Making boost at 60 mph at around 2000 rpm????

[20psiofevil]

What is it when youre making boost at cruise?

 

[EVIL]

It might be those square wheels and tires you Canadians use.

Now I'm hooked.
Can't wait to see what is causing this.

D

 

[Rafs-T-Type]

I'd sure like to see another boost gauge on it. My turbo makes whistlely noises even when still in vacuum. Me thinks the boost gauge is kaput. There's gotta be a way to test it, no? Something involving an air regulator and a compressor.

 

[gn_steve]

I will find a known good boost gauge and try it!


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[BOP4ever]

Id think it would be running hot if it truly is running positive boost all the time.

 

[EVIL]

Do you have a fuel pressure gauge?

If the boost is up and FP is still normal odds are it the gauge.

Either that or you have a worse problem..

D

 

[RmvBfrFlght]

At key-on, engine-off, does the boost gauge read 0? If so I'd say that it is building some boost on the highway.

On my car the turbo can create more flow then the engine can ingest. During normal driving when lifting to hold a steady speed the horse sneeze will occur. Yet the intake manifold pressure was never above barometric pressure. IOW, it wasn't in boost but the turbo was spooling.

RemoveBeforeFlight

 

[PSID6]

Its always in boost the turbo make that wistling noise so i know its in boos!


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Well here's my question... If it's making 3 to 5 lbs of boost at a steady 60 mph @ 2000 does the boost gauge drop to zero,when you take your foot of the gas? Just a suggestion..... I would change your gauge regardless,because knowing what your engine pulls for vacuum is just as important as boost. I would also inspect the intercooler,pipes etc. for any restrictions.

 

[Scarab]

also what exhaust do you have, is the muffler bad? or do you run a cat? if so a restriction could cause this to. But do check the gauge.

 

[TurboTnZ06]

I was cruising at lunch, I agree, maybe the muffler broke internally, could be a flow issue. Boost is just a measure of a restriction.

 

[Chuck Leeper]

Me thinks the boost gauge is kaput. There's gotta be a way to test it, no? Something involving an air regulator and a compressor.

Powerlog it, and look at the MAP reading vs the gauge??
I have a small gauge/regulator that goes down the about 5psi. I use that for such deals.

 

[No disintegrations]

I was cruising at lunch, I agree, maybe the muffler broke internally, could be a flow issue. Boost is just a measure of a restriction.

A poor flowing muffler doesn't add boost.

 

[Chuck Leeper]

A poor flowing muffler doesn't add boost.

Huh??

 

[TurboTnZ06]

My Buick has run 10's on 17-18 psi at 125 mph. Since then I have ported the heads and probably could run low 10's at that boost level. Boost measures the restriction in the setup. To chug at 60 mph, at 3 psi boost, means, air can't get through the engine, maybe the muffler is clogged enough such that to make enough power, it has to run more boost.

 

[Gene Van Horn]

The car should not be boosting cruising down the hiway. Check all your vacumn hoses, make sure all you intercooler pipes and clamps are tight, do the obvious first. Should not boost or whistle or sneeze or cough or anything like that with your foot barely on the gas at cruising speed. Zip tie everything,

 

[Scarab]

A poor flowing muffler doesn't add boost.

no it doesn't add boost but will make the engine create boost to keep the speed up as the muffler cant flow. May not be the case here but a restriction will cause boost as well as dragging brakes.

 

[No disintegrations]

The op has a nice car, its not likely for the car to have rotted out nasty clogged mufflers.

 

[Jerryl]

OP,
Do you recall what is the L8 (aka LV8) number is when it goes into boost?

What is the AFR or NB at when this happens?

 

[Scarab]

The op has a nice car, its not likely for the car to have rotted out nasty clogged mufflers.

Doesn't have to be rotted out, could be just coming apart inside, or the cat could be clogged if he has one. Car can be top notch but still have hidden problems. I also think the brakes could be doing it. But I would check the exhaust after I tried another gauge.

 

[TurboDave]

I would try another gauge. A compound vacuum/boost gauge is always best. Seeing what kind of vacuum is being pulled at idle can tell a lot..