sothpaw2

The Magnaflow muffler from Corvette Central, as I understand it, is just a perforated straight pipe with sound deadening material around the pipe and a muffler body around that.

Question: If it's truely a perforated straight pipe, how much would the turbulance caused by the holes restrict the exhaust flow? Has anyone tried this one?

I'm shooting for the least restriction muffler I can get, and I want LT1 tips. I could do the straight pipe, but I have to check into MD law and see if straight pipe is a problem. A really low restriction muffler would be the best thing.

bogus

why?

low restriction, at least as far as modern engines is concerned, has a point of diminishing returns.

the sound level will go up - and I am SURE that open pipes would SO fail DMV in MD... I had elims, with hooker resonated tips, and that nearly failed. I know that true open pipes would more than fail.

I would look at Corsa's myself.... that's what I did... no regrets!!!!!!!!!!!

sothpaw2

Fail what?

Not emmissions. I have to look into the law on this...

bogus

noise, my friend... noise.... delaware has a limit of 95db, 3ft off the pipe... I was at 94.3.... and that was with the resonated tips!!!!!!! they were tons quieter than the open pipes.

tjwong

I ran a dual 3" inlet single 4" outlet Magnaflow in my 02 8.1L supercharged suburban. There was virtually no back pressure at WOT but the noise was totally obnoxious. I ended up changing it out for a Banks SS muffler that had a couple baffles in it, still very throaty a tad bit of back pressure but the noise is acceptable.

I ran a SLP 3" system in my C4 for a long time it was basically straight through with a single 3" inlet going to dual oval outlets. The internal tubing was perforated and wrapped with a SS/ceramic wool material for sound deadening. They were loud at WOT but at normal speeds it was acceptable. I also ran their dual in/out 3" resonator and measure back pressure was near 0 measured after the cats, and after the resonator.

Measurement was done with calibrated electronic pressure measurement tools. So I am sure it was accurate.

sothpaw2

You measured the back pressure after the cats and resonator, but not the mufflers, correct?

Thanks guys--I'll have to look into if they check for noise.

skeet

I put the Corvette Central Magna Flows on "our" Corvette. Mine is the 88 and wife and I share the 95. Wife liked the totally whisper quiet stock mufflers. I find the Magna Flow, even though a true straight through design, are NOT loud at all. At WOT they have a nice mild powerful sound. Very slight rumble with moderate gas. Cruising at our legal 75 you hardly hear them. This is on a stock 95 LT1 auto with 3.07 gears. . Wife still wants the quiet vette back so I might sell them. I DO definitely feel more power through out the whole operating range. I guess the stock mufflers are very restrictive.

sothpaw2

Skeet,
Let me know if you truly want to sell. I am buying something by next week.
Do you have a noise abatement law in Az? We have something here, I just can't tell what yet.

skeet

I do not know of any noise abatement laws in Prescott but some small towns like Jerome have them. I have seen cops jump out in front of Harley's (with no mufflers) and give them tickets but then again Harley's with no mufflers are louder than any Vette I ever heard.
I am still trying to talk the wife into keeping the Magna Flows and think I can at least keep them on the car for another month or two. I really think the Vette sounds like a passenger sedan with the stock mufflers and more like a Vette with the Magna's. I will respect her feelings but will also stall, stall, stall - I really like them!
I think the cats make the flow through design of these mufflers more quiet than you would think they would be.
If I have to sell them I will try the " C4 parts for sale" forum first.

Darkness

Muff elims are the way to go in your situation, it wont be illegal cause you still have the center resonator.

Dark-Knight

ttt

sothpaw2

ttt

Lone Ranger

Skeet, did you lose any lwo end torque feel, or did it feel like it picked up some low end grunt w/ the Magna's?

oldace84

Just save yourself grief, and get the FlowMasters, good sound, with a little more HP.
Just my 7 cents worth.
tony

skeet

OldAce84 - FlowMaster does not sell just mufflers for the LT1 cars so you need to buy the whole cat back system for about $700-$800. The MagnaFlows are just the mufflers and they cost about $250-big difference and about $500 worth of "grief".

I feel a slight increase in off the line "grunt" and it seems to pull harder throughout the whole rpm range.

From what i read the perforations in the muffler were designed not to cause turbulance of the exhaust/air flow and to only trap sound waves which I believe are perpindicular(sp?) to the air flow but am not 100% sure about this last statement. I would imagine that FlowMasters have an advantage in that without the baffle material there is no heat build up which could be a problem in all out racing situations but I am not 100% sure about this too. There are a lot of things I am not 100% sure of:)

oldace84

Just a thought, go to http://www.jegs.com or http://www.summit.com
Best prices on these mufflers.
What do you think?
thanks
tony
I bought my FlowMaster's from Jeg's.

tjwong

Yep the pressure was measured after the cats and after the resonator, so it was measured behing the mufflers to give an indication of any back pressure that may have been from them.

BowTieBlood

Flowmaster exhaust and Tri-Flo exhaust (3") are both relatively quiet on my 95 lt1, both were cat-back. I know others have seen quite the opposite, maybe it's just my car, but they compared in NO way to my 97 trans am with a flowmaster and tips. Maybe you're the other guy with a quiet 95 to back me up :cheers: :lol: