Gti-6 Be3 Vs Mi16 Be1 - Closer Ratios?

[rodionski 3 1 Cars]

Hello there!

 

Tried to search but to no avail.

 

Just a quick question really - if compared in total (meaning a combination of differences in gears and CWP as a whole) to a 405 Mi16 BE1 gearbox, does the GTI-6 BE3 6 speed gearbox have closer ratios (and not just 'another' 6th gear added for highway fuel efficiency) than the Mi16 BE1, meaning that if fitted instead of the stock box into a stock Mi16, would it yield faster acceleration through a given gear over the stock box?

 

So far I've seen two opinions: 1. the box is essentially similar in practical ratios save for the additional 'longer 6th gear' and, therefore, not reasonable for track use at all, and 2. the box is in fact having closer ratios through the gears whereas the 6th gear would approx. equal to the stock 5th gear in the Mi16 box, if compared as a whole.

 

Many thanks in advance!

 

cheers

 

rodion.

 

 

[JeffR 51]

I don't think the '6' box is suitable for quicker acceleration. The top 2 gears are both overdrive (less than 1:1) & the FD is also taller, so ideal for cruising.

 

I fitted 3rd, 4th & 5th from an early 205 into the Mi gearbox keeping the original 4.4:1 FD. car accelerates a lot faster & of course top speed is down-now approx 200kph @ 7400rpm(it was hitting 195 @ 7200 at a recent track day).

 

You could always keep the std ratios & fit a 4.8:1 FD (hard to find these in Aust).

 

I hope Shaun doesn't mind me using his spreadsheet-

 

ratios

('box/FD) 1st 2nd 3rd 4th 5th 6th FD

205 Diesel 1.8 GRD 3.31 1.88 1.28 0.97 0.76 3.47

205 GTI 1.6/1.6 3.31 1.88 1.36 1.07 0.87 4.06

205 GTI 1.6/1.9 3.31 1.88 1.36 1.07 0.87 3.69

205 GTI 1.6/mi16 3.31 1.88 1.36 1.07 0.87 4.43

205 GTI 1.9 Gutmann 2.92 1.85 1.36 1.07 0.81 3.94

205 GTI 1.9/1.6 2.92 1.85 1.36 1.07 0.87 4.06

205 GTI 1.9/1.9 2.92 1.85 1.36 1.07 0.87 3.69

205 GTI 1.9/mi16 2.92 1.85 1.36 1.07 0.87 4.43

206 GTI 180 2.92 1.85 1.36 1.07 0.87 3.69

306 GTI/S16 2.92 1.85 1.28 0.97 0.76 4.43

306 gti6/gti6 2.92 1.87 1.41 1.15 0.95 0.80 4.05

309 GTI16 (90-91) 2.92 1.85 1.28 1.03 0.76 4.43

309 GTI16 (92-93) 3.42 1.95 1.36 1.05 0.85 4.43

405 1.6 carb 3.25 1.85 1.28 0.97 0.76 4.19

405 1.9 carb 3.25 1.85 1.28 0.97 0.76 4.06

405 SRI / 1.6 GTI C/R 3.31 1.88 1.28 0.97 0.76 4.06

405 T16 3.42 1.82 1.25 0.97 0.77 3.93

mi16/1.6 2.92 1.85 1.28 0.97 0.76 4.06

mi16/1.9 2.92 1.85 1.28 0.97 0.76 3.69

mi16/mi16 2.92 1.85 1.28 0.97 0.76 4.43

Xantia 2.0 SX 3.46 1.36 1.07 0.80 0.76 4.06

Xantia VSX (s16) 3.46 1.87 1.36 1.07 0.80 4.27

Xsara VTS 2.92 1.86 1.28 0.95 0.74 4.43

ZX (CB) 3.42 1.81 1.28 0.97 0.76 4.29

ZX (CL&CJ) 3.46 1.85 1.36 1.07 0.87 3.75

ZX 16v 2.92 1.85 1.28 0.97 0.76 4.43

ZX Volcane 2.0i 3.46 1.85 1.36 1.07 0.87 3.59

custom 3.31 1.88 1.36 1.07 0.87 0.00 4.43

(1.9 box with 4th, 5th from mi16, 6th from gti6 and mi16 final drive)

[petert1345402284 0]

To get the full picture you need to calculate the percentage change between the gears and the overall ratios. I've put this together using the GTi6 numbers above. Overall first is a tad longer, 6th gear is a fraction longer, but the rest are in between the Mi16 ratios. 3rd, 4th and 5th is where it's better. So yes, the ratios are considerably closer and would probably keep the engine on the boil better than the standard box. I've also included Jeff's setup for comparison.

 

[welshpug 1,622]

shame it doesn't bloody fit without chassis mods though, the end casing it 55mm longer than a 5 speed BE casing, and the chassis leg drops down lower than the end of the gearbox apparently.

 

I would have put one in my RS powered ZX16v, if it were not for the limited R/H steering lock.

[KRISKARRERA 2 1 Cars]

Peter's right.

The first gear of a 405 Mi16 is about as long as I'd ever want it to be. The engine is hardly a torque monster at low revs. Over on the GTI6 forum they like to make a fuss of their 6 speed boxes and what they supposedly do for acceleration, but it's not as if having a 5 speed box would suddenly make a huge difference. The acceleration times of the Xsara VTS prove my point. In fact the only reason the Xsara is a few tenths slower to 60 is that it needs a change to 3rd to reach 60 whereas the BE3/6 does not.

[Baz 421]

They're weak anyway too.

[KRISKARRERA 2 1 Cars]

Miles says they're weaker, so it must be true.

[Baz 421]

It would make sense, one extra, so the gears are smaller, packed into almost the same space.

Edited May 12, 2010 by BazGTMi

[rodionski 3 1 Cars]

Hey could you please confirm that chassis mods will be REQUIRED also to fit the 6-speed box into a 405 Mi16 running the stock D6C?

 

I've seen pics of a 405Mi16 where the guy tried fitting a GTI6 engine AND gearbox and there clearance from gearbox to suspension arm was an issue.

 

Thanks for the comments!

 

p.s. I am about to receive the 6speed box, so I really need to assess any potential problems with this.

[rodionski 3 1 Cars]

bump

[rodionski 3 1 Cars]

Come on people! Please make some input!

[rodionski 3 1 Cars]

Another question - can the 4.43 crown wheel pinion be fitted to the 6-speed box instead of the longer stock one?

 

Thanks!

 

 

p.s. I had some group A engine and gearbox mounts made which will bring the engine and gearbox 10mm lower - to avoid potential clearance problems.

[welshpug 1,622]

not from a factory PSA gearbox no.

 

you can get aftermarket CWP kits for about 800 euro's IIRC.