White.Lightning

iTrader: (53)

Long story short, I have the QTP LT's, Kook's 3" ORY and Magnaflow catback. There is a lot of 'rasp' at the 2500-3200 rpm zone. I have read that the ORY is the 'cause'. The fact that the Magnaflow single in/dual out muffler, and a flow thru design, it does not muffle this rasp at all.

There are a few options in the poll that could potentially solve this issue, or vote for keeping the Magnaflow if you think I am crazy for trying to remedy this 'issue'.

1. Keep the magnaflow muffler and stop crying
2. Replace the magnaflow muffler with a Flowmaster 80 series crossflow muffler http://www.summitracing.com/parts/FLO-43083/
3. Replace the magnaflow muffler with a Spintech split case 343SC http://www.spintechmufflers.com/muff.../prod_384.html
4. Remove the ORY and magnaflow catback and install true duals
5. Recommend me some other option

Thanks for looking

silverstreak98maro

iTrader: (7)

Have exhaust shop cut the ory and install magnaflow merge i have same shyt goin on with my lm1 exhaust lots of raspy shyt im bout to do merge install

White.Lightning

iTrader: (53)

I think you mean the flowmaster merge?

02silvaZ

iTrader: (12)

^ actually there is a magnaflow merge, and i voted other= Hooker Aerochamber, this is what i have and i have almost zero rasp

Element

iTrader: (5)

Change the merge. Doesn't matter how good the muffler on the car is, with a **** merge, there will always be rasp.

But, being a true duals guy, I'm gonna recommend those.

White.Lightning

iTrader: (53)

I found the magnaflow merge at Texas Speed for $27
http://www.texas-speed.com/p-2152-ma...10-length.aspx

Not a bad option. The flowmaster merge is only offered in 2.5" in/3" out, or 3" in/3.5" out.

turbo

iTrader: (10)

The Flowmaster merge comes in all kinds of sizes. Mine is 3" into 4" and probably best for the money.


I vote to custom make your own Y-Pipe with decent merge and a single chamber exhaust. Add a cutout by the axle as well.

dirkdiggler350

Put a bullet muffler in the I pipe that will kill rasp and deepen the exhaust note. I would use either a Dynomax race bullet, or a Magnaflow round muffler. The Dynomax will be cheaper but offer less sound reduction, while the Magnaflow will be little pricier but quiet it down more.

pewter2002

iTrader: (4)

What causes this "rasp" sound people are talking about? Does a stock car (ls1, LT1 etc) make this sound or does it only manifest itself after headers etc? Is due to overlap in an aftermarket cam? A smoother merge on the y pipe fixes this, why?

White.Lightning

iTrader: (53)

From what I have read it seems that the cause is the ypipe design and firing order. As the exhaust gases collide at the merge, the engines exhaust frequencies cause a 'rasp' noise when the firing order and rpm are at a certain point. This only happens with a small window of rpm, but it sounds like crap in my opinion.

People have used the 2 into 1 merge from flowmaster for a few years now with good success. Instead of colliding the exhaust gases, the merge allows them to both move in tandem and exit the exhaust system.

You won't hear this on a stock car since there are catalytic converters in place that will cancel these frequencies. My car has long tube headers and an off road ypipe with no cats.

babbage1109

iTrader: (11)

Cats meow meow

White.Lightning

iTrader: (53)

wut?!?

SSCamaro99_3

iTrader: (1)

This has been talked about since the inception of the LS1 into F-bodies. It is fairly simple:

- Stock car with cat-back. No problems, sounds is user preference

- Headers (mid-long), catless y-pipe. With anything but a full case muffler (SLP Dual/Dual, Hooker Aerochamber, possibly Flomaster) you will hear rasp. It is still there some, but the mufflers eat it up enough to make it liveable.

- Headers, catted y-pipe. The cats will et yup the vast majority of rasp. Can use most exhaust sytems.

- Headers, catless y-pipe, better merge. Helps reduce the rasp. Some find it makes it tolerable.

- Headers, true duals. Rasp is a thing of the past.

In short. True duals or cats are the only surefire rasp killers.

babbage1109

iTrader: (11)

Lol. Use cats in your y pipe.

SunsetOrangeZ

iTrader: (10)

+1 on the catted y-pipe, it will definately kill your rasp issue. That or a resonator in the i-pipe will reduce it too. The longer the resonator/bullet muffler the better. If you can squeeze a 18in dynomax bullet behind your ypipe it will help out alot.

Also, FWIW, the tips will amplify the rasp. I had a B&B catback originally and it hade a ton of rasp with my quad tips on. Once I took them off you could barely hear the rasp. Smaller shorter tips will reduce it too.

Steve Gunn

A 3-4" FM merge cured my rasp. sounds deeper too.

greg_74

iTrader: (9)

I'd go with a catted y-pipe. A better merge is a cheaper option but it won't cut down as much of the rasp. I had a magnaflow cat in my i-pipe on my SS and it cut down some rasp but not all of it. If you're willing to spend the cash, a catted y is your better option.

If you want to go a whole different route true duals won't have the much rasp but they will be loud as hell. Depends on what you want.

senicalj4579

iTrader: (41)

If you have no money issues then go with the duals.
If money is an issue then stfu and keep your mag you *****!

White.Lightning

iTrader: (53)

^^^ Thanks for calling me a ***** you phaggot

Anyways, I think I am going to put a spun high flow cat in the intermediate pipe. It goes along the lines of the bullet muffler in the i-pipe as well as the catted y-pipe. I think it will be a good, affordable option.

Flawless02SS

iTrader: (9)

Its a hot rod, if you want it quiet like a mini van, buy a mini van. Do what I do, just drive the damn thing!!!!