2G Need to make more noiiiiiiiiiiiiiise ! :)

[Heryst78]

Hi guys !!

Currently on the eclipse, I have an exhaust after catalyst 3 "HKS, and a homemade decat.
But I think it does not make enough noise.
Will a stainless steel downpipe make more noise?
Do I need to change the turbo collector and the O2 Housing too?
My turbo is an original turbo

Thank you

 

[1990TSIAWDTALON]

The Cat is quieting it down. Is it illegal to do a catalyst delete over where you are, across the pond???

 

[Heryst78]

My car is made for race, and in France there is no rules about noise for that
So my question is, does the downpipe will make my car more noise ?

 

[1990TSIAWDTALON]

It may be "deeper in tone or throatier" with a 3" downpipe but the noise is getting muffled at the catalyst. I have deleted my cat on both of my cars, because as an owner I can legally do it, but a shop can not.
I found catalyst "test pipes" on Ebay and put one in as a test for a plugged catalyst and just left it in.
I used a unit that is almost identical to this, although you could make your own.
https://www.ebay.com/itm/RACING-DOW...99-MITSUBISHI-ECLIPSE-NON-TURBO-/170715134495

Here are a couple video's that have the sound of a DSM without a cat for references:

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[OH91awd]

The Cat is quieting it down. Is it illegal to do a catalyst delete over where you are, across the pond???

if im understanding his post right he made his own testpipe (decat).

as far as the 3" downpipe it may make it louder but i dont think its going to be a real audible notice. youll get more of a deeper tone than anything. changing mufflers or going to a straight pipe is going to be your best option imo.

 

[1990TSIAWDTALON]

I may not have caught that part so thanks for the backup.....again
Ahhh....homemade decat. I see....
I assume that a bumper exit exhaust is not an option or a exhaust cutout?

 

[OH91awd]

I may not have caught that part so thanks for the backup.....again
Ahhh....homemade decat. I see....
I assume that a bumper exit exhaust is not an option or a exhaust cutout?

no problem i didnt think about the exhaust cutout idea. that would be another good option as well.

 

[streetraceboi]

Want more noise? Bumper side exit

 

[gofer]

The HKS catback has a resonator that actually hurts the performance because it necks down from 3" to 2.5" at the resonator, as well as quiet's the exhaust note. If you're looking for a louder exhaust with the HKS exhaust you've already got then cut out the resonator and weld in a 3" pipe in its place. If that's still not enough you can also get a 3" downpipe which will help performance and make the exhaust louder.

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[Kryndon]

A 3" catback all the way through definitely makes the stock sound way louder. Much throatier at idle and still very loud when going through a tunnel. However, it's nowhere near as loud as an open dump O2 or simply having a bigger turbo. Your stock T25 turbo has a very small exhaust outlet which significantly muffles the sound. For comparison, the N/A 2G Eclipse will be much louder with just a back box.

So if you REALLY want to make it louder, without just going for a bigger turbo (I'm sure you'll do that later on, since race car!), you can either buy or have a custom made O2 housing with an open dump. Or use an O2 housing from an EVO3 16G turbo, which has a bigger exit towards the downpipe (2.5"). I believe the material of the tubes also affects the sound, maybe @ec17pse can tell you more.

 

[FIBA M - EC17PSE]

The o2 housing wont effect sound, the DP will a bit but not alot. 2.5" will be higher oitched then a 3", on a low power level stick with a 2.5" though, 3" is just too big.

Smaller OD tube tends to make it higher pitched snd slightly louder, so perhaps 2.5".

Certainly get rid of all your resonators and that will help loads and ditch any cats if you have any,
Thinner walled tube tends to be a smidge louder also as the thicker it is the more it takes sound away.

 

[m_0ney_pit]

Yea open O2 dump if you want to make more noise like Kryndon said!!

https://stmtuned.com/products/stm-dsm-o2-housing-with-atmosphere-dump