Adam M

Hi all,

Have been mulling over what steve (dingy) has said about our cars having incredible 0-60s because our final drive ratios give us acceleration that can beat a cosworth but they kill us top end.

There is some truth in this in that some of their 500bhp cars seem to be able to do sub 4 second 0-60s liek us, but then they go on to 190 almost mph.

The reason I am bringing this up is because I am considering an uprated gearbox, the ratios of which i can choose myself. This is a nasty business so I would like to stick to something tried and tested which does not have enormous gaps between the gears and isnt stupidly long.

i dont know what their redline is, but I would like the same individual and final gear ratios as a standard escort cosworth, so I am hoping someone in the know might be able to provide this is point me in the right direction (preferably not the rsoc bbs).

mozzaITA

Not too sure about the escort cosworth ratios but ive driven a rs 2000 which uses the same gearbox (i think) gearing is very short, i used to own a astra gsi16v and it had longer gearing, i used to hit nearly 70 in 2nd and the rs 2000 could get to about 55mph.

But he used to keep up and sometimes gain on me!! not that we raced much!!!

Adam M

it cant be that short if a set of well stancked ratios can get to 188mph!

Disco

Could you not have 1st and 2nd Scoob ratios (or near as dammit) with 3rd and 4th lengthening to create a 5th ratio similar to that of the Escort, thus giving you the best of both worlds?

dingy

Maybe its because you diff is so high, hence the good 0-60 and poor top speed and pretty poor 0-100



4.4:1 compared to 3.6:1

BIG difference.

mozzaITA

Well im pretty sure the rs 2000 uses the same gearbox and he deffinatly dont hit 60 in 2nd gear!!!, ive driven aswell!

Adam M

steve, the final drive is completely irrelevant. You have to consider the indivdiual gear ratios multiplied by the final drive.


If I could find these out, then knowing the final drive of the cosworth, and the final drive of the impreza, I could work out what gears I need in the gearbox itself to have exactly the same.

I could just change the final drive but if I did that, all the gears would be too high, so although my top end would be great, I would not be able to get there because pulling off the line would be a nightmare.

dingy

The final drive is irrelavant, i'd say you very wrong there my friend, very wrong, how is the final drive not relevant, swap the CWP over to a 3.6 : 1 and see the top speed and see how slow to 60 you are.

Whats the gear Ratio of yous in 5th ???

dingy

1:3.608
2:2.082
3:1.363
4:1
5:0.829

MT75 Box

2.390 or 2.040
1.541
1.215
1:1
0.871

MT75 GRP N box like Martin Hadland.

dingy

22B

Gear ratios:
1: 3.083:1
2: 2.062:1
3: 1.545:1
4: 1.151:1
5: 0.825:1

Final drive ratio:
4.44:1

If for example you ran my dif in a 22b, 3.44:1 it would take you about 7 secs to 60.

Scoobs are only fast because of high gearing and 4wd grip, nothing more. hence why they either blow up at top speed or never get over 140.

ian/555

I can also confirm from past experiance that RS2000 16V's have a top speed of about 55mph in second gear.
ian

JohnBarnesAndHisGloves

and RS2000 gearboxes arnt the same anyway. btw i agree with dingy bout the scoobs, well yet to be proven otherwise anyway

Adam M

Steve, I agree I would be slow to 60, but then thats cos the gap between my first and second is nothing like the gap martin has.

He has a very high first, so that even though his final drive is v tall, his first is very short.

He still gets the benefits of the enormous top speed in the other gears.

IN fact If I change my final drive to 3.6 like you suggest, I would have a theoretical top speed of 195.56 mph. I am sure that if I stuck his high first gear in, I would not be struggling to get 0-60 in under 7 seconds.

So as I said originally it takes more than just changing the final drive my friend.

The fact is, the cars should perform similarly. If they have the same ratios and the same power, there is no reason why they shouldn't yield almost identical performance, except of course the weight advantage of the impreza, but thats it.

