Jump to content
SAU Community

Recommended Posts

I have done quite a bit of searching on here and didn't come up with any explanations on how it was done, and whether it was easy or worth it compared to strengthening the standard 5 speed.

So if anyone has done it, or had it done by a workshop let me know.

I am in the situation where it looks like my 5 speed has some internal problem, whilst driving at or over 100km/h if i let my foot off the throttle there is a horrible rattle sound from the gearbox area, strange thing there is no noise when i have my foot on the throttle. The noise gets worse as speed increases..

I dont want to buy a second hand 5 or 6 speed, i prefer to buy new unless a very low KM box can be sourced.

Any info would be appreciated, thanks

Shaun

Link to comment
https://www.sau.com.au/forums/topic/308331-r32-gtr-6-speed-conversion-getrag/
Share on other sites

Yeah that's fair enough, if im to stay with a 5 speed im likely to buy one new, thats why i was thinking along the lines of a 6 speed conversion as a second hand one is only a few hundred more than a new 5 speed, there's also the choice of PPG gears for the 5 speed which is another option, I believe the 6 speed is the better option IF it isn't ridiculously difficult. Living 350km from melb doesn't make it easy to leave your car at a mechanic for a week or two..

  • 2 weeks later...

Has anyone done the conversion of the 6 speed? Would love to hear the benifits of this conversion as to say a upgraded gear set/ dog box. Wouldn't the extra gear mean a close ratio gear set is more than likely while still maintaining daily driving and better acceleration?

IIRC the diff ratios are different in R34s, so you might want to change the diffs as well if you're doing the gearbox. I guess if you're changing the gearset ratios you could choose one that will work with non-R34 diffs.

Justjap used to sell new boxes for $3200. Maybe they still do.

You will need:

New clutch- and or push pull converter. 33 and 34 GTR clutches are pull, 32 is push.

Box- expensive for it's strenght. A 34 6 speed is debatable after 550 odd hp for racing.

Modified drive shaft/s

Modified g-box mounts

34 diffs or similar ratios

Adapt the 32 ATESSA actuator, to the 34 transfer case.

Adapt the speedo drive

OR

Get your old box built to new, with a nice OS gear set and twin syncro's.

Hope that helps

J.

Edited by XRATED

Thanks Xrated been looking for that sort of info for ages lol. what about if you put a gear set in a getrag box? would it be better for acceleration, fuel ecconomy and top speed? want something that is going to be tough but hopefully still a little street friendly. Not exactly the easiest thing to do but i had a mate with a dog box in a 33 gts type m making 850hp at the wheels but was still ok to drive on the street. It was a six speed. Would ask him but i no longer have contact :D so regreting not asking sooner lol

Cheers

Thanks Xrated been looking for that sort of info for ages lol. what about if you put a gear set in a getrag box? would it be better for acceleration, fuel ecconomy and top speed? want something that is going to be tough but hopefully still a little street friendly. Not exactly the easiest thing to do but i had a mate with a dog box in a 33 gts type m making 850hp at the wheels but was still ok to drive on the street. It was a six speed. Would ask him but i no longer have contact :D so regreting not asking sooner lol

Cheers

They're obviously stronger with a gear set. There are a few different options. Honestly I dont see there being much acceleration advantage with 6 gears, unless you have custom ratios. Fuel economy???? dude, it's a GTR... Top speed... how fast do you want to go? I did 312kph with my 5 speed PPG box and it had more in it (It was scary!).

I have a 1-4 helical cut PPG gog box. It's quiet and I find it easy to use (used to drive professionally) and 5th is standard- cyncro and ratio. 1-4th ratios are different ratios. But if you do big miles, go for the PPG cyncro gear set.... better 1-4th ratios for acceleration, standerd 5th gear for highway driving and will take plenty of HP.

Honestly a 34 6 speed conversion is alot of money for the result.

J.

  • 6 months later...
You will need:

New clutch- and or push pull converter. 33 and 34 GTR clutches are pull, 32 is push.

Box- expensive for it's strenght. A 34 6 speed is debatable after 550 odd hp for racing.

Modified drive shaft/s

Modified g-box mounts

34 diffs or similar ratios

Adapt the 32 ATESSA actuator, to the 34 transfer case.

Adapt the speedo drive

OR

Get your old box built to new, with a nice OS gear set and twin syncro's.

Hope that helps

J.

Sorry to revive an old thread but me and another mate were thinking about this the other day.

Why would you have to change the diff ratios?

I mean leaving the 4.1s in the 32 would mean that you would have the top end of the standard 32 gtr with the close gear set down low

allowing you to keep the engine/turbos better within there range.

I would have thought that this would have been better than just having a close gearset 5 speed. Especially if its still going to be a daily driver.

