Exhaust Get Very Loud Under Boost?

[pointblank9957]

Well i've finished my Spyder GS Turbo awhile ago and when i WOT pull from 3000rpm, it gets really loud like the whole tone changes. it does pull good and feels healthy (no jerks) but i just want to make sure i'm not harming my motor.

Injectors: SFI 660cc
Fuel Pump: Walbro 190
Turbo: Evo 3 16G
Boost Level: 12psi
Exhaust: full 3"
Intake: Custom snorkel and 2.5" FMIC
Engine Management: Black Box w/ ECUFlash

 

[Dsmkauai]

Check the exhaust for leaks, holes or bad gasket. It's probably a leak that is just more present in higher boost because of the added airflow.

 

[bo0st]

Try taking off the cat and see how much louder it can be You're probably fine dude.

 

[pointblank9957]

Try taking off the cat and see how much louder it can be You're probably fine dude.

you get what i'm sayin though right? . its quiet under vacuum, when it hits boost it turns into a completely different animal

No cat btw. i live in MI, no emissions

 

[Dsmkauai]

You don't have a open dump o2 housing by chance do you?

 

[norcalboostin707]

Do you have any cracks in the manifold.. You can easily.find holes in the exhaust system just keep your eye out for sooty areas like carbon build up from the exhaust escaping

 

[slickers111]

+1 on the O2 dump.

I have a catless 3" turbo back. Mine also gets angry like that while boosting. Always has. Just imagine the car saying "LETS GOOOOOOOOOOO"

 

[CellerDweller]

Hey, I see you are not too far from me. I am in Houghton, the frozen arsehole of the world.

I have a 3" SRS catback with a 3" DP (cat delete) and mine is loud as hell too under boost. Have to take off really slowly when cops are next to you! Even cruising there's a constant drone, I just turn up the radio!

 

[gsexxx]

Check for exhaust leaks. If you rule out your manifold and o2 housing (assuming you don't have an open dump), put a rag in the muffler to stop exhaust exiting out the end of the exhaust and check for leaks in the downpipe/flex section/exhaust/flanges. Don't do it for too long because you will be building pressure in the exhaust.

 

[Ghost_92TSi]

Maybe a crack by the o2 sensor? Kind of like an unintentional open dump. Is it louder in the front or louder in the back? If its the back maybe its the muffler design trying to flow the added air.

 

[black_gst]

this might apply, but i used to have a cheapo Apexi N1 style knock off exhaust, it was on the car when i bought it, but the muffler was a 4 or 5" outlet but it had internal baffles down to like 2" diameter and when i would run over 20PSi of boost it sounded like a jet plan taking off, all that air was rushing through the exhaust, it actually affected how much timing i could run because it was causing high back pressure, since your exhaust is likely designed for a non turbo car this could be a problem for you

 

[airmail96]

Bro your fine its just the internal wastegate opening up once you hit your targeted boost, your increasing your exhaust flow therefore increasing noise making the old girl sound like shes ready to rip some heads off.

 

[pointblank9957]

You don't have a open dump o2 housing by chance do you?

no i do not

this might apply, but i used to have a cheapo Apexi N1 style knock off exhaust, it was on the car when i bought it, but the muffler was a 4 or 5" outlet but it had internal baffles down to like 2" diameter and when i would run over 20PSi of boost it sounded like a jet plan taking off, all that air was rushing through the exhaust, it actually affected how much timing i could run because it was causing high back pressure, since your exhaust is likely designed for a non turbo car this could be a problem for you

at the time i was just running a 3" DP loud as hell but sounds amazing. i don't think 3" systems are for NA cars, 3" is as big as most people bother going.

Maybe a crack by the o2 sensor? Kind of like an unintentional open dump. Is it louder in the front or louder in the back? If its the back maybe its the muffler design trying to flow the added air.

louder out the end of the exhaust