TD42 exhaust flexy

[Nav230]

Fitted a new one to my Patrol. Mine was looking just a tiny bit sooty on the outside and when I looked inside I found it was just 39mm internal bore

Bought a flexy off ebay with 57mm diameter 100mm long tube welded to each end. The pipe on the Patrol is 55mm outer diameter and I wanted it to slide over the top so it was my only choice since the next size down is 54mm.

I cut out the original flexy with my dremel because I wanted to leave the front downpipe in place to help alignment and avoid potential problems with manifold fixings.

Because the flexy was a little larger than ideal I added 2 extra notches in the ends to allow it to close up more with the clamps. Plenty of exhaust paste and it was good to go. I had to make a new clamp to go onto the mounting on the gearbox because it had got thin due to rust, so used some stainless steel and put all stainless nuts and bolts in everything that had been removed.

Only had chance to take a short drive around town and the only difference I can tell is that it feels a bit smoother. I'm hoping that when I get out onto some faster roads there will be an improvement elsewhere, but I suspect that I really need to get rid of the massive centre silencer which looks like a baffled type to me and is probably very restrictive. I have a big straight through box to go in there soon.

 

[makeitfit]

Good work, 3" zorst is the size of choice in Aus :sly
I'll get to mine ....................................eventually

 

[Nav230]

Good work, 3" zorst is the size of choice in Aus :sly
I'll get to mine ....................................eventually

I'm non turbo and still resisting converting because I just can't be bothered. So I'm hoping the straight through box will be enough to help free things up a little and make it sound a bit nicer without losing low down torque and making it too noisy.

I did some research and found that a 39mm exhaust would restrict power to around 100hp, though of course that's a full length at that diameter. In theory then I may have freed up a little power, but we're only talking single figures I expect. When you add up the fuel adjustment, timing, snorkel and exhaust as well as setting the tappets and running synthetic oil, I might have 10 more hp than when I bought it. Even if it's not that much, it certainly goes better and must have helped the fuel economy.

 

[makeitfit]

Is yours the 4.2 ?

 

[puddle hoppers inc.]

Fitted a new one to my Patrol. Mine was looking just a tiny bit sooty on the outside and when I looked inside I found it was just 39mm internal bore

Bought a flexy off ebay with 57mm diameter 100mm long tube welded to each end. The pipe on the Patrol is 55mm outer diameter and I wanted it to slide over the top so it was my only choice since the next size down is 54mm.

I cut out the original flexy with my dremel because I wanted to leave the front downpipe in place to help alignment and avoid potential problems with manifold fixings.

Because the flexy was a little larger than ideal I added 2 extra notches in the ends to allow it to close up more with the clamps. Plenty of exhaust paste and it was good to go. I had to make a new clamp to go onto the mounting on the gearbox because it had got thin due to rust, so used some stainless steel and put all stainless nuts and bolts in everything that had been removed.
the middle baffles can be a pain, at the risk of sounding a little tight i generally get a long piece of inch and half steel and sharpen the end and hammer a hole thru them, careful not to go too far. i know it sounds a bit extreme but the end result is the same, bit throatier, bit easier flowing. mot friendly, they were scatching there heads when the ninja went in for mot with standard cans lol

 

[Nav230]

Makeitfit, yes its a 4.2

Puddle hoppers, I did think of that too but my only concern was if I ended up knocking a baffle loose and it blocking the exhaust. Having said that, now that I have another silencer if it all goes wrong might be worth a try.

 

[Nav230]

Drove to work today, mixture of country roads, mway and town driving. I just drove how I normally would. Definately not pressing the throttle pedal down as far for same speed and it pulls 5th gear easily up a long reasonably gentle hill at indicated 35mph and 1050 rpm, used to drop to 4th there.

It's a LWB with 265 75 16 tyres and I've gps calibrated the speedo to just slightly over read by about 1-2 mph at 30.

Will even stay in 4th right down to 1000 rpm and accelerate away without even the slightest hint of labouring.