Rear diff options...real LSD's...
- Thread starter gtfour77
- Start date
I am keeping everything, will take pictures tomorrow... looks like I caught it right before the explosion phase, couple of the small gears inside are broken and were starting to gring metal off of each other due to snapped shafts...the drive pinion is scored on top but the contact surfaces are still good... looks like I am just going to reuse the pinion shaft with the main gear and put in the old open diff until I can find a cusco one. Thanks! I'll check out japanparts in the mean time. Any ideas on the supra diffs???
Ok, so I thought we could bring some of the info from my other post on the WTB forums here....
Some quotes:
"there is a company that makes full spools for corollas that might could help you.
http://www.dwarfcarproducts.com/gears.html"
"A spool replaces your differential guts so that both wheels spin at the same rate, all the time. Thus, it is technically not a differential, since there is no difference in wheel speed. It would have the same effect as welding your gears, but will be more reliable, since it is purpose built and one piece. This is what you need if you're making mad power for drag racing, or want to drift or dirt race.
They are called spools because they look somewhat like a spool on which you'd put wire/cable.
The "dwarf" cars use these because they're raced on dirt and are constantly drifting around turns."
Some quotes:
"there is a company that makes full spools for corollas that might could help you.
http://www.dwarfcarproducts.com/gears.html"
"A spool replaces your differential guts so that both wheels spin at the same rate, all the time. Thus, it is technically not a differential, since there is no difference in wheel speed. It would have the same effect as welding your gears, but will be more reliable, since it is purpose built and one piece. This is what you need if you're making mad power for drag racing, or want to drift or dirt race.
They are called spools because they look somewhat like a spool on which you'd put wire/cable.
The "dwarf" cars use these because they're raced on dirt and are constantly drifting around turns."
"
You mean torsens?
Torsens are a must for a well balanced car. However, when you have lots of power, and such massive grip like 77 then it appears a torsen will not hold up to tarmac racing conditions.
_________________
Coldiron (Cold - Iron) "
Mafix: spools are only good for racing on smooth tracs. they will shatter under vibration.
gtfour77: "Good discussion guys... Thanks! Yes, I destroyed the torsen. What happens is I lift the inside rear wheel in sweepers and then when I give it gas right before or near apex it starts spinning the wheel...and by the time corner exit comes the turbo starts to spool and keeps the wheel roasting even though it's touching the ground....this is one of the things that helped destroy it, another is spinning the inside rear and staying on the gas, then when the wheel touches back down it makes a clunk as it suddenly catches up to the action of the other wheel... I have been "driving around" this problem but it's time for something that will get the out of corners... For now I pretty much have to briefly lift right before corner exit to somewhat let the wheel sit back down on the ground and then accelerate. I don;t even want to know how much time I am loosing doing this... doh
I am currently talking to Sam Strano and RHDJapan regarding options... any other ideas are greatly appreciated."
gtfour77:" I have never driven a car with a welded diff but from what I understand about car dynamics it would push horribly especially into tight corners. That's why I am leaning towards going with a 1Way Cusco RS diff to eliminate any issues. This means that it only locks (limits slip) under acceleration and not under braking and turning... both wheels turning at the same time would cause the car to want to go straight and if you wanted it to turn you would jave to work hard to make it and it would hop especially on sticky tires. For rally and lose surfacec (dirst racing) this would be fine since you are "drifting" around corners at all times anyway. Someone please correct me if I am wrong here...
BTW here is a video from this weekend, you can clearly see the issues on corner exit. Anytime you hear the engine rev higher after a turn, it's actually the inside rear wheel just spinning and not moving the car forward...
http://www.youtube.com/watch?v=NwBuUj9raz4"
You mean torsens?
Torsens are a must for a well balanced car. However, when you have lots of power, and such massive grip like 77 then it appears a torsen will not hold up to tarmac racing conditions.
_________________
Coldiron (Cold - Iron) "
Mafix: spools are only good for racing on smooth tracs. they will shatter under vibration.
gtfour77: "Good discussion guys... Thanks! Yes, I destroyed the torsen. What happens is I lift the inside rear wheel in sweepers and then when I give it gas right before or near apex it starts spinning the wheel...and by the time corner exit comes the turbo starts to spool and keeps the wheel roasting even though it's touching the ground....this is one of the things that helped destroy it, another is spinning the inside rear and staying on the gas, then when the wheel touches back down it makes a clunk as it suddenly catches up to the action of the other wheel... I have been "driving around" this problem but it's time for something that will get the out of corners... For now I pretty much have to briefly lift right before corner exit to somewhat let the wheel sit back down on the ground and then accelerate. I don;t even want to know how much time I am loosing doing this... doh
I am currently talking to Sam Strano and RHDJapan regarding options... any other ideas are greatly appreciated."
gtfour77:" I have never driven a car with a welded diff but from what I understand about car dynamics it would push horribly especially into tight corners. That's why I am leaning towards going with a 1Way Cusco RS diff to eliminate any issues. This means that it only locks (limits slip) under acceleration and not under braking and turning... both wheels turning at the same time would cause the car to want to go straight and if you wanted it to turn you would jave to work hard to make it and it would hop especially on sticky tires. For rally and lose surfacec (dirst racing) this would be fine since you are "drifting" around corners at all times anyway. Someone please correct me if I am wrong here...
