10 replies to this topic

[vxah]

Hi Guys, I'm interested in some thoughts on how you find the gear ratio's on tuned 220 turbo's...

I actually run a Europa s with the six speed M32 transmission and to be honest find the ratio's too low so,  as I am rebuilding the box I want to change the final drive ratio from the standard 3.94 to something a bit taller, I have 3.83, 3.65 or 3.35 to choose from?

As standard the first gear is a rather low 3.818:1 coupled to the 3.94 makes it almost useless, It seems I cannot change this as it's machined onto the input shaft! However I worked out that if I fit the 3.35 final drive it would give almost exactly the same overall ratio's as the 220 turbo in the first 5 gears, leaving the 6th as a cruising gear at 30mph per 1k rpm.

 

I guess what I'm asking is how would you tuned turbo owners find that? Do you find the standard 5 speeds ok or are they wrong with the added power and torque? Would you want the extra gear for cruising?

 

Sorry for asking on the vx forum but I'm not sure where else to go to get informed thoughts before I make any changes that I might regret!

 

Thanks in anticipation! 

[Nev]

I find the standard OEM F23 gear ratios too high in my car, I wish they were about 15% lower overall, as 4th gear takes me up to 160 MPH. Thus 5th gear is useless except for cruising.

 

Everyone has different desires though, longer gears makes for an easier drive, and as you have that extra gear maybe you are fed up with stirring the box !

Edited by Nev, 31 August 2016 - 03:52 PM.

[manus]

As standard the first gear is a rather low 3.818:1 coupled to the 3.94 makes it almost useless, ....

Fully agree with this (on the Europa) although 6th is all-right for cruising. The VXT220 F23 makes more sense on low gears, specially with a bit extended rev-range. Will be interesting to see if you manage a new final drive.

[tibby]

I find the standard OEM F23 gear ratios too high in my car, I wish they were about 15% lower overall, as 4th gear takes me up to 160 MPH. Thus 5th gear is useless except for cruising.   Everyone has different desires though, longer gears makes for an easier drive, and as you have that extra gear maybe you are fed up with stirring the box !

Idem. VXT box should have a 3.83 FD....

[Kieran McC]

http://www.vx220.org...conversion-kit/

 

Gear ratios on here compeared  to a F23

Edited by Kieran McC, 31 August 2016 - 07:10 PM.

[Duncan VXR]

I prefered the m32 std ratios as a road car v the std f23 but could argue you loose speed due to the extra gear change at times 167gps in da Germany was the most I ever saw in my vx with 6 speed box. Not my kind of thing really and prefer 0-100 times 😊 Nev is that gps or calculated? Cant remember your rev limit now DG

[vxah]

I was comparing with the turbo ratio's which I understand to be 0.79 5th and 3.63 fd, I could have got that wrong though? I have all the ring gears and pinions laying on the bench and just waiting for the gen3 end case and bearings. Maybe I should use the 3.65 fd as with the .744 6th will be just a little taller than 5th on the vx? Still have a pretty short 1st though! Have to do a bit more number crunching and thinking!

[siztenboots]

standard cars rev to 6800 , which suits 2nd and 3rd quite nicely on track for me, rev limit 7800, its very flexible with my torque curve, 120mph in 3rd , can't remember 2nd but its a lot harder to get all the traction you want in 2nd out of slower corners even with wider rear setup.

[Nev]

IMO, these tuned cars need a close ratio set with 1st gear being very long, and equal steps between each gear with top gear maybe taking you to 150 MPH rather than (a theoretical) 198 in my case.

 

The mere passing though of taking my gearbox out and trying to fix the problem is more than enough to give me nightmares. Hat's off to the OP for trying though!

[Nev]

Nev is that gps or calculated? Cant remember your rev limit now  

 

GPS max speed on mine in 4th is 156 MPH with my wheels (indicates about 160 on the speedo (apparently)).  

Edited by Nev, 01 September 2016 - 09:13 AM.

[vxah]

Would I be correct in thinking a stage 4 LE# runs out of power at about 5500 rpm? That's with vxr maf, injectors and turbo etc +C cooler, that's the thinking for the 3:35 gears.. But what would the curve look like with a hybrid turbo on a Dbilas manifold? Obviously not going to lift it to 7k but might it raise power to 6k or so? That might make the 3:65 a better choice?