smoothludey2

for a boosted H22A with Hondata 2b....which OBD1 ecu would produce the best results without any compromises? The p28 keeps the runners open while the p72 can still activate the runners. What's the advantage of leaving the runners open all the time as opposed to having them opened and closed?

VaporTrail

there is no advantage to leaving them open, you lose low end torque. P72 is your best choice, OR, you could use the cheaper P28 with an MSD rpm activated switch for the runners - a slight hack, but works well.

smoothludey2

I'm also getting an MSD Digital-6 and the HVC blaster coil....can i get this MSD to activate the runners or is there something else that does that?

philo

here is an important consideration, doug does all his development for a P28, that means ROM updates come out weeks or months earlier for that ECU.

but the P72 does have a knock sensor which is nice. I decided to go for the knock sensor and wait a while longer for updates, but it's just a matter or personal preference.

The P28 is also way cheaper...

Flamenco-T

isn;t the knock sensor only work up to 5000 rpm, which is kinda useless anyway since most wants to be able to catch it at high boost/higher rpm ?

VaporTrail

Correct. Also, the OEM knock sensor is not nearly aggressive enough to save your motor from detonating under boost. It was designed for old ladies who put the wrong octane in the car, not for a high pressure situation. Yet another reason to get rid of it.

Flamenco-T

exactly, the knock sensor is useless

falcongsr

yeah. pretty much. like Vaportrail said, it just adjusts the fuel trim settings, which changes things over a long period of time. No instant knock retard.

philo

the only detonation i have ever gotten on my setup is in the funny little area between 3200-4000rpm that is pretty easy to tune out with a P-ECU.

i definitely agree that the stock knock sensor is no protection worth speaking of to protect an F/I motor under full load, but neither is a safeguard. i was more thinking of situation where you may have a bad tank of gas.

the only sure way to get rid of detonation is decent tuning. detonation by it's very nature is hard to consistently detect and illiminate with any kind if reactive system (factory knock sensor or J&S).

i had both version of the j&s and even on max sensitivity still heard audible detonation when my timing was advanced too far. i would not recommend buying a safeguard but will swear by my P-ECU.

Jason kiDD

So again just to confirm. P28 is cheaper and has more updates. But what about the open runner thingy? What from MSD is needed to adjust.??

VaporTrail

all that's needed is a MSD rpm activated switch. You can put in pills to adjust the opening point. Really easy to set up and use.

Flamenco-T

it's basically a switch that operates automatically at a preset rpm, just like your shift light, but instead of just flashing a bright light, it'll activated something you set to do, in this case your secondary...and you can buy sets of RPM pills and set it at which RPM you want it to go..

stan

Jason kiDD

Okay that is fine. Then what would be a good RPM to set the secondary runner at. Especially if you changed your Vtec point to somewhere around 4600rpms.?

DLB1994

no one can really tell u that all u got to do is when u got to the dyno to it tune just try diff setting to see where it makes the most low-end power and still keep a clean power band

me my self i took my secondary runners out of my h23 but a h23 got a lot of
low-end power any how so

GruvyTune

what does that detonation feel like to you. I have funny engine coughs at about that too but not in boost just at very low idle in high gear going fast on the highway. I doubt it would be detonation running low throttle no boost. just kinda coughs a bit coming off the throttle after giving a little gas.

torin