[Hybrid]

I didn't want to hijack this thread but I thought it would be a waste to start another. I hand made a 2 inch extractors back system for my G16 powered sierra to twist and turn around my long range tank. I'm happy with how it's run now but its too noisy and I need a cat. I'm going to try what Steve suggested above. Do you guys think it would be cheaper if I pulled mine off and took it to a shop to replicate the shape or should I just drop the rig off and get it done on the Sierra?

[Che]

ball wrote:

Just mixing and fitting parts at random never really works as well as a correctly designed system.

Bingo - this is why i ask so many questions. Best to get it right first time than waste a lot of money and hope for results.

I myself want a system that is likely to boost power in the sub 4500RPM range - if the power gains are only at the far side of the tacho, i'm better off saving my money and sticking with the stock exhaust.

[Fatzook]

Hybrid wrote:

I didn't want to hijack this thread but I thought it would be a waste to start another. I hand made a 2 inch extractors back system for my G16 powered sierra to twist and turn around my long range tank. I'm happy with how it's run now but its too noisy and I need a cat. I'm going to try what Steve suggested above. Do you guys think it would be cheaper if I pulled mine off and took it to a shop to replicate the shape or should I just drop the rig off and get it done on the Sierra?

Have you got a straight section about 12" long? If yes then buy a hotdog style resonator and weld it in yourself. Also fit you cat just after the extractor flange. If you have the tools to do it yourself, then you should save $100-150 in labour.

JMO
Pete

[Fmoss3]

small exhaust bad. big exhaust good

[Fatzook]

Fmoss3 wrote:

small exhaust bad. big exhaust good

you are a turd.

[royce]

che_guitarra wrote:

ball wrote:

Just mixing and fitting parts at random never really works as well as a correctly designed system.

Bingo - this is why i ask so many questions. Best to get it right first time than waste a lot of money and hope for results.

I myself want a system that is likely to boost power in the sub 4500RPM range - if the power gains are only at the far side of the tacho, i'm better off saving my money and sticking with the stock exhaust.

I would think any decent brand (non ebay) tri-y extractors and exhaust (1.5 or 2 inch wont matter) is going to make useable gains around there, just cause a 1.3 revs higher than that doesnt mean its making anymore power

then get a cam before you toddle off and get all this dynoed, still waiting for these big power figures

[whincup]

on the topic of exhausts, ive heard the 4-1 extractors behave differently to the 4-2-1 extractors... is there any truth in this? as in, one produces more low end torque or something like that... apparently, but i dont really believe it...

i was told today that i need new extractors (i knew i had a major leak in exhaust somewhere, was just hoping it was a bad join somewhere) and dont have the coin to replace entire exhaust straight up. bigger extractors with original exhaust for short term: not going to cause problems?

[Fatzook]

whincup wrote:

on the topic of exhausts, ive heard the 4-1 extractors behave differently to the 4-2-1 extractors... is there any truth in this? as in, one produces more low end torque or something like that... apparently, but i dont really believe it...

i was told today that i need new extractors (i knew i had a major leak in exhaust somewhere, was just hoping it was a bad join somewhere) and dont have the coin to replace entire exhaust straight up. bigger extractors with original exhaust for short term: not going to cause problems?

That will be fine.

[ball]

whincup wrote:

on the topic of exhausts, ive heard the 4-1 extractors behave differently to the 4-2-1 extractors... is there any truth in this? as in, one produces more low end torque or something like that... apparently, but i dont really believe it...

i was told today that i need new extractors (i knew i had a major leak in exhaust somewhere, was just hoping it was a bad join somewhere) and dont have the coin to replace entire exhaust straight up. bigger extractors with original exhaust for short term: not going to cause problems?

yep, they definitely behave differently

[royce]

4-1 give more of a gain across a narrower rev band, 4-2-1 give smaller gains across a wider range

FWIW mine had 4-1 and behaved like normal low down then took off (lol) at highway speeds, worked pretty well

another thing to consider all you lot still barking on about backpressure (wrong term, the word is velocity) length of the pipe will have a hugely bigger effect than diameter

[Che]

Here's my first reply from the US Samurai forum I hop into - probably the best and clearest explaination i've recieved so far. Just FYI for those that are interested - don't read if you don't care.


