Offroad-Express

With the Prado SAS completed I would like a little further knowledge on exhaust system for it, from what i've searched and read 2.5 inch free flowing system with just a resonator is the best option

Sounds about right Tim.
Have yet to do mine but the research I did lead me to a 3" system.
Tis important to do it all the way forward to the Turbo outlet including a larger flexi pipe and larger flange.
Having looked at a 1KZ turbo in bits, the outlet casting (a seperate piece from Turbo) is quite restrictive. Some time ago we got some big gains in this area on a 2l-te. Just time and a die-grinder and then as above, a larger flange on the 1st pipe.

Good thread Tim, I am impressed with your progress so far and look forward to seeing your wee beastie in action.

2.5 is a nice size 3 is a bit large i would be going 2.5 thats what ive got on my old 2.4 and it perfect sound alright to

Hi Tim
I dont know about 1KZ motor. A big mistake a lot of people make is fitting too large of an exhaust pipe. The problem is that you retrict flow and pulsating can happen in the pipe and that is not good because it doesn't get rid of the gases.

A 2.5 inch pipe would probably sound right for a 3 litre engine.

Cheers Richard

Bulletproof wrote:Hi Tim
I dont know about 1KZ motor. A big mistake a lot of people make is fitting too large of an exhaust pipe. The problem is that you retrict flow and pulsating can happen in the pipe and that is not good because it doesn't get rid of the gases.

A 2.5 inch pipe would probably sound right for a 3 litre engine.

Cheers Richard

On a turbo motor there are no pulses worth worrying about left in the exhaust. The turbine chops them up into little bits and spits them back out.
So with all pulse tuning gone (well you still use it in the exhaust manifold) it's just a drainpipe from the turbo back. But past 2.5" on a 100kw motor isn't necessary. Your muffler choice will make a far bigger difference than anyting else.

Cheers chaps, will take it down this week and get a 2.5inch system with something like a flowmaster muffler or something similar which is straight through, will it be quiet or noisy ?

hosehustler wrote:Cheers chaps, will take it down this week and get a 2.5inch system with something like a flowmaster muffler or something similar which is straight through, will it be quiet or noisy ?

Turboed engines, as KiwiBacon pointed out, are normally quieter than non -turboed due to all the pulse noise having been mixed up in the turbo.
My Prado has the factory muffler, apart from a new bottom strengthened second skin. I am always surprised at how large it is. It is oval in section 200 x 320 and 500 long. The inlet and outlet are on differing sides of the oval so I suspect there are two perf tubes inside, i.e. not straight through. It is nice and quiet. Factory pipe ID is 2 & 1/16 ".

I know Auto-bend (Magoos) make a free flow triple pass muffler for V8's. This is effectively a straight through as the internal pipe ends are half donuts. The advantage of this type is that the noise of the middle pipe cancels the noise of the outer two. This is how true muffling works, similar frequencies travelling in opposite directions.

Maybe with the turbo this will be too quiet as they are designed for HSV's etc being non-turboed.

just my thoughts and observations, maybe someone else can offer more.
Cheers John

Hi Tim , congratulations on your Surf build. My Surf 2.4LTE has a 2.5" exhaust from the turbo flange with a straight through muffler and is NO NOISER than my Cruiser , , I am having you on the straight through will be fine, gives a nice growl and the turbo whistle can be heard on throttle off.

GO TO THE TOP OF THE CLASS,

FITZY.

Funny, the JizzBlizz has a 2lt and a 2.5" straight through and it is too noisy technically.
And it annoys others on the road, which in my mind, is too much.

You can hear it in the vids I posted on youpube, search tvanduyl - abuser name, or fangsitland.

Tim.

You've heard mine and mine is 2.5" straight through. Quiet as a mouse Now the LR on the other hand is a whole different story

Are we talking with mufflers of any kind? or litterally straight through?

I dont discount what you guys are saying, but the JizzBucket is far from street friendly.

See http://www.youtube.com/watch?v=HMminD3HRcY

mike wrote:You've heard mine and mine is 2.5" straight through. Quiet as a mouse Now the LR on the other hand is a whole different story

No muffler at all

Here too.
Perceptions perhaps.

I wouldnt do a straight through again for a daily driver.

When its all done, post a vid under full load if you can.

Tim.

got it done today, 2.5 inch and a straight through muffler.
I went to Kaiapoi exhaust and mufflers as I had a contact that recommended him as it's under new management.
A post for him.... absolutely fantastic service, he's a performance engine expert, his workmanship is second to none, and prices are competitive.
Oh and the exhaust sytem s fantastic as well

hosehustler wrote:got it done today, 2.5 inch and a straight through muffler.
I went to Kaiapoi exhaust and mufflers as I had a contact that recommended him as it's under new management.
A post for him.... absolutely fantastic service, he's a performance engine expert, his workmanship is second to none, and prices are competitive.
Oh and the exhaust sytem s fantastic as well

WHEN can we hear it Tim? NO I am NOT coming down specially to hear it, can you do the video thing? I want to do more mods to my wagon, and this thread is starting to look intersting.

5 cyl 2.9TDI, the cat converter has gone, made considerable difference to performance AND economy. wondering if a "no muffler" system would help even further.


B