I have heard that a replacement muffler on the series 2 155kw TJ Magnas increases power output as these series 2 engines already have the better cams, but does making the same tail pipe muffler change increase power output with the series 1 MY 2000 model TJ Magna?
Yes another question thread from me :redface: But how else will I find out without consulting the experts?.......that is you people :)

if a muffler is of poor design and restrictive on any car there is power to be gained by changing it. so yes

simple answer YES

On that note, does anyone know what the internal setup of the Sports/VRX/Ralliart muffler is.

Is it a TRI/Reverse flow, centre expansion, straight through, offset etc?

Probably about 8kw to be had I think, that's with the Mitsu supplied sports model exhaust. Don't know how much with other makers models (Lukeys et al).

I like to support my words with results:

http://hotrod.com/projectbuild/113_0411_trick/

Flowmaster made this test easy for us by cataloging complete 2.5- and 3-inch exhaust systems for '68-'72 GM A-body cars (Chevelles, GTOs, and so on) in its American Thunder line. Each consists of mandrel-bent aluminized exhaust tubing with H-style crossovers, over-the-axle tailpipes, and a choice of mufflers. With both systems, we tested Flowmaster's Super 40 series Delta Flow mufflers, which feature a series of three internal baffles, or deflectors, that reduce interior resonance to produce a quieter sound inside the vehicle. With the 3-inch system, we also tested a set of larger 30 series mufflers with Flowmasters' traditional single-baffle chambers head-to-head against the Delta Flow mufflers.

In theory, the larger the engine's displacement and the higher the rpm where peak horsepower occurs, the better it should respond to the reduced backpressure of a larger-diameter exhaust. Conversely, it's been said that a mild engine with too much exhaust flow may fall on its face with not enough backpressure, though we've never seen that to be true and can't even imagine how backpressure could help performance in a four-stroke engine.

So it came as no great surprise that our test revealed more power everywhere with the 3-inch system compared to the 2.5-inch system. Although our ZZ454 is relatively mild with its 2-inch-primary Hooker headers and Comp Cams 230/236-at-0.050 hydraulic-roller camshaft, it's still a 450-plus-cube big-block, and it pumps a lot of air to make 520-plus horsepower. On average, compared to the 2.5-inch system, the 3.0-inch system made an additional 13 hp and 15 lb-ft of torque from 3,500 to 6,000 rpm and picked up 14 hp and 18 lb-ft of torque at the peaks to finish with 522 hp at 5,700 rpm and 549 lb-ft at 4,400 rpm. Strike down the myth that the smaller system would favor low-end torque at the expense of high-rpm horsepower--in reality, it was weaker everywhere.

Also interesting is the comparison between the different-diameter exhausts and the open-exhaust configurations we tested last month (see "Header Flog," Oct. '04). In that test, using the same headers and 18-inch collector extensions, horsepower and torque were up 10 hp and 12 lb-ft (see graph) compared to the best run with the full 3-inch system. That's pretty much what we'd expect from the open exhaust. Last month we also proved that running open headers on this engine without collector extensions produced less power, and comparing the results of both rounds of testing shows that the full 3-inch exhaust system was on par with the open headers, which backs up our contention that running open headered (at least without collector extensions) is probably costing you power.

You can get a Berklee PEX cheaper than a Lukey (the one everyone will tell you you need). Go a cat back upgrade if funds exist, at least 2.5", 3" if you are REALLY going to turbo or supercharge.

For most daily drivers I think straight through (hi-flow) muffler and hi-flow cat would be sufficient, that said is anyone who knows able to answer my earlier question?

For most daily drivers I think straight through (hi-flow) muffler and hi-flow cat would be sufficient, that said is anyone who knows able to answer my earlier question?

TJ Sports/VRX comes with a 2 1/4 exhaust and a tri-flow rear muffler.

Oh, by the way, last post was plagarised from this link...(Info courtesy of "Gremlin")

http://www.aussiemagna.com/forums/showthread.php?t=9563&highlight=Ralliart+muffler

AKKO- pretty sure the mufflers are designed as below.

WARNING: picture is very sophisticated and may be very confusing lol

TJ Sports/VRX comes with a 2 1/4 exhaust and a tri-flow rear muffler.

No wonder there are gains to be had by replacing it then!

Funnily enough i remember reading an Autospeed article were mitsu claimed that they tested using a straight bit of pipe and it only flowled "marginally" better than the muffler they've used on the sports/vrx lol



Interestingly, Rod says there's not much more to be picked up from further mods to the exhaust. "At one stage we tried a straight length of pipe with no mufflers and it made no more extra power." Exhaust backpressure in the Ralliart Magna is said to be less than 400mm of mercury (53 kPa).

