VaMP

I wrote Auto Meter about it, and here's what they replied:
"
Hello.

I submitted your question to the OEM division and this is the answer that I received. I hope this helps.

This gauge moves its pointer
to a position indicated by a PWM signal which we receive from the GM instrument control unit. If that PWM signal does not indicate that the car is undergoing more than 12.5 PSI then the gauge will never go above 12.5PSI. We test our gauges to go to the full Vac limit and full boost limit, but if the GM control unit does not tell us to go to these extreme regions then the gauge will not go there.


Thank you.
Cory
Tech/Service
"
So someone needs to work up the ***** to toy with the instrument control unit
Just thought I'd share

clownhair

or just hook up a mechanical boost guage, problem solved.

turboeco

iTrader: (1)

Yep, took me two seconds today to throw my autometer mechanical guage on. Worked perfectly fine.

codyss

I would go with one of the Auto Meter Cobalt series gauges.

To bad the matching boost gauge is neat though.

selfinfliction

does autometer make one that looks the same that is mechanical?


why in the hell would they make an electronic boost guage if it's going to be all fubar'd like that?


anyone got a "how to" on switching them out?

VaMP

I'm not going to replace it with a mech one if it doesn't match the rest of my dash.

Shermen

do you really need to know how to install it, if you need instructions on how to install a replacement boost gage then you do not need to be modding your car. my lil sister could install a boost gage

selfinfliction

i didn't know lol.. i never switched out guages before

skoshi130

Since you guys are swapping out gauges(mechanical), Are you boosting more than 10-12.5psi? Are they boosting more than what the computer is sending out

VaMP

Does Auto meter make a gauge that looks just like our OEM one that is mechanical?

Saki XL

No need to flame, Shermen. I'm pretty sure there are plenty of people who have never had to swap boost gauges that know a few things about cars.

Weren't you also the one who claimed you had an SS all sorts of super modified back in January???



//Saki XL

codyss

Why not take the OEM gauge apart and remove the face.

Then use it on a mechanical gauge.

phxSS

Yea, good question. Has anyone swapped to a mech gage see any boost difference? More, less?

2K2CamaroSS

Couldn't you just use an AutoMeter sending unit(MAP sensor) and hook that up directly to the electric stock gauge??? That's the way my autometer cobalt series is for my camaro.

Anyone have pics of the back of the stock gauge?

DanM

I don't think that will work. AFAIK AutoMeter electronic gauges are usually just analog voltage controlled (like 0-5V from a pressure sensor they give you). This gauge uses PWM, so unless you can find a sending unit that sends PWM, it won't work.

Am I missing something here? Why does everyone want to replace the gauge in the first place? Has someone demonstrated that the stock one is inaccurate?? (and no, the fact that you don't see 12psi all the time does NOT prove that it's inaccurate. we've been over this on this forum 50 million times, you will NOT always see exactly 12psi all the time)

SS4ME

I have witnessed my stock gauge boosting to near 12.5 on several occasions. Only when I add octane boost though. Without it hovers between 11-12psi. I LOVE BOOST!!

carbombss

some of us like me r running smaller pulleys and r supposed to b runnin 14lbs and our gauges will not go past 12.5

DanM

The gauge should go higher than that. The gauge should be good up to around 14. If you're only seeing 12.5, it's probably because you're only making 12.5.

selfinfliction

some of us didn't read the first post in this thread

DanM

Eh? I read it. All the AutoMeter guy said was that the gauge does what the ECM tells it to do.

VaMP

The control unit is capped at 12.5psi even when you're at 14psi, then the boost will only read 12.5.... that was the point of this thread bud....

DanM

I'm sorry but I guess I missed where that came from, "bud". Who says it's capped at 12.5?

The guy from AutoMeter says "If that PWM signal does not indicate that the car is undergoing more than 12.5 PSI then the gauge will never go above 12.5PSI."....

He did not say the ECM could not read above 12.5psi. He only said that the gauge will display whatever the ECM reports. For that matter, the stock MAP sensor is rated for 2-bar, so it should be good up to or very close to 14.7psi.

Further, if what you are saying were true, that means the stock sensor is literally 100% maxed out with zero error margin. If you know anything aboute automotive electronics, you know this is not the case.

I suggest that if you only ever see 12.5psi on the gauge, that's probably because you're only making 12.5psi.

selfinfliction

wah wah wah................


yet i doubt you are correct

VaMP

Some people have changed out the pulley system with a smaller one and are still only getting 12.5 psi of boost when they should be at 14.7

DanM

A 3.25"? Or all the way down to a 2.8? And what (roughly) were they seeing before and after? Again you gotta remember that boost isn't absolute. You could go to a 3.25" that "in theory" should give you 2 lbs more, but get a hot day out, right conditions, it may REALLY only be 12.5. That's all I'm saying. Some ppl with stock cars don't see more than 10psi in most conditions... nothing's wrong, the gauge isn;t inaccurate, that's just how pressure works....

I know if you throw a 2.8"er on there, the stock gauge will top out for sure. But if you're talking only one size down, I bet the stock gauge is fine. It'd be a shame to fork out for a mech gauge to have it show 12.5 too... that's all I'm sayin.