I took our GXP to the track last night. I wanted to see if it could get the 14 sec qtr like GM says. Well here it is.... It was a mild sticky night in Donaldsonville, LA. very high humidity about 68-70 degrees. The car has exactly 505 miles on it when I arrived there. I let the turbo cool down for about an hour and then I lined up. I left very soft because the car is so new. I just punched it from a dead ,no boost no rev. The car was so smooth and well behaved no wheel spin or any problems. She ran a 14.60 at 93 miles per hour. I only did 1 run cause it's my wife ALPHA 1's car and she said she would seriously divorce me if I muffed it up. Next time I am going to spool it up with a little power breaking and see if it can achieve the GM numbers. The only thing that I found wierd is that the turbo under boost squeals like a banshee. I know it is probably the blow off valve but man is it loud. It happens about 14psi and doesn't quit until you lift the pedal. Is it supposed to be that loud. It sounds like a constant bleed not a shoosh sound. At the track everyone was like we could see the car and about half track all you could hear was the wheeeeee..... sound. I said it was because the car was having fun but then I explained it was a turbo 4 cyl and it was the blow off valve. I guess what I am asking is if the VERY loud blow off valve is normal or do I have an issue.WILL SOME OF YOU OTHER GXP OWNERS RESPOND??
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2007 Pontiac Solstice Auto SLY GXP 2006 Nissan 350z
Location: Rosamond, CA - Home of Willow Springs Raceway
It's not the blow off valve. You MIGHT hear a whoosh of air from the blow off valve between shifts or if you let off the gas quickly. That squeal is the turbo spinning up. Nothing wonrg there.
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2007 Cool GXP with Darkside Top, 5 spd, Ebony Cloth, Monsoon with Single CD, Sport Pedals, XM, A/C
Mods - Solo Street/Race Exhaust, K&N Drop-in Air Filter, EDAL
Location: Wilds of Canada, or the Pac NW, or the Upper Penninsula of MI...
Quote:
Originally Posted by sidewayz2
I took our GXP to the track last night. I wanted to see if it could get the 14 sec qtr like GM says. Well here it is.... It was a mild sticky night in Donaldsonville, LA. very high humidity about 68-70 degrees. The car has exactly 505 miles on it when I arrived there. I let the turbo cool down for about an hour and then I lined up. I left very soft because the car is so new. I just punched it from a dead ,no boost no rev. The car was so smooth and well behaved no wheel spin or any problems. She ran a 14.60 at 93 miles per hour. I only did 1 run cause it's my wife ALPHA 1's car and she said she would seriously divorce me if I muffed it up. Next time I am going to spool it up with a little power breaking and see if it can achieve the GM numbers. The only thing that I found wierd is that the turbo under boost squeals like a banshee. I know it is probably the blow off valve but man is it loud. It happens about 14psi and doesn't quit until you lift the pedal. Is it supposed to be that loud. It sounds like a constant bleed not a shoosh sound. At the track everyone was like we could see the car and about half track all you could hear was the wheeeeee..... sound. I said it was because the car was having fun but then I explained it was a turbo 4 cyl and it was the blow off valve. I guess what I am asking is if the VERY loud blow off valve is normal or do I have an issue.WILL SOME OF YOU OTHER GXP OWNERS RESPOND??
If your turbo makes a "fweeeee!" noise under boost, you have an airleak somewhere in the system. (sounds similar to blowing on a blade of grass between your thumbs). Get it back to the dealer and have them check all of the intake system attachments including the attachments to the intercooler. Tell them NOT TO OVERTORQUE the attachments, but make sure they are all correctly assembled.
The noise you describe is not normal, and could explain some of the subpar performance.
The other question is: did you do this with traction control on or off?
Location: Rosamond, CA - Home of Willow Springs Raceway
SM, he said he didn't go all out. And since loud is subjective, he may not like the sound of the turbo whine or may think it's too loud.
