Question about JUN P73 ECU VTEC engagement point ..
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Question about JUN P73 ECU VTEC engagement point ..
Simple question.. for you guys with JUN P73 ECUs, what RPM does the JUN ECU engage VTEC ?? I know it tops at 9500 but I want to know where it engages.. I have a JUN ECU that I will be installing shortly and I want to compare .. Thanks !!
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Mine is an original P73 JUN ECU, NOT a chipped ECU. I have yet to install it (as soon as I can get a hold of a harness), but it is supposed to top at 9500rpm..
Primo, if yours engages at 5700rpm, does your motor "bog" upon engagement ?? What cams are you running ??
My case is that I have JUN3s which make the car bog badly upon VTEC engagement and I will have to raise the VTEC point to somewhere around 7100-7300rpm.. I've spoken to a few guys who have had this problem with JUN3s .. I was hoping that the JUN ECU came with a higher VTEC engagement point already ...
Primo, if yours engages at 5700rpm, does your motor "bog" upon engagement ?? What cams are you running ??
My case is that I have JUN3s which make the car bog badly upon VTEC engagement and I will have to raise the VTEC point to somewhere around 7100-7300rpm.. I've spoken to a few guys who have had this problem with JUN3s .. I was hoping that the JUN ECU came with a higher VTEC engagement point already ...
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Re: (iperez)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by iperez »</TD></TR><TR><TD CLASS="quote">Mine is an original P73 JUN ECU, NOT a chipped ECU. I have yet to install it (as soon as I can get a hold of a harness), but it is supposed to top at 9500rpm..
Primo, if yours engages at 5700rpm, does your motor "bog" upon engagement ?? What cams are you running ??
My case is that I have JUN3s which make the car bog badly upon VTEC engagement and I will have to raise the VTEC point to somewhere around 7100-7300rpm.. I've spoken to a few guys who have had this problem with JUN3s .. I was hoping that the JUN ECU came with a higher VTEC engagement point already ...</TD></TR></TABLE>7100 is way too high a cross over, I have my Jun 3s crossing over at 5900 RPM with Hondata
Primo, if yours engages at 5700rpm, does your motor "bog" upon engagement ?? What cams are you running ??
My case is that I have JUN3s which make the car bog badly upon VTEC engagement and I will have to raise the VTEC point to somewhere around 7100-7300rpm.. I've spoken to a few guys who have had this problem with JUN3s .. I was hoping that the JUN ECU came with a higher VTEC engagement point already ...</TD></TR></TABLE>7100 is way too high a cross over, I have my Jun 3s crossing over at 5900 RPM with Hondata
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Re: (iperez)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by iperez »</TD></TR><TR><TD CLASS="quote">Primo, if yours engages at 5700rpm, does your motor "bog" upon engagement ?? What cams are you running ??
My case is that I have JUN3s which make the car bog badly upon VTEC engagement and I will have to raise the VTEC point to somewhere around 7100-7300rpm.. I've spoken to a few guys who have had this problem with JUN3s .. I was hoping that the JUN ECU came with a higher VTEC engagement point already ...</TD></TR></TABLE>
ahhh i know what you are going thru.
my jun ecus came with my jun crate motor.
(everything inside is jun/cosworth - top to bottom).
my first jun ecu engaged at 5700 with 9500 redline.
this ecu had the really bad bog issue.
if you didnt go screaming past the 5700 engagement point, it would bog badly (partial throttle).
this issue was really bad at lsir turn 5.
i swtiched to the newest jun ecu that does not have the bog issue.
ive done super partial throttle tests thru the engagement point and it won't bog now.
this ecu runs a bit more rich and has a 9300 rpm redline.
the first gen jun ecus had this problem, much like their first gen cams.
My case is that I have JUN3s which make the car bog badly upon VTEC engagement and I will have to raise the VTEC point to somewhere around 7100-7300rpm.. I've spoken to a few guys who have had this problem with JUN3s .. I was hoping that the JUN ECU came with a higher VTEC engagement point already ...</TD></TR></TABLE>
ahhh i know what you are going thru.
my jun ecus came with my jun crate motor.
(everything inside is jun/cosworth - top to bottom).
my first jun ecu engaged at 5700 with 9500 redline.
this ecu had the really bad bog issue.
if you didnt go screaming past the 5700 engagement point, it would bog badly (partial throttle).
this issue was really bad at lsir turn 5.
i swtiched to the newest jun ecu that does not have the bog issue.
ive done super partial throttle tests thru the engagement point and it won't bog now.
this ecu runs a bit more rich and has a 9300 rpm redline.
the first gen jun ecus had this problem, much like their first gen cams.
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From: Bayamon, PR, USA
Let me clarify, 7100 is what I've been told by other people and this may change with my setup and what the dyno shows .. Your x-over at 5900rpm is practically OEM which crosses over at ~5800rpm but I guess you have more tuning done ..
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From: Bayamon, PR, USA
Re: (Primo.)
So Primo, how can I tell which generation my ECU is ?? I thought that P73 was as latest as they came 
Still, assuming I have the early version, am I screwed with the bog issue or can I fix it with some tuning of the cam gears, gas pressure, timing, and maybe a VAFC ??
It sounds like you "suffered" through this problem like I am right now and I'll appreciate your help !!
Still, assuming I have the early version, am I screwed with the bog issue or can I fix it with some tuning of the cam gears, gas pressure, timing, and maybe a VAFC ?? It sounds like you "suffered" through this problem like I am right now and I'll appreciate your help !!
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Re: (iperez)
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by iperez »</TD></TR><TR><TD CLASS="quote">So Primo, how can I tell which generation my ECU is??</TD></TR></TABLE>
the older jun chip in the ecu is the problem (older program/software version).
jun usa/japan worked on this issue a lot after i showed them my in car video of it bogging while road racing.
luckily i was sponsored and had all the bugs worked out by them for free.
i have almost 50K miles on my crate engine (this is my second crate), and it's still runing great.
the older jun chip in the ecu is the problem (older program/software version).
jun usa/japan worked on this issue a lot after i showed them my in car video of it bogging while road racing.
luckily i was sponsored and had all the bugs worked out by them for free.
i have almost 50K miles on my crate engine (this is my second crate), and it's still runing great.
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