Mandrel Bent or Not

[herks]

Folks

Have an 02 100 series 4.5 petrol and am looking at sticking a set of tuned headers and straight through exhaust to give me a little better fuel economy as well as a minor increase in performance.

What are peoples opinion as to going a mandrel bent system against a standard 2 1/2 inch bend.

I am advised that with the mandrel you loose to much wall thickness (.9mm average) and all for only a limited % performance increase when used in conjunction with tuned headers and good quality straight through CAT /Muffler etc.

the difference is a couple of hundred $ so is it worth the effort when you look at the thinner wall thickness etc as well ,which severely reduces the life of the pipe anyway.

Ta

Herks

[PGS 4WD]

Mandrel is better, but straight through system on that engine will drone like a bastard, you'll need minimum offset flow muffler, probably a reverse flow.
They chip well, can take more timing and tend to cruise too rich as they havent an O2 sensor for mixture control. Nice improvements in power too.

Joel

[TWISTY]

If you go mandrel, dont get a mild steel one, go stainless.

I put a mild steel madrel bent exhuast on my 4runner when the lexus V8 went in. It was lucky to last 2 years before it was starting to rust out. I did do beach trips in it, but anyone who seen the runner would know I always kept it spotless.

[herks]

Yes Twisty, that is because with mandrel you thin out the wall thickness on the bends and hence the very short life span.

Hey Joel, any more info on the Chip issue you mentioned in your post? Interested in this as well.
Have been warned about the straight through effect earlier. will now probably include a decent muffler or CAT as well.

Ta

Herks

[lshobie]

Here is my mandrel bent 3 inch with aeroturbine exhaust, I love it:

http://youtube.com/watch?v=Edy7k11tLGs

[herks]

Well finally made up my mind. Fitted a Pacemaker Tri-Y set of Headers and 21/2 inch pipes, no Cat as there was not one fitted at factory. Straight through muffler. Now has a good note and a noticeably better amount of low down torque. Will now see how the fuel economy goes. Got it at a good price as well with a 2 year warranty on whole system. Very happy.

[bj on roids]

Did you go Mandrel or not, i dont reckon you get much more value for the extra price you pay, personally.

[Troopy93]

Mandrel systems are better suited to Turbo Diesel vehicles, no benefit on a petty or n/a diesel says my exhaust bloke.

[DIRTY ROCK STAR]

no Cat as there was not one fitted at factory. .

mate i dont own a 100 series petrol. but for their age i find this very hard to believe.
They are mandatory on all vehicles that came out running ULP from factory unless im mistaken..
i would watch out come rego time or if the note is too good and RTA pull you over.
i was looking at not running a cat and the figure escapes me but i thoguht it was close to 5 grand fine for not having one fitted.

[fester2au]

no Cat as there was not one fitted at factory. .

mate i dont own a 100 series petrol. but for their age i find this very hard to believe.
They are mandatory on all vehicles that came out running ULP from factory unless im mistaken..
i would watch out come rego time or if the note is too good and RTA pull you over.
i was looking at not running a cat and the figure escapes me but i thoguht it was close to 5 grand fine for not having one fitted.

Not necessarily, commercial petrol vehicles didn't always have to run them and 4WD wagons were classed in this category but I'm not sure when/if that ever changed. You would think by 2002 it would have though but if the cat was previously removed and the rest of the system was standard it should be pretty obvious that something was removed.

[herks]

Nope The system I pulled off was the original and there was no Cat although there was a section in the pipe to fit one. My exhaust fitter confirmed all was still original., no mods evident.

Went the standard bent piping with the one straight through muffler. A bloody good throaty raw but way to loud especially over 2k RPM, real cop bate. the exhaust guy did say it may be loud and to bring it back if so.

Took it back today and had added an additional muffler, again straight through and what a difference. Much quieter but still with a good note (not what I did it for by the way).

found that down low performance is noticeable (on road) cant wait to see what I get in the weeds!

The extra muffler did not cost me either. Whold system, headers to tail pipe $1200 neat with a 2 year warranty. will now see how the fuel economy goes, will let you know.

Herks