umm that doesn't look so good. Thats kinda hard to believe that those 235/40/17 nankang tires caused the shaft to break before they would break traction. Replace the gearbox and hopefully you can hit some 13's. good luck.

note to self: don't buy slicks yet.

 

Dont buy triple plate clutches either!

 

Wtf!?

From what I understand of your situation, you are running an RB20 gearbox with a TRIPLE PLATE CLUTCH, correct? Why would you do this? The RB20 gearbox is the weakest of all the RB boxes and shouldn't be taken above 350whp. Normally with a single plate clutch, the clutch will slip long before you start snapping driveshafts or tranny parts. I like to think of it as the fuse in the circuit (hey, I'm into electronics.) By using the triple plate clutch, you've effectively turned the gearbox and/or the rear end into the fuse. I would suggest upgrading to an RB25 box or taking out that damn triple plate because if you don't, after you fix the broken tranny you'll likely be replacing something in the rear end. :nono

Just my $.02

 

Or another transmission?

 

also dumping the clutch at 6k isnt good and teh tripple plate clutch isnt helping much.

 

.................................

Your problem is your doing a 6k Rpm Drop. Next time slip it out of the hole. You won't shock your drive line so bad. . . . shit you might as well just drop in a Rb25 tranny.

 

can you just replace that gear in the trans that goes inside the driveshaft?

 

Dropping the clutch at 5-6K... :nono

What you need to do is get a single disk or at most double disk clutch w/ the RB20 capabilities and ease in at 3-4K.

kouki-gymkhana- Isn't the RB20, KA24, and SR20 trans all the same, just different bell housing? So wouldn't that mean it's good to 4-500hp?

 

If I'm not mistaken, the internals of the KA and RB25 tranny are swappable but the RB20 is not the same as either the KA or the SR. You are correct in ascribing the problem to his 6k clutch drop and the tremendous driveline shock that it causes. I personally wouldn't do a 6k clutch drop on an RB25 either but I'm a poor cheap bastard who'd rather replace a fried clutch from slipping that bitch than buying/replacing trannys. :gaylaugh :crazyrant :happyfing

 

RB20DET silver Top
3" full Ex. W/O cat
pod air filter
FMIC
15psi @stock turbo

15psi and that thing didn't come apart on you? How long have you had the boost up that high?

 

If I'm not mistaken, the internals of the KA and RB25 tranny are swappable but the RB20 is not the same as either the KA or the SR.

Not sure about the 25.. but umm... I know someone who just did the KA --> RB20 internal swap. Worked fine :12dunno

 

........................

Not sure about the 25.. but umm... I know someone who just did the KA --> RB20 internal swap. Worked fine :12dunno

Yeah your right. The RB20,SR20 and KA are kinda the same. The RB25 gears are more like the 300zx.

 

Yeah your right. The RB20,SR20 and KA are kinda the same. The RB25 gears are more like the 300zx.

Yeah, probably right... I never looked into it. But it would make sense. I mean... look at that comparison! :gaylaugh The 20 is so little! :gaylaugh


(RB20 v. RB25 ~ picture taken by OpeLok)

 

lol.. good job. should have done more research.

 

Hi guys

thanks for your help and your post.

about the tranny, I bought a RB20DET gearbox and will fix it today and see what will happen ( hope not broken again)

BTW, I forget to say that yesterday I saw one of the Engine mount is broken, can it be the resone for the broken shift.

about the 6k rpm drop clutch, I do that coz when I drop the clutch the RPM drop to 3.5K-4K RPM so the Turbo alrady spooled and @ full boost so the car is jump from the start line faster

But when I drop the clutch in 4K the RPM drop to 2K-2.5K so the turbo is not at full boost it need some time to spool up. and you feel the car is take time to jump from the start line

and guys I alrady buy the OS Triple clutch so I can not change it again so I need a diff. idea about it.

Yellow4g63 : I upper the boost only at the track (15psi) and in normal day I run it at 8 psi(I use manual Boost controller)
I test it one time with 15psi at the street and it was :thumbsup and I did not hear a knoke or detination. I forget to say I have a supra fuel pump


thanks guys for your help

 

I think you are missing the point. the reson your transmission broke is SHOCK, not power. the trans can handle the power you are giving it, just not the sudden torque.

DO NOT DROP THE CLUTCH!

I guarantee that if you drop the clutch at 6K with GOOD motor mounts you will have the same problem.

 

I think you are missing the point. the reson your transmission broke is SHOCK, not power. the trans can handle the power you are giving it, just not the sudden torque.

DO NOT DROP THE CLUTCH!

I guarantee that if you drop the clutch at 6K with GOOD motor mounts you will have the same problem.

thanks man

but why there is some car drop the clutch at high RPM and nothing happen.

we have a 280z with RB20DET stock SMIC, 3" EX, slick,7psi and NOS(75 or 100 shot) he get 12.0 sec

I want to pass him

 

Clutches are designed to slip a little....yours did not.

A 1000HP motor will cause your triple plate clutch to slip, like the stock clutch will slip with stock power....the triple plate will NOT slip at all on the the stock and basically make the tires and engine lock up. The shock is what kills it.

 

Hi guys

need help PLZ

I install a new RB20 Tranny and new engine mount then drive the car in test run and found that:

I stop the car at the start line rev the engine 3K then drop the clutch the RPM drop then the turbo spool up but the proplem here is:

the end of the car have alot alot of vibration, why the vibration came and what is the resone for it?

I think the Tranny borked from this vibration

PLZ help me guys

thanks

 

bottom line is that the rb20 tranny is weak- so an upgreade will have to come into play - wether its a aftermarket gear set-up or a rb25 tranny swap i guess... any thoughts.???

 

get a single disk clutch!!!

 

What type of driveshaft do you have? If you didn't mark exactly how the driveshaft was mounted and mounted it differently then you will get vibrations. It could also be clutch chatter.

 

slows@stinkys14
bottom line is that the rb20 tranny is weak- so an upgreade will have to come into play - wether its a aftermarket gear set-up or a rb25 tranny swap i guess... any thoughts.???

I think it is hard to swap a RB25 tranny in RB20 engine, or not

thanks

JerryRigRB240
get a single disk clutch!!!

you mean that the vibration from the clutch ?

But now I buy it alrady so I think it is hard to sell it and buy another clutch

thanks

DLSracing
What type of driveshaft do you have? If you didn't mark exactly how the driveshaft was mounted and mounted it differently then you will get vibrations. It could also be clutch chatter.

I do not know what you mean :12dunno

what is you mean by driveshaft type

I have the stock driveshaft (with center bearing)
stock diff. but LSD ( as I search it is 3.700 Euro ver. 200sx,,not sure)

stock suspension

I hear from some body that if I change me driveshift from centerbearing one to 1 peice it will be ok, is it right?

or mabye my suspension coz it is stock and I need race suspension


thanks

 

This vibration could be from a broken diff, unbalanced driveshaft, broken axle, blown wheel bearing, bad tire, bent wheel, warped rotor, unbalanced wheel, bad bushings, blown bushings any number of things.

 

I'm pretty sure it's not easy to swap the 25's trans into the 20. Might as well just get a whole engine/trans at that point.

You can put in a 1 piece if it's lighter than stock, for instance aluminum or carbon fiber.

It would be wise of you to not have bought that clutch in the first place, since when you asked everyone said not to. Now that you have it, I'd say sell it unless you want to do more damage to your driveline.