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Registered:
January 2004
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1jz dyno... whats wrong!?
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Wed, 03 March 2004 16:25
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Finally took my car (1jz-gte engined 240z) to the dyno, ran very well at 11psi (although on garages boost gauge said 9psi).
so all looked good to turn up the boost, which I asked the operator to set at a maximum of 15 psi. Then all went wrong, when on boost, the power peaked then fell away, the operator said it was running very lean, but I'm not sure if it was run way over my stated max of 15psi due to his faulty gauge..
He said he would have a go with the haltech software, but his understanding seemed to be a bit lacking, so asked him to leave it..
what are peoples opinions?? does it look like I just need to up the fuelling at higher boost? or do I need to check fuel filter etc. or should I just try again using what I believe to be 14-15 psi
Dyno is here:
lower graph is 11psi higher graph is at raised boost
Next step is trying to find anyone in the UK that has any haltech knowledge!!
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Location:
Adelaide, SA
Registered:
May 2002
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Re: 1jz dyno... whats wrong!?
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Wed, 03 March 2004 22:50
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Is this a dead stock 1jz - including airfilter etc? On the dyno mine spiked boost at 11psi but then went back down to 9psi - I'd never noticed this before on my boost gauge (but then again I'm not staring at the boost gauge for a great deal of time whilst at wide open throttle). I'd say a similar thing is happening to yours.
You are running a haltec and not the original ECU? I'd expect the original ECU to run very rich at higher rpm at std boost (mine did)or even higher boost. Either your map is not right for the engine...
or it could be that you're running the stock 1jz MAP sensor. Apparently this has a max limit of 1 bar so if you were over this than you'd be getting no increased signal from the map sensor as the boost went up to 16-17psi and the Haltech may not be adding more fuel for the incresead airflow over 1 bar.
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Location:
Perth
Registered:
October 2002
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Re: 1jz dyno... whats wrong!?
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Thu, 04 March 2004 02:50
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1JZ ... 240Z ... UK ... Haltech ....  , that sounds like Ben Whatsisnamefromzoom's old car!
How is it going (aside from below mention problem which I have no useful advice to offer)? Any changes made? That's an amazing intake on your car - what's the verdict on it? Is the cold air feed worth obstructing the intercooler and lengthening of intake length? Please tell me more  .
cheers,
Justin
JZA61
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Registered:
January 2004
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 Re: 1jz dyno... whats wrong!?
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Thu, 04 March 2004 11:13
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yep its ben ellis's old car! good spot!
Since I've had it, i've done relatively little. The haltech boost controller was not working, so after a bit of figuring out, ended up just replacing it.. which is why I thought I'd better try it out at higher boost on the dyno, though it runs so well at standard boost, its not that I actually NEED more power, but if it is there..!
Difficult to comment on the intake as I've had no experience of anything else, seems pretty good though. And a front mount intake was on the 280zx, nissan must have thought it a good idea too.
As for the problem, I've got a 3 bar map sensor and the car has only really been mapped properly at 11psi, so could be just be mapping, very frustrating though!
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Location:
UK
Registered:
May 2002
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Re: 1jz dyno... whats wrong!?
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Thu, 04 March 2004 12:32
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just a guess. but perhaps your boost is tailing off at the top end due to the boost controller..
but you really need to sort that mapping out..
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Location:
Melbourne
Registered:
August 2003
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Re: 1jz dyno... whats wrong!?
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Fri, 05 March 2004 03:46
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It could be the turbos.
I have had many problems with the standard turbos once I started tweaking them past stock boost.
First I would say, I know from experience that the standard twin CT-12As won't last very long if you're running them past 11psi. They have quite fragile ceramic wheels, which are prone to falling to bits once they are stressed too much. Yes, you can run it up to 16 psi, yes they will do it, but don't expect them to last long.
My suggestion would be that if you want more power, to replace them sooner rather than later - you will save yourself from lots of headaches later.
I also had a problem with the cat converter ended up collapsing & blocking the exhaust flow... I didn't really notice until I started getting more power out of the engine.
