chishifu

iTrader: (5)

Hi everyone, I just installed some resonated TP's today onto stock Y-pipe-back and although I was expecting a bit of rasp, what I'm hearing is absolutely unbearable! Starting at 1.5k and up, at almost any amount of throttle, sounds like my exhaust is tearing itself apart and will fall off my car at any moment. Accel, decel, coast, and even idle all have a loud rasping sound.

I'm pretty sure that's not normal and i'm wondering if anyone here could help me diagnose the problem. I have rather cheap knock-offs (Megan RTP's) but even so, I don't think this amount of rasp is typical. I read through some threads about rasp, but the problem seemed to lie solely with non-resonated test pipes. Thus, I'm absolutely baffled as to what it can be. Would an exhaust leak cause excess rasp?

Some problems during the install were that the passenger side test pipe sat extremely close to the undercarriage, so would the vibrations under load cause it to be rattling against my undercarriage? Another was that I was unable to get a torque wrench to many of the bolts, so I simply tightened till it was tight + a half turn. I don't think theres a problem with the torque, but i'm hoping someone can make something of this information. Anyways, if anyone can help, any information is greatly appreciated. Thanks for reading.

EDIT WITH VIDS:
http://www.youtube.com/watch?v=1NGagAvqHk8
http://www.youtube.com/watch?v=6Fyc8oEUz7I
http://www.youtube.com/watch?v=s6y-7iSVBh8

chriskabobbers

iTrader: (13)

damn benny, didn't know you installed tp's, they're that bad? do they sound like jon's?

SuperBlack350z

iTrader: (59)

It's those Megan test pipes. I guarentee it. There is another Z owner i met locally and he had some megan resonanted test pipes because i told him i had some test pipes. I specifically told him not to go cheap on those since they tend to break and such.

So when i heard his megan's,they sounded horrible. Like a weedwacker or something. The kid has money so i told him to get higher quality which he got soem Labrees. They sound really good. Not all Resonated ones sound the same. IMO, all non resonated should sound the same since they are a straight through pipe.

You are better just taking those megans off since they will probably crack soon and sound worse.

Here is my car with NON resonated Helix v2 test pipes on a stock z with stock y pipe and rear muffler and as you can see has very to no rasp. And these are non resonated which you probably bought resonated to get little rasp. Brands come into play. You know you have something bad when your resonated test pipes has more rasp then non resonated test pipes.

chriskabobbers

iTrader: (13)

nice video man, sounds good.

yeah benny, it's obvious from a lot of members that megan's products just don't hold up and or perform as should, you should try to sell yours before they crack, and maybe get helix or something.

SuperBlack350z

iTrader: (59)

Thanks bro.

I'm trying to help him out since i understand the reason why he probably got those megans. When you see little pipes like that and price ranging from 75-600 dollars for just some pipes that probably took 50 dollars to make, you feel like just getting any of them.

Hydrazine

iTrader: (53)

I've tried test pipes on a stock exhaust and I thought it sounded good.

Yes, there was a little rasp at 3-4 K but it sounded awesome at high RPM.

ISMSOLUTIONS

Yea - the Megan pipes are notorious for breaking and bad sound. You definitely want resonated though.....they don't 'make' rasp by being resonated, they help tremendously to reduce it, without affecting performance by more than about ~1HP if any at all.

Make sure you get a good quality set - with an 8" resonator...not sure who makes them like that other than Fast Intentions...but look around.

www.fastintentions.com

Rick

06MagneticZ

iTrader: (13)

Toss those Megan tp's. Thats your problem right there.

shifty711

A sound clip would be helpfull

I just put my stock exhaust back on with Resonated Test Pipes and Headers, I think it sounds good.

Alot better than the old sound
check it out

https://my350z.com/forum/intake-exhaust/291920-strupp-headers-and-utr-resonated-tp-vid-clip.html

CarlosZ

I put some tp's on my stock 04. Raspy from around 3-4k but I think the sound or exhaust build up in the piping made the most of the rasp go away after a month or so. The y-pipe broke due to the extra stress of the tp's w/o the exhaust support bracket.

Zexy

iTrader: (55)

TP's sound like *** on stock exhuast.

I've had that setup for a while.

