TD42 New exhaust????????

[89GQ]

Sorry mods went through the search and couldn't find answer!! Anyhow Iv'e been told 2 1/4.-2 1/2 inch exhaust is good for performance,economy etc on the TD42. Im'e not after the cool sound! Question is will the performance /economy be better with just the larger pipe from manifold or do you need extractors/headers aswell???? My original has busted at the braided bit near the front. Just wondering whats best to do. Cheers.

[Finly Owner]

Easy answer is any system that move exhaust gases quicker gives a better performance hence increasing economy to varying percentages. Extractors(free flow) exhausts allows an even collection of exhaust gases to send through the pipe quicker than a standard manifold.

Tim

[89GQ]

Cheers tim! Iv'e seen the complete sets on ebay with extractors from 2 1/4 to 3 inch so will go through loosing sleep again picking which way to go.

[Finly Owner]

Earlier threads her recommend mandrel bends (no lessoning of size at bend + no restriction), I understand this is important for performance motors, but have not asked why it is needed for standards like mine.

[89GQ]

Earlier threads her recommend mandrel bends (no lessoning of size at bend + no restriction), I understand this is important for performance motors, but have not asked why it is needed for standards like mine.Yeh i see some are advertised having them! So they would be the way to go. The old girl wont know whats happening, Taking off her 21 year old intestine.

[Finly Owner]

let us know what you decide and the results and costs.

Tim

[89GQ]

No worries Tim will do a drive around to some places aswell. Cheapest on ebay is 770 including headers 2 1/2 inch

[red92gq]

just make sure ifyou get extractors that they also fit a decent sized flex joint(bellows) otherwise you will be for ever welding your extractors up

[89GQ]

Well !! Interesting! A Few exhaust shops, And one of the 4WD Mobs that do the work said we're doing our self out of a sale, but Headers are not needed on the TD42 !!!! The design of the exhaust manifold is sufficient and does not restrict Flow! So therefore go 2 1/2 inch from manifold down to a Flexjoint and then follow on through a sports muffler too the back. My local Parts place i use rang Lukey Whatever there name is and can do it from manifold back for around $400. Of coarse i went too a couple that said you cant buy 2 1/2 and we have to bench bend it all up and $900 later have an exhaust! So good to see the honest ones who steered me straight!

[Bigrig]

Well !! Interesting! A Few exhaust shops, And one of the 4WD Mobs that do the work said we're doing our self out of a sale, but Headers are not needed on the TD42 !!!! The design of the exhaust manifold is sufficient and does not restrict Flow! So therefore go 2 1/2 inch from manifold down to a Flexjoint and then follow on through a sports muffler too the back. My local Parts place i use rang Lukey Whatever there name is and can do it from manifold back for around $400. Of coarse i went too a couple that said you cant buy 2 1/2 and we have to bench bend it all up and $900 later have an exhaust! So good to see the honest ones who steered me straight!

Wait till you here the tone come out of that thing, I fell in love with mine all over again when I got the exhaust done!

[89GQ]

Wait till you here the tone come out of that thing, I fell in love with mine all over again when I got the exhaust done! Yeh cant wait! She's abit noisy with the flex joint collapsed/broken at the moment. Did you do similar in 2 1/2 inch, With sports muffler? Dunno the difference between sports and normal muffler?

[Bigrig]

Yeh cant wait! She's abit noisy with the flex joint collapsed/broken at the moment. Did you do similar in 2 1/2 inch, With sports muffler? Dunno the difference between sports and normal muffler?

I ended up putting on pacemaker extractors and a 2.75" mandrel bent pipe (no cat converter) so now it makes a very nice tune through the rev range!!!

[Finly Owner]

GQ sorry about bum steer on headers/manifold, most times extractors are better than factory manifold

Tim

[89GQ]

GQ sorry about bum steer on headers/manifold, most times extractors are better than factory manifold

Tim No bum steer at all Tim! It was one of the blokes at the 4by shop that said it! Im'e still not really convincerd the original manifold would have as much free flow as headers!! Will be looking into it more, He quoted that the manifold on the TD42's had a large internal diameter and wouldnt really notice a huge difference, Mind you he also said bench bends are better than mandrel???? So will still see a few more places and get some more feedback. Cheers Jeff

[YNOT]

The factory exhaust manifold may have a large internal diameter but extractors use tuned length pipes to draw the exhaust gases out of the cylinders.
Bench bends better than mandrel........in what universe???

Tony

[89GQ]

The factory exhaust manifold may have a large internal diameter but extractors use tuned length pipes to draw the exhaust gases out of the cylinders.
Bench bends better than mandrel........in what universe???

Tony Yeh he rekond bench bent for better back preasure as well, What the!!!!!!

[89GQ]

I can get a complete system with headers for $770, but its 3 inch! Does it make that much diff with 3 inch? Just that iv'e been told 2 1/2 is better.

[YNOT]

A bit of back pressure is good (apparently) on a naturally aspirated motor but there should be enough in the mufflers.
3" on a naturally aspirated 4.2 is over kill, 2.5" is heaps, but as Scotty has proven with his 2 3/4 mandrel bent system it will still work well.
In rough terms a 3" press bent pipe would flow roughly the same as a 2.5" mandrel bent pipe.
Also, just be aware that any petrol powered vehicle built after about 1984 legally must have a catlytic converter, you risk large fines if you don't have one.

Tony