increase in HP required to run an overdrive by comparison to a 1:1.

JD Tone told me that its also better to run a high ratio crown wheel and pinion in a Quick-change for the same reason.

Hope this helps.

Your resident armchair expert! LOL
DON NOBLE ... DLRA # 281

Post by DON NOBLE ... DLRA # 281 »

hi there , my bit of advice . this year i took 3 different size tyres for the rear, lot easier than changing ratios if you run out of revs or cant get it to rev high enough .
i use a non standard 5 speed with a .75 overdrive . with tallest tyres was overgeared ( it was great for driving there to the lake ) and then changed to smaller tyres till i figured i had the right combo . ha then it started starving for fuel but thats another prob unrelated .
blownvn
Posts: 182
Joined: Fri Jun 04, 2004 5:57 pm

Post by blownvn »

So Don, was it pulling higher mph in 5th gear than it was in 4th before the fuel starvation problem?

I understand that it will creat more drag using an overdrive gear but I figure with a 0.85 overdrive it's not going to be as bad as a 0.75 overdrive.

I'll look into the costs (i already have the 4-speed) but like I said before, if the overdrive proves too tall I can always run the car in 4th gear. If I run out of revs in 4th though with the 4-speed then I stuck with it unless I take some taller tyres like Don suggested.
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