Brentis

I just installed my used pfc and would like to know your thoughts on adjusting the boost up "just a little bit more" to 13 psi.

From SR it comes with a 10 psi & 12psi setting and I know other ecu's are jacked up to 16psi (Pettit Unlimited).

My car is not a daily driver, so I am not worried about "un-appreciated" wear & tear, but I also don't want my motor to pop anytime soon.

I appreciate everyone's insight!

1994 rx7 20k orig miles
cb, hiflow cat, dp, modified k&n airbox, greddy smic, 2piece pipe kit, pfc

Brentis

no thoughts?

TwinTriangles

Dude goto a dyno, dont up your boost until you know what your AFRs are, you cant just pop in a used pretuned PFC drive around the block then decide you want more boost...

cewrx7r1

iTrader: (2)

The mods are basically stock: DP and hiflow.
What engine mods were the PFC originally programmed for?

Adjust for 12PSI boost with a friend riding with you.
Make a couple of 4th gear runs and have him monitor knock reading. Do not go over 40. If all is well, do 2 more runs and have him monitor the stock O2 sensor voltage. Do not continue if it is below .88v.

I do not think you should go higher until you get an IC upgrade! What injector duty cycle are you running at 12psi?

Brentis

Thanks. - I got a greddy IC in the stock location. The mods that the previous owner was configured for were a SMIC, CB, High flow cat, and intake. All of which I have except I have the k&n stock intake modified w/ ducting.. (prior to the pfc I would boost pretty high and didn't drive the car hard due to the mods.


As far as the boost settings from SR they came as follows:

1. pr. .80 kg/cm 52%
sc. .75 kg/cm 60%

2. pr. .90 kg/cm 62%
sc. .80 kg/cm 70%

After just taking out for a spin - at no time could I boost higher than .69-.70 (~10 psi), regardless if I was on setting 1 or 2

suggestions? I know some dyno time is in the cards, but what would keep the boost from going over 10psi

twokrx7

iTrader: (1)

You have to adjust the % duty cycle for the corresponding boost setting until the car achieves the desired boost response. Did you not get an instruction manual for the PFC?

Brentis

I did get the paper thing that came with the pfc - I suppose one could call it a manual - but typically manuals are helpful - .

The manual says to change the base duty setting when modifying the boost setting. Doesn't provide a reason or correlation.

So if I change the boost setting - it has no impact? I simply change the base duty to achieve the boost numbers I want? Could you explain the correlation?

Thansk for your patience & help!

books

iTrader: (8)

sent you a pm regarding this topic...did some searching on boost control yesterday

Brentis

Ok - so now I'm getting frusterated... I just took my car for another spin after reading what Books had sent.

I upped my base duty %ages to .66 & .76 (previously .64 & .72) with my pri being .90 and sec .85.

At no time did my boost exceed .71!?!?! What gives?
I haven't seen folks with duty cycles this high - should I still move upwards?

My injector %age peaked at 82% and my knock never exceeded 30.

Thanks!

books

iTrader: (8)

just rereading what I had sent you....noticed spyfish had his set at mid 80s for 13 lbs....just making an observation

redbase

I have my PFC set on the first base setting .75 pri and .8 sec with duty cycle base setting and have seen my boost at .92! I have a friend in MS who can only make .82 on second base setting and has most of the same upgrades as I. Intake temps do play a role in boost. I didn't boost at .92 until intake temps were 17C. As intake temps and humidity go up, boost goes down.

Brentis

found it - boost leak - thought it was a little weird that right at 10psi I was loosing boost. Anyway, I think wade or scuderini website had it nailed in the boost leak order. First - check the turbo to IC coupler.....

Oh yeah 12.5 psi is *much* better than 10psi. Feels like a good 30 horsepower. Injector readings are at 86%, fwiw...

Starting to feel like my old mkiv...