Merlin's 4G Time Attack Lude

[Merlin]

Short ratio M2p4? oem ratios and final drive?

TBH I'm not 100% what these numbers mean, but I presume its the circumference of the gear, I have never taken the time to learn about it:



But what I do know is that its the same gearbox thats in my 5G and me likey!! Same as your U2Q7 Dino but without LSD so its a fuckton cheaper.

[indigolemon]

A metric fuckton?

[Merlin]

You know it I don't do imperial

[Dino]

The F5 box FD ratio you have listed is wrong. Should be 4.026.

Ive not got the U2Q7 ratios in my box. Ive just used the casing as a housing for my lsd.

[Merlin]

Thanks for the heads up. I was wondering how both had the same 5th and FD ratios but resulted in different speeds I copied the info from that list of gearboxes that has done the rounds.

[Dino]

Ive seen it.... no worries bud.

You do realise you get quite a rev drop between 3rd & 4th gear.

Important as they are the two gears you use most on track.
Dropping down lower in the rev range than other gears in 4th means you will be further down the power band, wher you need it most.

Im sure you know that, and if you are happy with the box and it performs the way you like it, then why change it

What LSD are you fitting?

[Merlin]

I have never really noticed before but I watched a vid and there is more of a rev drop. What did you do? Take 3rd gear from a 4th gen gearbox?

Im not sure on what LSD. Going by the Quaife LSD which is the same for both 4th & 5th, I'm hopeful that any Prelude or ATR LSD will fit. But havent looked into it much.

[Dino]

Im using the M2F5 Gearset.

Try experimenting with Ratios using this thread:
http://www.ludegeneration.co.uk/honda-p ... -t894.html

List of Ratios here:

This may help a little





M2A4 - JDM 4G

M2B4 - JDM 4G LSD

M2F4 - USDM 4G

M2F5 - EuDM 4G

M2P4 - EuDM 5g Vti-S 4WS

M2V5 - EuDM 5g Base 4WS

M2U4 - JDM 5G Type-S ATTS/USDM Type-SH ATTS

M2Y4 - JDM/USDM 5G Base

M2Z4 - JDM 5G SiR S-Spec/JDM 5G w/ LSD option



Accord



T2T4 - JDM Accord SiR-T (F20B) LSD

T2W4 - JDM Accord Euro-R LSD

U2Q7 - EDM Accord Type-R LSD







Full Gear Ratios



M2A4 - 3.307 - 1.950 - 1.360 - 1.071 - 0.787 - 4.266

M2B4 - 3.307 - 1.950 - 1.360 - 1.071 - 0.787 - 4.266 LSD

M2F4 - 3.307 - 1.950 - 1.360 - 1.071 - 0.870 - 4.266

M2F5 - 3.307 - 1.950 - 1.360 - 1.071 - 0.870 - 4.062

M2P4 - 3.285 - 2.090 - 1.481 - 1.071 - 0.870 - 4.266

M2V5 - 3.285 - 1.950 - 1.344 - 1.071 - 0.870 - 4.062

M2U4 - 3.285 - 1.956 - 1.344 - 1.034 - 0.812 - 4.266 ATTS

M2Y4 - 3.285 - 1.956 - 1.344 - 1.034 - 0.812 - 4.266

M2Z4 - 3.285 - 1.956 - 1.344 - 1.034 - 0.812 - 4.266 LSD



Accord



T2T4 - 3.285 - 1.956 - 1.344 - 1.034 - 0.812 - 4.266 LSD

T2W4 - 3.285 - 2.090 - 1.481 - 1.071 - 0.812 - 4.266 LSD

U2Q7 - 3.285 - 2.090 - 1.481 - 1.071 - 0.870 - 4.266 LSD

[Merlin]

Cheers. I did do a little experiement on the way to work today in the 5G. Changing gear at the start of the red (7.4K?) in both 2nd-3rd and 3rd-4th resulted in the revs dropping to 5.5K, so I was still in VTEC. In the 4th gen with its H22a2 and chipped ECU I get VTEC at 5K, in the 5th @ 5.5K, and with the H22a7 I dont know where the power will be once its properly tuned:?

Here is my 4th Vs 5th dyno runs overlayed. I dont like this dyno much as it give really low whp figures so I have started using another place but I havent taken the 4G there yet I know this is straying slightly off the point but you can see the difference in the torque between the two, while the 5G make more its all over the place due to its stock map. The 4G has a "tuned" Spoon ECU.








Why didnt you use the M2F5 if you are using all of its gears? The LSD from the U2Q7 should have fit?

[Dino]

From what i can remember It was to do with the vss.
I had to use an Atr Vss to utilise the ATR diff.
The vss on the 4th gen is different to that of the Q7.
Plus the diff would already have been shimmed for that box.
Ive done a few different box builds and is a blur of info across the three.
Pretty sure this is the reason why.