accuracy of autometer boost gauge

[mhrallyteam]

My boost gauge reads 7psi max when i drive hard. My turbo is good so i wondered if the gauge had a big error %. The zero mark is quite large and the needle sits at the bottom of that mark.

anybody else had accuracy problem w/ those

I don't want to run 14psi when i think its 12psi

[QuickDrive]

Bad accuracy problems, I think anyway....

Try vrg's scantool and a buddy with a laptop.

That's how I set my MBC, now the boost gauge is just there for "Just in case"

[vrg3]

I've personally seen two OBX boost gauges come very poorly calibrated from the factory. Those were the only two OBX gauges I've seen.

If your boost control solenoid is malfunctioning, or if the ECU has decided to limit boost, you'll only get wastegate-controlled boost, which is somewhere between 5 and 7 psi. So that could be what's happening too.

[georryan]

My gauge jumps around. It will stick at 7 usually after I have a good run were it will jump from 10-12. hehe

Normally when everything is correct it will run at 9 to 9.5 psi. I need a manual boost gauge. I've cleaned my boost control solenoid twice and it doesn't seem to help.

-Ryan

[BAC5.2]

My Phantom seems to be right on...

[mhrallyteam]

If the ecu decide to limit boost wont it show a cel. I never rode in another leg turbo, but i think mine is already pulling hard. IT sure feels like at least stock 160hp.

I will cheat the wastegate with my cheap mbc, just to see what it does.

[morgie]

My stock Leg T was boosting 5psi max on hard acceleration.

absolutely no idea why, i replaced the solenoid with a MBC.

[mikec]

I had a looonnnggg time (almost a year) of only 5psi. Never got a CEL for it, and actually thought it was my gauge until I used vrg3's Scantool.

Discovered I wasn't doing the clear memory procedure properly (the one where you drive around until the CEL flashes every half second).

[vrg3]

I'm not 100% certain about it, but I do believe the ECU limits boost when it detects excessive pinging, and this action does not result in a trouble code.

[mhrallyteam]

I would be surprised to have any pinging at all, the knock sensor must be acting up. I'll reset the ecu and try it again. I'll keep you in touch

Wondering: if i plug the pressure line directly into the wastegate actuator what psi would a get. the failsafe 5psi or more?

[vrg3]

You mean if you connect the nipple on the compressor housing straight to the nipple on the wastegate actuator? Yes, you'd get 5ish-7ish psi.

[mhrallyteam]

I'll try that with a needle valve in between, will i get a cel from the wastegate solenoid if it does see any air

And i tought my engine was already pulling strong....silly me

[vrg3]

What do you expect to happen with the needle valve?

Be careful... you definitely don't want to end up blocking the pressure signal to the actuator.

The ECU won't throw a CEL for the wastegate solenoid unless the solenoid is electrically not present. So if you leave it connected to the electrical harness you can do whatever you want with its vacuum connections.

[mTk]

my autometer gauge is dead on. It is liquid filled.. so i have to vent it when the tyemperature changes more than 10 degrees or so, but it works great.

On the dyno it was reading just under 10psi, the dyno's boost gauge read 9.3psi steady.


MK

[mhrallyteam]

I tried the direct path to the wastegate w/ the needle valve to bleed the pressure signal. I read 9 psi steady now with a small bleed from the valve.

It's has far as i will go without my intercooler installed.(Ok, i admit, i tried at 11psi just to see, good power, crappy crappy gas mileage )