Sorry if this is a dumb question and i've missed something lol

Cheers Matt

Sorry to revive an old thread but me and another mate were thinking about this the other day.

Why would you have to change the diff ratios?

I mean leaving the 4.1s in the 32 would mean that you would have the top end of the standard 32 gtr with the close gear set down low

allowing you to keep the engine/turbos better within there range.

I would have thought that this would have been better than just having a close gearset 5 speed. Especially if its still going to be a daily driver.

Sorry if this is a dumb question and i've missed something lol

Cheers Matt

You are right. There have been a few R34 GTRs here change their diffs for R33 4.1 diffs.

  • 9 months later...

You are right. There have been a few R34 GTRs here change their diffs for R33 4.1 diffs.

I found the Nismo Getrag transmission conversion http://www.nengun.com/nismo/getrag-transmission-conversion-kit

Its too pricey to buy new unless your building a show car, but it seems it is quite easy to do.

Use an R34 gearbox, transfer case, front prop shaft, transmission cross-member, transmission mount, and clutch.

Then for the rear prop shaft use the front section off an R34, and the rear section from an R32.

The transmission tunnel needs hammering for clearance on both sides, only about 10mm either side, not a big deal in my opinion.

Im thinking it could be done for 6-7 grand depending on the cost of the gearbox second hand.

2nd hand boxes seem to get roughly 4500 give/take.

Certainly costly, also need the diffs too as ratios are totally different. So that adds cost as they are hard to get as well.

Id say k would be bare minimum and likely quite a bit more.

More than a OS gearset replacement by a good 3k. Given people like Piggaz, Lee wah etc have proven 400rwkw & big launches is no problem for the gearsets, probably the better choice.

Be interesting to see how much a getrag would hold without blowing apart. Not aware of anyone going above 400-420rwkw. And none of those guys were doing big launches etc.

2nd hand boxes seem to get roughly 4500 give/take.

Certainly costly, also need the diffs too as ratios are totally different. So that adds cost as they are hard to get as well.

Id say k would be bare minimum and likely quite a bit more.

More than a OS gearset replacement by a good 3k. Given people like Piggaz, Lee wah etc have proven 400rwkw & big launches is no problem for the gearsets, probably the better choice.

Be interesting to see how much a getrag would hold without blowing apart. Not aware of anyone going above 400-420rwkw. And none of those guys were doing big launches etc.

Apparently the 4.1 diff is fine, first gear is just very fast. I don't understand why people break the getrag if it has the same gears as the Supra which is known to handle 800hp with slicks on a drag track (no wheelspin). Im willing to do something different and it could transfer the car into a better machine. My brother has just put a 6 speed in his 5 speed WRX and it feels 200% better because of the close ratio gears. Much easier to drive on the street and feels heaps livelier. Another option for me to think about i guess, lucky i don't rely on the GTR every day :)

A WRX is not a good example. They are a lowdown punch motor.

You need the extra length of gearing IMO for a 350-400rwkw 2.6ltr.

The OS box has a longer first (over stock) by about 12-15km/h IIRC. Might not sound like much on the screen but on the street it makes quite a difference indeed, very noticeable when his car is still powering in gear, pulling ahead whilst you look to grab another gear :(

Chopping it backwards would make it very hard to deal with and not generate much load potentially. Without load you ain't going to decrease boost response etc.

With 4.1/getrag compared to a 33 box with O/S gears. You will have almost shifted 1.7 times before the OS box has shifted once.

Shifting = time wasted.

But whatever dude, your money :)

A WRX is not a good example. They are a lowdown punch motor.

You need the extra length of gearing IMO for a 350-400rwkw 2.6ltr.

The OS box has a longer first (over stock) by about 12-15km/h IIRC. Might not sound like much on the screen but on the street it makes quite a difference indeed, very noticeable when his car is still powering in gear, pulling ahead whilst you look to grab another gear :(

Chopping it backwards would make it very hard to deal with and not generate much load potentially. Without load you ain't going to decrease boost response etc.

With 4.1/getrag compared to a 33 box with O/S gears. You will have almost shifted 1.7 times before the OS box has shifted once.

Shifting = time wasted.

But whatever dude, your money :)

You raise valid points, I have noticed the GTR's have very poor response under 3,000rpm compared to a 2.0L WRX, I don't see why that is though? I plan on rebuilding my motor with a 2.8L stroker kit in future, the extra cubes along with other mods should help with torque.

im right in the middle of this debate also. i can't decide between a getrag or a full dog box. seeing as i will use my gtr for 99% circuit use, im leaning toward a 6spd but in the back of my mind the safety of billet gears may persuade me... i think my power level will require a dog box too.

hmmmm.........wat to do!! lol *slaps forrid

im right in the middle of this debate also. i can't decide between a getrag or a full dog box. seeing as i will use my gtr for 99% circuit use, im leaning toward a 6spd but in the back of my mind the safety of billet gears may persuade me... i think my power level will require a dog box too.

hmmmm.........wat to do!! lol *slaps forrid

In your situation i would definitely go a rebuilt 5 speed, my car will be 99% street use and an extra gear is nice and won't hurt performance as its a street car. Im going to be sticking with the 5 speed, the potential for future hassles just isn't worth it for me.

