Front Diff Damaged. Options

[MJTru]

I guys i have just droken my front diff. Some teeth off the diff got damaged refer to the photo. The car is a R32 gts4. Ive been puching it very hard with this new ETS PRO

so now im stuck with the option of the parts i have here. I either replace the front diff with a r32 gtr unit i have and then replace the rear diff to a r32 gtr unit or replace the actual front diff to a gts4 ratio. Which i dont have.

Now im limited to option i have here because i have a full front diff for a r32 gtr but not a rear one. I see on ebay a guy selling a kaaz rear diff with crown gear alone. Can this work with the original gts4 pinion gear to get a gtr rear diff ratio. ?? Or do i need both the crown and pinion gear. ??

[GTSBoy]

Don't buy mismatched CW &/or pinion gears. Could be a right pain in the arse to set up.

GTS4 front diff gears are hard to find because the drag GTR boys like them. So unless you can get lucky, you'll be better off finding some 4.11s for the rear diff (any R32/33 GTSt manual diff would be a suitable donor). Doesn't have to be GTR diff stuff.

[Duncan]

but yes, you need the gtr crownwheel and pinion, not just a centre like Kaaz.

bit late to mention....but lots of people start breaking front diffs after trying to get more FWD in a powerful car. Afterall they are F160 size while the rear is pretty much indestructible at R200 size.

If you intend (or expect....) to keep breaking them, you will find GTR ratios much easier to find replacements

[MJTru]

Sadly i also cracked the oil pan so the whole motor had to be pulled. Its now fixed and car is driving. I went with gtr front diff and changed out to gtr r200 rear diff. Thank goodness i had these parts right here after a good clean up. Cant believe the price for r200 gtr rear diff.

Anyways is there any good solution to prevent the front from getting damaged. Oh and yes i am looking for more FWD at least 50/50 split. Would quife front diff be stronger. ??

Car is back up and running now. But i use this car as a testing bench mark to build the rest of my cars. I can already see me busting up a front diff. Therr has to be a good solution guys use for drag. Here goes the reading.

Thanks guys.

[GTSBoy]

The solution is not to send so much torque to the front. Although a Quaife will likely be stronger than the open diff......I have seen Toyota Torsens literally torn apart in Supras. And those diffs are even bigger and stronger than R200s.

[R31Nismoid]

Sadly i also cracked the oil pan so the whole motor had to be pulled. Its now fixed and car is driving. I went with gtr front diff and changed out to gtr r200 rear diff. Thank goodness i had these parts right here after a good clean up. Cant believe the price for r200 gtr rear diff.

Anyways is there any good solution to prevent the front from getting damaged. Oh and yes i am looking for more FWD at least 50/50 split. Would quife front diff be stronger. ??

Car is back up and running now. But i use this car as a testing bench mark to build the rest of my cars. I can already see me busting up a front diff. Therr has to be a good solution guys use for drag. Here goes the reading.

Thanks guys.

Totally depends on the power.

A good centre, shouldn't break.

I had the same issue as you, broke a stock front R33 GTR diff/370rwkw... Took out my lovely Racepace sump as well, destroyed it is probably a more accurate description.

Put in a Nismo centre in the front/rear, didn't break it again even after a year of giving it a beating.

Failing that you'd need to fab up some sorta sump that'll take more stress (and won't fail). That would be high end drag racer stuff though, I've not seen/heard anyone doing it in a common sense but then even guys running 450rwkw and big launches don't smash things with aftermarket diffs (that I've heard about)

[MJTru]

Well thanks for the info. The oil pan cracked due to peaces being wedged on the crown gear and the housing. I find it hard to see the diff house busting up. Well it very well could but the power needed i dont think i would ever be there. So a clutch type front lsd should hold up to 800hp. Its all cause i have installed an ets pro and locking in 50/50 split on launches. I can tell it works at the mercy of the front diff. I have heard that the nismo unit is very aggressive on street driving and most people like the quife unit. I dont mind a harsh engagement on the streets to much but if you were to recommend one ill take it that you would go nismo??? Can you tell first hand to me how it worked. What power levels did you have and did it hold up to some big launches.

Thanks for all the info mate

[Duncan]

Hmmm I've heard of a few big power/big FWD race cars regularly breaking front diffs including quaife. and once you get the centre stronger you can just break driveshafts instead.

just do what everyone else has learned and back off the fwd a bit....you can't win from the side of the track watching everyone drive past

[GTRPSI]

The crown and pinion looked fine, you blew the center because it was single spinning and putting all the power down through the smaller gears while one wheel free balled.

