ecarver2

So we tunned it to 12psi and all is fine 11.5 average A/F ratios. we turned it up to 15psi and again we tuned to 11.5 A/F ratios. but @ 15 PSi the car seams to pulse in power a bit. almost like it is missing under WOT. any ideas?

I have a full 3' Exhaust, Greddy FMIC and New ported motor. PFC Ect Ect Ect. stock ignition.

overkill

More than likely you will need to upgrade your ignition. When you start exceeding stock boost levels it is harder for the ignition to ignite all the fuel. Try the HKS Twin Power. I was missing big time up top during a dyno session. Misfiring dissappeared once I installed the HKS TP. Big plus is that you will be extracting all the available HP from the unburnt fuel.

On the dyno, the hp graph was heading to 300rwhp, but with my stock ignition, misfiring made ithe graph plateau to only 280rwhp. I'm almost positive you need an aftermarket ignition.

rynberg

What plugs are you running? Even with the HKS TP, I have some light ignition breakup above 14 psi. I need to switch from NGK 9s to the NGK 10BRIEX, just haven't got around to it.

ecarver2

could it really be the ignition? my buddy has a single and pulles 15+psi on the stock ignition. I beleive he runs 9s for leading and trailing plugs, I am running 7s and 9s like stock.

rynberg

Jeez, you are trying to run 15 psi on 7s leading? Bad idea!

dubulup

you've got a lot to learn...keep reading.

CCarlisi

I believe it is your ignition. I had the same symptoms. When I put it on the dyno the curve got really rough above 14 psi. I installed an HKS twinpower and it completely eliminated the problem. If you install an amp watch your afrs carefully. Mine leaned out significantly at high rpm with the amp. Keep in mind this was an extreme case. Without the amp the motor was really rough at 6000rpms + .

ecarver2

what is the ideal spark plug setup (without running $35 race plugs?)

XSTransAm

i run 9's in all 4 at 17psi with just a jacobs fc 1000.

rynberg

Well, you should try running all 9s first. Then, if that doesn't work, you can move up to the Iridium BR10EIX, which are only $7-8 each. Like I said above.

dubulup

first I've seen these mentioned...interesting

do you need a shallow socket to install these?

gap recommendations? same as any other 10?

rt turbo

yeah, definatly spark blowout. get an HKS twin power ignition. i have the same thing. same power at 15psi as 12psi

rynberg

They work very well...better than the BGVs. Yes, you need a cut-down socket, just like the BGVs. A lot of people have had good success with the default gap (.022 IIRC).

papsmagu

iTrader: (19)

it could also be the distance between the crank angle sensor and the pulley/wheel. the PFC has trouble if the distance from the sensor to the wheel is greater than 2mm. happend to me and caused ing. breakup at higher boost levels. also, the above recommendations of plugs and twin power are ideal.