240z + 1JZ-GTE (manual)

tel240z

Club Member
i'm not to sure about that John........ but i am going to up the rev limiter a bit and dismiss from my mind any worry about the drive shafts breaking :eek:
 

johnymd

Club Member
I think I need to consider raising my rev limit too as I was pretty close to the limit in 4th at 132mph. I'm expecting nearer 140mph across the line now and I don't want to be changing into 5th right at the end. Just made a few calculations and if I raise the limit to 7500 that equates to up to 145mph before I need to change into 5th. Should be fine.
 

Mark N

Club Member
I think I need to consider raising my rev limit too as I was pretty close to the limit in 4th at 132mph. I'm expecting nearer 140mph across the line now and I don't want to be changing into 5th right at the end. Just made a few calculations and if I raise the limit to 7500 that equates to up to 145mph before I need to change into 5th. Should be fine.

Until I read the engine specs, I didn't realise how similar they were to RB25/26s (same bore, CR and similar stroke).
What is the factory limiter set at on the 1JZ-GTE?
 

johnymd

Club Member
The limiter was 7100 on the factory ECU. From what I've read, you can get away with 7500. It was taken to the limit of 7400 many times on Wednesday.

Both engines were built at around the same time to compete with each other and both were put together by skilled people with great attention to detail. This is why I would prefer to not take it apart.
 

Mark N

Club Member
Both engines were built at around the same time to compete with each other and both were put together by skilled people with great attention to detail. This is why I would prefer to not take it apart.

I totally agree with you, in stock form it should be able to easily cope with anything a GT35 can throw at it!

Unfortunately, when I bought it, my engine had been rebuilt by someone allegedly skilled with very little attention to detail which was the only reason I pulled it completely apart!
 

johnymd

Club Member
Went to check out the car today to see the extent of the damage. I had assumed the z31 cv had broken but it is actually the shaft. These are not standard z31 but the chequered flag chomolly 4340 upgrades. I'm a little surprised how easy they broke as I wasn't Erving high and was on a low boost setting. On the plus side I do have a new spare that I'll fit tomorrow.
 

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tel240z

Club Member
See the twist at the end
1ce73775deb9b22e75891f7aceeac5f1.jpg
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d77619bd26f69f29129aab994fc4239f.jpg
71e69ce4994269a9d489a23fab1f53ce.jpg


Sent from my SM-G930F using Tapatalk
 

AliK

Vehicle Dating Officer
Staff member
Club Member
Forgive me for speaking with utter ignorance on the topic: are those heat marks anything to do with the metal being made brittle through heating and cooling rapidly in the past?
 

johnymd

Club Member
The heat marks are from the shafts having the ends hardened to prevent breakages. There was a lot of talk about a batch that didn't have this and people were concerned that the ends hadn't been hardened. It was reassuring to see my shafts had been hardened.l although it didn't stop them breaking.
 

jonbills

Membership Secretary
Site Administrator
It's always nice when your shaft is hardened.

Doesn't the twist suggest a lack of hardening?
 

AliK

Vehicle Dating Officer
Staff member
Club Member
Jon, I did wonder how long it would take! :D

Johny, will you be sending the shaft back to the manufacturer for analysis? Of course they will likely give the usual vanilla corporate standard response but you never know, they may just apologise and sort something out. Worst case they may analyse to improve their product.
 

Rob Gaskin

Treasurer
Staff member
Site Administrator
Jon, I did wonder how long it would take! :D

Johny, will you be sending the shaft back to the manufacturer for analysis? Of course they will likely give the usual vanilla corporate standard response but you never know, they may just apologise and sort something out. Worst case they may analyse to improve their product.

Smiley - John's application will no doubt negate any 'wear and tear' and 'fit for purpose' clause unless it was sold as an unbreakable shaft.
 
Jon, I did wonder how long it would take! :D

Johny, will you be sending the shaft back to the manufacturer for analysis? Of course they will likely give the usual vanilla corporate standard response but you never know, they may just apologise and sort something out. Worst case they may analyse to improve their product.

I was wondering why Tel was measuring johnnys shaft?
 

Mark N

Club Member
It's hard to tell from the photos but was a fresh break.....no signs of a crack propagating over time?
 

Moriarty

Well-Known Forum User
It's hard to tell from the photos but was a fresh break.....no signs of a crack propagating over time?

There is one big tell tale on the photos, the splines have deformed at the break point indicating some degree of plasticity, given that these shafts were supposedly "hardened" it looks like failure in the hardening process rather than failure due to a crack or fatigue. For it to be a crack or fatigue I would expect to see less ductility (deformation) and more of a sharp clean break with an obvious crystalline structure on each face

It looks like they have been either flame or induction hardened due to the localised heat marks (discolouration of the steel)
 

johnymd

Club Member
Thanks for all the input. I suspect they were incorrectly hardened. I have spoken to the supplier and he has explained some of the problems he had at the time with different machinists. I am not looking for any warranty replacement and I'm more confident that the currently supplied shafts would be better than the one I broke.

I have rebuilt the shaft with the spare shorter axle I had and reused the cv's as I have no alternatives. May test again at Santa pod this weekend if the weather stays dry. Current Saturday is looking the best day. I'll start the burnout in the water and slip the clutch from the start line to lessen the shock loading just to get a feel of the power. The main thing I'm looking for is the terminal speed to assess the sort of power increase I have. I have very little faith in rolling road figures so the only way to really assess improvement in power is with the terminal speed.
 
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