With full on track work with fast shifting the syncros in the Getrag won't last.... gears will last forever but syncros won't. I picked up the whole kit to fit R32/R33, shatfs, cross member, shifter and including Nismo Twin Coppermix clutch with flywheel. Intended to go in my R33 GTR but selling car now :(

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • I'm looking for some real world experiences/feed back from anyone who has personally ran a EFR7670 with a 1.05 exhaust housing or a .83 I'm leaning towards the .83 because its a street car used mostly for spirited driving in the canyons roads. I"m not looking for big numbers on paper. I want a responsive powerband that will be very linear to 8000 rpm. I dont mind if power remains somewhat flat but dont want power to drop off on top. The turbo I've purchased is a 1.05, although the mounting flange T3 vs T4 and internal vs external waste gates are different on both housings, I not concern about swapping parts or making fabrication mods to get what I want. Based on some of the research I've done with chat gpt, the 1.05 housing seems to be the way to go with slightly more lag and future proofing for more mods but recommends .83 for best response/street car setup. AI doesn't have the same emotions as real people driving a GTR so I think you guys will be able to give me better feed back 😀   
    • Surely somebody has one in VIC. Have you asked at any shops?  Is this the yearly inspection or did you get a canary?
    • This is where I share pain with you, @Duncan. The move to change so many cooling system pieces to plastic is a killer! Plastic end tanks and a few plastic hose flanges on my car's fail after so little time.  Curious about the need for a bigger rad, is that just for long sessions in the summer or because the car generally needs more cooling?
    • So, that is it! It is a pretty expensive process with the ATF costing 50-100 per 5 litres, and a mechanic will probably charge plenty because they don't want to do it. Still, considering how dirty my fluid was at 120,000klm I think it would be worth doing more like every 80,000 to keep the trans happy, they are very expensive to replace. The job is not that hard if you have the specialist tools so you can save a bit of money and do it yourself!
    • OK, onto filling. So I don't really have any pics, but will describe the process as best I can. The USDM workshop manual also covers it from TM-285 onwards. First, make sure the drain plug (17mm) is snug. Not too tight yet because it is coming off again. Note it does have a copper washer that you could replace or anneal (heat up with a blow torch) to seal nicely. Remove the fill plug, which has an inhex (I think it was 6mm but didn't check). Then, screw in the fill fitting, making sure it has a suitable o-ring (mine came without but I think it is meant to be supplied). It is important that you only screw it in hand tight. I didn't get a good pic of it, but the fill plug leads to a tube about 70mm long inside the transmission. This sets the factory level for fluid in the trans (above the join line for the pan!) and will take about 3l to fill. You then need to connect your fluid pump to the fitting via a hose, and pump in whatever amount of fluid you removed (maybe 3 litres, in my case 7 litres). If you put in more than 3l, it will spill out when you remove the fitting, so do quickly and with a drain pan underneath. Once you have pumped in the required amount of clean ATF, you start the engine and run it for 3 minutes to let the fluid circulate. Don't run it longer and if possible check the fluid temp is under 40oC (Ecutek shows Auto Trans Fluid temp now, or you could use an infrared temp gun on the bottom of the pan). The manual stresses the bit about fluid temperature because it expands when hot an might result in an underfil. So from here, the factory manual says to do the "spill and fill" again, and I did. That is, put an oil pan under the drain plug and undo it with a 17mm spanner, then watch your expensive fluid fall back out again, you should get about 3 litres.  Then, put the drain plug back in, pump 3 litres back in through the fill plug with the fitting and pump, disconnect the fill fitting and replace the fill plug, start the car and run for another 3 minutes (making sure the temp is still under 40oC). The manual then asks for a 3rd "spill and fill" just like above. I also did that and so had put 13l in by now.  This time they want you to keep the engine running and run the transmission through R and D (I hope the wheels are still off the ground!) for a while, and allow the trans temp to get to 40oC, then engine off. Finally, back under the car and undo the fill plug to let the overfill drain out; it will stop running when fluid is at the top of the levelling tube. According to the factory, that is job done! Post that, I reconnected the fill fitting and pumped in an extra 0.5l. AMS says 1.5l overfill is safe, but I started with less to see how it goes, I will add another 1.0 litres later if I'm still not happy with the hot shifts.
×
×
  • Create New...