DIY Intake + Foil Delete - Now strange noise during shifts

[southern7.3]

I dont think im gettin surge because ive seen some vids with people getting surge but after I installed my diy I can get on it hard and let off and it will make a sound like shhiiiuunn (say sheeee on the eee's get higher and then un kinda like nun w/o the first n) just like right after I release then it goes away and sounds normal. just noticed it when I installed the diy intake is that just the air being sucked or what??


Its kinda funny to see all of us tryin to make noises thru typin

[dieselcrawler]

Originally Posted by southern7.3

Its kinda funny to see all of us tryin to make noises thru typin

I have a hard enough time replicating noises in person, on top of that, I'm a terrible speller, so when I try to do it with a keyboard, look out! LOL Think we all might be in the same boat!

[Ditty]

OK...here are the sounds and what it is:

ONE big WHOOSH or PIISHTTT when letting off the pedel under load = Is the excess pressurized air....and totally normal

Anything like WEEEEEEEEE (high pitched) = normal. Let that turbo sing!!!

MULTIPLE and VERY fast WHOOSHes or PIISHTTT's = Compressor Surge or Stall. This is NOT good. Fix is either Wicked Wheel and ATS housing or an aftermarket turbo.

Anything like a CLUNK CLUNK CLUNK or metalic sounding = BAD!!! Go get a new turbo

------------

To kill a few myths/wrong thoughts:

Wastegates are on the exhaust side of the turbo...they re-route the exhaust gasses around the exhaust wheel so that it isn't spinning as fast, therefore, less boost. Deleting the WG CAN cause over boosting and toasting your turbo if you are not careful. :SHIFAN: (I do not have a WG anymore.)

Blow off Valves or BOVs are on the intake side of the turbo...after the compressor and before the THROTTLE plate. (Diesel's do not have a throttle plate.) They operate on vacuum on the opposite side of the throttle plate. When the plate closes, it creates a vacuum between the cylinder and the plate, this vacuum is read by the BOV and the BOV opens, releasing the excess boost pressure on the pressurized side of the plate. This stops the turbo compressor from having to try and slowdown to vent the pressure, keeping shaft speed up and allowing boost to be made immediately when the throttle plate is opened again.

These are not technical definitions, these are personnal explainations of how I understand the workings of turboed engines.

[southern7.3]

sweeeet im in the clear lol thanks ditty

[dieselcrawler]

Ditty, great job, thanks for the discriptions... but need one thing cleared up... our trucks do or don't have a blow off valve? You stated that we don't have throttle plates, but in your discription, it seems the throttle plate is needed for there to be a blow off valve, and that, my friend, is where I get lost... the sound we are all hearing, the 'whoosh', the un-needed, compressed air, as it is released. It would make sence to me that there IS a blow off valve, when used, releases the air, and "whoosh", we hear it... and the throttle plates are only in gas motors.

Sorry if I"m splitin' hairs, but... as I said earlier, still learnin'... thanks again for your knowlage in this area...

[Ditty]

There is not a BOV on diesels. The WHOOSH is just the air escaping through the turbo...at least as well as I can tell. I don't really know how to explain it correctly...maybe one of the other guys can.

[rookie_j]

thanks for the info everyone.

[Lord Tauk]

That pretty much works.

So basically what the deal is what you hear you did not create, it's always been there.

[psychomoto]

contrair mofrair.i have a lot of experience with the noises .....i have a stock 2000 psd and put an 18k diffuser box in..... basically a trick that tells the injectors to flow 150% at 100% throttle or to flow 50% at 10% throttle etc.,no real noticeable difference.then removed red vac hose from turbo! boom lots of extra balls and neat noises.1st noise is under load.light p phishhhhhphish phish.determined that the turbo is still spooling but as truck shifts the extra boost that magically appeared when the fuel pressure went up is simply no longer going in the right direction .or spitting out around the wheel.i dont see a problem with this.after these simple mods i built a nice big unrestrictive filter set up and took the turbo off to see how i could get more boost.dtermined that exhaust valve needed to be a lot harder to open.fixed accordingly and reinstalled.then started messing with the resisters in the dfuser box.(bypassing different ones and fount a setting that with the added boost and huge increase in fuel delivery will cook the rear tires on my dually while completely blocking out all rear vision.....very kool. but with the good comes the bad and surge kicked in in a bad way.basically had to put a throttle switch activator on the module cause if it stayed on once the pedal was released it wouldnt rev down.just sat there and chattered at about 2800 rpm.this is surge and is not good .cutting the module immediately when you let off the gas helps surge dissipate rapidly.now the really bad sound .if truck is goosed from 0 to about 30 or so then released from wot i get the whoosh and pphishh and belt squeeling sound all at once.popped hood/took off intake boot to turbo/punched it real quick then released throttle at high power setting and in about 2 seconds went from idle to 3200 rpm /boost pegged almost immediately then upon throttle release turbo fan immediatly and violently stopped and went in reversedue to the massive pressure build up slamming back out the intake.very bad but can be dealt with by simply not instantly releasing the throttle just to hear the kool noises it makes.......
disclaimer.these mods (by my estimate ) are puttin at least 150 hp to the ground on my truck but are not endorsed or recommended by me for use by anyone who pays someone else to work on their truck as they are as cheap and effective aas they are destructive.
so if you hear the belt slip sound when you let off .you have gone too far with the redneck engeneering and need to back it up and do it right.
on the other hand if you love a greasy night under your rig then have at it and ill help if i can................

[Sarasota]

that's a lot of jargin - but again, how is it that simply changing the filter "causes" this noise / occurance????? it's my opinion that the stock airbox muffled the noise - now that the stock airbox is gone and a free-flowing system is in place, you can hear the noise