3" Exhaust on a 200tdi

[Paul]

For some reason I thought I'd already posted this up a couple of weeks ago. Obviously not, so here it is.

Apologies to AULROians who may have already seen this.

After umming & aaahing for months, I finally took the plunge and did the 3" exhaust thing.

Having damaged the rear section of the original system a couple of times, I went through the initial idea of just fitting a 2½" tail section, then maybe going right back to somewhere near the engine sump. Finally I convinced myself that it was worth messing around with a 3" system right back to the end of the turbo dump pipe. It was only after I picked up a spare 200tdi Defender engine and taking the dump pipe off that, that I realised how restrctive the dump pipe actually is. Although it connects to a 2½" initial pipe, the outlet for the cast iron dump pipe has an I.D. of just 40mm!! The section where it connects to the turbo and drops down at a right angle is even more restrictive.

It was this piont which finally convinced me that I wouldn't get the best out of a 3" system without doing something about that dump pipe. The result is I had someone make up a new dump pipe from the flange on the tubo back, all in 3" mild steel. In the best "in for a pound, in for a penny" fashion, I also had them fit a 3" stainless flexible section along the lines of a 300tdi (just bigger).

Well, here's a few photos:

Can't see much here but the bloke who made up the new 3" dump pipe did an excellent job, even managing to get the bend tight enough for the original heat shield to go back on:

The new stainless flexible coupling, just after the system straightens out by the engine sump:

Mid section on the way past the gearbox. I now have proper flange joints by the engine and after the transmissions, so that I can take out the centre section easily for the inevitable geabox/clutch swaps etc:

Just enough room to squeeze past the Maxidrive actuator on the rear axle housing:

The front section is all mandrel bends welded together, but the rear is just one pipe with normal bends (in the interests of economy). I figured with 3" pipe I wouldn't notice a slight drop in diameter at the bends with a 200tdi.

Tailpipe is tucked up quite tight, hopefully less likely for me to squish it in the future:

Paul

[cols110]

Very nice mate, but did it make any difference.

I want to put a 3 inch system on mine when the time comes, there`s are a crowd up in Brisbane who sell stainless 3 inch exhusts with a nice free flow muffler, but the price ain`t real nice. $1350

[Paul]

Very nice mate, but did it make any difference.

Well, let's just say I've spent a lot less on things in the past for a lot bigger effect.

[rick]

Well, let's just say I've spent a lot less on things in the past for a lot bigger effect.

law of diminishing returns

the better spool up and better rev range for overtaking was worth it on mine in my opinion. I try not to think of the time involved building it

The stock 300Tdi system is a pretty good compromise, and much better than the OE Japanese systems.

[cols110]

Interesting, thats why the thought of blowing over a grand for a ready made system is a bit OTT.

If I can get someone out here to make me one locally at a decent price I think I`ll give it a go, to reduce the lag a wee bit would be a bonus.

[rick]

Interesting, thats why the thought of blowing over a grand for a ready made system is a bit OTT.

If I can get someone out here to make me one locally at a decent price I think I`ll give it a go, to reduce the lag a wee bit would be a bonus.

a few of the blokes on the AULRO board, IIRC Hiline was one, reckon it was well worth it on their TD5's. He had his made up for a bit over $400. (mate's rates)

It cost me $300+ in materials, but at least I have enough 3" aluminised tube plus a couple of 3" mandrel bends left to do a complete system for the Patrol with only having to buy about 4 more bends and some flanges, oh, and a muffler (if I really want to subject myself to all that cutting and welding again........ )

To give you an idea on pricing, MTQ engine services have a deal on 3" mandrel bent TD42T Patrol systems, including a new cast 3" dump pipe of $660 which makes me reluctant to make a Patrol system as the dump pipe is $220 on it's own. Makes $1100 for a TD5 system look very exxy.

I built the exhaust before I tweaked the pump, so these comments reflect that. When I first did mine I was very underwhelmed, until I gave it a big rev in third and suddenly I could go past 80km/h in third and it kept accelerating !

With the OE system 80-85km/h was the maximum speed in third with the 255/85's, it just stopped accelerating and was very harsh. Now, if I have to, it can go to 95-100km/h (not that I do that too often)

Maximum EGT's also dropped over 20*C (below 600*-stock fueling) and the quicker spool up is very noticeable on the 130 with the big tyres.

Don't be tempted by those that say don't bother with a muffler as the turbo acts like one. They obviously have never run one without a muffler !

