radkins

I had a new Pineapple Racing large race port motor put in recently. After tuning I am realizing that I am having a hard time reaching desired boost levels. No matter what the PFC is set for it never really goes over.8-.85 bar, even if the PFC is set to .9-.95 with relative duty cycles. My mods of importance are M2 intake, M2 med IC, DP, MP, Greddy PE exhaust. I was expecting to have a hard time keeping the boost down, but it has turned out to be the opposite. I have done the obvious check for boost leaks/bad vacume hoses. Is this motor so air hungry that the stock twins can't keep up? My secondary appeared to be leaking oil when it was pulled, but has always worked fine. What do YOU think?

skunks

what are you mods? also, you do know that your at the limits of efficiency with stock turbos right?
Lastly, PowerFC sucks at controlling boost, try a after market boost controller or perhaps a manual boost controller to get more boost (although i think your probally gonna pop your engine )

rynberg

First of all, do not rely on the PFC commander for accurate boost readings. It has been proven that it displays the incorrect readings. Do you have an independent boost gauge or are your numbers from the commander?

radkins

My mods are in the 1st message. I have a manual boost guage that peaks at 11-12 and drops to 10 and stays. I seem to think I should be able to hold more than 10lbs steadily. I thought the stockers were good up till 14lbs. Why would I pop my engine trying to run a steady 12-13, or is it cause I have such a big port that the efficiency is lowered as far as lbs go.

SleepR1

Power FC does a GREAT JOB controlling boost for FDs with twin sequential turbos. I don't have problems with mine ('99 JDM twins). No spikes. My "high" boost setting is set to 0.90 kg/cm^2 (13.5 psi) on the primaries, and 0.90 kg/cm^2 (12.8 psi) on the secondaries. Wastegate solenoid duty cycles are 72% and 70%, respectively. Ryan's motor is well enriched with fuel, and has been tuned by Badog of Columbus.

skunks

opps hehe, i forgot about the mods you listed. in anycase, i was thinking your were gonna pop your enigne cuz I'm assuming you want over .85 bar boost=12.5 psi boost and you dont have any fuel mods listed...

SleepR1

Bar, Atmosphere, kg/cm^2 conversion to psi units.

Bar is 14.5 psi. Atmosphere is 14.7 psi. kg/cm^2 is 14.2 psi. 0.85 kg/cm^2 = 12.07 psi, ~12.1 psi. You're confusing Atmosphere, Bar, and kg/cm^2, which is why you converted 0.85 kg/cm^2 incorrectly to 12.5 psi (you multiplied 0.85 kg/cm^2 by 14.7 psi, which is 1 Atmosphere, not 1 kg/cm^2).

Ryan has 1600 cc secondary injectors, upgraded fuel pressure regulator, upgraded fuel pump. If anything Ryan's motor runs a bit on the rich side.

skunks

With those fuel mods, he should be fine, but he did not have them listed. On another note, 14.7 and 14.5 is damn near the same thing (this really does not matter man!).

BTW: Ryan=radkins or rynberg???

SleepR1

radkins is Ryan. 14.2 psi = 1 kg/cm^2. That's different enough from 14.7 psi, which is the number you multiplied by to get 12.5 psi. The correct psi conversion for 0.85 kg/cm^2 is 12.1 psi.

Here's a handy online reference

http://www.onlineconversion.com/pressure.htm