For your purposes 1.5 to 1.75 is fine. The point of a header is to smooth out the flow of the exhaust as it leaves the engine. The pulses from the different ports are plumbed so that they compliment each other instead of the stock manifold where all of the pulses just colide outside the port. Once you hit the collector, you can tune the curve of your power@rpm by adjusting the pipe size after the collecter, but the overall preformance increase and throttle response is all done by the header before the collector. If you want you can experiment with different sizes, you can just put on the collector mounting plate with the 2.5" pipe and then put reducer adapters on the end of the pipe and take it for a spin to see what it feels like with different backflow pressures. It's going to be loud as hell with just a reducer on the collector, so you might want to plumb 2.5 all the way to the muffler and then put the reducer on after the muffler. The exhaust is only as large as it's smallest section of pipe, so technically you could just put 2.5 inch exhaust in and then put a restrictor at the tail pipe. You would have some response lag though due to the volume of that length of pipe and the fact that exhaust gas compresses.

[whincup]

Haha... knew who it was before i even checked. wish i had half the brains and knowledge of that guy.

[royce]

che_guitarra wrote:

Here's my first reply from the US Samurai forum I hop into - probably the best and clearest explaination i've recieved so far. Just FYI for those that are interested - don't read if you don't care.


For your purposes 1.5 to 1.75 is fine. The point of a header is to smooth out the flow of the exhaust as it leaves the engine. The pulses from the different ports are plumbed so that they compliment each other instead of the stock manifold where all of the pulses just colide outside the port. Once you hit the collector, you can tune the curve of your power@rpm by adjusting the pipe size after the collecter, but the overall preformance increase and throttle response is all done by the header before the collector. If you want you can experiment with different sizes, you can just put on the collector mounting plate with the 2.5" pipe and then put reducer adapters on the end of the pipe and take it for a spin to see what it feels like with different backflow pressures. It's going to be loud as hell with just a reducer on the collector, so you might want to plumb 2.5 all the way to the muffler and then put the reducer on after the muffler. The exhaust is only as large as it's smallest section of pipe, so technically you could just put 2.5 inch exhaust in and then put a restrictor at the tail pipe. You would have some response lag though due to the volume of that length of pipe and the fact that exhaust gas compresses.

Typical American response

Dead set stop typing and just go get something put on, I doubt there is 2hp difference between a 1.75 and 3 inch exhaust behind some decent extractors, of which you probably cant buy anyway cause they would be too dear for the decent manufacturers to produce

[Che]

too funny - thought I recognised your name!

Baratacus is king, hey! Not a question that can stump him, no dealling with shitballer attitude, just the best answers. Don't tell anyone where to find him though, or else he'll be answering 1000 questions a day!!!

[Zook_Fan]

yep that was one of the hardest things to find http://www.suzuki-forums.com/suzuki-jim ... -zook.html

[Moph]

I'm with Royce ... just go get it done already

Half decent extractors (Wildcat, Genie, whatever), 1.75" or 2" pipe, cat, triple flow muffler, hot dog resonator. Done. You'll love either option if installed well and could split straws all week long about which is 'better'.

At the end of the day we're talking about Zooks ... you might see gains of half a pony out of an exhaust at the low end of the rev range from a 'tuned' exhaust. The biggest gain for me was replacing the blocked cat and opening it up a little ... that made a HUUUUGE difference at the top end.

[ball]

che_guitarra wrote:

Here's my first reply from the US Samurai forum I hop into - probably the best and clearest explaination i've recieved so far. Just FYI for those that are interested - don't read if you don't care.


For your purposes 1.5 to 1.75 is fine. The point of a header is to smooth out the flow of the exhaust as it leaves the engine. The pulses from the different ports are plumbed so that they compliment each other instead of the stock manifold where all of the pulses just colide outside the port. Once you hit the collector, you can tune the curve of your power@rpm by adjusting the pipe size after the collecter, but the overall preformance increase and throttle response is all done by the header before the collector. If you want you can experiment with different sizes, you can just put on the collector mounting plate with the 2.5" pipe and then put reducer adapters on the end of the pipe and take it for a spin to see what it feels like with different backflow pressures. It's going to be loud as hell with just a reducer on the collector, so you might want to plumb 2.5 all the way to the muffler and then put the reducer on after the muffler. The exhaust is only as large as it's smallest section of pipe, so technically you could just put 2.5 inch exhaust in and then put a restrictor at the tail pipe. You would have some response lag though due to the volume of that length of pipe and the fact that exhaust gas compresses.

