Andreika609 4gen BB2 Value sports prelude

[Andreika609]

just wondering about gear boxes. im using m2j4 gear box on my h22 prelude , that box was laying around so i put in car. found gear ratios on internet and it says that gear box has shortest gear ratios? other peaoples says to change it to h22 series gear box , but if im not going to drag race do i need to do it? is there a massive diference? how it affects? i like how it is now start is fast , 2nd gear burns that one tire driving in city only no long distances

[mercutio]

there is a whole thread on here somewhere I started about gearboxes and ratios


I think we are all after the perfect gearbox quick and slick when you need it good on the motorway and good on the track.

problem is until they invent a constantly variable ratio box we have to live with compromise ( and yes I know there is already a constantly variable ratio box out there I mean one that is up to the job of high horsepower)

[Donald]

I might be reading this wrong, but...

I know the M2P4 and U2Q7 are shorter than the M2B4 and M2V5 boxes.

The numbers on the M2P4/U2Q7 are higher than those of M2B4 and M2V5, which you would expect considering it's a ratio... the shorter the gear the further from 1:1 it is. This fits the pattern you see in the numbers.

The numbers for the M2J4 are closer to 1:1 than another of the others I've mentioned, so in fact it's longer(/st)?

I'm not sure what really happens with 5th gear because they're all below 1, but I presume the pattern inverts and the further you are from 1 in that direction means it's getting longer?


I don't really know that much about boxes and ratios and how it all works together so I'm probably wrong somewhere, but the numbers above (if they are correct) suggest I'm theoretically correct?

[Andreika609]

is there the bigger number for gear it means longer gear? im confused now

[mercutio]

Its a black art I tells ya but then its all affected by the final drive

[Donald]

is there the bigger number for gear it means longer gear? im confused now

No, think like on a pedal bike. If the gear on the rear wheel is the same size as the one on the crank, it takes say 1 pedal revolution to turn the rear wheel gear 1 time. If the crank gear is bigger than the rear, it takes less than one crank revolution to turn the rear gear once. The bigger it is, the less you have to pedal to turn the rear (shorter travel). If it's smaller, you have to pedal more to turn the rear gear.

And you need to look at the differences between two gears as well.

Say you have a gearbox with one gear at at 3.5:1 ratio and the next gear at 3:1.
Then you have a gearbox with one gear at 4:1 and the next at 2.5:1.

The first is much closer than the second.


And final drive I don't know really anything

I'm not explaining properly I don't think

[K30DPC]

Bigger the number = shorter gear.
Just look on revers gear. Always 3.000 and how fast you can drive on reverse?

Its a black art I tells ya but then its all affected by the final drive

Gearboxes aren't so complicated to understand. If you ever open one of them then you will see it very clearly.
Basically There is two sections (I would call).
One of them is constant gear (called final drive) which can't be changed by driver. This is between countershaft and dif/lsd. For boxes matching H22 there is two of them: 4.266 and 4.062 where first one is shorter one. But this did not say the whole gearbox will be shorter.
Second one is our 5 gears which can be changed with gear stick knob. This are between mainshaft and countershaft. And here we have a lot of different ratios, but again higher the number = shorter gear.
Combination of them two deciding about final gear ratio.

So for eg
M2L5 with 4.062 (FD) and 3.310 (1stG) will be shorter then M2J4 with 4.062 (FD) and 3.285 (1stG) because 4.062x3.310>4.062x3.285 (different 1st gear ratio)

Also
M2S4 with 4.266 (FD) and 3.307 (1stG) will be shorter then M2K4 with 4.062 (FD) and 3.307 (1stG) (different final drive)

Gearbox ratio decides how much power/torque will be on wheels but also about top speed. And here for better understanding we can compare it to bicycle. On short gears you can speed up easily but top speed is small, and if you try to start on long gears it is a lot more difficult to speed up but top speed is a lot higher.


At the end to make it more confusing...
NonLSD, ATTS or LSD has nothing to do with gearbox ratio. Its only the way how power is passed to the wheels. But still it makes a lot of different how your car will speed up

[Andreika609]

update is coming soon

[Andreika609]

Hi again lets start with good news so far

so car passed mot after 3 years staying in garage wohooo

after that i put my hands in to work.

first i installed my rs*r 60mm exhaust , which are super quiet, i didnt expect that. But at high rpm sound awesome

new vs old


then TEIN super streets and goodridge braided brake hoses

dont have pic of rears but i repainted them before install and removed helper springs from fronts.



after upgrade car drives very good and brakes are more accurate now

few photos of the car as it looks now








so far so good new front wings is primered also no need 1cm spacers all around and it will be finished with outside of the car.

[Rudelude]

Cool car dude, like the work u have been doing....