If you really want to stick with the standard turbos make sure you have a twin dump pipe setup & if you want to go to the little extra effort to tweak the CT-12As (without a full rebuild / Highflow - which I would say would be a complete waste of time) I would also suggest the wastegate mod to ensure it can cope with the higher boost levels without spikes etc..
So if you don't have any luck with other solutions, try the ones I have mentioned above.
Let us know how you go.
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Location:
Seattle area, USA
Registered:
June 2002
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Re: 1jz dyno... whats wrong!?
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Tue, 09 March 2004 08:24
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stock injectors?
whats the Fuel pressure?
Did you get a copy of the air fuel ratios during the dyno runs?
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Registered:
January 2004
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Re: 1jz dyno... whats wrong!?
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Tue, 09 March 2004 09:47
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Well, looks like I'm going back to a more competant dyno..
this time I'll have a fuel pressure gauge, get plots of air/fuel ratio, and boost. Also I'll do data logging with the haltech, see what the haltech believes the boost to be.
I have stock injectors btw, not even close to full duty cycle, so should be ok.
never thought of the cat, but whole system is fairly new and custom, with a high flow cat, so 'should' be ok
I'm interested in the dumps (y pipe), but a bit nervous due to the boost creep stories, what do people think to this replacement available here: http://www.uniqueautosports.com.au/
dyno on 22nd march, I'll let you know how i go!
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Location:
Seattle area, USA
Registered:
June 2002
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Re: 1jz dyno... whats wrong!?
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Tue, 09 March 2004 10:44
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trying to tune a programmable EFI ECU without any EGT, A/F ratios and other sensors or gauges is a complete shot in the dark... 
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Registered:
January 2004
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Re: 1jz dyno... whats wrong!?
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Tue, 23 March 2004 17:00
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Finally got my car tuned on the dyno and all went well!
Turned out it was mainly a case of the boost map being very bad, but also fuelling. I recently had to replace the haltech boost solenoid, and I guess its properties were very different, I couldn't tell from my gauge, but after I hit the defined boost it dropped away reasonably significantly..
Anyhow, got the boost map set, and ran at 14 psi, afr set to around 12, getting slightly richer at 6000+ rpm and timing set. All took about 4 hrs, but got a much better result than I had hoped for! 320 hp and 330 ft/lb torque at the hubs, I benefitted from a bitterly cold day though.
will post up the plot shortly..
just very pleased is all sorted now!
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Location:
Seattle area, USA
Registered:
June 2002
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 Re: 1jz dyno... whats wrong!?
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Tue, 23 March 2004 19:08
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that sounds more like a 1zjgte should do on a programmble.
Good job.
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Registered:
January 2004
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Re: 1jz dyno... whats wrong!?
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Wed, 24 March 2004 09:31
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the plot...
shall I put it on a new thread in case people interested might miss it?
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Location:
newcastle
Registered:
June 2002
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Re: 1jz dyno... whats wrong!?
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Wed, 24 March 2004 10:04
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In reference to these dumps .they appear to rejoin after only only a few inches .
what a lot of people dont understand about the design concept behind the dumps is removal of heat
Its excessive heat that kills factory turbos . to get the huge torque gains from twim pipes they need to be BIG
so you need twin 2.5 inch dumps and i would run them at least half way down the car before re-joining .
ALL the flow probs come from having excessivly large pipe after that .rejoin then 3 inch and you can still run 10 psi boost .
i do and easily still make 300 rwhp at 15 psi with an auto .so around 320 with a manual
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Registered:
January 2004
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Re: 1jz dyno... whats wrong!?
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Wed, 24 March 2004 14:37
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Thanks for the info!
I'm thinking I might try and find some good photos of a known good design and try and get an exhaust shop in this country to make something similar up and fit them, any ideas where to get some pics from?
cheers again!
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Location:
newcastle
Registered:
June 2002
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Re: 1jz dyno... whats wrong!?
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Wed, 24 March 2004 20:49
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here they are
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Registered:
January 2004
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Re: 1jz dyno... whats wrong!?
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Thu, 25 March 2004 09:39
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thank you
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