That probably applies quite well to a performance engine. The suzuki engine doesn't really fit that category.

In your other threads you say you are chasing economy.

Is the cam correct for this?

What about valve sizes and port flows ? Are they optimised for economy?

Compression??

Ignition timing??

When dealing with an engine EVERYTHING has a trade off. If you want good economy, power will be reduced. If you want good power the economy suffers.

The manufacturer tries to design the engine to have sufficient power with an acceptable fuel consumption. If you want to change one of these things to be better then the other will suffer.

I'm with Royce here. Buy a quality set of pipes and just bolt them on.

You seem to be over thinking some things and ignoring others.

[Hybrid]

Fatzook wrote:

Have you got a straight section about 12" long? If yes then buy a hotdog style resonator and weld it in yourself. Also fit you cat just after the extractor flange. If you have the tools to do it yourself, then you should save $100-150 in labour.

JMO
Pete

True. I've done the rest I may as well. I'll run the cat directly after the extractors, the hotdog behind the transfer crossmember then a triflow muffler tucked up behind where the floor raises behind the front seats.

[BUZOOKA]

shep wrote:

steknig wrote:

Jccck wrote:

che_guitarra wrote:

A flamethrowing exhaust would be just the ticket!!! I want one, I want one now!! Perfect for the arsehole tailgater.

Mine can do that, haha

Drive along at about 50, turn the car off in neutral.. Keep your foot flat to the carpet for 5-10 seconds, turn it on with your foot still flat!

Booooom, with a foot long flame
I don't think it's good for the car however

Your 100% correct.

yeah key bangers are best done in other peoples cars.

tell ya now thats the best way to rip open ur muffler box been there and done that in my brothers first car (gemini )

[Hybrid]

BUZOOKA wrote:

tell ya now thats the best way to rip open ur muffler box been there and done that in my brothers first car (gemini )

Yep. Had a short in my ignition wire on my hilux. engine cut out on the downhill section of a bridge. Couldn't pull over and couldn't work out what the issue was. All of a sudden it kicked back in and tore my muffler open along the seam. It pretty much just unrolled the muffler. Had the back sliding window open. I think my ears are still ringing.

[Gwagensteve]

che_guitarra wrote:

Here's my first reply from the US Samurai forum I hop into - probably the best and clearest explaination i've recieved so far. Just FYI for those that are interested - don't read if you don't care.


For your purposes 1.5 to 1.75 is fine. The point of a header is to smooth out the flow of the exhaust as it leaves the engine. The pulses from the different ports are plumbed so that they compliment each other instead of the stock manifold where all of the pulses just colide outside the port. Once you hit the collector, you can tune the curve of your power@rpm by adjusting the pipe size after the collecter, but the overall preformance increase and throttle response is all done by the header before the collector. If you want you can experiment with different sizes, you can just put on the collector mounting plate with the 2.5" pipe and then put reducer adapters on the end of the pipe and take it for a spin to see what it feels like with different backflow pressures. It's going to be loud as hell with just a reducer on the collector, so you might want to plumb 2.5 all the way to the muffler and then put the reducer on after the muffler. The exhaust is only as large as it's smallest section of pipe, so technically you could just put 2.5 inch exhaust in and then put a restrictor at the tail pipe. You would have some response lag though due to the volume of that length of pipe and the fact that exhaust gas compresses.

Sorry, I don't care how knowledgeable this guy seems to be, but he knows very little about exhaust.

A) A sierra (and especially a vitara) already has very close to an extractor. We're not talking about a log manifold here- the exhaust is quite well designed. The pulses don't "just collide near the port" and in fact in a G16A, the design is a proper 4-2-1 design with a very long secondary pipe.

B) He's got it around the wrong way - The change in powerband will occur with changes [i]upstream[/] of the collector and at the collector. That's why there's lots of header lengths available for something like a SBC or LS motor. The scavenging effect etc is all upstream of the collector. Collector diameter will have an effect on powerband as it's a potential flow restriction and will therefore have an affect on scavenging. If the collector is 2" though, for instance, stepping up to 2.5" will have no effect on powerband at all as the engine has already "seen" it's restriction at the collector.

