What goes on the F20?

[Nova_Tek]

When attached to a LET what is it that actually dies?
:thumb:

[bazil]

depends whats in it, my mate has a standard let with a standard F20 but with a quaiffe ATB diff and it works fine, but he aint to hard on it.

[Rickardo]

Mine was ok, never had any trouble.

edit: Mine was running stage 1 EDS 245 bhp.. No problems.

[Nova_Tek]

Well Standard LET mate, I'm not no boy racer but obviously one with a LET Nova will inevitably give it the beans now and again.

I'm just weighing up certain things. F20 are cheap so if it's weakness is uprated then it should fine especially when they are cheap to buy, need less work/hassle to fit and weigh a bit less.

[Rickardo]

I drove my Let Nova as a daily for over 12 months. Never had any trouble with the F20 box.

Saying that, if you drove round like your pubes were on fire it will ( eventually) go bang.

[blue_peg_16v]

ive had an f20 on mine for the last 12months with no problem its running phase3 and its still in one piece touch wood

also mark watts had one on his for years and he only replaced it once

my theory is i can replace my f20 6 times for the same cost as replacing an f28 once and f28s are renownd for the syncros going too (f20= £50max f28 = alleast 300)

[Nova_Tek]

^ makes sense but what is it that pops on them?

If its £250 for a ok F28 but £75 for an ok F20 and £100 to get the weakness uprated, then it works out much better to fit the F20 as less parts are needed to fit it and it isn't so heavy.

This is what I'm trying to weigh up before I decide.

[bazil]

ive been told that flat out redline gear changing can damage the gears themselves and driving like a mega chav will kill the diff. alot seam to use a f16?

[blue_peg_16v]

ive never had one go on the let so couldnt say went through 4 on the xe but never inspected them just threw another one on

[blue_peg_16v]

ive been told that flat out redline gear changing can damage the gears themselves and driving like a mega chav will kill the diff. alot seam to use a f16?

there are 2 f16s close and long ratio they are both weeker than the f20 though but can be used dependent on were your after performance long ratio f16 is good if your on motorway as cuts rpm at 70 by about 500

[bazil]

there are 2 f16s close and long ratio they are both weeker than the f20 though but can be used dependent on were your after performance long ratio f16 is good if your on motorway as cuts rpm at 70 by about 500

now i know why its used, cheers:thumb:

[fearless]

3rd gear will be the first to shread it's teeth ;)

[Nova_Tek]

Well I have done a bit of searching and found that there are 3 F20 boxes. one CR and two wide with the third type being even wider. The ratios seem to be exactly the same apart from the 5th gear. The widest F20 does something like 170mph the other around 160mph and the CR around 140.

So the 2nd box would be a good option for economy on motorway driving but the same as the rest from 1 - 4.

I'm assuming the diff would be more likely to go with lead foot driving if gear changes were done properly.

[vx kev]

Had a mk3 astra gsi LET running approx 300bhp and completely shredded 3rd gear!

[Nova_Tek]

so the diff and 3rd gear are most common faults.

[Lee H]

Heard of several cases of 5th gear stripping as well when it comes on boost hard.

3rd usually dies most commonly though as it's the first gear you can get proper traction in.

[Nova_Tek]

Right, was expecting 5th to go aswell due to the torque. Are there known kits that can be bought or would refurbed 3rd,4th,5th gear last?

[Lee H]

Nothing apart from buying quaife gears @ £1500ish but still won't last as well as an F28.

Can't see how refurbed gears would be cost effective or any stronger for that matter. I'm pretty sure Vauxhall fitted the F28 instead for a reason.

[Paul]

On one of mine, I could only get 2nd and 4th, Reverse, 1st, 3rd and 5th just did nothing.

Another one I snapped the casting in half.

On two I think I destroyed 3rd gear

Destroyed fifth gear on another

And there was another 6 in total, in about 18 months.

50quid a time, thats 300quid. plus pissing about fitting them.

While you have the chance stick a F28 on, you will not regret it.

There will be a time in the not to distant future where F20s start to go up in price, as when they break, they dont get repaired, they get binned.

[blue_peg_16v]

Nothing apart from buying quaife gears @ £1500ish but still won't last as well as an F28.

Can't see how refurbed gears would be cost effective or any stronger for that matter. I'm pretty sure Vauxhall fitted the F28 instead for a reason.

wouldnt bother with quaife gears would be an expensive mess as there not designed for the torque