f20 vs f16 the mass-debate!!

[turbojolt]

right i fully intend to run both boxes to come to my own conclusion of which is best for me, but that wont be for a while yet.

I just want to hear some different views of both boxes, even better if you have run both i want to know how you found them, did you really find a massive difference between the 2 boxes, top end, acceleration, reliability etc etc....



cheers :thumb:

[Stuart]

whatever one you have, just fit it.

[camels toe]

All the f20`s ive had have being great.Quick enough through the gears yet still comfy enough in 5th cruising. The problem lays with the f16 and which ratio is fitted.I had a wide ratio one fitted to my mk2 cav that was really tall in 5th and you had to change down even on the motorway up a slight hill. Then the close ratio one is way too revvy.60mph at 3k in 5th and top out at 125. Very quick though through the gears. If you can find a straight f16 like the mk2 astra gte 8v came with theres not much difference with that and the f20.
In short stick with the f20!!

[John]

The xe came with f20 fitted as standard, so just fit that.

[Benn]

I'd be amazed if you noticed the difference. Just fit the F20.

[Dan Stanley]

All the f20`s ive had have being great.Quick enough through the gears yet still comfy enough in 5th cruising. The problem lays with the f16 and which ratio is fitted.I had a wide ratio one fitted to my mk2 cav that was really tall in 5th and you had to change down even on the motorway up a slight hill. Then the close ratio one is way too revvy.60mph at 3k in 5th and top out at 125. Very quick though through the gears. If you can find a straight f16 like the mk2 astra gte 8v came with theres not much difference with that and the f20.
In short stick with the f20!!

Didn't know that. ^^^
That's a handy bit of info. I always thought it was just the F16CR they used from a Cav SRI130.
I know its not the same, but I ran a F13 (nova GSI g'box) on a 2.0 8v. It gave it loads of acceleration but ran out of guts at indicated 120mph and was juicy-ish on motorways. Suited the low down grunt of that engine set up though, so wouldnt have had it any other way.
I also ran a F13 on my X16XE and that was just too close. It made it quick from a standstill but you soon got sick of changing gears and high cruising rpm. The F15 its on now is far better suited to the car and makes it more comfortable. Even if it has lost its edge on acceleration.

[8valve-craig]

There is no difinitive answer, It all depends on what the car is used for. There are many combinations, not just "f16 or f20" You should consider final drives too, which in the real world needs to be done using trial and error.

Just choosing an F20 and deciding you dont like it may well put you off F20's, but then the same box with a 3.9FD fitted would transform the car.

[turbojolt]

thats why im asking for peoples real world experiences mate, like i said im more then likely going to run a few different boxes

[8valve-craig]

Here is a pic taken inside my Nova. F16 box with a GM final drive of 3.9.

Not reccomended if its a daily driver, but spot on for a track with short straights.

http://i995.photobucket.com/albums/af79/smith9051/04092012214.jpg

[pie]

my white gsi runs 4x4 f20 internals in a f16 casing (only internals i had spare) and lets say it aint good for motorways lol lol rev happy in a 2wd car

[Mieran]

I had 2x C20XE Novas at one point one fitted with F20 and other fitted with F16 and preferred the F16 tbh

For a track car I would pick F16 without a doubt

[blue_peg_16v]

Long ratio f16 is pants f16cr is bloody rapid through the gears but revs like mad on motorway, I'd say best all rounder is f20 decent for getting to track and not to bad through the gears.

[Graeme]

Another vote here for the f20 will still get up to speed quick enough but won't be spinning the wheels in third

[staggy_gsi]

Could you put the 5th gear from a long ratio f16 onto an f16cr? Quicker acceleration thru the gears without being too revvy on the motorway.