You need a locking center, then your next weak point will be the crown and pinion, as said by others, transmitting less bias to the front usually does the trick.

Unfortunately due to the design of the diff being built into the sump, when things go wrong inside its bye bye sump......you would rather prefer to break a drive shaft, so much simpler and cheaper to deal with.

[MJTru]

Hmm. I understand that having a stronger front diff will help abit. What power does the crown and pinion gear brake at.?

I can back off on the front what would you say is a safe amount using the ets pro. Seems like i set myself up for this to happen. First i rebuild the t case wit new friction disks and plates. Then i got the ets pro and lock it up 50/50. Boom there goes the front diff on its 3rd harf launch.

What front diff would be best for drag. I read the quife is smooth but never locks. Nismo IIRC locks up. I really dont think that this car has the power to brake crown and pinion gear. I think its really because of the twin solid hub clutch im using. Im not surprised if the box goes soon to. Thank god i have a spare one here. Just really testing the limits of the drive line parts. I guess the factory worked it out pretty good. The rears would spin then the front pulls. That way i can se the front surviving longer as the pressure isnt instant.

Im looking to buy a front diff now. Then go from there.

Thanks guys. I like the inputs

[Greekos]

its pretty simple upgrade the front diff centre, quaffie diff is great cause there are no clutch plates and its smooth and don't run a 50/50 power split.

[R31Nismoid]

Well thanks for the info. The oil pan cracked due to peaces being wedged on the crown gear and the housing. I find it hard to see the diff house busting up. Well it very well could but the power needed i dont think i would ever be there. So a clutch type front lsd should hold up to 800hp. Its all cause i have installed an ets pro and locking in 50/50 split on launches. I can tell it works at the mercy of the front diff. I have heard that the nismo unit is very aggressive on street driving and most people like the quife unit. I dont mind a harsh engagement on the streets to much but if you were to recommend one ill take it that you would go nismo??? Can you tell first hand to me how it worked. What power levels did you have and did it hold up to some big launches.

Thanks for all the info mate

As I said, 370rwkw and I had a modified transfer case, so sending a lot of power forward over factory. I never ran a electronic controller however, it was factory in that regard but I still do believe the 4WD is 70% mechanical (transfer case) and 30% electronic (4WD controller). So doing the transfer case negates need for electronic, I mean you can keep using it but then you're sending even MORE front. That's a lot of stress the drivetrain was simply never designed for.

Held up fine once replaced. I loved the Nismo personally. I did take a good 1,500kms of driving to settle down... And by settle I mean the car used to try change lanes on a big launch/power put down when it was new as it was savage initially. I know others prefer the Quaife and I haven't have the chance to drive one with a Quaife (yet), one day Paul will stop breaking his car and I'll go to Syd and give it a hiding

For me, Nismo suited my driving style and the motorkhana stuff I used to do in it as I could essentially 4 wheel power slide around cones etc due to the way it could lock (in conjunction with Nismo rear). IT certainly wasn't as street friendly as a Quaife would be, but I didn't care for that essentially.

Hmmm I've heard of a few big power/big FWD race cars regularly breaking front diffs including quaife. and once you get the centre stronger you can just break driveshafts instead.

just do what everyone else has learned and back off the fwd a bit....you can't win from the side of the track watching everyone drive past

Yeah agreed. When making big power (500rwkw+) nothing is going to last IMO with a "dumb" setup that just sends as much to the front as it can, just too much stress all the time. I would suspect the super big boys (8 sec) are doing some trickery with how much is sent depending on car speed etc. Some serious ECU programming there.

[Duncan]

I should add....this isn't exactly a new problem. Even the Gibson GTR touring cars used to launch in rwd and not switch to 4wd until 2nd....

While I've done a lot of race and rally launches and never broken anything (except overheating clutches), I also don't have much power compared to your average 400kw street car these days.

[KiwiRS4T]

Yeah agreed. When making big power (500rwkw+) nothing is going to last IMO with a "dumb" setup that just sends as much to the front as it can, just too much stress all the time. I would suspect the super big boys (8 sec) are doing some trickery with how much is sent depending on car speed etc. Some serious ECU programming there.