I am at the moment still none the wiser as to which ratios I should choose.

mozzaITA

i bet the rs 2000 g/box's is the same as the cossie!! i will ask my mate he's in motorsport and he owns 1 and dreams about owning the other!!

mozzaITA

he says they are the same!!! he should know as he designs parts for rally and f3 cars!!!! the mtx***** g/box is used still today, in whot i dont know!

dazc2

the RS2000 box (MTX75) is completely different to the cossie (MT75) box as one is front wheel drive and transverse mounted and the other is longitudinaly mounted and 4 wheel drive with a bloody big transfer box on the back of it. completely different casing, internals, diff etc. the only car with the same box as the cossie is th XR4x4 sierra. the only thing remotely related to each of these boxes is the similarity between the names

dazc2

oh and the MTX75 box is fitted to every focus, escort, fiesta mondeo etc that rolls off the production line and has done for the last 8 or so years. its the front wheel drive box.

ian/555

Adam I obtained these from this site

http://www.rallycars.com

The specs with speeds obtained as listed at that site using the MT75 box with 8" by 16" wheels, with 225/45ZR16 Pirelli PZero rubber are:

Final drive ratio 3.62.
1:3.608 57 kmh
2:2.082 99 kmh
3:1.363 151 kmh
4:1 206 kmh
5:0.829 233 kmh
with reverse being :3.256

These specs and many others are at http://www.rallycars.com/Cars/Cosworth/Escort.html and http://www.rallycars.com/Cars/Cosworth/My_Escort.html

hth ian

R19KET

Adam,

These are Martin's in gear speeds based on the gear ratio's Steve listed, and a 3.6 fd. SHORT 1st/2nd ????

1st 66.89
2nd 103.75
3rd 131.59
4th 159.88
5th 183.56

And I thought my 81mph in 2nd was long !!!!!

Mark.

Adam M

Perhaps your 81 in second is actually fine.

If I stick with those same ratios, and a final dricve good for 180mph then all will be well as far as I am concerned, it would also give me 90mph at 4000rpm, although I miht extend that a little, to say 95mph at 4000rpm.

I cant imagine it wont have the torque to drive it and so long as the jump from fourth isnt too big, it should retain all its drivabality.

R19KET

Adam,

This is all very interesting but since your car has NEVER seen over 90mph (unless someone else has been driving it for you LET ALONE 180mph, it seems pretty pointless.

Mark. And stop phoning me about it.....

Adam M

bugger off you @rse hole.

R19KET

Adam,

Every body knows that you have homosexual tendencies, so I get very nervous when you start using "bugger", and "arsehole" in the same sentence

Your advances are not welcome.

Mark.

Adam M

If I were to be gay, do you think I would choose you?

a sad old man? (and dont take that wink as being an advance - it isnt)

I dont think so.

R19KET

Adam,

Just as well the rest of us aren't ageist, or you'd be stuck with the rest of the children in NW London

Maybe you should stick to playing with your PRIDE AND JOY, your Tonka toy collection.......

Besides, it's nearly 7pm, and you should be in bed

Mark, aka Old Man

mozzaITA

ok i agree that the cossie g/box is different to the rs2000 BUT the rs 2000 did come in 4wd u will find!!!!...n + reg limitted numbers only.

47 NAT

If my memory serves me right they made 499 4X4's

Nath

martin-reyland

my escort uses standard ratios,
1st 3.608
2nd 2.082
3rd 1.363
4th 1:1
5th 0.828

diff ratio 3.6

tyre size 245,40-18

rev limit 8200rpm

hope this helps

martin

Richie1

Does it have to be a 5 speed box or could you fit a 6 speeder in there ??

If so then lemme know and I can give you the gear ratios used in the GETRAG box of my car. Top speed of 150+MPH and 0-60 of 6.5 altho this is from a standard car running 204BHP and 206lb/ft. If you have more power then it can get to 5 second 0-60 (or less) and higher top speeds.

dazc2

the RS20004x4 was still a transverse mounted engine and box with an adapted MTX75 g/box.

you will also find that the same system was used in the mondeo 4x4

[Edited by dazc2 - 2/5/2002 8:50:26 PM]