Mi16 Gearbox Choice: 1900 With 1600 F/d Or All 1600?

[Stu 18]

As above peeps, i may have landed some 309 bottom arms and shafts, so while im at it i want to sort the gearbox/fd combo out.

 

Im running a stock 1900 BE3 at the moment, its good, but i want it a little lower in ratio, its primarily a track car, but with occassional road use so id like it not to buzz its tits off at 70..

 

Sooo.. do i keep the 19 box and use a 16 f/d to keep the longer first gear, or just swap the box entirely for a 1600 one?

 

My box is ok, and if i did just swap the diff, can i do it in the car without removing the gearbox?

[Anthony 1,000]

1900 gearset and 1600 final drive would be my prefered choice, but it's alot more involved than just swapping to a complete 1600 box - you need to strip the gearbox and change both the output shaft and CWP to change the final drive as I understand it, and that's much more of a PITA than just whipping the diff out to swap the CWP over.

[Tom Fenton 1,526]

My 205 Mi16 track car runs a 1600 gearbox, I find it fine for road use personally, yes its a little tiresome on the motorway, but that is more to do with the fact that it is totally stripped in the rear of the car, so its the drumming noise that gets to you. If I have to go on the motorway more than 20min or so I wear ear defenders whilst driving it.

[Stu 18]

1900 gearset and 1600 final drive would be my prefered choice, but it's alot more involved than just swapping to a complete 1600 box - you need to strip the gearbox and change both the output shaft and CWP to change the final drive as I understand it, and that's much more of a PITA than just whipping the diff out to swap the CWP over.

 

I figured as much, i remember reading that someone had 'just' swapped the diff, but when i think about it the pinion would have to be changed too else the mesh would be wrong.

 

Tom: Mine is stripped out totally bar the buckets and cage too, and i do want to drive it to and from track days so it looks like ill invest in a set of good ear defenders...

[Stu 18]

Right, ive now got both a BE3 1600 and 1900 box's at my disposal..

 

Is it worth stripping both boxes to build a 1900 with a 1600 f/d, or just fit the 1600 item? The car is primarily for Santa Pod, trackdays, and i quite fancy a hill climb or two (if im eligible).

 

So, what do we think? am i going to struggle to get off the line with the 1600 box? I notice the two boxes are nigh on identical in terms of speed per rpm bar the first gear, i think Welshpug put a post up a while back that stated top speed in 1st was something like 32 versus 36 for the 1600/1900 combo, the rest were the same.

 

The car is a stock Mi, running motronic, with a PeterT Stage 1 inlet cam and chip package.

 

I do also own a pair of ear defenders..

[philfingers 5]

if you want a hill climb or sprint then you'd be better with a 4.4. You can have a run in mine when it's done if you like, I'm only in Halesowen.

[Baz 421]

I figured as much, i remember reading that someone had 'just' swapped the diff, but when i think about it the pinion would have to be changed too else the mesh would be wrong.

 

Tom: Mine is stripped out totally bar the buckets and cage too, and i do want to drive it to and from track days so it looks like ill invest in a set of good ear defenders...

 

Ear plugs work well, and don't look as silly!!

 

or an mp3 player.

 

 

if you want a hill climb or sprint then you'd be better with a 4.4.

 

That's what mine has.

[Stu 18]

Im not that serious about hillclimbs at the mo, im more into doing a few trackdays, so will the 1600 left as is be the best bet?

[Baz 421]

Easiest yes. Otherwise the next best thing if you don't wanna really short box but want a decent spread of gears with a almost recognisable 1st would be the 1.9/1.6FD.

[Stu 18]

How do you mean baz? Is first next to useless then?

 

Ive just been having a look at the Mckeown calculator, and what worries me slightly is the big drop in upshift rpm from 1st - 2nd, i wonder if this could be a problem for the 1/4mile times.

[Baz 421]

On a 1.6 box with lots of power behind it, the first gear is so small/short it's gone in no time... That's the main reason for the 1.9/1.6FD.

 

It's not that bad tho, you get used to it, it'll be fine.

[Stu 18]

Is the drop from 1st - 2nd not too much of a problem then?

[RonnieG 0]

Interesting post this as in a similar way there are a lot of recommendations for an Mi box but with a 1.9 Final Drive.

 

To bring it back to your post just how big/difficult a job is it to change the Pinion within the gearbox that drives the Crownwheel as even doing a search there is very little I could find on this....

[pip470 61]

Hi stu, Ive been looking at gearbox choices too and for me that drop in revs from 1st to second (even if i rev to 7000) wil drop me right of the power. I think the 1.9 box with either the 1.6 or as mentioned the 4.4 final drive would be good for the quarter mile. However Quaife seem to have the perfect 1st to 2nd ratios but thats just a bit expensive, interesting though. As you want it quite good on the road at 70 i really think the 1.9 with the 1.6 fd. Phill

[sorr 0]

Is the drop from 1st - 2nd not too much of a problem then?

 

 

No problem at all in my opinion. Infact I believe it is spot on and I have a Catcams inlet so an even narrower power band than normal. Just for clarity I have a 1.9 box with 1.6 final drive.

Edited April 21, 2008 by sorr

[petert 554]

I've got a custom BE3 in my Mi16 which has the 3.25:1 1st gear from a 1.6 and the normal 4.43:1 cwp. I actually think it's heaps better for launching the heavier car off the line and it doesn't bog when going into second. You hardly notice the bigger gap. I'd just stick the 1.6L box in.

[philfingers 5]

you're other option would be 4.44 CWP with 1900 gears with an Mi16 5th, which would give you more relaxed cruising.

basically from memory the 1900 and mi16 gears are the same 1, 2 & 3. The Mi16 has a bigger gap to 4 and 5 though. As 3/4 are tied together you'd have to use the 1900 first four gears. You'll end up with a bigger gap 4th to 5th but it's an option. You could also go with a GTi6 box if you've no worries about the longer box and restricting lock, for track days and sprints would probably be ok. For road rallying it's a no option!

[Stu 18]

Yeah, i did think about a '6 box, i just happened to fall on a 1600 box locally so got that instead!

 

I think for now ill try the stock 1600 box, if it seems first is too short, then ill build my 1900 with the 1600 f/d, and dependant on how the track days go, might invest in an LSD at the same time.

[James_m 0]

Is the drop from 1st - 2nd not too much of a problem then?

 

I guess its a matter of opinion as i really dont like it, especially for the road when you dont always want to go for the limiter in 1st just to get something in 2nd.

I much prefered the Mi16 box with the longer 1st and shorter 2nd. But for a track car you probably wont use 1st at all anyway, so the 1.6 might be quite suitable.

[philfingers 5]

the other option if you want to go quick 1 2 3 but bigger gap to 4 and 5 is to use the std Mi box. It's like most thing, it's a compromise!