7M--->2JZ, EquallengthT4--->DM Tubular T4, Same Trust 3" but WAY Louder?

Flateric · 10-30-2009, 11:28 PM

I'm curious why my exhaust is noticably WAY louder now that it used to be with my old setup?

Old setup.....

7mGTE, equal length runner T4 exhaust manifold, Turbonetics T71 (journal bearing), 3" Trust exhaust (transfered to new setup below)

New setup.....

2JZGTE, Driftmotion Tubular T4 exhaust manifold, GT4088R, 3" Trust exhaust (carried over from previous setup above)

The new setup also includes HKS 264 cams on both intake and exhaust which was not present on the 7M configuration.

Here are pics of both of the actual T4 exhaust manifolds.

Why is the new 2JZ so very much louder? Even at idle it is dramatically louder by a substantial amount too! The exhaust system after the manifold is the same one for both and has not been changed at all.

Is the 2JZ really that much louder on the exhaust side than a 7M? Why is this? Does it boil down to just my larger CAMS causing this?

What can be done to help tone this down a bit. With my old setup I didn't have any second thoughts about going for a 2 AM run to the store. With my new setup I'm concerned about bothering the people who live on each side of me. I also think I may get more attention than I want when passing the cops who are bitchy about loud cars in our city. (But a harley with straight pipes has no problems, go figure!?)

*lewis15498* · 10-31-2009, 12:06 AM

Aftermarket cams can dramatically change the sound of an engine.

mk3_chris · 10-31-2009, 12:14 AM

Yes, the 2JZ has a louder exhaust compared to the 7M when setup similarly.
No the 7M does NOT produce a louder exhaust when setup similarly.

I've had kind of a long day so maybe I'm just not thinking properly, but aren't those the same answer? Being that the jz is louder?

Mikael_7m · 10-31-2009, 12:21 AM

Quote:

Originally Posted by mk3_chris

Yes, the 2JZ has a louder exhaust compared to the 7M when setup similarly.
No the 7M does NOT produce a louder exhaust when setup similarly.

I've had kind of a long day so maybe I'm just not thinking properly, but aren't those the same answer? Being that the jz is louder?

Im with him ^ on this one.

Hmong_1G · 10-31-2009, 01:03 AM

Your like comparing apples and oranges. Bore, stroke, valvetrain configurations, cams, all play a role. My 7M is loud on HKS DP, RSR full exhaust, no cat, bored .040 block, fully rebuilt.... blah blah blah. Before my motor pooped, my RSR on the same exhaust configure was more quite and easier on the ears at highway speeds. My suggestion is add in a cat or resonator to help ease the DB's.

Flateric · 10-31-2009, 03:31 AM

Ya, your right, I also have had a long and tiring day, questions are the same.

I have no cat (no emissions requirments here), but the trust exhaust does have a resonator that came originally with it.

So I guess as far as my setup is concerned I am pretty much stuck with my audio levels. Wonder if placing another resonator (is a glasspack the same thing?) in the system, for instance where my test pipe is (where cat would normally be) would help any further to tone things down more?

I also noticed the runners for the manifold are substantially larger on the 2J. I also speculate the GT4088R, being a larger turbo is no acting as a buffer as well as the smaller Turbonetics was.

I don't pretend to be highly knowledgable in any way shape or form in the automotive field. Wanted to see what you guys who are more knowledgable might suggest for me.

Donnie · 10-31-2009, 03:46 AM

Quote:

Originally Posted by Flateric

So I guess as far as my setup is concerned I am pretty much stuck with my audio levels. Wonder if placing another resonator (is a glasspack the same thing?) in the system, for instance where my test pipe is (where cat would normally be) would help any further to tone things down more?

Most certainly will. Go with something 26"ish long. You'll be pleased with how much depth it can add to an exhaust note.

Don't pick up a cheap-o Cherry Bomb, or something of the sort. The packing can be blown out as quickly as a year.

bloodasp90 · 10-31-2009, 04:42 AM

well, im just throwing this out there, since im a deisel mechanic and all, but, ive noticed that the shorter the muffler, and longer the pipe from the turbo, with, or without a resanator, the quiteter the sound is, but also, the size of the turbo dose make a big differance, cause the more turbine blades you have in there, cause of the size, it will basicly act almost like a resanator just cause of the turbo basicly.

i could be wrong, i could be right, but thats just me $.02 into it.

Donnie · 10-31-2009, 12:36 PM

Quote:

Originally Posted by bloodasp90

well, im just throwing this out there, since im a deisel mechanic and all, but, ive noticed that the shorter the muffler, and longer the pipe from the turbo, with, or without a resanator, the quiteter the sound is, but also, the size of the turbo dose make a big differance, cause the more turbine blades you have in there, cause of the size, it will basicly act almost like a resanator just cause of the turbo basicly.

i could be wrong, i could be right, but thats just me $.02 into it.

I don't understand what you mean about the length of the DP. But the second part is certainly true.

Ever compared the sound of a Revving Straight-piped GE compared to a GTE? The difference is huge. Turbo (With the exception of while spooling up) always quiets things down.

*tissimo* · 10-31-2009, 01:07 PM

Most likely the turbine wheel is bigger on the GT4088 vs the T71 you had allowing the exhaust to flow easier through it and being less muffled.