My TF has developed a small hole in the up-and-over exhaust pipe, close to the rear muffler, so it's time I worked out what to do on the exhaust side of things.

Now on the 3 litre, it appears that the pipe after the cat and the first (larger) resonator, the pipe outside diameter is a pinch larger than 2.3 inches. Just before it gets to the second (small hotdog) resonator, the pipe size appears to shrink to 2". I don't have a problem with this, exhaust cooling and becoming more dense probably doesn't warrant more than 2" in the latter quarter of the exhaust.

The next bit is the up-and-over bit of pipe. It obviously needs replacing on mine, due to a hole. However, being only around the 2" outside diameter (oval, due to mandrel bends), exhaust shops are more likely only going to be able to press bend a new pipe in.

So from the sounds of things, the easiest compromise I have thought of is the following: (for free flow and reasonable velocity, low resonance)

Step up the pipe size to 2.25" from the end of the hot dog, up-and-over (press bent), and then fit the biggest physical volume rear muffler in 2" offset straight through design.

Any thoughts?

Cheers,

Dave

I don't have a problem with this, exhaust cooling and becoming more dense probably doesn't warrant more than 2" in the latter quarter of the exhaust.
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Step up the pipe size to 2.25" from the end of the hot dog, up-and-over (press bent), and then fit the biggest physical volume rear muffler in 2" offset straight through design.

Any thoughts?

Cheers,

Dave

In my opinion it looks like you are amming for a bit of extra performance since you wish to fit a straght through muffler. If this is the case I'd go for 2.5" mendrel bent piping catback with 2.5" resonators. But if you want somthing quieter and possiblly less costlly go for 2.25" mandrel bent piping. I personally wouldn't go for pressbent piping as the bends in 2.25" piping are reduced to about 2" (so no decrease in restriction from stock).

I personally had a 2.5" press-bent system with an earlier type of Lukey offset straight through muffler (non-magna specific). While this system flowed better than the stock muffler, it was the fact the muffler was changed that did the differance not piping. I now have the same muffler fitted but this time with 2.5" mendrel bends and the car a little extra pickup than previouslly. :P

I've heard some people say it's possible to improve on the way that pipe works - iron out some of the bends and make it less restrictive. Probably a good time to look at that too.

Hi Phonic,

I'm definitely going for something with a bit quieter exhaust. Even the parents' stock TL VR exhaust is a bit too resonant in the car at some revs/load for my liking. Pity though, it's quite a nice sound outside the car!

If 2.25" mandrel is an option, I'll certainly check it out for cost, but from the feedback from a couple of places has been that they generally only do mandrel in 2.5 and up.

I suppose each exhaust shop will have a different agenda as to which pipe and muffler sizes they want to sell too.

I suppose when I think about it, the magna has at least as much power as my VH had at its last dyno, and it has a 2.25" exhaust, 1 offset straight through front muffler and 1 large rear straight through resonator, so realistically the magna could do with at least a 2.25" rear straight through muffler.

Anyone got a 2.25" rear muffler on their 3L, or has everyone gone to the common replacement 2.5"s ?

Cheers,

Dave

cthulhu - which pipe - the up-and-over?

Cheers,

Dave

cthulhu - which pipe - the up-and-over?

Cheers,

Dave

That's the one. I'm sure I've read on here that people have managed to fit a bit of straight(er) pipe in its place.

Are there any benefits, cost or performance, to installing a sports/VRX Magna piping to a 3.0 Magna? Obviously, there will be a straight through muffler at the end of it all. I'm just wondering about the rest of it?

Screaming TE,

The 3.5 has all larger pipe diameter from the start from what people say - so it would be capable of better flow. Whether the 3.0 needs it or not, and whether the 3.0 would become a DroneMachine (tm) or not, would be hard to say.

If I had an adapter to hook up a pressure gauge to the exhaust pre and post cat, I'd be able to show how much relieving the exhaust needs...but I don't, so can't dwell on it :P

Cheers,

Dave

It was something that i ahd just thought of when i read this post. If one of the 3.5 boys would be willing to donate an old exhaust that they have discarded due to an upgrade, then i would be happy to supply a donor car. :D
I would take it that extractors would benefit this mod as well?

Screamin TE,

I'm sure it's worth a shot if you can grab a 3.5 owner from here going for an exhaust. I think most people would have gotten their old system chucked by the exhaust place.

I suppose it would depend on the design of the extractor as to whether it'd love the larger pipe size. The only options so far would be the Pacies and the Street or Race RPW ones.

I'm only after an exhaust though, but would be interested in your results if you try it...

Cheers,

Dave

Just got a quote from one place:

To replace from before the hotdog with: a 2.25" hotdog, 2.25" press bent over and a 2.25" sports muff is $225. Mandrel up-and-over would be approx and extra $100.

Will see what other places say...

Cheers,

Dave

Update - Just got another quote that I decided to go with - the sports system from cat back for $210. Booked in for tomorrow lunchtime.

If anyone wants some stock 3L mufflers...let me know quickly :D

Cheers,

Dave

That's the one. I'm sure I've read on here that people have managed to fit a bit of straight(er) pipe in its place.

Your avatar is cute

Well ... thought I'd give the logan (moss st) exhaust places a go as they're renowned for being cheap. I think I regret that now!

I booked in with the one mob to get the exhaust done yesterday, but when I got there, they didn't have me booked on, and their exhaust tech wasn't there either.

I then went up to the other one where I got a quote, and luckily enough they had time to do the exhaust. Now I told them what I wanted on the phone (replace from the hot dog [2nd] resonator back, with a straight-through rear muffler. I went around to see what they were doing a little later, and the exhaust guy was cutting off the exhaust just past the flexi bend (before the 1st (!!) bend.) I went and informed the guy that it was not what I wanted, and explained that I wanted the front resonator and the pipe before the hot dog left there.

What happens when I leave them to do the rest of the exhaust? They stick the front resonator back on, but then put a 2.25" hot dog res STRAIGHT after the first res (virtually no pipe in between), give me press bent pipe from there onwards to a rear muffler, which I don't even know if it's straight through or not (will check.) I'd better check the pipe size too - make sure they haven't given me 2" pipe!

So effectively, anything I told them was wasted, as I lost the nice mandrel (in slightly larger than 2.25") to where the hot dog used to be (which was the point!)

I'm in two minds if I like the exhaust note either! Arrrghh!!

Not happy, may pay them a revisit and have a few words...

Cheers,

Dave