F20, and F28??

[TUBZGSXR]

wot is the difference, is one 5speed and one 6 ?? i was lookin at the comments under andy bishops wicked 2litre turbo and he's changin from f20 to f28, wot advantages does the 28 hav over the 20 with the 2litre or 2litre turbo engine?
thanx
Tubz

[burgo]

yes the f20 is 5 and the f28 is 6 and i beleave the the f28 has longer ratio's so therefore can go kwiker

[Gsidecturbo]

its not the point of goin quicker it makes the engine economical on moterway driving ie not on boost also its built to handle the power better.


cheers
dec

[brian]

and its not worth fitting to a non turbo valver

[PeteG]

It goes back to that age old thing about the F number. Apparently this relates to its torque capacity. Remember torque is the force that turns wheels(and will also strip gear teeth if enough force is applied) Thought is that its the lb/ft it can reliably handle. So the 5 speed F20 is 200 lb/ft and the 6 speed F28 is 280lb/ft.

wether its true or not is regularly disccussed,but it seems a good rule of thumb.
Basically the the F28 is stonger and tougher than the F20 but also with the longer ratios.(4th is closest to 1:1 iirc-5th and 6th are both over drives)
Hope that helps.

[Dicko]

its a pain in the ass to get into a nova AND you loose more bhp due to drag AND its heavier and expensive+rare.

so unless u really MUST be difficult or have over 300bhp then dont bother

[Rick Draper]

Dicko i totally disagree with everything you have just said in your post. The F28 is relativley easy to fit and if someone can fit a C20LET engine in a nova then they can fit the F28 gearbox. Also a F20 gearbox will expire with just a STD LEt engine after only a few months of driving so they need the F28 from the off really. Rick

[Dicko]

yes rick to an LET but he was on about a non turbo 16v purely so he could have more gears.

dont u haveto put them in at an angle which fekcs the shafts/cvs quicker?

[Rick Draper]

Nope they go in the same position as the STD F20 gearbox, and he was asking about LET and XE engines. Rick

[TUBZGSXR]

cheers guys, wot difference does the f28 hav over the 20 on the LET? better accelleration? top speed? driveability? thanx
tubs

[Dicko]

lol@myself

iv either lost the plot of i have confused this with another post i was reading, i swear somebody said on a non turbo engine :(

[PeteG]

cheers guys, wot difference does the f28 hav over the 20 on the LET? better accelleration? top speed? driveability? thanx
tubs

F28 6 speed ratios mean better economy at crusing speed,better driveablity,cos its better matched to the power band of the LET and the spread of torque.
As rick says,if your fitting a LET and want to know which box ,then it has to the 28 cos the 20 just won't last.