PR3 GSR?

[aLLmOtOr]

I just picked up a CRX with a USDM GSR motor but runing a JDM PR3 ODB0 ECU, any concerns about using this ECU? Any thoughts and comments would help also.

 

[88bluehf]

nothing wrong with this ecu except at higher rpms when your butterflies dont open up...so in effect it gets choked...i would disable butterflies(IAB)(unless this has been done already) or order a skunk 2 manifold that doesnt have them.

 

[darien234]

I'm running the PR3 also rich as hell at idle in my CRX. Would that that also be the reason.

 

[88bluehf]

Originally posted by darien234@Dec 10 2004, 09:58 AM
I'm running the PR3 also rich as hell at idle in my CRX. Would that that also be the reason.

[post=429981]Quoted post[/post]​

on what engine? is this rich condition verifiable through an air/fuel meter? hondas usually run on the richer side at idle. does it just run a little rich under normail conditions i.e. normal driving? and real rich under acceleratoin? if so everything is normal....at least its not running lean.

 

[darien234]

Originally posted by 88bluehf+Dec 10 2004, 11:36 AM-->

darien234

@Dec 10 2004, 09:58 AM
I'm running the PR3 also rich as hell at idle in my CRX. Would that that also be the reason.

[post=429981]Quoted post[/post]​

on what engine? is this rich condition verifiable through an air/fuel meter? hondas usually run on the richer side at idle. does it just run a little rich under normail conditions i.e. normal driving? and real rich under acceleratoin? if so everything is normal....at least its not running lean.

[post=430012]Quoted post[/post]​

Its a d16 z6 PR3 is for my LS VTEC but I also used to run vtec on the Z6 since it was a cleaner look, and easier process.

 

[nfn15037]

Originally posted by 88bluehf@Dec 10 2004, 10:29 AM
nothing wrong with this ecu except at higher rpms when your butterflies dont open up...so in effect it gets choked...i would disable butterflies(IAB)(unless this has been done already) or order a skunk 2 manifold that doesnt have them.

[post=429957]Quoted post[/post]​

Wrong, the butterflies(IAB) will be open all the time, making you lose low-midrange torque.

Unless it is chipped, that ECU does not have the proper fuel maps either, meaning it is probably lean most anywhere at WOT unless it is chipped to run a P72 motor.

 

[88bluehf]

Originally posted by nfn15037+Dec 10 2004, 11:55 AM-->

88bluehf

@Dec 10 2004, 10:29 AM
nothing wrong with this ecu except at higher rpms when your butterflies dont open up...so in effect it gets choked...i would disable butterflies(IAB)(unless this has been done already) or order a skunk 2  manifold that doesnt have them.

[post=429957]Quoted post[/post]​

Wrong, the butterflies(IAB) will be open all the time, making you lose low-midrange torque.

Unless it is chipped, that ECU does not have the proper fuel maps either, meaning it is probably lean most anywhere at WOT unless it is chipped to run a P72 motor.

[post=430048]Quoted post[/post]​

nice avatar....the fuel map should be relatively close, it will run a bit on the lean but nothing that should cause any problems i ran an lsvtec integra on a stock p28 and my air/fuel meter was ususally on the slightly rich side under normal operation and rich under WOT.....as far as the butterflies go ive always been told they open more at higher rpm, but if i am wrong about this i will concede.

 

[nfn15037]

Thanks, I like Hondabond

If they don't have the ECU to tell them to close, the seconadries will stay open all the time. Watch a GSR running on a P72 ECU at startup, the butterflies pull closed when the car is started. They operate via vacume, a solenoid keeps vac trapped in a little canister and at ~5700 RPMs, the ECU tells the solenoid(by grounding pin A17) to release the vacume and let the IAB open.

As for the P28 running an LS/VTEC, do you have a wideband 02 sensor? That combo would run insanely lean(1.6 SOHC map on a 1.8 DOHC motor) unless of course the ECU was chipped to DOHC specs. Either way, a PR3 in a GSR will run lean, by a decent amount, enough to cause detonation on a hot day or in a high load/low RPM situation.

FWIW, a 1.8 moves a good amount more air than a 1.6, making more fuel necessary.