SR Exhaust Note??

[cbh148]

So I've been curious if any of you can answer this question for me -- What gives some SR20DET's that high pitched exhaust note? Seems like most SR's have the low pitch, but I want the high pitch (granted, I've got a CA18. Dunno if it can even make the high-pitch SR sound, or if I'll just have to wait till I build an SR.).

Is it just the exhaust? Or having a screamer pipe or external wastegate? Aftermarket cams? Tubular manifold? I've found exhaust videos with the right sound, but if you look up another video of that same model exhaust, it'll be deep low pitch. Just looking to see what the defining factor is for the high pitch vs low pitch sound.

High Pitch:
[youtube]http://www.youtube.com/watch?v=-mqXXqB7 ... re=related[/youtube]

Low Pitch:
[youtube]http://www.youtube.com/watch?v=cGdVn5L4CcY[/youtube]

[Seishuku]

I know with my T25, the turbine chokes down the exhaust so much that it acts as a pretty decent muffler... I would think that with a larger (super 60, maybe smaller T3) will flow more exhaust, not choking it down so much and giving a different exhaust note.

[cbh148]

I wouldn't imagine that every high-pitch SR is running a T3 flange'd turbo, and every low-pitch SR is running a T2.

Come to think of it, I've got a buddy whose SR has the high-pitch, and he's just got an s14 T28 (so, high-pitch with T2).

[Seishuku]

Just a thought

Exhaust tubing size factors in too.

[cbh148]

^^^Yeah I figured it would. I'm assuming you're talking mostly about the exhaust itself (elbow through catback) rather than the turbo manifold tubing.

My friend's SR s13 that does have the high-pitch sound has BC or JWT cams (stage 2 or 3) with aftermarket valves/springs/retainers, with an x-angle valve job. I can't remember if his s14 T28 is mounted on a tubular manifold or the stock cast iron unit, I'll have to ask. As far as his exhaust goes, it's just an eBay catback with the muffler removed. I think it still has the resonator, but I'm sure he doesn't have a cat. Don't know about his elbow/downpipe combo.

Fingers crossed that it's not the cams and headwork that make all the difference, since that'll be a long ways off for me and my budget. I wouldn't bother to do either of those to my CA18 since I know I'm gonna go SR20 eventually.

[D-UNIT]

Ever thought that the low pitched video cars are KA powered? Just kidding! maybe... From my experience it seems like low pitched sound comes from stock (small) turbos and low to medium low boost levels. But mainly stock turbos have tiny inlet and outlet holes which restrict sound levels causing low pitched/low turbo sounds. Whereas upgraded turbos are bigger in everyway , equaling more power at the the same boost levels. Therefore more spooling and turbine sounds are emitted causing a higher pitch. 7 psi vs 14 psi is technically double the air flow going in and out. Just imagine your typical house fan. At the low speed setting it sounds very low pitch and soft , but when you turn it to high , the pitch and decibels increase dramatically. And we all know those japanese SR's are hammers.

[cbh148]

Ever thought that the low pitched video cars are KA powered? Just kidding! maybe... From my experience it seems like low pitched sound comes from stock (small) turbos and low to medium low boost levels. But mainly stock turbos have tiny inlet and outlet holes which restrict sound levels causing low pitched/low turbo sounds. Whereas upgraded turbos are bigger in everyway , equaling more power at the the same boost levels. Therefore more spooling and turbine sounds are emitted causing a higher pitch. 7 psi vs 14 psi is technically double the air flow going in and out. Just imagine your typical house fan. At the low speed setting it sounds very low pitch and soft , but when you turn it to high , the pitch and decibels increase dramatically. And we all know those japanese SR's are hammers.

I'm now convinced that it's the cams that make the sound difference, because my friend with the cam'd t28 SR has the glorious high-pitch sound, whereas all my other friends with SR's have stock cams and t25/t28's, with all different types of manifolds/exhausts, yet all of them are low-pitch.

Kinda sucks, cause I'm not gonna get cams for my obsolete CA18, so no high pitch glory for me (until after college when I can build an SR).