BTW here is a video from this weekend, you can clearly see the issues on corner exit. Anytime you hear the engine rev higher after a turn, it's actually the inside rear wheel just spinning and not moving the car forward...
http://www.youtube.com/watch?v=NwBuUj9raz4"
By the way, if you want the Cusco rear diff, here are the part numbers:
1 Way: CUSCO#: LSD 133 F
1.5 Way: LSD 133-L15
You can get them directly from Cusco master distributor here in the US, NUKABE, Toll Free Phone: (888) 591-6277 , or where I am going: RHDJapan.com....seems like these guys have the best prices since they are going straight to Cusco in Japan.
Kaaz has discontinued their diffs for our cars as well as TRD... There is still a possibility of getting a TRD unit but it would have to be a used one or from some shop that had it on display or such. TRD does not have them anymore. This is all the reasearch I've done...
1 Way: CUSCO#: LSD 133 F
1.5 Way: LSD 133-L15
You can get them directly from Cusco master distributor here in the US, NUKABE, Toll Free Phone: (888) 591-6277 , or where I am going: RHDJapan.com....seems like these guys have the best prices since they are going straight to Cusco in Japan.
Kaaz has discontinued their diffs for our cars as well as TRD... There is still a possibility of getting a TRD unit but it would have to be a used one or from some shop that had it on display or such. TRD does not have them anymore. This is all the reasearch I've done...
They actually make a 2 way I just didn't get the part number...
I am thinking about the 1 way beacuse it won't mess with corner entry and mid corner push...I am not decided yet though. I'll be ordering one as soon as rhdjapan gets back to me... anyone has any experience with them? Are they good?
I am thinking about the 1 way beacuse it won't mess with corner entry and mid corner push...I am not decided yet though. I'll be ordering one as soon as rhdjapan gets back to me... anyone has any experience with them? Are they good?
CMS-GT4
Active member
I have never heard of one breaking. I have heard they are loud and can be aggressive depending on how they are set.
Its a shame you don't know anyone with a mk4 supra dif laying around. Part of me wonders if you can change the gears in the front parts of the dif housing to make them all compatible.
Its a shame you don't know anyone with a mk4 supra dif laying around. Part of me wonders if you can change the gears in the front parts of the dif housing to make them all compatible.
CMS-GT4":aphtk2ac said:
I mean RHDJapan....if they are a good company... :wink: Cusco seems to be decent, the RS is supposed to last quite a bit longer than that MZ which is also much louder....
As far as supra diffs, I doubt they'll work because there are several major differences. The shaft stub has 6 holes I think and the gear ratio is completelly different plus I think the diff itself is bigger... adapting our ring gear and pinion might be too much work I think...
A welded diff is a unique experience, requires quite a different driving style. You can overcome a lot with power and sliding it around. BUT, it becomes twitchy and a wild ride on rough surfaces. It also puts a great deal of stress on the rest of the driveline and tires (ended up breaking many other things besides the diff and cooking the tires). It is a cheap fix for for straight line racing; For a road course a LSD is the better way.
Go for the 2 way LSD you will be much happier and faster.
Well I finally installed the Cusco rear diff and had a chance to test it at an autocross yesterday. The diff is unbelievably affective and once I change the fluid in it and put less friction modifier in the housing I am expecting it to be even better. Coming out of corners is a night and day difference compared to the Torsen or open diffs. Of course the torsen was better than open but this Cusco unit blows it away! Daily driving is unaffected, no noise at all...smooth as can be... More updated to follow after I drive it with some better tires on the 31st at BeaveRun in Pa.... we need more alltracs there so come out if you can! 
Hotrodhendrix
New member
Did you get the 2 or 1 way? How much did it total?
It's a 1-way with the option of switching it to 2-way...it looks pretty simple and straight forward construction-wise so I am sure a hybrid adjustments are possible...
RHDJapan helped me quite a bit and gave me excellent service with very fast shipping. Total cost was a little under $1200 shipped with brand new toyota stub axles...direct replacement to an open diff, nothing else needed. Perfect fit!
I am going to play with the fluid viscosities a bit as I'd like it to be a little more aggresive. (it's new so it might need some time to break in to engage 100% even after the initial break in after installation)
If anyone has any recommendations on fluids please feel free to post. I heard synthetics are not recommended but I think it's only due to the noise...I am going to try Redline 80W-90 as Redline recommended it for this diff... Any info would be appreciated...
RHDJapan helped me quite a bit and gave me excellent service with very fast shipping. Total cost was a little under $1200 shipped with brand new toyota stub axles...direct replacement to an open diff, nothing else needed. Perfect fit!
I am going to play with the fluid viscosities a bit as I'd like it to be a little more aggresive. (it's new so it might need some time to break in to engage 100% even after the initial break in after installation)
If anyone has any recommendations on fluids please feel free to post. I heard synthetics are not recommended but I think it's only due to the noise...I am going to try Redline 80W-90 as Redline recommended it for this diff... Any info would be appreciated...
RedCelicaTRD
Moderator
He got new stubs so he was able to use an open diff.