Thread: Is modifying a series exhaust worthwhile

the extractors with a mandrel bent 2 1/4 inch system is worth doing failing that go for a stock bent 2.5 inch exhuast on the end of the extractors, straightening it out as much as you can and using lower angle bends where possable is always a good thing.

Thanks Dave, does a straight line exhaust have repercussions?

I have noticed some towtruck exhausts have intentional 180 degree bends in them just before or after the muffler.. i presumed they were for a good reason. maybe for an increase in torque?

not that I can think of.

What Dave said.

Way back when I was a kid my uncle had a Series III with the 2.25 in it.

He fitted some Perry headers and a straight through muffler/2" system and the thing flew.

I kid you not, with a Fairey overdrive he pulled away from Dad in a near new HJ Holden van (202, the HX had just come out too which gives you a time frame) on the southern freeway. Dad backed out at 140km/h and the Landy pulled away.
A couple of truckies thought they were seeing things from the CB chatter.

Thanks gents. I'm still unsure why the towtrucks etc use these bends, a bit of research may yeild an answer.

So it sounds like a 2 or 2 1/4 straighty is the go. Just have to find a route underneath that is nice and straight but not too exposed.

Cheers,

Sam

Originally Posted by series3

Thanks gents. I'm still unsure why the towtrucks etc use these bends, a bit of research may yeild an answer.

[snip]

Cheers,

Sam

usually it's a space thing between mufflers and stacks.
A neighbour has a stack on his Hilux and it has a 180 after the muffler so it can get to the stack.

Originally Posted by series3

Thanks gents. I'm still unsure why the towtrucks etc use these bends, a bit of research may yeild an answer.

So it sounds like a 2 or 2 1/4 straighty is the go. Just have to find a route underneath that is nice and straight but not too exposed.

Cheers,

Sam

down and out behind the left wheel run straight to the side of the left front fire wall support a long bend or a mandrel bend and run it down alongside the fuel tank thusly...



from there on a shorty angle up and back towards the chassis and put a small muffler there, follow the chassis between the wheel and the chassis over the top of the shocky and then turn it back out and down to spit out just behind the wheel infront of the cross member

I have 2 1/4" to 2" on my 88", Runs a stage two head, cam (from UK) and SU. Had it all dynoed in years ago. It flies.
Has a bad habit of snaping the short rear half shaft if driven hard in lower gears. Leaves the GMH powered series to dead as will sustain revs.

The exhaust runs inside the chassis rail. I wouldnt go any bigger as low end torque may drop off a little.