5 speed vs 6 speed vs 6 speed with JDM MR gears...

[thor'svr4]

so ive got a semi bad syncro on 2nd gear right now. i was thinking about replacing it, or buying a 6 speed trans. the prob is the 5 speed has perfect gearing for my car in the 1/4 mile right now since im right about at redline in 3rd as i cross the line. if i get the 6 speed i think ill have to shift into 4th gear which might cause me to loose some time. but what about the 6 speed with MR gears? are they short enough that i could grab 4th and actually use 4th gear?

I’ve searched stealth316 and cant find any info on the MR gears.

as far as i can tell (without any slips from the track) my trap speeds are more or less in-between the orange dots on the pic below. obviously my speedo / tach could be slightly off or my '1/4 mile' could be a little shorter or longer than 1320' but nothings an exact science on the street.

http://i366.photobucket.com/albums/oo110/streetracer4688/gearing.png

you can see the 6 speed's 3rd might be a little to short, and the 5 speeds 3rd is pretty good but what about the 6 speed MR? would it work just as good or maybe even better than the 5 speeds 3rd gear? anyone have any good info on it?

[stealthee]

Cant help with the question, but ALL JDM 6 speeds had the shorter gearing, not just MR's. Just wanted to correct that. :)

[Polygon]

I thought about doing this and it's more than swapping a trans. You have to swap the rear diff as well. There could be more work depending on if your an 18 spline or not. My conclusion was that it wasn't worth it.

[stealthee]

5 speed 3s's won't need to swap rear diffs if using JDM 6 speed gearing.

[3000GT MR]

I hit 4th with time to use it with TD04 running 118 traps

[thor'svr4]

5 speed 3s's won't need to swap rear diffs if using JDM 6 speed gearing.

so i should only need the trans, t case, and maybe a drive shaft?


I hit 4th with time to use it with TD04 running 118 traps

im assuming from you username it was with the MR 6 speed right?

[Polygon]

5 speed 3s's won't need to swap rear diffs if using JDM 6 speed gearing.

Ah, good to know.

[Jeremy C]

from what I've seen, the JDM 6-spd gearing for it's first 5 cogs is almost identical to the FWD 5-spd trans. So expect to top 3rd at ~105mph or so. If I can, I will use that 6-spd in my car as I love the shorter gearing.

[MR2]

if your worried about not using much of 4th, just run smaller rolling diameter wheels :p

fwiw get the 5 speed fixed and use that to fund the 6 speed + mods(beef plates)

[thor'svr4]

my main issue is pulling the trans. i HATE pulling the trans in the vr4, it does not like coming out at all! after i unbolted it i simply could not get it out no matter what i did. i tried rotating it, twisting it, lifting, pulling everything. it took me 2 days to get it out once it was fully unbolted. the only way i got it back in was because i pulled the motor and trans so i was able to bolt the motor and trans together than lift my car up ~3' and pull the motor and trans up into the engine bay from under the car. ive never had to fight any trans as much as i had to fight my vr4's. my rt is soooooo easy i figured the vr4 would be about the same. so if im pulling the 5 speed out again than im going to do whatever i can to avoid ever having to go through that hell again. i would hate to rebuild it and then 6 months later have to pull it again to get a 6 speed in there.

[donniekak]

I thought about doing this and it's more than swapping a trans. You have to swap the rear diff as well. There could be more work depending on if your an 18 spline or not. My conclusion was that it wasn't worth it.

When you swap in a jdm 6-speed, it uses the 5-speed rear end. You just need the front section of a 6-speed driveshaft.

[MR2]

if your having problems pulling the trans then it sounds like your doing something wrong....you tried the old tricks like lubing the shafts and guides(forget the technical name) also having a jack under the gb so it's not hanging off everything? I agree I hate it...but it only takes 2-3 hours ish(ish is a greek term)

[thor'svr4]

my issue was that it would slide out ~1.5"-2" and then hit a cross member. stealth316 says to rotate the trans counter clockwise so that it will clear this cross member but i couldnt get my trans to rotate enough. i could move it freely pretty much anywhere i wanted except i just couldnt get that last little bit for it to be free of the crank.

