raptor

Hi guys

does anyone have this exhaust under his car?
http://www.gotuning.com/product_info.php?f...roducts_id=1322

Reason for this question is that i want to know the position and dimension of the helmholtz resonator, which is fitted a few inches behind the cat.

i'm going to get a GReddy SE single and this one seem to be very similar to the ASM regarding pipe diameter and muffler design.
http://www.gotuning.com/product_info.php?f...roducts_id=1283

So when fitting this helmholtz to the Greddy i suppose to get rid off the last bit drone in low rpms

so if anyone has the ASM please take a tape measure and give me the dimensions

regards
Pat

Vik2000

lol interesting. Let me know how it turns out.

bpaspi

https://www.s2ki.com/forums/index.php?showt...&#entry11098713

but it doesn't help much, you have to read the whole story

https://www.s2ki.com/forums/index.php?showt...0&#entry2307224

Nevertheless, a pure Helmholtz-Resonator has to have a Resonance-Volume and a small entry opening. I didn't had a closer look into the OEM exhaust, but my guess is, this small tube doesn't work as a Helmholtz-Resonator. It must be something different.
The sound drone frquency at 4,000rpm must be round about 133Hz, the speed of sound is higher due to the exhaust gas temperature. But my guess is that a volume of 6litre is needed for dampening the 133Hz drone.

A silencer a the end of the exhaust works as a Helmholtz-Resonator with the whole exhaust volume as resonance chamber. This is the reason why silencers kill the 3,000 - 4,000 rpm droning.
Just a thought.....

raptor

Hi bpaspi

nice to "read" you here
i'm patrick_S from s2k.de

i also think that this "resonator" is to small to kill the drone, but the ASM has this tube and it doesn't have any drone.
Resonator and Muffler layout and dimensions are very similar to the GReddy SE

i hope i can mount the SE this week and check if this one also has this droning

keep u informed

bpaspi

You're sure? I thought that ASM redesigned the front resonator. Not just only added the "Helmholtz"-Stuff.

I didn't like that exhaust. Looks a little bit cheap....

raptor

if the pics are true, then the resonator is a absorber type like the Greddy has
this ASM is the re-newed version, maybe this makes the "cheap" look

but the GReddy SE-single looks very good - i hope it sounds as well

raptor

Greddy SE single mounted - sounds good
but there's still a "boom" at 3000-4000 rpm when going WOT


Does nobody have this ASM exhaust?
i only want to know if this helmholtz tube will kill the boom in low rpms

modMonkey

Sorry, just realized I never followed up with this.

I tried both ASM 70mm exhausts back to back ( ASM 07 without Helmholtz, ASM 08 with Helmholtz). The ASM 08 actually produced more resonance at low RPM compared to the ASM 07. At a certain RPM, there would be a resonance that could be felt in the cabin, can't remember exactly when. This is with the stock cat. I'm sure with a test pipe, the issue would be less severe.

If you need more info, feel free to PM me.