slwazgsr

I'm in the process of getting a Jumper Harness for my 96 GSR, but it's hard to find a USDM p72

I've got lots of friends with stock unchipped p28, would that work with my set-up?

TIA

Bleed Black

Youre going to at least want to have the DOHC program. Try to find someone with a P28 from a Del sol (the B16 one...DOHC). Or get one of those SOHC P28s and send it out to get chipped for DOHC, but make sure to specify its for a turbo application (ie. no advanced timing/funky fuel maps).

LOwrestling2001

is it possible to get it chipped for dohc if u have hondata p28? thx

Arturbo

Yes it will work and it doesnt matter if its DOHC or SOHC. The only thing you wont have controll over is the secondary runner control that the P72(GSR) has. If you have a skunk2 or JG intake manifold there are no secondary runners, so the p28 will work.

slwazgsr

thanks jeff,

But once I get it chipped to DOHC, I've heard that I can' use it because I won't have the ability to use the secondary runners

Are there any ill effects to using this ECU on the b18c1

Bleed Black

Matt G (black eg w/Advans and GSR swap) put his Kenji ECU in long before he installed his Skunk2 IM and didnt lose any power by not having the secondaries(dyno proven).

TeStUdO

i lost no power with the secondaries not hooked up at all, but the whole time i knew i was switching to the skunk2 though.

LOwrestling2001

did u leave ur secondaries open or closed?

TeStUdO

i just left them closed, i didnt even have a vacuum line hooked up to the diaphram on the side of the manifold.

Arturbo

Have any dynos to prove that?

tony1

With the secondaries not hooked up they will remain open at all times. You will not lose any power above 5700 because nothing has changed. You will loose hp and torque below 5700 rpm, dyno proven....

Bleed Black

If he says so....I believe it

slwazgsr

Ok,

so once I get my hands on a p28, I need to have it rechipped to DOHC and what else? change the rev limiter? etc etc?

TIA, I hope this will solve my turbo woes....

and how exactly do I leave the secondaries open at all times? Just unhook that vacuum line on the back?

coyotes fan

I plugged it with a BB, looks cleaner that way.

tony1

The way the secondaries work.....
The secondaries are always open when the car is off. When you start the car the ecu sends a ground signal to a soleniod which sends vacuum to the diaphram. This closes the butterflies. At 5700rpm the ecu cuts the ground which opens the butterflies. If everything is hooked up like normal and the ecu doesn't send the signal (P28) then they will just stay open. There is no need to disconnect anything. I would keep them functional unless you are going to change to another manifold (skunk or jg). If you want to feel the difference they make you can just unhook the vacuum line to the diaphram and they will stay open. Drive it and see if you feel the difference below 5700.

LOwrestling2001

DOH! haha i have a obdI p28 cuz i was too poor to afford an OBDI p72...screw meeeeee....guess i'll have to go w JG later..

slwazgsr

thanks

TeStUdO

on the dyno i lost about 3-5 hp midrange with them open at all times, but i gave my diaphram to my buddy with an h23 swap so it could work his runners. thats when i dynoed again and lost the 3-5hp midrange (3500-4200rpm). when i put the skunk2 on i gained 13hp at 6500, and about 5hp midrange. overall it increased the whole powerband. i think the way the stock IM is on the gsr is a pretty shitty design anyway.

slwazgsr

ok

so once again

IF i get a p28, what do I have to chip it for to make it work on my gsr?

just make it from SOHC to DOHC? anything else?

Arturbo

The ECU doesnt know if the motor has one or two cams.

FredoSP

We are only talking about a GSR right? Cause I have a 2000 Civic Si and the itake manifolds are VERY different from the B16 to B18 (for the second runners).

I have Hondata 2B, DSM 450's, P28 and an OBD2 to 1 Harness for my setup, NO MORE BLUE BOX!!

LOwrestling2001

yea only stupid gsr has secondaries...well and vtec preludes.