MFactory custom 1st gear for better 1-2 shifts

[CyborgGT]

... because his F-series is more betterer?

[Domesticated]

Did I miss something? I though the custom gear was for the H trans? To make it a little better.

[af_1132]

Why not just purchase an H22 or the H23 trans and problem solved?

The M2S4 (USDM H23A1), the M2K4 (AuDM H23A1 and EuDM H23A2) and the N2D4 (EuDM H23A3) all have 1st gear at 3.307 with 2nd gear at 1.809 or 1.857 (M2S4). The problem of having to rev uncomfortably high in 1st to get into decent power in 2nd remains whether we have H22, H23, F22, or F23 engines.

Are you saying that having an H22 will allow us to rev high enough to make this custom gear not worth it? I'm just a little confused.

Source I got those numbers from (Thank you Joey GT-R!):
www.cb7tuner.com/vbb/showthread.php?t=203209

[Sordz]

Is there a advantage for H guys who rev to 8k instead of the 72-7500? This could help getting our somewhat heavy chassis moving, I would hate to shift into 5th in the 1/4 though.

[af_1132]

Is there a advantage for H guys who rev to 8k instead of the 72-7500? This could help getting our somewhat heavy chassis moving, I would hate to shift into 5th in the 1/4 though.

How much power are you making out of your H? What transmission do you have?

If you have the M2S4, then a 1st gear shift at 8k rpms gives you almost 4500 rpms in 2nd. I don't have an H, but I would guess that there is no VTEC at that rpm.

If you have the M2A4/B4, then a 1st gear shift at 8k rpms gives you just over 4700 rpms in 2nd. Same guess as to no VTEC there as well.

I would say you would benefit from a longer first gear. I would also say that if you are shifting in every gear at 8k rpms, you would not need 5th in the 1/4 mile, with or without this custom first gear.

Anyone, if I am off, please correct me. I don't want to be dishing out misinformation.

[wagon-r]

I might be interested. I've done a lot of engine work, but never got into transmissions and I would be paying someone to do the install. On the other hand, I have a Quaife LSD that I need to have someone install for me anyway. While I'm at it, might be worthwhile to redo 1st gear.

Some questions (remember, I'm not an expert on transmissions):

1) Would the 3.0 custom 1st gear work with an F22 tranny, such as 4th gen H2A5/H2U5 or the 5th gen P2A5/P2U5? They have the same 3.307 1st gear as the M2 transmissions, but I don't know if there are other differences. Rather than replace 1st and 5th gears and the final drive ratio in an H22 tranny, I could just replace 1st gear and the final drive ratio (4.6:1) in a cheaper F22 tranny - and still have the tall cruising gear. I only do autocrossing, so I don't care much what happens after shifting into 3rd.

2) There is a separate gear for 1st on the countershaft, but 1st is built into the mainshaft. Would the mainshaft have to be replaced as well to get the custom 3.0 1st gear? Or is the custom countershaft gear designed to work with the OEM mainshaft?

3) If I did this, I would need to replace the final drive ratio as well. Where can I buy a 4.6 final drive and how much would it cost?

[jdm92_accorn]

as long as the mainshaft gear is the same it should work. mfactory sells a 4.64FD, im buying mine from synchrotech.

[af_1132]

Trying to help make sure this gets adequate viewing time.

After reading through, it looks like 4, possibly 5 members are at least semi-committed (XRCN, did you end up selling the CB?).

Have there been any developments on this other than this thread?

[Domesticated]

I'm buying a trans this summer from them, possibly in a month. So well see how the timeline ends up.

[jdm92_accorn]

the only thing we have to keep in mind is that we all have to agree on the same first gear ratio and it will only work in the m2 cases. now that a few members are interested, what ratio?

[af_1132]

the only thing we have to keep in mind is that we all have to agree on the same first gear ratio and it will only work in the m2 cases. now that a few members are interested, what ratio?

3.000 looks great on paper for the m2a/b. That seemed too long for a T2W4 on an F series if shifts are below 7000rpms, just my opinion though.

[sonikaccord]

Only the m2 cases eh? Fine, even though I wanted to keep my long H2 gears.

What shift point and where in second do we want the rpms to land? Personally, I plan on running turbo so I'd like a longer first anyway.

2.85 gear at 8k rpm in first will land you at right around 5200 rpm in 2nd on the M2S4

3 seems good for all the h22ax native trans. It puts you at 5100.