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2007 Cool GXP with Darkside Top, 5 spd, Ebony Cloth, Monsoon with Single CD, Sport Pedals, XM, A/C
Mods - Solo Street/Race Exhaust, K&N Drop-in Air Filter, EDAL
Sideways mentions "man is it loud"(out of context). Nothing I've ever heard from mine would ever be construed as man was that loud. I hear the woosh (love it) but never loud. Sounds like SMan has something here. Definitely not routine, do check it out.
So you think it is leaking boost? The boost guage is reading full boost and it definatly pulls hard. It is an auto so there is no change in sound because I don't have to shift gears.
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2007 Pontiac Solstice Auto SLY GXP 2006 Nissan 350z
If your turbo makes a "fweeeee!" noise under boost, you have an airleak somewhere in the system. (sounds similar to blowing on a blade of grass between your thumbs). Get it back to the dealer and have them check all of the intake system attachments including the attachments to the intercooler. Tell them NOT TO OVERTORQUE the attachments, but make sure they are all correctly assembled.
The noise you describe is not normal, and could explain some of the subpar performance.
The other question is: did you do this with traction control on or off?
Boost leaks are never that loud, as a dsm owner i've had plenty of them and at best they're audible inside the car but thats it. You'd had to have a pretty large hole somewhere to make that much noise, but then there'd be no way he would run a 14.6@93mph while loosing so much air. The car would loose power and probably get spanked by a civic but thats it.
Im glad that the turbo is this loud, with a metal intake pipe and a cone filter it'll get even louder... music to my ears
Quote:
Originally Posted by RODEO
Q) Is the GXP using a BOV or a bypass valve? I had assumed it would be a bypass valve for some reason.....
Bypass valve, blow off valve, its basically the same thing.
Cool I just wanted to be sure about the sound. I do like it now though. Also I saw that auto cross track at no problem and I think they race on sat. ? Thanks for the responses.
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2007 Pontiac Solstice Auto SLY GXP 2006 Nissan 350z
thanks! They may be similar, but I don't care for the venting to atmosphere noise of the BOV.
Its not venting to the atmosphere, that would be a noise violation with the local cops if they ever catch you. It gets vented back into the intake just like any other oem turbo setup. You might hear it during shifts but its not as audible as venting it to the atmosphere.
Its not venting to the atmosphere, that would be a noise violation with the local cops if they ever catch you. It gets vented back into the intake just like any other oem turbo setup. You might hear it during shifts but its not as audible as venting it to the atmosphere.
I'm pretty sure we're talking about the same thing. The BPV recirculates, that I know. The BOV vents to the atmosphere. My MSM is a BPV, and I've driven the Hahn turbo that has a BOV, and I didn't care for the venting noise. I'm glad to hear the GXP has a recirculating BPV.
I didn't know what I think you're inferring, that oem turbos are always BPV.
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All of the animals except for man know that the principle business of life is to enjoy it.-- Samuel Butler
You can find me at the lake -- RODEOSOLSTICE @ YAHOO.COM
All this talk about the various possible ways of turbo venting are Greek to me. What isn't is the presence (or absence) of sound. What has been described in the original post is not normal. I have 2500 miles on mine now, and make regular red-line runs through the gears (quite sweet, BTW ). Under full throttle acceleration you can barely here any turbo whine. When I shift gears, you can hear just a little "whistle" from the BOV. As has been mentioned in other posts, the car is spooky quiet. Other than the very slight BOV whistle at shift points, all but the highly initiated wouldn't have a clue this car is turbo charged. I've driven a few other turbo charged cars, and this one has, by far, the most quiet engine I've been in. Suggest you get your car to the dealer ASAP.....
__________________ Yes,actually, I am driving that Deep GXP!!!!!
This car is loud. It is a loud wheeee sound that will turn your head or scare someone when you pass them at speed. It was there from day one. I let the dealer drive the car when we picked it up and it made the loud squeal for him. I don't think this is normal but it does not seem to affect the performance. I will bring it to the dealer but being the first one in town I know they have not seen this car. Any one else have this situation?
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2007 Pontiac Solstice Auto SLY GXP 2006 Nissan 350z
