Gearbox Set Up 1.9 Mi

[large 33]

I am looking to change the gearbox on the rally car as it is a bit to tall (I think it is a Mi box).

what I would like is a tall 1st like in the 1.9 box 2,3 & 4th quite low and close and a longer 5th.

what would be the best way to do this or do people know of a better combination.

[Baz 421]

it depends how short you want to go, what sort of speeds are you getting up to?

 

1.6 box is easiest, or 1.9 with a 1.6 FD. Or even shorter, either with a Mi 4.4 FD.

[large 33]

90 flat in 4th with a long 5th would be spot on . I have been told that a 1.6 box with the Mi f/d is the way to go what sort of speeds would I be looking at?

[petert 588]

Mi16 and 1.9L GTi have the same 1st gear, 2.92:1. All 2nd gears are the same, 1.85:1. Third and fourth come as a pair and can't be separated, 1.360/1.069 (GTi) and 1.280/0.969 (Mi16). Fifth is free, 0.865, 0.81 and 0.76:1. As is the final drive, 3.62, 3.94, 4.06 and 4.43:1 being the four most commonly available. Put it all together however you like!

 

I prefer the 1.9L GTi ratios with the 4.43 (Mi16) final drive. It does approx. 125 km/h in 3rd, 160 in 4th and 200 in 5th (@7100).

Edited June 23, 2009 by petert

[Craigb 2]

Think I have tried most of the std boxes for road rallying .

 

IMHO

 

1.9 box awful , only use three gears

1.6 A bit bettter but 1st is too low

1.9 with a 4.4 (same as my current box ) Good , but still only use 4 gears.

1.9 with a 4.8 (what I had on my car orginally and what i am currenly having rebuilt) the best I have tried

 

Andy at AB recomended a 1.9 with a 4.4 but 3rd 4th and 5th modified from a 6 speed box. That looks good on paper , but are parts readily available if you damage a cog ?

 

What you need to consider is it a Road Rally , how many times will you be doing 90mph on the off highway bits

[unariciflocos 49 1 Cars]

I find this spredsheet EXTREMELY helpful when it comes to gearbox issues. You have there all the info you'll ever need to build the gearbox that's perfect for you.

[brumster 135 1 Cars]

The tallest first you can find is on the Quaife gearset (2.692), otherwise the next tallest is the 2.92 out of a 1.9 (and various others). Coupled with a 4.4 diff that should net you around 45mph with the Quaiffe kit, or 42 with the 1.9 1st. Problem is, of course, the Quaife kit is the wrong side of £1k.

 

Like Craigb said, I've got the hybrid solution of a 1.9 1st/2nd using 3rd/4th/5th from a GTi6 box which gets you the shortest, packed-up ratios you can for not-silly-money and the figures compare close to the Quaife kit. Coupled with an mi16 my figures come out at as follows (on 15" rims, 8000rpm limit) :-

 

Top Speeds @ limiter (mph)								
Box	FD	Gears						
	1	2	3	4	5	6	Description
1	1	37	65	90	114	140	-	1.6 GTI 'box / MI16 final drive
3	1	42	66	90	114	140	-	1.9 GTI 'box / MI16 final drive
6	1	42	66	86	106	128	-	Hybrid 1.9 'box / MI16 final drive
8	1	45	63	84	107	127	-	Quaife 'box / MI16 final drive
7	1	37	65	86	106	128	-	Hybrid 1.6 'box / MI16 final drive
1	6	34	60	83	105	130	-	1.6 GTI 'box / PTS 4.8 final drive
3	6	39	61	83	105	130	-	1.9 GTI 'box / PTS 4.8 final drive
8	6	42	58	78	99	118	-	Quaife 'box / PTS 4.8 final drive

 

I've even put the 4.8 PTS final drive ratios in there in case you want something mega-short

 

Hard to come by? I disagree. To get anywhere near the same - and it can make a big difference out there on the stages having the right spread of ratios - you're talking mega-bucks Quaife gearset, and/or a 4.8 final drive which are like hens teeth now unless you want one from - yep, you guessed it - Quaife.

 

I ditched my 4.8 gearbox and had Andy build me up a hybrid. It uses the more readily available 4.4 diff and standard production gears and I've not had problems finding another set so he's going to soon be building me up another 5-speed hybrid but this time in a gti6 casing.

 

Double-thumbs up recommendation, if you think the ratios suit you. For road rallying on a standard 1.9/mi, maybe 128 is a bit tall, but you could go 4.8 to shorten it even further if you wanted....

Edited June 23, 2009 by brumster

[PaulJLLD 0]

Quaife Gear kit is the way forwards have one in my road rally car with a 4.4 cwp going to put a 4.8 in it next to try.

[Craigb 2]

Just refitted My box , now with the 4.8 , just need some gear oil, And i'll let you know if i can feel any difference

[unariciflocos 49 1 Cars]

I found a gearbox from a 1998 Peugeot 605 2 liter 16 valve that I read has a 4.44 final drive that I'd like to install in my 1.9 box. Is there any way I can tell exactly if it's a 4.44, something like number of teeth or a code of some sort?

 

Another alternative would be bolting the 605 gearbox on, since I'm guessing it has stronger internals, but I don't know the ratios. I use the car in hill climb rallies and as said above I only ever use 3 gears, 70mph in 2nd and 100 in 3rd.

[Tom Fenton 1,542]

Count the teeth on the crown wheel and pinion, divide crown wheel no of teeth by pinion no of teeth = the final drive ratio.

[andychalmers 0]

Like Craigb said, I've got the hybrid solution of a 1.9 1st/2nd using 3rd/4th/5th from a GTi6 box which gets you the shortest, packed-up ratios you can for not-silly-money and the figures compare close to the Quaife kit. Coupled with an mi16 my figures come out at as follows (on 15" rims, 8000rpm limit) :-

 

Hi mate, I just pm you on britishrally forum but will ask the same here. Im looking at building another hybrid BE3 gearbox and wanted to use the GTI6 3rd 4th & 5th gears, are these direct replacements for the 5 speed box, if not do they need machining?

 

Cheers

[brumster 135 1 Cars]

As replied on the other forum yes, they need machining - it's not a straight swap

[Craigb 2]

Took the car out for the first run with the new 4.8 CWP.

 

Result . Far better , don't have to drop to first for the tight 90Deg slots. Pick up out of the corners is sweet . think i will actually use 5th on a event now . Roll on the drytsone on the 19th ...