F18 or F20

[Mike]

Any info or useful opinions/facts with regards to which has better in gear acceleration on a 20XE motor.

[comptoncj]

F18s are made of chocolate. Ive replaced loads of diffs in vectras and calibras that have had f18s in them.

[Mike]

I wont be using the standard diff anyway lol

[Damo]

Ive got an f18 in mine mike with an XE motor the gearing is a little long winded tbh but its great on the motorway but if your wanting acceleration then either f16/f20 is the way mate.

[General Baxter]

i think i had a f18 WR on my old xe, top a ton in 2rd lol

take ages to get to 60 tho lol

[Mieran]

F18 is only good for a LET imo, mine used to hit limiter in 4th doing 145 lol Put that on a XE and will be slow as fook

Best box for acceleration is F16C imo

[General Baxter]

yeah but 70mph down the motor way, you could see around 45mpg lol

[Damo]

yeah but 70mph down the motor way, you could see around 45mpg lol

Yep as i regulary do lol.

[GRUNT 16V]

ERRRRRRRMMMMMMMMM F18 or F20 !!!!

Is this a trick question ????


















F20
F18 = 5HITE CR$P WASTE OF TIME!

[blue_peg_16v]

f16cr

[Saloony]

F20, remove the 5th gearset from the F18w put in the f20 then you have best of both worlds.

[Mazz]

Thats something i intend on doing as my F20 rev's quite high at about 70/80

What cars did F18W come in?

[Paul]

Apart from the different gear ratio's, what is the difference between a F18 and F20?

Im pretty sure the gear's sychros etc would have been made in the same factory in the same way, same as the bearings etc. The diffs are the same AFAIK. So why do people always say the F18 is sh!t?

I think its a fact that the F18 is as strong as the F20?

~awaits to be proven wrong~

[Mieran]

Ran a F18 on ph2 and was fine, also never killed gearbox in my life

People need to start learning how use them properly

[Lewis.]

F18 is only good for a LET imo, mine used to hit limiter in 4th doing 145 lol Put that on a XE and will be slow as fook

Best box for acceleration is F16C imo

but an LET will blow an F18 to sh*t rags. they are only made of biscuits lol

F20 all day long, it's basicly a stronger version of the F16, as the gearing is very similar

[Mazz]

Ran a F18 on ph2 LET and was fine, also never killed gearbox in my life


but an LET will blow an F18 to sh*t rags. they are only made of biscuits lol


umm

[Paul]

And I've actually been told by a very well trusted man that the F16s are stronger than the F20's, stronger bearings?

[Lewis.]

/\ as a general rule, the number indicates the torque the box can stand.
eg; F10 100Nm, F13 130Nm, F28 280Nm etc etc obviously with the red herring of the F18 which can barely support its own weight

[Paul]

Ok, whats different in the F16/F18/F20 that makes them 160Nm/180Nm/200Nm?

Why is the F18 so weak, what is different in the F18 to the F20 for example?

I generally am interested, not being an idiot. Cause all people seem to say is the F18 is sh!t but nobody can tell me why.

[Nova_Tek]

Ran a F18 on ph2 and was fine, also never killed gearbox in my life

People need to start learning how use them properly

I agree.

I'd stick a F20 on a XE coz that's what it came with. There are a few types of F20 but what you need to know is they're all the same except the final drive IIRC 3 in total. Some will hit limiter at around in the 130's, some will go to 150's and others geared for more.

I'm hoping I've got one of the boxes with a longer 5th so that I don't get silly revs on motorway cruises.

My bro has a early F18CR in his Cav XEV SRi. Good box, no problems. The later ones were apparently made of chocolate and cheese (so I've heard).

People have stuck F16's on to LET's and send them down a strip with no problems. So it's all down to how you drive and how well the box has been looked after.

[Mieran]

but an LET will blow an F18 to sh*t rags. they are only made of biscuits lol

F20 all day long, it's basicly a stronger version of the F16, as the gearing is very similar

just to make things even harder for the F18 I then put in a plate diff and paddle clutch and still survived lol

According to the internet that box should not last more than 20 miles

[NOVA saloon]

F16 out of a deuo how ever you spell it lol on my best mates xe Corsa flat out 132 mph.

My f16 in my nova sat next to my mated vec vxr at 155 there all different IMO wish I had vids to back this up.

[Jeff16v]

I had an f16 on my let, it blew it to bits. F20 on the current one, and they're bloody cheap to replacelol

[Mike]

The only reason I asked this was I stumbled on a nice diff from a Vectra challenge car going for a lovely price removed from an F18 lol

[blue_peg_16v]

mike have a word with stupot he had a brand new f18 he wanted rid of for a very reasonable price

[comptoncj]

I have the opinion of f18s being weak because being a mechanic i have changed loads of diffs in them, the gears themselves are fine and so are the bearings its just the diffs that cant take the punishment. All the f18s i have took out have suffered the planet gears flying to bits usually smashing a hole in the casing rendering the gearbox useless so putting an uprated diff in will solve the problem.

[Mike]

uprated diff in will solve the problem.

Was exactly the reason I originally asked this qeustion as I came across an Ex Vectra Challenge car F18 diff for a very very modest price indeed.

