# Transmission Issue?



## calvin200sx (Oct 14, 2003)

I have started to raise the boost level on my 1996 200sx GA16de turbo from about 9 psi to 12 psi. And in doing so, I have started haveing hesitation at an rpm range between 4500 and 6000 rpm. It is the worst at 5500 rpm under WOT. After 6000 rpm, the hesitation stops. This hesitation feels a lot like hitting the rev limiter. I recently put a A/F meter on the car and verified that it is not the A/F ration (runs slightly rich under WOT at that rpm). I also check ignition and that doesn't seem to be a problem. With the turbo clutch and lightened flywheel from JWT, I don't think the clutch is a problem. Could my transmission be slipping? I've seen from others dyno graphs that the max power from the turbo is around the 5500 rpm range, so could my transmission be affected by the higher power levels? Any help / info would be appreciated.


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## James (Apr 29, 2002)

calvin200sx said:


> I have started to raise the boost level on my 1996 200sx GA16de turbo from about 9 psi to 12 psi. And in doing so, I have started haveing hesitation at an rpm range between 4500 and 6000 rpm. It is the worst at 5500 rpm under WOT. After 6000 rpm, the hesitation stops. This hesitation feels a lot like hitting the rev limiter. I recently put a A/F meter on the car and verified that it is not the A/F ration (runs slightly rich under WOT at that rpm). I also check ignition and that doesn't seem to be a problem. With the turbo clutch and lightened flywheel from JWT, I don't think the clutch is a problem. Could my transmission be slipping? I've seen from others dyno graphs that the max power from the turbo is around the 5500 rpm range, so could my transmission be affected by the higher power levels? Any help / info would be appreciated.


What kind of clutch are you using?


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## calvin200sx (Oct 14, 2003)

I am using the JWT high pressure clutch (their new clutch they recommend for the HotShot Turbo Application). I think it is a dual diaphram pressure plate and I have a metal / organic friction disk.


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## James (Apr 29, 2002)

Hmm that is strange. I have the same setup and ran 12psi yesterday... outside of the pinging I noticed no hesitation.

The only thing I have noticed is what I guess would be called chatter... when I put the car into a higher gear and its not fast enough yet to be in that gear... I floor it and I get this little shaking for a second then goes away....


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## calvin200sx (Oct 14, 2003)

I have felt that as well. I have also seen that once and a while when I downshift and the rpm's rise to around 4500 rpm, then I get a little bit of a "slipping" feeling. It only happens once and a while though. 
Another thing I have noticed, it seems to be getting harder and harder to get into first gear after stopping. Don't know why exactly, but it sounds like my syncros might be going out. If that's possible...


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## James (Apr 29, 2002)

Yeah I have that too... sometimes I can't tell if its in first and I take it out and have to hit the clutch again.

I noticed the same thing on downshifts rpm shoots up and you get a bit of that little shudder in there and then it grabs again... I looked at the boost gauge and it seemed to match the shudder, if you can picture what I'm saying... like when it shudders the boost doesn't build during that time...

Well for your problem, can you check the ecu to see if your throwing a code?


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## calvin200sx (Oct 14, 2003)

Yeah, I could check the ecu for codes. I am not sure what code I would be looking for though.


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## James (Apr 29, 2002)

I don't know but sometimes it stores codes that don't set off the CEL.... 

How old is your MAF?


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## calvin200sx (Oct 14, 2003)

I have a MAF from a 1996 240SX. I had it installed with the turbo.


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## James (Apr 29, 2002)

You know I'm beginning to think this clutch isn't the crackshot highspeed clutch it was designed to be... This morning, I'm cruising down to a light so I have the clutch depressed and cruising into the light in 4th... the light changes all of a sudden and I gas it, no speed, some of that shuddering we were talking about before... so I decide to downshift to 3rd... I gas it... almost felt as if it was in 4th still! It felt like it was slipping!


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## calvin200sx (Oct 14, 2003)

I agree, the clutch might be the root of all of the problems. I hate to think that since it was so expensive. I wonder if Mike Y. or Wes is have any of these problems? Do you know of any other clutch options we have?


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## James (Apr 29, 2002)

When Javier had his car done he was using an ACT setup I believe... I wonder if JWT will do anything about this, I believe the guarantee their clutch to withhold these power levels... Wes is using a JWT clutch but he is using the single diaphram pp I believe.


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## calvin200sx (Oct 14, 2003)

Thanks for the info James. I hope Wes is having better luck with his clutch then we seem to be having. If you hear of anyone else who is having problems, we will need to get together and address these issues with JWT. I hate to buy defective parts, if that is indeed the case.


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## James (Apr 29, 2002)

calvin200sx said:


> Thanks for the info James. I hope Wes is having better luck with his clutch then we seem to be having. If you hear of anyone else who is having problems, we will need to get together and address these issues with JWT. I hate to buy defective parts, if that is indeed the case.


Well my tranny took a dump on me yesterday so I won't be able to look into it for a bit... Its stuck in 1st gear.

I think if you still feel any slipping you should call JWT because then they can work on a new design and maybe even replace your clutch with the new design since they claimed it would hold this power.


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## calvin200sx (Oct 14, 2003)

Sorry to hear about your tranny. I hope you can get it fixed soon. Good Luck! I will let you know if i find out anything from JWT.


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## AznVirus (May 8, 2002)

what happened James? how did it get stuck in 1st gear? clutch not engaging? i myself have felt this shudder when downshifting in low-mid rpms.

btw, i have a single diaphragm pp as well. the clutch feels solid for me except its a damn stiff clutch. does anyone else, with a single diaphragm pp (earlier of the two jwt turbo clutches), notice the stiffness of the clutch? im thinking that if no one else with this clutch has the same problem of stiffness, then it might be due to my auto-manual swap (i think im a bit off on where the clutch pedal is supposed to be stock).


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## James (Apr 29, 2002)

Deric, after I spoke with you last weds night it went out on the way to class as I feared. I put a post up in the B14 section (Clunk... Clunk... Clunk...). The new tranny should be here today and Sam is coming out to help me tomorrow to put it on but if you can help too that'd be great.


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