Hey everyone.

I've got me a stock white tr v6 5spd (which i love:))

anyway i figure its about time to replace the stock cat back exhaust with something a little more free-er flowing. So i've been reading around the other threads here and at mogwa and mufflers seem to be covered comprehenively and it seems the lukey is the way to go. thats fine. but my question is about the rest of the piping.

It seems to me that it is precieved that 2.5" mandrel bent piping is the way to go. However i'm i poor uni student so my budget retricts me to a press bent system. Now could the press bent pipe be slightly larger to try and help offset the restrictions of the poor bends. Would say a 2.75" press bent pipe to a 2.5" muffler be a better performing system than a 2.5" press bent pipe to a 2.5" muffler?

i realize that there the press bend prolly cause turblence which would lower the flow rate, but could this be offset with size?

Welcome.

Well, I reckon your piping is going to be 2.25 already so going to 2.5 could be beneficial but I'd imagine that without headers and other stuff, it might not be needed meaning the biggest benefit will be from a free flowing muffler. Also, going to mandrel bent piping might be worth it. I'm a 3rd gen though so someone like TZA-BOY or Killbilly would be best to answer this. 2.75 would be overkill on an NA engine with minimal mods.

thats what i was thinking. I know my car has 2.25" pipe now as standard (guessing its press bent too, maybe i should crawl under and have a look :confused: ). So i'm thinking 2.5" is they way to go. But i can only afford press bent piping and i know mandrel bent is the way to go...

So i was wondering if the flow rate restrictions of press bent piping (compared to the same size mandrel bent piping) can be overcome by increasing the pipe diametre?

Has anyone compared volumetric flow-rates of press bent piping against mandrel bent piping?

For the time being I think your better off just getting a decent muffler, the problem with press bent piping (even if you increase the size to over come restrictions in the bends) is the the constant increase and decrease in diameter from bend to bend creates uneven flow and suppossedlly increases droning and decrease flow further, buts what I have been told so I can't garentee my information :D

If you dont have much money...stick with the stock cat back system and just change your muffler.

Get the 2.5" mandrel bent piping later. I would recommend, if you can, to save up and get it all done at once. I got a 2.5" mandrel bent cat back exhaust, lukey LR2779 and chrome tip for 490 fitted. It's a bit more than some other places but the quality of their work is impeccible and I trust them a lot, they also made my custom extractors for the DOHC conversion (NOT cheap lol).

I would wait if you can, but if not..just get a straight through muffler for now and do the rest later.

Once again, i have to recommend the Lukey bolt on system.

Very economical and will make a lot of difference on your car.

Why consider anything else ??

Hey, hijack time. Any one reckon making the piping follow a more direct route to the back and under the rear cross member would give an improvement? I mean, Mitsu quote smaller figures on the AWD's.

exhaust rap would make more difference i would imagine than shortcutting 30cm of piping

Once again, i have to recommend the Lukey bolt on system.

Very economical and will make a lot of difference on your car.

Why consider anything else ??
Alot of difference to an otherwize stock car? even with extractors and hi-flown heads a muffler will not make "alot of difference" :redface:

exhaust rap would make more difference i would imagine than shortcutting 30cm of piping

What's exhaust rap? I'm not talking about making it shorter, more along the lines of removing all the 90 degree bends.


Alot of difference to an otherwize stock car? even with extractors and hi-flown heads a muffler will not make "alot of difference" :redface:

Is 11HP 'alot of difference'?

Sorry turbo_charade I'll have to argue with you there. When I got the straight through muffler and cat back exhaust, it DID make a lot of difference.

The reason being that the stock magna mufflers (barre the sports/vrx) are very restrictive. I had a huge difference in top end, quite noticeable difference in mid power, there was no difference to bottom end, as was expected.

Once again, i have to recommend the Lukey bolt on system.

Very economical and will make a lot of difference on your car.

Why consider anything else ??
umm, gee i dunno. better quality at lower prices maybe??????

stay away from press bent piping if upgrading, this creates more exhaust volume than velocity so its louder and while ultimate flow can be as good with larger piping, bottom end feels lacking. as someothers have said, u better off spending the money on decent headers.

Sorry turbo_charade I'll have to argue with you there. When I got the straight through muffler and cat back exhaust, it DID make a lot of difference.

The reason being that the stock magna mufflers (barre the sports/vrx) are very restrictive. I had a huge difference in top end, quite noticeable difference in mid power, there was no difference to bottom end, as was expected.
but your cat back exhaust would have help aswell, im talking bolt on muffler change alone. on a dyno your going to be flat pushed for 2kw from a muffler. That might be "alot" of difference on my engine (only has 50kw) but on a 150kw engine its not even 1.5% gain.

probably still worth it but dont expect to notice any change kids. sex'n'TF got it done, sounds nice and would be helping mildly but it sure wasnt noticable

as kb pointed the stock magna muffler is very quiet and very restrictive, mitsubishi themselves claim 8kw gain just with the muffler. on your car a free flow muffler would make a big difference because it is turbo, with turbos the less backpressure u can achieve after the turbo the less lag u have.

jsut a quick question

your saying 2.5" for a V6, well i'l get the good old 4 cyl so what size would you reccomend for that. i was thinking no bigger than 2.25" for the 4 cyl but yeah whats the reccomended?

but your cat back exhaust would have help aswell, im talking bolt on muffler change alone. on a dyno your going to be flat pushed for 2kw from a muffler. That might be "alot" of difference on my engine (only has 50kw) but on a 150kw engine its not even 1.5% gain.

Well, I did a before and after within 1.5hrs and gained 11HP at the wheels. That's a little more than 1.5%. The stock mufflers are very restrictive. That's why there's a difference between Exec's and VR-X's and the difference is only the muffler.

That's why there's a difference between Exec's and VR-X's and the difference is only the muffler.

The VRX (180kw) has upgraded cams too ... the sports has just an exhaust upgrade (163kw)

Both have better than standard tuning :)

Umm... that's the Ralliart with 180. It's mods were upgraded internals, higher compression, headers, cams, extractors and ECU to match.

Both the VR-X and Sports have 163.

i believe u r correct redav for the TJ, but is the same true for TL?

i believe u r correct redav for the TJ, but is the same true for TL?

YEP :D

but your cat back exhaust would have help aswell, im talking bolt on muffler change alone. on a dyno your going to be flat pushed for 2kw from a muffler. That might be "alot" of difference on my engine (only has 50kw) but on a 150kw engine its not even 1.5% gain.

probably still worth it but dont expect to notice any change kids. sex'n'TF got it done, sounds nice and would be helping mildly but it sure wasnt noticable

The 155kW to 163kW difference in the TJ's was due to a muffler change.

The statement you made was much too broad, because with magna's they have a very restrictive muffler and it DOES yield a noticeable and decent gain from a muffler swap.

So really, depending on what type of muffler you have stock, depends on how much gain you get from a muffler swap.