Chad68

iTrader: (1)

Is it my imagintaion or do any given TP's rasp more on the stock exhaust than say a Nismo? Seems like the people who have the worst rasp are still using the stock exhaust.

SuperBlack350z

iTrader: (59)

well if you think about it, people are putting 2.5 inch diameter test pipes on smaller stock y pipe which i think that's where the rasp comes from as well. The nismo is 2.5 piping through the back so the flow is a bit better.

terrasmak

iTrader: (8)

Ive got X02 test pipes and a Megan y pipe and love it , Little rasp mostly heard inside , not out , sounds great and many others with Z's here in Vegas like my setup too.

chishifu

iTrader: (5)

and,

6 - RASP is something that happens when the pulses cannot line up properly and the car kind of burps...really that is what happens. Even if you like rasp, it's actually NOT a good thing performance-wise. It takes a LOT of HP to have a pretty open exhaust and not rasp.

Hi, i'm becoming rather confused as to what rasp actually is now. I've been under the impression that it's the loud metallic rattling sounds coming from under the car, but I'm rather sure that's because my resonators are vibrating against the undercarriage of my car. However, this definition above from IMSOLUTIONS in another thread IMO states that rasp is the backfiring pops when the revs fall. I'll try to get a clip up soon. Thanks for the replies guys, didn't realize even resonated tp's when low quality would rattle this intensely.

SuperBlack350z

iTrader: (59)

rasp is def not the backfiring pops. It sounds like a rattle. Its sounds like vibrating sheet metal or something like that.

Armitage

iTrader: (15)

And then people wonder why the forum bashes Megan TP's.

I <3 my UR HFC+Nismo combo.

Mr_Drifter

iTrader: (4)

does anyone get a sound when letting off the throttle only, like around 2,000 RPM's?

ISMSOLUTIONS

OK -

So I've NEVER said rasp is when you hear the pops and stuff from your exhaust...

Put your lips together and force air through them...when your lips flap around, like a fan beating a raw piece of meat - that slapping sound - is real similar to rasp...only rasp is worse, louder and can cause grown men to cry!

Rasp is indicative of a non-balanced exhaust system. It CAN also be characteristic of an engine's firing order - if it cannot keep up with the pulse expulsion. When the exhaust cools too much during it's travels, the pulse backs up against the colder air. So as it 'gasps' you get that 'rasp' sound.

Now - you can have a wide open exhaust - and not enough exhaust pressure to keep the air hot enough to keep flowing through the pipe - you can get rasp and extreme drone from this. EVEN WITH MUFFLERS!

The with 'mufflers' scenario is when a system has been designed to work a specific way - say, a catback system. If it has not been designed to work with headers or testpipes or HFC's - then you're gambling on the result when you change it's specifically designed dynamic of flow characteristics.

So - you can speed-up the pulse - but if it backs up because of other deficiencies - you'll have back pressure, rasp, drone, loss of performance - among possibly other things.

So it's really important to know what the capabilities of an exhaust system are before you buy it - because if you decide to augment that environment, you may not have a completely compatible system - and you wont be happy in the end.

Testpipes are known for causing rasp to appear - as most system are not designed to allow that level of flow. Some do work however, like HKS, Stillen and Fast Intentions - and depending on the parts chosen, they can rasp as well. Some people like a certain degree of rasp - and technically, all exhaust sound is a form of rasp. If there is not a bottleneck, filtering or rasp - just run your car on open headers to see what ZERO rasp sounds like - you'll be more than happy with your rasp

So - in re-reading this thread - there are also some possibilities that the OP doesn't really know what rasp is or sounds like...in his case - this could be pipes rattling the undercarriage...

We need a sound clip...if you can't hear it outside...it's likely not rasp - could be an exhaust leak??? Where is the sound coming from? Tailpipes? Under car?

Rick

ISMSOLUTIONS

This is pretty common. Sounds like BB's in the pipe - not real loud, but almost like an air leak - not exhaust, but air? Yes?

If so - it's usually associated with y-pips and flex joints. We've heard it on catbacks - showing factory cats/housing/heat shields make the noise when exhaust pressure and heat build up. We have also seen that it may be the sound of the firing order resonating in the pipes as well.

I had it - as most do, but don't realize it's there - until I put headers on - it went away instantly.

Rick