DIY Intake + Foil Delete - Now strange noise during shifts

[rookie_j]

correct me if I am wrong. but are we talking about two totally different things here.

D-man is talking about turbo surge.

the sound i hear on my truck is the waste gate opening and dumping pressure.

[Sarasota]

so that has always occured but I just haven't been able to hear it?

[dieselcrawler]

how does turbo surge compair to what we're talking about, the wastegate blow-off? Is the sound simular, or.....? I'm (obviously) not farmiliar with turbo surge.... and what it does, how it sounds, etc... still learnin'...

[rookie_j]

Originally Posted by Sarasota

so that has always occured but I just haven't been able to hear it?

i didn't notice it until i did the intake, then again maybe i wasn't paying attention to it?

i can hear the whine of the turbo better after the exhaust too.

Originally Posted by dieselcrawler

how it sounds, etc... still learnin'...

x2

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Last edited by rookie_j : 10-24-2007 at 01:06 PM.

[D-man]

Originally Posted by dieselcrawler

how does turbo surge compair to what we're talking about, the wastegate blow-off? Is the sound simular, or.....? I'm (obviously) not farmiliar with turbo surge.... and what it does, how it sounds, etc... still learnin'...

I'm not sure what is being heard without hearing it myself but I do know that almost everyone that does an aftermarket intake with a 7.3 experiences turbo surge. It is more of a "pht pht pht" barking than a constant blowing noise.
It is when you are building so much boost and then the truck shifts and the rpm's drop, the truck can no longer use the boost it has built and then it blows back through the intake. It actually stops the compressor wheel violently fast. You may also notice it when pulling a load up a long hill, it will continually do it throughout the pull. Very hard on the turbo.
I 'm not sure if this is what is being experienced.

[Sarasota]

Originally Posted by D-man

I'm not sure what is being heard without hearing it myself but I do know that almost everyone that does an aftermarket intake with a 7.3 experiences turbo surge. It is more of a "pht pht pht" barking than a constant blowing noise.
It is when you are building so much boost and then the truck shifts and the rpm's drop, the truck can no longer use the boost it has built and then it blows back through the intake. It actually stops the compressor wheel violently fast. You may also notice it when pulling a load up a long hill, it will continually do it throughout the pull. Very hard on the turbo.
I 'm not sure if this is what is being experienced.

Believe me, I'm not questioning your intelligence cause I'm as dumb as they come about this stuff BUT, if you're pulling, won't the RPM's remain constant? Seems logical if the RPM's drop that it could be blown back out of the intake but if your RPM's are high and remain high, how can it blow backward? And why does an aftermarket intake cause this - there can't be THAT much difference b/w stock and aftermarket filter-resistance?

[D-man]

Originally Posted by Sarasota

Believe me, I'm not questioning your intelligence cause I'm as dumb as they come about this stuff BUT, if you're pulling, won't the RPM's remain constant? Seems logical if the RPM's drop that it could be blown back out of the intake but if your RPM's are high and remain high, how can it blow backward? And why does an aftermarket intake cause this - there can't be THAT much difference b/w stock and aftermarket filter-resistance?

Well, my intelligence only goes as far as what I learned from others on this forum, other forums and talking to others I know that have PSD's.
I got surge when I installed my AFE stage II. It surged only when it shifted under heavy throttle. Others I have spoke to, also experienced it while pulling a load. I never pulled a load with my truck after the AFE install. This, I am told, is where it get's really hard on the turbo. I was told under certain pulling conditions, it will continually keep doing it. I can't give any more details on the pulling instances because I didn't experience it myself. I was just told about it. Do some more research and ask around. Someone else might chime in and be able to give you more information than what I have
But, if you are experiencing what you think is "turbo surge" I would look cautiously at it before just dismissing it as a "cool" sound.

[Lord Tauk]

Turbo surge sounds more like a rattle snake, IMO.

If you hear the constant whistle as you are applying load/throttle, then after TQ lockup and 4th gear (OD) you hear a slight whistle but more of a "shhhhhh" constant sound, that's normal. You're in OD, less RPMs, less load, less whatever it takes to maintain the same MPH. The noise when letting out of the throttle under load is normal, air will find the least resistance way out, and the only way out for some of it is back through the intake. The compressor wheel cannot physically turn the other way unless you have a big time mechanical failure, how could it? It's constantly spining in one direction with the exhaust gas being the driving force.

PSDs don't have anything to necessitate a blow off valve for the turbo, ie throttle plates. I also don't think you can hear our wastegates in our PSDs, not sure how accurate that is though. Mine makes the same amount of sounds with or without the red wastegate hose connected.

Without knowing how fast you're driving;
Leave overdrive off at the speeds you think are weird, you'll still have the converter locking up but you will have more RPMs at the same MPH, and more of a "load" obviously.. plus the turbo will be spooled a little higher.

Dont know how correct all this was, but I usually leave OD off when I'm under 50MPH, the turbo is always spooled around 4-5PSI, plus all you hear is whistle coming at you whereas if I was cruising around in OD, you wouldn't hear the turbo as much incab as explained why. Plus with the straight pipe, it's cool to leave it in 3rd with those higher RPMs, noise! I usually race the PSD with Overdrive off as well.

So what you are hearing IMO has always been there, you have just eliminated the sound dampening. You haven't created any new sounds, you can just hear them better now with less restriction.

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Last edited by Lord Tauk : 10-24-2007 at 03:15 PM.

[Sarasota]

Originally Posted by Lord Tauk

So what you are hearing IMO has always been there, you have just eliminated the sound dampening. You haven't created any new sounds, you can just hear them better now with less restriction.

I agree - thanks for sharing your wisdom

[miron42069]

mine has been making some weird sound after i did the DIY intake. when it shifts and the RPM's drop its like a bazzzzz zzzzzz zzz somthing like that lol. its kinda hard to describe
.