2.5" Redback Exhaust D22 3L. VIC. S/E Melb

[Rabbid-chop]

FOR SALE 2.5" Redback Exhaust D22 3L. VIC. S/E Melb

Redback 2.5" cat-back as fitted by Midas about 8 years ago. Straight through muffler. Aluminised steel. Has chrome tip.

Jig made dump pipe with high flow cat from local exhaust shop, probably about 4 years ago. Has an m8 egt hole, can be plugged with any m8 bolt and a dab of silicone.

All in very good condition, a quick clean and maybe some cheap paint and will come up a million bucks.

$300 ono

 

[308bever]

have you noticed much change in the truck going from 2.5 to 3 inch?

 

[Rabbid-chop]

Nope.
I was running a 3" into 2.5" Dump pipe and no cat into this exhaust for the last week or two with the turbo conversion and it just seemed neater to make the whole thing 3" and put a cat in again.

There might be something to be said for the theory that once you go over a certain size you're losing flow from lack of velocity. In general the bigger exhaust will be louder and if not louder, deeper in tone.

Both exhausts are quiet with a subtle note, especially at low revs with some load.
Was running the 2.5 redback last week with no cat and it had quite a healthy note. Sounded like a proper little truck!

If you wanted more loud would be easy enough to accidentally slip and fall on the cat with a big screwdriver and a hammer.

 

[Rabbid-chop]

By the way, that brown colour isnt rust - its 8 years of baked on road grime and dirt. I just gave a couple different spots a quick wipe with some wd40 - its still black paint underneath. There is some surface rust on the flange plates though - they arent aluminised.

Price is negotiable.

 

[Stelianos]

Nope.
There might be something to be said for the theory that once you go over a certain size you're losing flow from lack of velocity. In general the bigger exhaust will be louder and if not louder, deeper in tone.

internet BS (bullshit) mostly and it certainly doesnt apply to a turbocharged engine with wastegate. the bigger the better is what is true on turbochargers with wastegate. lack of "velocity" that most people who write about it like true interner warriors, applies to naturally aspirated engines.2.5 or 3 inch wont make big if any differance at all anyway. descent vid here and it barely does on a V8 with 600 horsepower

[YT]https://www.youtube.com/watch?v=_PVXvHkr-Vs[/YT]

 

[Rabbid-chop]

Haha, yes i saw that the other week. And i agree with you stelianos that bigger is better on a turbo engine, but i was not talking about back pressure - i was saying that there is a theory that to an extent, velocity aids flow. That is why the people who design the headers for v8s like the one in the vid use 2" not 3" pipe.
So anyway, in that vid we a looking at a 600hp big block v8 and the difference between 2.5 and 3" was 20hp and a lot of noise. I know which one id be having if it was for a street car.

On my ute i can genuinely say that i can not notice a difference in performance between the two exhausts in feel or watching the boost gauge and the tacho for spool.

 

[Rabbid-chop]

Also, i made 400hp at the treads on a mazda rotary turbo car with a single 3" exhaust. Which would be probably 500hp on an engine dyno. You'd get abou 30% more than that from a piston engine taking into acount rotary inefficiencies and exhaust energy. Not really that far off what the BBV8 was making in that vid with twice the exhaust and no turbo - go figure.

But i digress, I've been saying all along that 2.5" is enough for our diesel utes but there is nothing wrong with 3" either. In all the threads where someone is agonising over which size exhaust to get and the Beaudesert fan club chimes in saying only a beudesert 2.75 will work because they've been exposed to all the infotizing on 4x4 weekly magazine, I just saying it doesnt even matter as long as its a nice performance exhaust, all the nasty backpressure is before the turbo, the difference between 2.5 an 3 wont affect spool, and if there is a difference, it will be higher in the rev range where both the compressor and turbine are choking out and wont even make a difference.

 

[happy john]

internet BS (bullshit) mostly and it certainly doesnt apply to a turbocharged engine with wastegate. the bigger the better is what is true on turbochargers with wastegate. lack of "velocity" that most people who write about it like true interner warriors, applies to naturally aspirated engines.2.5 or 3 inch wont make big if any differance at all anyway. descent vid here and it barely does on a V8 with 600 horsepower

[YT]https://www.youtube.com/watch?v=_PVXvHkr-Vs[/YT]

How does a 600hp V8 relate to our little donks?.

