yeah I've got a AAU gearbox off a 1.1 engine. What did you mean by 8p, Tahrey1043? Would a gearbox from a 1.3 AAV engine give much better performance because of the ratio difference on the gearboxes?
Need to test whether fuel consumption has gotten better, but I think I want performance more than mpg lol.
thanks for all the help, it was a releaf finding other suggestions on how to fix my engine!
starting troubles on a gt engine
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Gareth_GT_Hatch
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- Location: Manchester Drives: '83 GL Classic
theres four 5-speed boxes worth worrying about: (unless youve got a g40)
1.0 close ratio - AHZ and the one GC's got
1.0 economy - AYZ
1.3 close ratio - AHD
1.3 Economy - 8P
Only difference between the 1.0 boxes and the 1.3 boxes of the same type is the 1.0 ones have a slightly higher final drive ratio (so all gears are slightly shorter on them)
They would all work on a 1.0, especially the mk2 which is lighter and a bit pokier anyway.
1.0 close ratio - AHZ and the one GC's got
1.0 economy - AYZ
1.3 close ratio - AHD
1.3 Economy - 8P
Only difference between the 1.0 boxes and the 1.3 boxes of the same type is the 1.0 ones have a slightly higher final drive ratio (so all gears are slightly shorter on them)
They would all work on a 1.0, especially the mk2 which is lighter and a bit pokier anyway.
gearboxe ratios
so are the short ratio 1.0 AHZ and 1.3 AHD gearboxes good for acceleration and the other two are worse but have a better top speed?
thanks for the information seems to be very useful on obtaining the best performance from the 1.3 3f engine.
thanks for the information seems to be very useful on obtaining the best performance from the 1.3 3f engine.
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Tahrey1043
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- Location: Birmingham! Enjoys: The pseudo-G-Smiles provided by a 1.6 Megane Sport valver...
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The short ratio boxes should actually have as good a top speed or possibly better than the wide ones - the economy boxes are of the type where your top speed is in 4th (and may not be entirely optimal, but is pretty close), with 5th being a 20 to 25% higher "overdrive" cruising gear where you can't quite go as fast (say 85 instead of 90mph) but get quite a bit better economy when you're not pushing the engine hard - like when you're easy going at the legal limit. Whereas the close ratio ones have 5th either around the same as 4th, or slightly higher (which will give the power band a slightly longer reach up the mph scale, particularly if you've tuned it mildly)
So getting top speed out of it is much of a muchness unless you're either eager for that very last 1 mph on some kind of sprint, or have done a fair bit of tuneage. (However, with its extra long ratio diff, the factory G40 box is probably right out for getting high speeds unless you have a suitably stonking engine)..... what they do make a difference to is acceleration vs economy and comfort. Short boxes will give you the accelerative edge but make the engine loud and thirsty even at comparitively low speeds (65mph up - makes it seem like you have a 4 speed).... longer boxes will see you further down the power band with each upshift, so not getting so great acceleration, but will be less wearing and expensive on a long haul.
the "long" ratio on the 1.0 seems a bit of a rarity and oddity - the only "possible" i've seen of it is on Metz's saloon (it was possibly a saloon only jobbie) and it's still yet to be properly checked out - it may be a GT styled one instead? (maybe?)
there actually seems to have been three different types of 1.0 box if that one's included.... here's all the "major" polo boxes i know of that are worth considering... forgetting the wierd mk2 3+E things, and extra-low-ratio differential 900cc ones
unfortunately i'm none too good with remembering the codes but im sure someone can supply them, not to mention put me right yet again on various repeated mistakes
[all polos i know of have a 3.45:1 first gear]
1.0, all 4.267:1 differential:
4 speed (mine), 0.89:1 top gear --- uber-tight 5 speed, same 1st / top gears as 4spd but narrower 2nd/3rd/4th --- GT-style 5 speed (probably most common), 0.85:1 top --- possible saloon economy box, same ratios as 4spd plus 0.74:1 5th gear
1.3 CL, all (?) 4.063:1 differential
4 speed, same as 1-litre --- "economy" 5 speed (the 8P) which adds the 0.74:1 top --- possibly some GT style ones slipped in
1.3 GT, could be a 4.063 or 4.267 depending on date???
one 5 speed close ratio box, 0.85:1 top gear and 2nd/3rd/4th not *quite* as tight as the 1-litres-only jobbie (but nearly).
1.3 G40 - factory fit is a 3.333 differential thanks to all the torque
factory fit gearbox has almost identical ratios to GT, but 2nd is very, VERY slightly different, probably due to fitting a strengthened gearset or something (most likely gear it will be spanked in!).
Modified G40s might have nearly anything in
If you come across an oh-so-ever-so-rare 1.4 diesel box (euro import etc) it'll be set like an 8P, but 4th is slightly lower (0.91), 5th slightly taller (0.71), and the differential is about 3.8 ... assuming they used the existing diesel box for the 850cc "oko" superdiesel rather than making a whole new one
So getting top speed out of it is much of a muchness unless you're either eager for that very last 1 mph on some kind of sprint, or have done a fair bit of tuneage. (However, with its extra long ratio diff, the factory G40 box is probably right out for getting high speeds unless you have a suitably stonking engine)..... what they do make a difference to is acceleration vs economy and comfort. Short boxes will give you the accelerative edge but make the engine loud and thirsty even at comparitively low speeds (65mph up - makes it seem like you have a 4 speed).... longer boxes will see you further down the power band with each upshift, so not getting so great acceleration, but will be less wearing and expensive on a long haul.
the "long" ratio on the 1.0 seems a bit of a rarity and oddity - the only "possible" i've seen of it is on Metz's saloon (it was possibly a saloon only jobbie) and it's still yet to be properly checked out - it may be a GT styled one instead? (maybe?)
there actually seems to have been three different types of 1.0 box if that one's included.... here's all the "major" polo boxes i know of that are worth considering... forgetting the wierd mk2 3+E things, and extra-low-ratio differential 900cc ones
unfortunately i'm none too good with remembering the codes but im sure someone can supply them, not to mention put me right yet again on various repeated mistakes
[all polos i know of have a 3.45:1 first gear]
1.0, all 4.267:1 differential:
4 speed (mine), 0.89:1 top gear --- uber-tight 5 speed, same 1st / top gears as 4spd but narrower 2nd/3rd/4th --- GT-style 5 speed (probably most common), 0.85:1 top --- possible saloon economy box, same ratios as 4spd plus 0.74:1 5th gear
1.3 CL, all (?) 4.063:1 differential
4 speed, same as 1-litre --- "economy" 5 speed (the 8P) which adds the 0.74:1 top --- possibly some GT style ones slipped in
1.3 GT, could be a 4.063 or 4.267 depending on date???
one 5 speed close ratio box, 0.85:1 top gear and 2nd/3rd/4th not *quite* as tight as the 1-litres-only jobbie (but nearly).
1.3 G40 - factory fit is a 3.333 differential thanks to all the torque
factory fit gearbox has almost identical ratios to GT, but 2nd is very, VERY slightly different, probably due to fitting a strengthened gearset or something (most likely gear it will be spanked in!).
Modified G40s might have nearly anything in
If you come across an oh-so-ever-so-rare 1.4 diesel box (euro import etc) it'll be set like an 8P, but 4th is slightly lower (0.91), 5th slightly taller (0.71), and the differential is about 3.8 ... assuming they used the existing diesel box for the 850cc "oko" superdiesel rather than making a whole new one