deltron63
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| posted on 25/6/10 at 08:02 PM |
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lack of power in 5th gear
Hi all, iv'e still got a problem with the car.
I can hit the red line in all gears with no problem,a part from 5th. At 80mph i can put my foot down and not a lot happens, It just feels like
it's bogging down.
Any ideas?
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Paul TigerB6
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| posted on 25/6/10 at 08:04 PM |
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Fit an engine with more than 50bhp?? 
Sorry - it was either ^^^ or fit a 4spd box and problem solved
[Edited on 25/6/10 by Paul TigerB6]
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BenB
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| posted on 25/6/10 at 08:06 PM |
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What engine is it? Vacuum is vacuum so if it doesn't bog down at that level in any other gear it does kind of suggest it's just running
out of puff....
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jacko
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| posted on 25/6/10 at 08:07 PM |
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quote:
Originally posted by deltron63
Hi all, iv'e still got a problem with the car.
I can hit the red line in all gears with no problem,a part from 5th. At 80mph i can put my foot down and not a lot happens, It just feels like
it's bogging down.
Any ideas?
Have you posted about this before ?
We need more info
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deltron63
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| posted on 25/6/10 at 08:07 PM |
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quote:
Originally posted by Paul TigerB6
Fit an engine with more than 50bhp??
Sorry - it was either ^^^ or fit a 4spd box and problem solved
[Edited on 25/6/10 by Paul TigerB6]
i just took the 4 speed out 
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deltron63
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| posted on 25/6/10 at 08:11 PM |
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1800 zetec, 136 cams, ninja bike carbs, megajolt.
i thought i had found the problem but it wasn't it.
i've replaced the fuel pump and dumped the regulator. still no joy
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deltron63
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| posted on 25/6/10 at 08:13 PM |
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quote:
Originally posted by BenB
What engine is it? Vacuum is vacuum so if it doesn't bog down at that level in any other gear it does kind of suggest it's just running
out of puff....
i can do over 110 in 4th ( still some to go )
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Ivan
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| posted on 25/6/10 at 08:14 PM |
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Yep - it's all about power, gearing and aerodynamic drag - if your gears are too long and put you in the wrong spot on the power band to
overcome the drag that's growing exponentially at 80 + MPH you will be going nowhere.
What happens when you drop to fourth gear at those speeds - do you regain acceleration - if so then your in the wrong spot on the power curve for your
engine in 5th at those speeds.
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tomgregory2000
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| posted on 25/6/10 at 08:15 PM |
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do your butterflys open fully under full pedal travel?
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paulf
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| posted on 25/6/10 at 08:16 PM |
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Have you experimented with the ignition timing? you should have about 24 degrees at full throttle above 3000 revs.
Paul
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mcerd1
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| posted on 25/6/10 at 08:19 PM |
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what gearbox and diff have you got ?
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deltron63
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| posted on 25/6/10 at 08:19 PM |
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quote:
Originally posted by Ivan
Yep - it's all about power, gearing and aerodynamic drag - if your gears are too long and put you in the wrong spot on the power band to
overcome the drag that's growing exponentially at 80 + MPH you will be going nowhere.
What happens when you drop to fourth gear at those speeds - do you regain
acceleration - if so then your in the wrong spot on the power curve for your engine in 5th at those speeds.
i can change down and take off again.
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deltron63
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| posted on 25/6/10 at 08:20 PM |
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quote:
Originally posted by mcerd1
what gearbox and diff have you got ?
type 9 from a seirra. escort axle. i dont know the diff ratio
[Edited on 25/6/10 by deltron63]
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mcerd1
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| posted on 25/6/10 at 08:23 PM |
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quote:
Originally posted by deltron63
quote:
Originally posted by mcerd1
what gearbox and diff have you got ?
type 9 from a seirra
sierra 4cyl ratios:
1st = 3.65
2nd = 1.97
3rd = 1.37
4th = 1.00
5th = 0.82
thats a 22% increase in the gear ratio when you change from 4th to 5th then
what revs does your engine drop to when you change ?
[Edited on 25/6/2010 by mcerd1]
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dinosaurjuice
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| posted on 25/6/10 at 08:27 PM |
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need a diesel engine 
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deltron63
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| posted on 25/6/10 at 08:28 PM |
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it drops to about 4500
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deltron63
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| posted on 25/6/10 at 08:30 PM |
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quote:
Originally posted by dinosaurjuice
need a diesel engine
or put the v8 mg back on the road 
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mcerd1
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| posted on 25/6/10 at 08:31 PM |
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sorry, is that 4500 when you drop into 4th @ 80mph ?
if thats what you ment then it could just be too high a gear
on my focus (stock 1.8 blacktop) the power only starts co come in properly at ~4000rpm
and by my calcs you'd be doing 3750 in 5th which might not be making enough power yet to pull that gear at that speed
how does it perform if you stick in 4th till say 90mph+ then change to 5th ?
(obviously your going to try this off the public roads)
[Edited on 25/6/2010 by mcerd1]
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deltron63
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| posted on 25/6/10 at 08:42 PM |
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quote:
Originally posted by mcerd1
sorry, is that 4500 when you drop into 4th @ 80mph ?
no thats in 5th i haven't looked at the revs when i drop down to 4th. i haven't changed up at 110+ .some thing always gets in the way
!!
[Edited on 25/6/10 by deltron63]
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mcerd1
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| posted on 25/6/10 at 08:46 PM |
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that'd be 5400rpm in 4th then - which seems a bit high too not be in the power band
ever had the car on the rollers ?
[Edited on 25/6/2010 by mcerd1]
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deltron63
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| posted on 25/6/10 at 08:47 PM |
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I know i'll put on a 4 speed gear knob, problem solved 
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deltron63
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| posted on 25/6/10 at 08:49 PM |
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quote:
Originally posted by mcerd1
that'd be 5400rpm in 5th then - which seems a bit high too not be in the power band
ever had the car on the rollers ?
not yet , i'm looking for a rr local
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mcerd1
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| posted on 25/6/10 at 08:50 PM |
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btw - I can have a go at working out your diff ratio for you if you tell me what size your rear tyres are
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BenB
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| posted on 25/6/10 at 08:52 PM |
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quote:
Originally posted by mcerd1
that'd be 5400rpm in 5th then - which seems a bit high too not be in the power band
ever had the car on the rollers ?
Or even 4500 in 5th
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deltron63
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| posted on 25/6/10 at 08:54 PM |
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quote:
Originally posted by mcerd1
btw - I can have a go at working out your diff ratio for you if you tell me what size your rear tyres are
185/65/14 i think?
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