[MR2]

oh ok, usually I remove the GB mount and then start to lower as soon as she hits the frame

[GTOJOE]

5 speed 3s's won't need to swap rear diffs if using JDM 6 speed gearing.

Correct. Both are the same ratio. However the drive shafts are different between 5 and 6 speed. How do you get around this?

[JasonY]

The more power you make the more you will want the 5spd....The shorter gears suck with how wide of a powerband our cars retain with a proper choice of turbos.

Jason

[stealthee]

Correct. Both are the same ratio. However the drive shafts are different between 5 and 6 speed. How do you get around this?

As was stated in a previous post all you need to swap is the front section of the driveshaft to the 6 speed style.

[GTOJOE]

As was stated in a previous post all you need to swap is the front section of the driveshaft to the 6 speed style.

Shit didn't read that. My bad :D

[Chris GTO TT]

The more power you make the more you will want the 5spd....The shorter gears suck with how wide of a powerband our cars retain with a proper choice of turbos.

Jason

Yes but on stock or smaller upgraded turbos the JDM 6spd is better geared. For daily driving i feel that the 5spd has rather bad gearing. 3rd gear is too short for around town but 4th is too long. Once you start putting up huge power numbers and only care about the 1/4 mi then yes the 5spd is much more desirable for both its gearing and its strength.

[JasonY]

Up to 450awhp the 6spd is perfectly fine. After that i greatly preferred my 5spd. The 6spd is MUCH easier on clutches though with that shorter first gear, which is a huge plus imo.

Jason

[Chris GTO TT]

Agreed all three set ups have their place. I'd love to have a JDM geared 6spd in my nearly stock VR-4. I feel it with a CFDS would make the car a lot more fun to drive.

[JasonY]

I forever wish to this day i installed my MR gear set on my 99 when i had 13g's on the stock fuel(just a denso). CFDS, light wheels, 15psi, no tuning, no BS, just a whole lot of fun!.

Would have saved me a lot of headaches thats for sure!

Jason

[Chris GTO TT]

Exactly simple and fun is where its at.

[thor'svr4]

Up to 450awhp the 6spd is perfectly fine. After that i greatly preferred my 5spd. The 6spd is MUCH easier on clutches though with that shorter first gear, which is a huge plus imo.

Jason

what would you suggest if im already in the mid 400's for power?

[GTOJOE]

Ditto above. Currently mine is stock power with a 5 speed but i'm planning some upgrades soon [DR750s] and am aiming for the 600awhp mark. I like the 5 speed but sometimes I feel a 6th gear is needed when on the open road.

[MR2]

honestly I wish I had longer gears :p

[aaronatstate]

Who's awesome.

http://i210.photobucket.com/albums/bb53/aaronatstate/Speedin5th.jpg

http://i210.photobucket.com/albums/bb53/aaronatstate/Speedin6th.jpg

http://i210.photobucket.com/albums/bb53/aaronatstate/Speedin6thMR.jpg

[GTOJOE]

So the 5sp and the 6sp jdm top gear ratio is the same. So no point going to 6 speed for me then.

[enollava]

If you look at the picture again you will see it isn't the same between the 5 and JDM 6 speed. My car is a 6 speed JDM geared car, and the best part of the 6 speed in the JDM flavor is that even in the city, I can use 6th gear. I don't have to be going 70+ for it to be useful. If I am driving, I'll pop her into 6th as low as 45-50 mph. I ain't gonna be flooring it at that speed in 6th gear, but it is a usable gear at those low speeds. At highway speeds, 6th is actually useful for passing as long as you aren't doing a really fast pass.

[GTOJOE]

They are slightly different [6 is higher] but not enough for me to justify the cost.

[stealthee]

The point of the JDM 6 speed is shorter overall gearing. Top speed is not the game.

[GTOJOE]

The point of the JDM 6 speed is shorter overall gearing. Top speed is not the game.

For me it's not though. I like the gearing on the 5 speed. I just wanted a taller top gear for highway cruising.

[stealthee]

Then you would need a USDM 6 speed

[Polygon]

It a classic case of not being able to have your cake and eat it too.

