alistairolsen
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| posted on 1/7/08 at 08:09 AM |
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Speeds in gear
Im looking at transmission options just now, running a 4:1 final drive and an undecided box.
Im planning on running around 225bhp.
Can anyone with similar power stick up their speeds in gear at revs and comment on how you find them to deal with? Too short, high rpm at cruise, too
long etc.
For instance, If I use a vauxhall box I will have these speeds at my 6800 limiter
29, 53, 84, 112, 148
I know the easy answer is to run a lower final drive, but I cant easily, so I need to know if this will be ok
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alistairolsen
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| posted on 1/7/08 at 09:40 AM |
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problem is Im running an mx5 rear end, and I have a noce torsen style LSD but its a 4:1 they did an uber rare 3.9 and nothing lower, and the mazda box
had weird ratios to match.
I reckon its goin to make firt too short for launching making it essentially a 4 sped box, 2nd wont see 60, 3rd wont see 100, 5th is too short for
cruising......
anyone else care to confirm my fears?
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smart51
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| posted on 1/7/08 at 10:00 AM |
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I had one of the first saxos when they were launched. The carried over the engines and gearboxes from the AX. The AX was pretty quick for its
engine size but the saxo was heavier and so slower. I swapped it for the second generation saxo which was I think 3 seconds faster to 60 than the
first. Partly it was because they'd saved a few kilos and partly because they'd shortened the final drive.
The car was quicker but the result was that 1st was too short. If you pulled out of a side street onto a main road, before you'd straightened
up, you'd be on the limiter in 1st. Even if you drove gently, you looked like a boy racer. I ended up shifting to 2nd whilst still crossing
the white lines.
29 in 1st at 6800 might be a bit like that. A scalded cat of the line but always at top revs.
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alistairolsen
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| posted on 1/7/08 at 10:20 AM |
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I think so too, but with 2.3 litres, a 230mm clutch and 550kg ill just pull away in second when driving gently on the road!
Im more worried about motorway stuff where Ill be sitting at 3400rpm at 75, and whether Ill find myself doing too many gear changes on track.
Id use the mx5 box but I dont think itll cope well with 200+ftlbs
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