My kit car is under geared
Discussion
Hi,
I have a Fisher Fury with a 2.0 Zetec engine, Type 9 gearbox, 3.62:1 Sierra Cosworth LSD, and 185/60/14 tyres. The problem is that it feels very under geared when driven on motorways, and I would really like to sort this out.
I get about 22mph / 1000 rpm.
I want to retain an LSD.
The possibilities appear to be:
Raise the ratio of 5th gear in my gearbox.
Replace the gears in my diff to raise the final drive ratio.
Fit an overdrive.
Stay off motorways.
The first two options would be preferred. Has anyone had any luck with this, without having to spend a fortune?
Thanks for any advice.
Richard
I have a Fisher Fury with a 2.0 Zetec engine, Type 9 gearbox, 3.62:1 Sierra Cosworth LSD, and 185/60/14 tyres. The problem is that it feels very under geared when driven on motorways, and I would really like to sort this out.
I get about 22mph / 1000 rpm.
I want to retain an LSD.
The possibilities appear to be:
Raise the ratio of 5th gear in my gearbox.
Replace the gears in my diff to raise the final drive ratio.
Fit an overdrive.
Stay off motorways.
The first two options would be preferred. Has anyone had any luck with this, without having to spend a fortune?
Thanks for any advice.
Richard
Had the same issue with the Westy, although much simplified by it being an open dif. Simply swapped it for a taller one. Very glad I did too - made a much bigger difference to the general driving experience than the relatively small change in dif ratio would have suggested.
Same engine, gearbox and wheel sizes as youself as it happens. Sadly, can't recall the dif ratio though - sorry.
Of course, this does blunt the acceleration, but you pays your money and takes your choice. For us, it was an obvious choice with no practical downside for how we use the car.
Same engine, gearbox and wheel sizes as youself as it happens. Sadly, can't recall the dif ratio though - sorry.
Of course, this does blunt the acceleration, but you pays your money and takes your choice. For us, it was an obvious choice with no practical downside for how we use the car.
Thanks for the suggestions.
Space is definitely tight in the wheel arches so bigger road wheels would be difficult. The front wheels already scuff the chassis and underside of the bonnet, so I think these are already at the limit. Could maybe just fit bigger rear wheels though.
A 3.38 diff is probably the best way to go. I'd need Lobro joints to connect with my existing drive shafts (which are shortened Sierra items). I'd lose the limited slip mechanism I think, unless it were possible to swap the gears into my existing diff. I quite like having the LSD.
Space is definitely tight in the wheel arches so bigger road wheels would be difficult. The front wheels already scuff the chassis and underside of the bonnet, so I think these are already at the limit. Could maybe just fit bigger rear wheels though.
A 3.38 diff is probably the best way to go. I'd need Lobro joints to connect with my existing drive shafts (which are shortened Sierra items). I'd lose the limited slip mechanism I think, unless it were possible to swap the gears into my existing diff. I quite like having the LSD.
What revs would you like to be doing at 80mph?
If you change the ratios to achieve that; will it really make motorway cruising much more relaxed, or just slightly less engine noise?
When motorway cruising in your car, where does most of the occupant disturbance come from? Will dropping the engine revs make an appreciable difference?
What's the most exciting aspect of the car - what's it all about?
If you blunt the in-gear performance, the ability to overtake on short straights; will you spoil that part of the driving experience that it does best?
Have you tried ear plugs? - Seriously, I found them a great help on motorway cruising.
I think your gearing is about right for that type of car. It will never make a cruiser.
If you change the ratios to achieve that; will it really make motorway cruising much more relaxed, or just slightly less engine noise?
When motorway cruising in your car, where does most of the occupant disturbance come from? Will dropping the engine revs make an appreciable difference?
What's the most exciting aspect of the car - what's it all about?
If you blunt the in-gear performance, the ability to overtake on short straights; will you spoil that part of the driving experience that it does best?
Have you tried ear plugs? - Seriously, I found them a great help on motorway cruising.
I think your gearing is about right for that type of car. It will never make a cruiser.
3.38 diffs are available with lsd , I found that it was to high in my RH ,std t9 120 ish at crank 5 gear was good on motor ways but not much use else where put a 3.62 in first is now a little short but rest is fine ,suppose it needs the BGH long 1st gear but for normal touring use I'm happy enough, my ops only
330p4 said:
Overdrive services in Sheffield do a stand alone overdrive unit to fit in the prop tunnel not sure if the fury tunnel would be big enough though
Ian
Ian, do you (or any other PH forum member for that matter) have experience of fitting one of these units? I have a V6 Cologne powered kit with a 5-speed box which could do with some higher gearing especially for motorway use, etc but, like other posters here suggested, I feel that the 1st gear doesn't need to be much higher - how easy / difficult is it to fit given that there is sufficient physical space?Ian
Sorry (in a way!) OP to hijack the original question - but it's obviously related
Just been out for a bit of a spin, and the current gearing is great on A and B roads. Returning on the motorway, and the engine just sounds really busy. Even at 60 mph (measured by GPS), where my tacho is reading 3000.
It may be the lack of sound proofing in the engine bay that's altering my perception somewhat. With the rain hood up, the experience is something like having the engine in the car with you. I've done about 2500 miles so far, and it has taken a little bit of getting used to. Ear plugs are definitely appreciated.
rog3k, I'd be interested to know if you get anywhere with fitting an overdrive.
Huff, comparing notes some time sounds good.
On another subject, I fitted my new quick steering rack this afternoon, and that has made a big improvement to the responsiveness of my steering
It may be the lack of sound proofing in the engine bay that's altering my perception somewhat. With the rain hood up, the experience is something like having the engine in the car with you. I've done about 2500 miles so far, and it has taken a little bit of getting used to. Ear plugs are definitely appreciated.
rog3k, I'd be interested to know if you get anywhere with fitting an overdrive.
Huff, comparing notes some time sounds good.
On another subject, I fitted my new quick steering rack this afternoon, and that has made a big improvement to the responsiveness of my steering
Ear plugs are defiantly a good idea.
It doesn't sound like the engine is revving that high, its lower than a Honda S2000 for example, might just need to get used to it...
I don't have experience with the overdrive but I assume it is like a basic gearbox that changes the drive ratio, if this is the case then it sound like a reversing box which I do have experience with and must recommend against. There seamed to be mechanical losses, and an oil reservoir was needed, quite heavy in all so will give a noticeable reduction in performance.
It doesn't sound like the engine is revving that high, its lower than a Honda S2000 for example, might just need to get used to it...
I don't have experience with the overdrive but I assume it is like a basic gearbox that changes the drive ratio, if this is the case then it sound like a reversing box which I do have experience with and must recommend against. There seamed to be mechanical losses, and an oil reservoir was needed, quite heavy in all so will give a noticeable reduction in performance.
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