 

[Stelianos]

How does a 600hp V8 relate to our little donks?.

it does because no matter how many cylinders an engine has way they work is the same. in the video it makes most horsepower without exhaust all the way from 3,000 rpms to redline. 3 inch system recudes a bit and with 2,5 inch it loses around 20 hp. your engine is the same. first of all it breaths more air because it runs on 17:1 compression unlike the v8 on the video running 9:1. so yea 2.5 litre engine breathing heavily you really need the biggest exhaust you can fit.

 

[Rabbid-chop]

Its not even the same ball park, the amount of gas we are talking about moving. The compression ratio has nothing to do with the amount of gasses being pumped in an engine either. And we are talking a 600hp engine that was tuned with NO exhaust where the 2.5 lost 20 hp on 600 which you wouldnt even feel, and the 3" gained a LOT of noise.
Also, the pissy little turbos on our rigs run out of puff WELL before even a standard exhaust does. If there is any gain its in the spool up, and between a 2.5" and a 3" it is undetectable and i'd be willing to bet measured on a dyno it wouldn't even be conclusive.

 

[happy john]

No worries lol, sorry to but into your thread R/C.

 

[Rabbid-chop]

Thats cool, its an interesting discussion. The thead is ****ed as a far as trying to sell my exhaust goes though. No matter, i'll open a new one.

 

[happy john]

Thats cool, its an interesting discussion. The thead is ****ed as a far as trying to sell my exhaust goes though. No matter, i'll open a new one.

Try arsebook not that I do, anyone will pay what your asking. Gumtree is good too.

 

[Stelianos]

well excuse me but i never said it will make a differance on a stock nissan motor. thats why i still run the factory exhaust because i think its more than enough for the truck. but you mentioned velocity which is just whatever and you also have upgraded the turbo anyway and had thoughts about "velocity" while you shouldnt. compression does matter. i am not saying a 8,000 rpm v8 breaths less than a diesel but 3,000 rpm to 3,000 rpm it will be pretty damn close (assumin the cc is not vastly different.) so yea to however wants to go ahead and get a new exhaust, just fit the biggest you can get your hands on.

 

[happy john]

No need to excuse yourself fella, RC is on the ball I got a little H/P gain with exhaust only, the main goal was faster/earlier spool and that it did. The chip and boost all worked together with lower EGT'S, now as the turbo cannot keep up I'll upgrade as RC did, it's finding time and coin.

 

[Rabbid-chop]

Ok, since this has turned into an argument for argument's sake, I may or may not be wrong about "velocity" but in the vid they are talking about "back-pressure" and it is the age old myth that a V8 needs a "bit of back pressure" that everyone's grand dad has always pushed.
And compression ratio has absolutely nothing to do with airflow. Its swept volume, rpm and intake pressure.
Like I've said i agree that theoretically bigger is better, but size isnt everything and enough is also enough. On our engines 2.5" is enough. The main point is that its a nice free flowing exhaust with straight through mufflers and no crush bends.
Anyway, earlier i said this was an interesting discussion - I changed my mind - its not until someone can actually add something else to it instead of getting hung up on an american youtube channel for fanboys..

 

[Stelianos]

Anyway, earlier i said this was an interesting discussion - I changed my mind - its not until someone can actually add something else to it instead of getting hung up on an american youtube channel for fanboys..

retarded level over 100%. yet another drama queen post by you well done. and clueless. you have 2 engines both being 2500 cc. one runs on 19:1 compression other on 16:1. no throttles along the intake like the yd25 engine. which draws more air at same given rpm? make the math lol. can you?

 

[Rabbid-chop]

Good on ya mate. Get back to us when you've got some 1st hand experience.

 

[jonney]

one of the biggest boosts in the extra power gain will come from the better Dump Pipe thats going with this Redback exhaust system for sale. as we know the stock dump pipe is quite restrictive compared to the stocky. also the stock mufflers are also quite restrictive compared to the aftermarket muffler . so i say this redback system [ good brand by the way ] is cheap for what your getting.

 

[Leprechaun]

retarded level over 100%. yet another drama queen post by you well done. and clueless. you have 2 engines both being 2500 cc. one runs on 19:1 compression other on 16:1. no throttles along the intake like the yd25 engine. which draws more air at same given rpm? make the math lol. can you?

Compression is the amount that your 2500cc is squeezed, the volume is still 2500cc. Any increase in gas volume would depend on the amount of fuel injected, timing, load, cylinder temps......