Glen Suckling said he had three computers operating his awd on his 7 second R32

[R31Nismoid]

Well there you go

I should add....this isn't exactly a new problem. Even the Gibson GTR touring cars used to launch in rwd and not switch to 4wd until 2nd....

While I've done a lot of race and rally launches and never broken anything (except overheating clutches), I also don't have much power compared to your average 400kw street car these days.

haha yeah 400rwkw is the new 300rwkw, and as a result people are busting shit now more than ever - coupled with ever aging components, it's just never gonna end well.

[MJTru]

I can remember seeing some drag guys pumping up and locking the transfer case clutches. How can a computer control it. And if it did it would be some sort of bleed off. But its starting out at 100% lock (50/50) split.

Damn thought these gtr 4wd systems were one of the strongest. Well i understand not out the box but using after market parts would bring it up to some really surprising results. I see rally car rip it up, but i guess thats in the dirt and not on a sticky track. Well i think ill go with the nismo unit from RHDJapan. Knowing me ill still 9k drop it and see what happens. For how long.

Heres a question. Do they sell stronger crown and pinion gears for these gtrs.

Thanks guys. Intresting to hear all the experience you guys went through.

[tricstar]

I had the OSGiken 2-way in the front with 600+whp. Launched the crap of that with the ETS pro turned to max in manual and auto modes, felt like the car was trying to tear itself in half. Anyway that diff was strong, did hundreds of launches. Just moved the weak point to gearboxes. Snapped input shafts, smashed 2nd's and 3rd's. But OS 2way was nice front diff, no where near as harsh as Nismo GT-pro rear.

[MJTru]

Hmm. Lol. I dont mind killing gear boxes. Because i pay 500 usd for a whole gear box, and soon i can see myself opening up boxes and swaping out parts to make a new one. I just was looking for way to fix the common problems with gtrs. First i wanted to rebuild transfer case. I then found the new disks and rebuild the case which i would say was very easy. Next i wanted to lock the transfer case up to have full 50/50 split. I wanted the mechanical pump system to do so. I even made a one year plan to do so starting out with a manual pump and slowly started to buy fittings and priority valves. Next i was now willing to wait and went with an electronic controller (ets pro) next i was suprised to find out that the front diff was the weak point. This is a resent result. But now the manual option is on hold, if im breaking stuff using the electronic 50/50 split option. So that being said im looking to find a way to prolong the weak points, knowing that i would have to be open minded to the way the drag guys leave 4 tire marks off the line all the way to the 1320 feet mark. But i know its not easily done. For me life has always been hard to learn, and i dont expect anything easily. As i can say nothing from this site has come that way, and i dont blame anyone for that. Im actually grateful for all the help even if i have to decipher the bits. I love it that way really, because that way i can take ownership of the idea. Rather than someone just telling me an answer, and it leaves the door open to actually see who may actually know whats going on. Bottom line is on your side of the world there is way more invention and products to give these cars a certain result than anywhere else. So thank you all for that.

Edited December 14, 2015 by MJTru

[R31Nismoid]

You'll care when boxes start becoming harder to find

I hate to say it, but an Auto will make life a lot easier on all of it... There is a reason the people have trended to Auto GTRs (more the last few years) - Reliability/Consistency are key. Don't break shit and don't need to service it anywhere near as often.

The H pattern days of 8 sec Jap GTRs from the 90 and early 00's, I can only imagine how often they must have been breaking shit. IMO that was the pinnacle of GT-R drag racing though - 8 sec passes with H pattern boxes and huge RPM, that is insanity.

I had the OSGiken 2-way in the front with 600+whp. Launched the crap of that with the ETS pro turned to max in manual and auto modes, felt like the car was trying to tear itself in half. Anyway that diff was strong, did hundreds of launches. Just moved the weak point to gearboxes. Snapped input shafts, smashed 2nd's and 3rd's. But OS 2way was nice front diff, no where near as harsh as Nismo GT-pro rear.

A 2 way in the front? I didn't know you did that man, would've been interesting on decel

Can't compare front/rear though, they are two different types of diffs essentially. Agree the Nismo rear is harsh, well, it does settle down and you can back it off to the "lowest" lock or whatever and it does come good. If it's too chattery you can always add some friction modifier (Penrite etc), not that I did,. That does the trick too - I suspect not a consideration in MJ's case tohugh

[niZmO_Man]

Just get Holinger to put together the HKS 6spd drag gearbox