I ran mine for about a month without anything and the sound was just too much. I could be heard about 5km away at full noise, and the resonance at 100km/h was just too painful (obviously that would be different in a TD5) Mufflers and resonators are good ! (or Paul and I are just getting too old ) Currently only have a twelve inch resonator right at the back, but after a recent trip to Qld I think a muffler in the centre would be a good idea too.

[white90]

I removed all boxes when I fitted the underdrive

drove 20miles and purchased a box

as the noise was embarrassing as well as annoying

a straight through oval box fitted and normal service resumed

EGT max 720 18psi boost and a reasonable amount of fuel added

[rick]

there's a few blokes out here running RRC's and 'Fenders sans mufflers and I don't know how they can stand it, apart from the fact that a 4cyl diesel isn't the most evocative of sounds......

The worst part was the resonance. It actually had a muffler, it was the cabin..........

Anyway, back to this BAS

[rick]

as to fuelling, I'm pretty happy with where I've got it now. I can sail past 720* if I'm not careful on our long climbs at speed if it's a warm to hot day, yet on a quick trip up to Brisbane to see Dad at Easter I averaged 10.8l/100km travelling at pretty much 110km/h everywhere.

Not too shabby for a 130 with muddies and more bar area than a leagues club.

[Paul]

To maintain 110kmh on the flat on a cool (sub 25*C) day, my EGT sits at around 600*C constant. Any kind of incline will see it blast up to 750*C and beyond easily. Hot days and 110kmh is pretty much out of the question, more like 100kmh unless I ignore the EGT. Boost is limited to 15psi max. 110kmh requires about 12psi constant.

I also can't rev past about 3100rpm with any kind of mechanical sympathy. I take it you do a bit better than that Rick?

[rick]

hmmm, 100km/h is somewhere from 380-460* depending on breeze, road surface, gradient, etc.

Probe is in classic 300Tdi spot (EGR blanking port)

Steady 100km/h is 11-12psi, with a headwind or gentle grade (barely noticeable except with a boost gauge/EGT or on the push bike) this will jump to 13-14 psi. The roads around here are quite 'dead' in cycling terms, very coarse bitumen.

Climbing the range at Murrurundi, the climb is about 150-170m over 2 km and I'll hit 720* at the crest of the range, sometimes a bit before and so feather the throttle for last few hundred metres.

When I bumped up the fueling the boost jumped 1-1.5 psi over stock, so I'm running around 16.5psi, sometimes spiking to 17psi. Bit hard to judge as the gauge only goes to 15 !

I've fine tuned/backed off all my settings from where I had them originally for no (apparent) decrease in performance. There's still copious amount's of black smoke from takeoff and at gearchanges.

[rick]

One thing that I did years ago (and there was no immediate benefit from) was replacing the hose between the wing and the air box with an 80mm ID pipe and removing the restriction on the snorkel where it necks down to around 53mm ID.

I know the 200 is totally different in this area, but may be worth looking at ?

[Paul]

Are you still using the stock intercooler Rick?

I might try backing off the fueling a bit and feeding in a pond or so more boost. That might cool things down a tad.

[rick]

yep, stock I/C

[Paul]

on a quick trip up to Brisbane to see Dad at Easter I averaged 10.8l/100km travelling at pretty much 110km/h everywhere.

Hmmm...trying to hold a steady 110kmh on the way back from Robe, I averaged just under 14l/100km.

[rick]

waaay too much fuel going through there Paul, something's not right, although I don't know how you were loaded, etc. Running around here fully loaded with work gear (600kg) and ladders on the roof I've never gotten worse than 11.8l/100km. Checking the odometer against the RTA 5km check it's reading under (showing less on the odo than the actual distance) by about 50m, so that's pretty good for calcs.

I have the pump wound up a fair bit, the difference is anywhere from 10-20km/h on most hills, depending on the gear and the hill. I actually crested the range here at 115km/h and 720* without a load on that Qld trip, the best in the past empty was 85 !

That's a good thought re bumping up the boost. It really does sound like it's lacking air. A pound or so is a fair bit more air.

[rick]

forgot to add, check the pump timing as well.

Ideally you actually need a little advance when increasing the fueling, as all you are doing upping the fuel is increasing the injection duration.

[Peterla]

Paul,

Looks like a few interesting thing to look at on my disco too.

If nothing else the 3" exhaust looks good and sounds might fine.

All you need now is to find the speed to keep up with me on the road

and for another 10 grand I might be able to keep up with you off road.

Pete

[Paul]

and for another 10 grand I might be able to keep up with you off road.

Pete

A Disco keep up with a Defender off road? No chance fella!!

Besides, my crystal ball tells me your Disco's going to be on the end of my winch rope soon, and I'll be posting photos of it on here!!