M factory final drives, practicality?

Post by **JEBB4** » Sat Mar 25, 2017 11:03 pm

So I'm trying to get an idea of what either the 4.6 or 5.1 m factory final drives actually be like to live with..

Which ever one I buy will most likely be going in an M2A4 box as that is the most common lower ratio box here in Aus and I will also be putting an LSD in too..

i like the idea of the 5.1 but a lot of things I see on the net say even the 4.6 is hard work on a daily basis just for the cruising rpm in 5th..

I know a few people on here have had the 4.6 so what did you think? Would the 5.1 be too much for a daily?

Any input appreciated

Dino · Post by **Dino** » Sat Mar 25, 2017 11:13 pm

Ive had two 4.64FD boxes.

Although manageable on a day to day, it does push the boundaries of a Daily driveable car IMHO. Personally i wouldnt even consider a 5.1 unless it was a race car.

Post by **RattyMcClelland** » Sat Mar 25, 2017 11:28 pm

As above. Don't even think about a 5.1 on a daily drive.

I have a 4.64 fd and it's the single best mod I have ever done. Better than the supercharger.

However....i also own a 6 speed VW t6. It's my daily drive and I'm used to 6 gears.

On The Prelude I get through the gears quick and when in 5th I go to change to 6th at 50mph..... but wait it's not there.

At 70mph I'm at 3900rpm iirc. It's fine at those speeds. More annoying of course but as above the limit of a daily drive.

10% increase in wheel torque. Epic difference in acceleration.

Therealjj91 · Post by **Therealjj91** » Sun Mar 26, 2017 5:57 pm

Yeah I agree with the above, only annoying thing for me is the higher rpm in 5th.

Post by **JEBB4** » Mon Mar 27, 2017 10:15 am

Thanks guys, just as I thought really, 4.6 it is..
Diff wise I take it the m factory helical is the one to go for?

Post by **Merlin** » Mon Mar 27, 2017 10:19 am

Yeah the Torsen (helical) the best daily use diff.

Echoing the other two, the 4.64 is ok to live with but a pain on the motorway. The 4.64 in a M2F5 gives even higher cruising rpm, but stronger 5th gear acceleration. The 5.1 would be too much.

Post by **JEBB4** » Mon Mar 27, 2017 10:25 am

Cool, now I just need to source a box

Thinking of doing the gearbox build myself as well..

Anyone on here done it and are there any special tools I need?

Post by **Merlin** » Mon Mar 27, 2017 10:55 am

What box do you want to use?

Post by **JEBB4** » Mon Mar 27, 2017 11:18 am

Merlin wrote:What box do you want to use?

Guna be using an m2a4 (AUDM VTEC manual) I think as it's the most common VTEC h series box over here..

EDIT: Missinformation alert!!!

The native VTEC box here in Australia is actually M2F5 same as uk... M2A4 is JDM VTEC box..

Poop's