AKKO- pretty sure the mufflers are designed as below.

WARNING: picture is very sophisticated and may be very confusing lol

Thanks for the pic, they actually have a shockwave animation on the Lukey website which shows and explains it also. Ta.

For most daily drivers I think straight through (hi-flow) muffler and hi-flow cat would be sufficient, that said is anyone who knows able to answer my earlier question?

I believe it's offset. Waste of time calling it highflow otherwise. :)

so you rekcons a lukey would be fine improvement over a stock TJ?

By a coincidence, my best friend's rear muffler broke this weekend on her 2.6 TE. I rang up this morning to arrange a new one and was amazed to discover that a lukey was actually *cheaper* than a standard replacement muffler - $180 instead of $240. Guess what she's getting. :)

Z

sorry to "hijack" this thread!! :D
i have the TH sports (147kw) and i went to hornsby northshore and performance exhaust shop, and he quoted $200 for an upgraded,free-er flowing muffler for my car.

does this sound right?good price?
he said it will give it a nice note,wont drone or sound like a 4cyl and will give a nice increase.

what do you magna folk think?
yay or nay!

:D

Chris

My very FIRST ride in a MAGNA was in a gold coast council owned 2.4 TF (I think it was 2.4. Four potter) in 1998. We went for a drive to Noosa. She'd hunt through the gears up and down hills. I remember thinking 2.4 was a very small engine for such a large car. I droooled later that night as some 3.0 versions drifted by. But I digress.

So, from what has been said, is there that much more to be gained from changig even the standard Mitsu sports / vrx exhaust?

TJ Sports/VRX comes with a 2 1/4 exhaust and a tri-flow rear muffler.

Apart from the fact that a number of people have measured the exhaust on the 3.5L cars to be closer to 2.5" than 2.25", what kind of muffler would you say came with the non Sports/VR-X models given that the 8kW power increase between the standard Exec and the VR-X is solely attributable to the muffler swap?

sorry to "hijack" this thread!! :D
i have the TH sports (147kw) and i went to hornsby northshore and performance exhaust shop, and he quoted $200 for an upgraded,free-er flowing muffler for my car.

does this sound right?good price?
he said it will give it a nice note,wont drone or sound like a 4cyl and will give a nice increase.

what do you magna folk think?
yay or nay!

:D

Chris

depends what sort of muffler you get mate, i payed $250 for a good quality stainless steel straight through muffler(xforce) and i'm expecting to pay around $50-$80 to have it fitted

I replaced my TH Magna 2000 model with cat back 2.5" system. Straight through Berklee resonator, and 2 straight through Berklee mufflers with 2 dual tips. It drones a little inside the cabin, but sounds so damn awesome. To get everything installed, about $800 from TTF.
I have noticed a nice power increase in the higher revs area, especially after 3000rpm. And it revs more freely now above the 5000RPM, where it used to back off.

sorry to "hijack" this thread!! :D
i have the TH sports (147kw) and i went to hornsby northshore and performance exhaust shop, and he quoted $200 for an upgraded,free-er flowing muffler for my car.

does this sound right?good price?
he said it will give it a nice note,wont drone or sound like a 4cyl and will give a nice increase.

what do you magna folk think?
yay or nay!

:D

Chris

Sounds slightly dear, but ok. As I mentioned above, friend of mine just got a lukey (almost certainly what you've been quoted for) today, for $180 fitted. I also have a 147Kw TH Sports, and if she doesn't like the extra noise of the lukey, I'll swap her for mine! :)

Z

Apart from the fact that a number of people have measured the exhaust on the 3.5L cars to be closer to 2.5" than 2.25", what kind of muffler would you say came with the non Sports/VR-X models given that the 8kW power increase between the standard Exec and the VR-X is solely attributable to the muffler swap?

I measured my pipe when I put 3" thru and it's 2.25" internal. Closer to 2.4"+ on external walls if you held a tape measure up to it :doubt:

I measured my pipe when I put 3" thru and it's 2.25" internal. Closer to 2.4"+ on external walls if you held a tape measure up to it :doubt:

That raises an interesting question.. when ppl talk about 2.5" piping or 3" pipes, do you expect them to be talking about the internal or external diameter?

Exhaust are quoted using external for some reason, weird considering wall thickness varies.

Usually "pipe" is quoted as the external diameter, and "tube" is quoted as the internal. No clue why.