[Chris GTO TT]

For me it's not though. I like the gearing on the 5 speed. I just wanted a taller top gear for highway cruising.

How fast do you cruise at that you need more gear for the highway? It's not till i get close to doing about 80 mph that the engine speed gets remotely high in my 5spd. At 80mph the engine is less than 3000RPM. For comparison sake my 2001 Nissan Maxima with a 5spd is at 3000RPM at 70mph....

[GTOJOE]

How fast do you cruise at that you need more gear for the highway? It's not till i get close to doing about 80 mph that the engine speed gets remotely high in my 5spd. At 80mph the engine is less than 3000RPM. For comparison sake my 2001 Nissan Maxima with a 5spd is at 3000RPM at 70mph....

When cruising at 110km/h it sits just above 3000rpm IIRC. and I would like it to sit around 2k for better economy. Not a major issue really > I just plan on building a tuff gearbox soon and thought maybe it's worth doing a 6 speed swap for the taller gears. However I think the 5 speed is stronger anyway. But will then need to upgrade the TC. Oh well it's a while off yet so will think more about it then.

[Chris GTO TT]

When cruising at 110km/h it sits just above 3000rpm IIRC. and I would like it to sit around 2k for better economy. Not a major issue really > I just plan on building a tuff gearbox soon and thought maybe it's worth doing a 6 speed swap for the taller gears. However I think the 5 speed is stronger anyway. But will then need to upgrade the TC. Oh well it's a while off yet so will think more about it then.
110kph is only 68mph are you using stock sized wheels and tires?

[GTOJOE]

Wheels are 19" with 245/35 tyres. I'll check the rpm on the way home tonight. While driving around town etc I don't even look at it or think about it. I just remember when on the open road thinking that I could really do with a 6th gear LOL.

[Chris GTO TT]

Just plugged everything into a gearing calculator. At 3000 RPM in 4th you'd be doing 112kph and in 5th you'd be doing 144kph.

[mschwantz]

My vr4 is a 1994, when I acquired it, it only had the rear end and drive shaft in it, I just received my jdm engine swap, I know I need a 5 speed rear end, but can I just take the gears out of the 5 speed rear end and put them in my 6 speed rear end, I am not sure if the rear axles would be different between the 5 speed and 6 speed rear ends, I am new to these cars, sorry if it seems like a stupid question, I just dont want to mess it up. What will I need as far as a drive shaft, I figured since I have the 6 speed drive shaft if I could just switch the gears it would be alot easier

[J. Fast]

Who's awesome.

http://i210.photobucket.com/albums/bb53/aaronatstate/Speedin5th.jpg

http://i210.photobucket.com/albums/bb53/aaronatstate/Speedin6th.jpg

http://i210.photobucket.com/albums/bb53/aaronatstate/Speedin6thMR.jpg

can someone zoom in on 8000 rpm range fo me? I want to see what rpm will fetch me 130mph in third gear and 165mph in 4th for a US 6 speed with a 275/45/r18.

Thanks ahead of time.

[Chris@Rvengeperformance]

you'd be better off just calculating it

[stealthee]

Yep. Do the math. Take the car out. Go to 4000 RPM in 3rd, multiply times two. You have your answer.

[Chris@Rvengeperformance]

I mean you could just plug the gear ratios, final drives, and tire sizes into any of the 1 million gear ratio calculators on the internet, or calculate it by hand with a little bit of math, but that would work too.

hell the formula is even on the page:

http://www.stealth316.com/2-gears.htm

Speed in gear (MPH) = [RPM x tire diameter in inches] / [final gear ratio x 336]

[J. Fast]

Thanks for inserting the formula... Made things so much easier since I'm using my phone.

My tires are 26.13". Reving to 8000 on USDM

3rd gear (209040/1613.81) = 130 mph
4th gear (209040/1193.81) = 175 mph

Man, fourth gear looks abnormally high. I calc'd 4th gear like 5 times... Seemed inflated but the math works out. That's correct, yes? Sorry guys, long day...

[anyonebutme]

175 looks correct via graph