cute wee gem Posted November 22, 2011 Share Posted November 22, 2011 Any ideas why the power dips off at around 4200? There's 3 runs on there and they all do it. Don't care much as I'm getting a new engine eventually, just intrigued as to what would cause it and if it's an easy fix Engine is a bog standard 1jz-ge with 255ks on the clock Quote Link to comment Share on other sites More sharing options...
UTERUS Posted November 22, 2011 Share Posted November 22, 2011 Did you have a wideband connected during the runs, and what readings were you getting before/after that area of revs. You didn't happen to be logging the AFR's did ye? Quote Link to comment Share on other sites More sharing options...
cute wee gem Posted November 22, 2011 Author Share Posted November 22, 2011 Nah nothing fancy like that, just a simple dyno run at powercruise for a laugh. Answer = #jz-gte? Quote Link to comment Share on other sites More sharing options...
Evan Posted November 22, 2011 Share Posted November 22, 2011 Is the ECU electronically restricting the throttle? No idea if this is even possible in older engines but newer engines with the fly by wire shit are sometimes electronically restricted between different vehicle models ( 317kw HSV clubsport vs 325kw HSV Clubsport GTS is an example that comes to mind) Quote Link to comment Share on other sites More sharing options...
barf Posted November 23, 2011 Share Posted November 23, 2011 my e30/m20b20 has a similar curve, AFAIK it's an acoustic/pneumatic type of issue with intake manifold. i thought Toyota solved this with TVIS though? seeing the torque fall with it raises an eyebrow though, i assume that would be timing - what's your spark map/advance table look like? Quote Link to comment Share on other sites More sharing options...
JoKer Posted November 23, 2011 Share Posted November 23, 2011 nothing wrong? engine is more efficient over 4.2k? not many engines have a smooth rate/climbing power curve Quote Link to comment Share on other sites More sharing options...
bosozoku_gx71 Posted November 23, 2011 Share Posted November 23, 2011 That power figure makes me sad. Any mods to it? Auto or manual? Quote Link to comment Share on other sites More sharing options...
keltik Posted November 23, 2011 Share Posted November 23, 2011 Does the JZ have a variable intake system of some sort? TVIS or whatever? I had a pretty big dip on my EZ30 from the Subaru TVIS equivalent thing switching over from low RPM to high mode. This caused a rich spike which in turn caused the power dip. Quote Link to comment Share on other sites More sharing options...
thegreatestben Posted November 23, 2011 Share Posted November 23, 2011 Nah this is pretty much the first car to have the 1jzge afaik. It does have a butterfly flap thingo in the inlet manifold - http://www.toyodiy.com/parts/p_J_1992_T ... _1701.html Trawled internet for any other 1jzge dyno plots? Quote Link to comment Share on other sites More sharing options...
Testament Posted November 23, 2011 Share Posted November 23, 2011 as above it's probably just how it is due to either -tvis thing -inlet tract tuning -exhaust manifold tuning (what exhaust does it have?) do you feel the dip in power during real world driving? Quote Link to comment Share on other sites More sharing options...
cute wee gem Posted November 24, 2011 Author Share Posted November 24, 2011 Don't really feel it unless you're really trying hard to. No TVIS, exhaust is factory I think but is pretty crushed up under the diff from hitting the road. Just seemed weird that it actually drops in power so sharply. That power figure makes me sad. Any mods to it? Auto or manual? No mods at all, manual trans - engine feels a bit tired though Quote Link to comment Share on other sites More sharing options...
Dell'orto Posted November 24, 2011 Share Posted November 24, 2011 seeing the torque fall with it raises an eyebrow though, Que? They're entirely related. Its very much like a TVIS dip, so maybe there is some sort of throttle butterfly related trickery there. A/F plot would help, but most likely it goes quite rich there. Quote Link to comment Share on other sites More sharing options...
Spencer Posted November 24, 2011 Share Posted November 24, 2011 Yea its just the 2 stage intake manifold no biggie theres no TVIS on a JZ guys, go wash your mouths/keyboards out with soap Quote Link to comment Share on other sites More sharing options...
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