[turbojolt]

Could you put the 5th gear from a long ratio f16 onto an f16cr? Quicker acceleration thru the gears without being too revvy on the motorway.

ive read somewhere about putting the 5th gear from a f18 box, but not a f20

[Peanut_119]

I have a tall 5th out of a f16wr in my f20 and its belting on the motorway.
I'm looking for a f18 5th gear tho

[Nobby]

Just fitted a f18 in my V6 ratios are similar to f20 with 3.58fd compared to 3.55 fd in f20

[Jeff16v]

Twisty roads and fast blasts f16cr, longer runs require the f20. The f16 was fantastic to work blasting off the lights etc but screamed it nuts off going to pv. Either will be fine and both are cheap to replace anyway.

[8valve-craig]

I think what a lot of people are forgetting here is that it depends which car the box comes out of. There are many combinations of F16 and F20, so simply saying "an f16 is better than an f20" just isnt accurate as an annalysis.

[turbojolt]

tbh i didnt think there were any diffrent f20's is there a way to tell what they came from etc?

[8valve-craig]

The end casing will be stamped with what FD is fitted, but as for the cluster its just normall CR or WR

The best way is to decide what you want, drive on a few different combinations then just build your own.

Dont rule out Daewoo D16 and D20 boxes either. Thery are normally low milage, non abused and in some cases can have 4+ FD's fitted. (although granted thats not a very road friendly ratio for a 20xe road car)

[paddy235]

What's wrong with an f18? I've always used them

[Stuart]

In a blind test I bet you wouldnt 'really' notice bar motorway cruising...

Bit like cars with/without a quick rack, you cant really tell (imho) unless you are told. Otherwise the car just does what you want it to.

[Alex J]

there all ****, debate closed lol

[Mieran]

Craig any idea what cars had the D16 and is the FD stamped same place as vauxhall boxes?

[8valve-craig]

Yeah a Daewoo Nexia or Lanos 1.5 16v will have a D16 / D20 box, which is basically identical to the F16, just with hydraulic clutch that needs swapping, but thats no real drama.

The all important FD is stamped at the bottom left of the 5th gear housing. Not the end cap, but the flat surface which holds the input / output shafts when you pull the cluster out.

3.944 and 4.176-1, are quite common, and there are a load of other cars like the Chevrolet lacetti i think which could also be donors

[Mieran]

Cheers for that, I'm lookng for a box for acceleration not top speed so will be on a hunt for one with 4.1 FD

One more question, how do you identify a D16 or D20 gearbox? Will it be stamped same as F16/F20?

[8valve-craig]

Just remembered the FD is stamped top left not bottom right. Its a lot easier to find on a daewoo box anyway.

I cant remember where d20 / d16 is stamped, its not by the fork like an F though.

A site called Daewootech is great for info.

[Mieran]

Would be great if you can post a pic to show where FD is written.

Am I asking too much now? lol

[8valve-craig]

Pics.

http://i995.photobucket.com/albums/af79/smith9051/gearbox01ps5.jpg

http://i995.photobucket.com/albums/af79/smith9051/gearbox06mg7.jpg

[Mieran]

Cheers for the pic

Found a local one on ebay, going to take a big block clutch plate with me to try it on just in case its daewoo version of the f13

[Mieran]

Craig I bought a box and it doesnt have a stamp there, its from Lanos 1.4 16v

Is there another way to check?

[8valve-craig]

Are you sure its a D16 from a big block Daewoo? sounds like a small block box to me.

Try fitting a cv joint.

[Mieran]

Deffo big block box, tried shafts and clutch

[8valve-craig]

Might have to count the teeth and search for a match. It will be something like 72-teeth - 17-teeth. Once you have both numbers you can search for an answer on Daewootech.

Im sure it will be stamped on the casing somewhere though, It usually is. Sometimes on the old Combo vans i get to the point where i swear its not there, but then a little more scraping and it magically appears.

[Mieran]

I'll give it a clean tomorrow and post some pics, but looking at the net chances are it wont be anything lower than 3.94 so thats good but ideally I wanted a 4.1