STX 550 exhaust

[WAS550 STX Nav]

Hi everyone, new member, just got an STX550 and was looking at doing intercooler, piping (hot and cold side), catch can, exhaust and tune.
I’ve already purchased the Plazmaman intercooler kit with hot and cold side pipes. Have posted about catch cans on another thread so I’ll leave that there.
Here I’m interested in what exhaust people are using for these utes. I’ve spoken to numerous shops and an exhaust shop as well. Seems redback is the go to? I did a search on here, but couldn’t find much. I just want something that’s going to work, offer better flow, not to loud (the quieter the better for me). Not fussed on cost.
Also chasing an intake pipe to replace the factory, was looking at ordering the Plazmaman, thoughts? Or what else is available?
Cosmetically ill be replacing the headlights with new items, powder coating the nudge bar Saturn black and getting the Ute ceramic coated. I’m a tradie so will be carrying me and my tools from job site to job site and towing the project car on occasions.

 

[Old.Tony]

You're right, there hasn't been a lot of chatter about exhaust replacements for the STX550. Plenty on the D22 because it's underpowered, quite a bit on the D40 YD25 because it could use a few extra ponies, but the V9X powerplant produces quite enough to keep most people happy.

That, plus the location of the exhaust itself (which isn't easy to access), the size of the exhaust which only just fits in the space it has now, and the fact that changing the exhaust has a relatively small impact making the additional effort seem worthless all add up to the most common result: leave it alone.

The turbocharger (necessarily) has a significant restriction in it, with the following dump pipe being relatively quite open. The actual pony gain by replacing the dump pipe and beyond with something larger isn't going to change the flow characteristics of the exhaust gas sufficiently to produce enough gain to make the expense worthwhile.

However, there are still things you can do to get more beans. The piping work you're doing might not give you a lot of gain, but will give you some more reliability as long as the clamps don't let go. Installing a snorkel (drawing air from outside the engine bay) will give you instant additional cooling particularly at speed - engine bay temps are quite high, and pulling cooler air only helps.

Spending more $, you might consider a water-to-air (W2A) intercooler. These are much more efficient than the installed air-to-air units. Some people have had success with misting systems - almost like a garden sprinkler - that directly wets the outside of the factory intercooler, improving the rate at which it exchanges heat. This alternative is a low-cost, effective method that doesn't fail when the system runs out of water (it uses a separate water tank for the misting system), it just returns it to factory (and really, with the power of the V9X, you might not notice it).

Other more expensive solutions are possible. Upgrading to a higher flow turbocharger will obviously produce benefits. Alcohol injection will also add some ponies (and we're talking straight methanol here, not Johnny Walker Black Label). You'll get some additional beans from blocking the EGR but you'd need to remove the EGR flow detection commands from the ECU or you'll trigger an error.

 

[trimb]

Hi everyone, new member, just got an STX550 and was looking at doing intercooler, piping (hot and cold side), catch can, exhaust and tune.
I’ve already purchased the Plazmaman intercooler kit with hot and cold side pipes. Have posted about catch cans on another thread so I’ll leave that there.
Here I’m interested in what exhaust people are using for these utes. I’ve spoken to numerous shops and an exhaust shop as well. Seems redback is the go to? I did a search on here, but couldn’t find much. I just want something that’s going to work, offer better flow, not to loud (the quieter the better for me). Not fussed on cost.
Also chasing an intake pipe to replace the factory, was looking at ordering the Plazmaman, thoughts? Or what else is available?
Cosmetically ill be replacing the headlights with new items, powder coating the nudge bar Saturn black and getting the Ute ceramic coated. I’m a tradie so will be carrying me and my tools from job site to job site and towing the project car on occasions.

Congrats on your 550 mate.
Re plazmaman to replace the factory rubbish. I can vouch for that on my 550. Excellent improvement on progressive throttle input. You can tell the engine is pulling far better at very minor throttle increments. I coupled this with replacing the rubbish factory intercooler also.

 

[WAS550 STX Nav]

Congrats on your 550 mate.
Re plazmaman to replace the factory rubbish. I can vouch for that on my 550. Excellent improvement on progressive throttle input. You can tell the engine is pulling far better at very minor throttle increments. I coupled this with replacing the rubbish factory intercooler also.

Thanks, yes, I will be replacing the intercooler as well, mine is leaking. Will be f do ping catch can, exhaust and tune/remap

 

[user 10312]

Big Dump pipe and exhaust with a variable vane turbo wont help a lot. There maybe marginal gains. Decent intercooler, especially if yours is leaking will help. Although one with larger capacity will help lower charge air temps and therefore exhaust temps. Probably increase power in the top end. However I often wonder if the larger capacity increases throttle lag, the turbo boost has to fill more volume before it arrives at the inlet valves.

Water/meth injection maybe a worthy of consideration. It can definitely increase mid range power and torque. It has the added benefit that it virtually steam cleans the combustion chambers. (I know this as i had a vehicle that had it and when I removed the head you could eat you dinner out of the combustion chambers) Although probably doesn't increase outright power as it displaces oxygen in the combustion process. You would want someone who knows exactly what they're doing with it. Done wrong, it could destroy the engine.

As for remap. Probably better than plug in aftermarket trickery but again you want someone who knows exactly what they are doing. There has been horror stories with remaps.

Your best bet is to keep it stock, really well serviced and maintained. 550's are great and will keep pace with a V6 Amarok. Even the mighty VQ40 V6 petrol Nav and you will still be dusting off Hilux's Then again I am the party pooper

 

[WAS550 STX Nav]

Interesting take, most things I’ve read have been positive in regards to exhaust and tune, people have seen decent gains in torque and better fuel economy. This is what pushed me in that direction.
I have a very good tuner who I’ll be using, done a heap of diesels as well as performance cars.
But if you are going to put an exhaust on, what’s the go to, for fitment and decent quality?

 

[Cowboy550]

Hello WAS550... I have left my exhaust stock since new, I did consider changing it to 3in and remapping. I drive fast and tow big loads, I use the manual sports mode to slow down all the time, then click it back to auto to take off.
When I changed the exhaust on a XB 351 from single to twin it was awful lost all back pressure, it went from tight to ringing out like and old sloppy 2stroke... anyway my stock 550 pulls up very nice 93k and I’m still on factory pads and rotors
I think every 550 has had an intercooler change ... good move get a really nice one. For remapping I drive with 2 feet ... spool her up at the lights and bingo out in front in DC utes not much is going to beat you if anything even with a trailer.... yet I read a post here taking about a Stx550 pulling 800NM WOW ... maybe have a good drive first after fixing your intercooler, best luck with your new STX550,congratulations, I hope you really enjoy it

 

[AdzeeB]

Evening....
Just for the record I have found a massive improvement with the Legend X 3' stainless steel mandrel bent system by Genie...
I was lucky enough being in the trade to get it a little cheaper and as a test I installed it up at my cousin's farm with nothing more than a set of old rams and found it still relatively easy....
Biggest issue you will find is bolt at the bottom of existing turbo dump pipe/dpf to removing of the system but new one there is no issues easy as all 3 bolts on turbo dump pipe to reinstall...