[Paul]

So the std. diff is different in a F18 to F20? What about the F16? I know a quaife diff is identical for F16/F18/F20, so did Vauxhall really make them different?

What else is different in them, what limits the boxes to;
F16's 160Nm, F18's 180Nm and F20 200Nm?

Or is that an old wives tail?

As far as I can tell all the gearboxes are identical inside, just different ratios etc?

[Damo]

Ive run a f18 on my XE for nigh on 8months now and its fine despite being a little crunchy going in second and third due to worn syncros.

[comptoncj]

Im not sure about the diffs but im sure you could run an f20 diff on a f18, ive never put them side to side to have a look though only thing that could be different is the diameter of the bearings. Damo is your f18 an early one? IIRC they are a bit better than the later f18 that appeared on vectra b's.

[Damo]

Im not sure about the diffs but im sure you could run an f20 diff on a f18, ive never put them side to side to have a look though only thing that could be different is the diameter of the bearings. Damo is your f18 an early one? IIRC they are a bit better than the later f18 that appeared on vectra b's.

Tbh honest mate im not sure it came from iain grants old blue ecotec nova that w88rdy broke so presume its a later one.

[Pancho]

this is funny. specky runs an f18. that says it all really.

[mowgli]

So the std. diff is different in a F18 to F20? What about the F16? I know a quaife diff is identical for F16/F18/F20, so did Vauxhall really make them different?

What else is different in them, what limits the boxes to;
F16's 160Nm, F18's 180Nm and F20 200Nm?

Or is that an old wives tail?

As far as I can tell all the gearboxes are identical inside, just different ratios etc?

different ratios, and i would imagine different bearings.

the single biggest reason gearboxes blow up is the fact that we will happily buy expensive engine oil & change it regularly, but most people don't do a thing with their gear oil, not even checking it once in a while

[Lewis.]

this is funny. specky runs an f18. that says it all really.

but as has been discussed, the weak point of the F18 is the diff, and he certainly does not run a standard diff does he.

[Paul]

this is funny. specky runs an f18. that says it all really.

No he doesnt.

[Lewis.]

Specky runs an F28 doesn't he?

[mowgli]

f23 i believe, its taller geared

[Paul]

Gone back to f28 iirc

[Andy]

This site used to be full of usefull info,these days its full of shi7 if threads like this are to go by.
Why would vauxhall make their gearboxes out of different "strengths" of metal.
Honestly its laughable how naive some people are lol
Having previously worked in a clutch and gearbox centre i can 100% say gearbox failure is down to driver error and or abuse
How many of you/the public who owned the bangers these boxes came from, have changed your/their gearbox oil at regular intervals???
Nuff said

[Lewis.]

Usefull input, that. Thanks. And no one has mentioned different strengths of metal either, so not sure where you got that from either. But F18's DO have a reputation of eating themselves, and as comptoncj said, in his experience of dealing with many of them, the planet gears jump out.
So by your logic, people only abuse F18's? hence their high failure rate compared to other F boxes?

[Andy]

Usefull input, that. Thanks. And no one has mentioned different strengths of metal either, so not sure where you got that from either. But F18's DO have a reputation of eating themselves, and as comptoncj said, in his experience of dealing with many of them, the planet gears jump out.
So by your logic, people only abuse F18's? hence their high failure rate compared to other F boxes?
Ok,some people in the thread have said theyre made from "chocolate" "Biscuits" to name but a few.
Where is this info gained from?? cos having seen the inside of literally hundreds of various vaux boxes,theyre all the same.
They have gained a reputation of "eating themselves" from where??
Honestly i ve heard just as much/and better still SEEN all the others do the same.
But in all seriousness,from my experince the Astra mk4 was the most popular customer at the gearbox centre i worked at,with The 6speed Renault/Vauxhall vans coming a very close 2nd.
Again,ive never heard of a truthful,proven reputation of any of the f16/18/20 boxes being any worse than each other.
Lets not forget,that these boxes are in a car they were never designed to go in,thus when people set their gears up,whos to say that isnt the cause of them failing,due to not being enagaged enough/too much.
And again,people not changing oil in them and their style of driving isnt going to help them either.

[mowgli]

buying any gearbox that has done 150000miles dragging a 1.5t repmobile up the country at high speeds, & sticking it into a car without stripping & fitting new bearings/bushes is always a risk....

andy, manufacturers do 2 things regularly.

1. they cheapen a component so it has a design life.
2. they put it out to the lowest bidder to get it made..

this means that some gearboxes will be weaker than others that are dimensionally identical..

personally, i don't know if buying one that has only been tickled round town is any better than a high miler

[mowgli]

buying any gearbox that has done 150000miles dragging a 1.5t repmobile up the country at high speeds, & sticking it into a car without stripping & fitting new bearings/bushes is always a risk....

andy, manufacturers do 2 things regularly.

1. they cheapen a component so it has a design life.
2. they put it out to the lowest bidder to get it made..

this means that some gearboxes will be weaker than others that are dimensionally identical..

personally, i don't know if buying one that has only been tickled round town is any better than a high miler

[mowgli]

accidental dupl.