2G Turbo Whistle

[ryancampbell98]

Go easy on me. For starters I’m a new school guy. I know a lot of old school guys aren’t fond of doing mods for cool sounds only but sound plays a huge part in my enjoyment in a vehicle. I know this isn’t a WRX forum but I am curious about this topic With that being said why are MHI turbos so quiet compared to other stock turbos like the Garrett MGT2259S in the 16-21 WRX ? For example, you throw a J pipe (downpipe) on a stock turbo WRX and a catback and the turbo whistle spool down literally sounds like a diesel. Very pronounced. I know a bigger turbo plays a huge part in turbo whistle volume but the WRX stock turbo ain’t big and doesn’t have the highest airflow either. So why is it that the turbo whistle is so pronounced when you open the exhaust up but when you throw a 14b, big 16g or a turbo around the same size and airflow as a WRX with an open exhaust the whistle still doesn’t sound nearly as loud? Is it just the design of the stock wrx turbo or engine that makes it that way? I’m about to throw on a MHI Evo 3 big 16g with all supporting fueling mods and Speed density setup/catless straight pipe exhaust, dyno tuned etc. It would be a bummer if the turbo was still quiet and didn’t have a pronounced whistle spool down while driving in lower rpms and decel.
I am not going Big 16g just for sound. That’s just a plus. Performance gains are my goal.

If you search up WRX tomei catless or catted j pipe you’ll see what I’m talking about when I say the whistle is comparable to a diesel.

 

[evil_eagletalon]

Even a “big 16g” is tiny. Probably related to the wheel design. Theres a guy on here that builds turbo maybe you can send him your turbo for some wheel upgrades.

Here is a “big 16g” sitting next to a borgwarner s257-sxe which is not that big of a turbo. And i still dont have that “diesel” sound with a billet compressor wheel.

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[TJCTalon]

If you want turbo sound so bad you need to get a turbo with a t51R mod on the compressor cover.

You'll need more turbo then a 16g for that unfortunately.

 

[idkiliketurbos]

Even any of the FP turbos with the anti-surge compressor housing will have an awesome spool up sound.

 

[ryancampbell98]

Here is a “big 16g” sitting next to a borgwarner s257-sxe which is not that big of a turbo. And i still dont have that “diesel” sound with a billet compressor wheel.

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that’s interesting. The wrx stock turbo must have some design element then. Cause it’s a smaller turbo than the big 16g yet it sounds ridiculous. The diesel turbo whistle sound is basically all you hear in the low to mid rpms with an opened up exhuast. It’s interesting that the sound is still not prevalent for you even with a turbo or that size.

 

[99dsmer4g63]

You want turbo noise. Put a hx40 on it and and cut the exhaust off at the oil pan.

If you want it to sound like a wrx loosen some head bolts and drive it.

-Daniel

 

[freebird_43]

Good day all..I'm currently researching exhaust replacement on my 91 tsi awd. I found this thread interesting and somewhat in line for what I'm after... my questions concerning exhaust on my DSM. Do these cars need the cat? Do they need a muffler? Has anyone bolted on a wicked wheel to a turbo for the diesel whistle? I am considering a STI Tuned exhaust for my 1 g. Once they get the down pipe fitted for the 2.5 " O2 stock housing. Any thoughts on this Diesel whistle? On a DSM?
Thanks!!

 

[ryancampbell98]

Good day all..I'm currently researching exhaust replacement on my 91 tsi awd. I found this thread interesting and somewhat in line for what I'm after... my questions concerning exhaust on my DSM. Do these cars need the cat? Do they need a muffler? Has anyone bolted on a wicked wheel to a turbo for the diesel whistle? I am considering a STI Tuned exhaust for my 1 g. Once they get the down pipe fitted for the 2.5 " O2 stock housing. Any thoughts on this Diesel whistle? On a DSM?
Thanks!!

the other day I talked to my mechanic who specializes in the working on dsm and evos, who currently works on my car at the moment. When I brought up this topic to him he explained to me that it’s really comes down to the design of the engine paired with the turbo in regards to the wrx. The diesel whistle sound that those small turbos produce is specific to the wrx and opening the exhaust up just makes it more pronounced. This doesn’t seem like a possibility for us without a larger turbo upgrade even with an opened up exhaust . I’ve seen people with upgraded turbos on dsm’s, (larger than a stock turbo on a wrx obviously) and it still doesn’t produce that loud diesel whistle spool down.

 

[Bud92gsx]

Good day all..I'm currently researching exhaust replacement on my 91 tsi awd. I found this thread interesting and somewhat in line for what I'm after... my questions concerning exhaust on my DSM. Do these cars need the cat? Do they need a muffler? Has anyone bolted on a wicked wheel to a turbo for the diesel whistle? I am considering a STI Tuned exhaust for my 1 g. Once they get the down pipe fitted for the 2.5 " O2 stock housing. Any thoughts on this Diesel whistle? On a DSM?
Thanks!!

Need a cat or muffler, hell no. depending on local laws of course. 2.5 inch is tiny in the first place. Could just go to punishment racing and get 3 inch but whatever.

 

[Pjj]

i run an FP black catless with a full apexi exhaust. my spool is super loud with it, mainly hear it in the engine bay. the way it sounds out the back always has a lot to do with exhaust routing and resistance of the air coming out.

 

[freebird_43]

Need a cat or muffler, hell no. depending on local laws of course. 2.5 inch is tiny in the first place. Could just go to punishment racing and get 3 inch but whatever.

Thanks for the feedback concerning the exhaust.. I'm considering the sti S/S turbo back exhaust. It's pricey but will last forever I will plan to remove the cat and muffler from this kit when I'm able to purchase it (@ 2K) hopefully the DSM will make a bit of noise while running! Thanks again for the input all!