C) Even a sensitive driver will struggle to detect a change in engine performance of 10%. Detecting a change in power curve and performance by changing the size of the tailpipe from say 1.5 to 1.75" is just wrong.

D) Reducing the pipe diameter at the end of the exhaust will have very little affect on anything. By the time the exhaust gas has got that far it's cooled enormously, it's lost hundreds of degrees of temperature so it's slowed because it's now taking up far less volume. It's quite possible even 1.5" will flow plenty of exhaust gas at the tailpipe but nowhere near enough at the collector. so to say "the exhaust is only as large as it's smallest section of pipe" is only true if proximity from the motor and therefore temperature and gas speed is taken into account.

I hope all of this guy's responses aren't as misleading as this if he's considered some sort of guru.

Steve.

[Che]

I dunno where the cam suggestion came from - definitely chasing efficiency and economy. I'd have had the exhaust on weeks ago if I could put a lid on all the other bills (namely the GF) and priority car issues grabbing my spending money away. Hopefully one more week in the red before I can spend up again.


LPG + K&N + extractors are the only performance mods I'll spend money on. Coz, honestly - if balls out performance was what i'm chasing a Sierra is the worst place to start. I just want a fun toy.


Maybe this guy's not a guru to all the backshed legends out there - but at least he's explaining to me exactly what I am trying to find out in a way I can understand, and a way I can trial for myself, without trying to make a dickhead outta me (hey, I can manage that all by myself!!). His Samurai is sick too. Just remember I record bands and play gigs for a living, I don't spin spanners for 8 hours a day.



Anyway, took the car in to a dyno tuner on Tuesday - pushed the dist timing forward a tad, told me not to bother with a re-curve, waste of money. Went to my LPG installer straight after for a tune up and tighten up and now my car is running like I always wanted. Back to 600kms on a $40 tank with way-better-than-stock performance. Yeehah!

[MacDaddy]

There are still many Myths about Extractors and Performance Exhaust systems, and some take these Myths as truth, Back Pressure being the biggest Myth... and some still believe biggest is best... while these Myths persist, there will be many opinions, and often stated facts...

I have learnt alot about how they work being here on AZ... but what we really need is a clear and precise, 100% factual and proven, simple explanation, of how Extractors and performance exhaust systems work, seperate and together, and what are reasonable expected performance gains from them... is there any info like that ?...

[royce]

I have a 160 page book here called how to modify intake and exhaust systems that scratches the surface on a lot of bits, to understand it fully you could always get an engineering degree, majoring in fluid dynamics or something

[whincup]

if i can afford it, im going to see about getting mine on a dyno run (no tuning, just on the dyno and do the test then off) before i get my exhaust changed, then again after. depends on what they charge for a single run...

btw, i think im getting the 2"...

[ball]

royce wrote:

I have a 160 page book here called how to modify intake and exhaust systems that scratches the surface on a lot of bits, to understand it fully you could always get an engineering degree, majoring in fluid dynamics or something

Is that a David Vizard one?

[royce]

ball wrote:

royce wrote:

I have a 160 page book here called how to modify intake and exhaust systems that scratches the surface on a lot of bits, to understand it fully you could always get an engineering degree, majoring in fluid dynamics or something

Is that a David Vizard one?

Ben Watson, only Vizard I have are mini books oh and a nitrous one

[MacDaddy]

royce wrote:

I have a 160 page book here called how to modify intake and exhaust systems that scratches the surface on a lot of bits, to understand it fully you could always get an engineering degree, majoring in fluid dynamics or something

Ha Ha yeah
When i did my Refrigeration Apprenticeship, we had to learn about basic fluid dynamics under pressure and temp, gas states under pressure and temp, heat exchangers, pressure differences, air flows and resistance, pipe sizing and resistance... etc... i understand whats happening within the exhaust system with temp and pressure, its very similar to half an AC system, just with all gases, no liquid... i know how to tweek a AC system to get max performance... would just like to know how to tweek a Zook exhaust system to get max performance... i know when i put extractors and a 2in sports system on my 89 Vit with G16A engine, i definitely felt a difference at 4000rpm... i like to know why things do what they do, and would like to know why doing this has and will make a difference... i know what you have said in previous threads about standard and sports exhaust systems has helped me alot in understanding why it does what it does... but i think after so many threads on this topic, and so many different opinions/truths, we need a definite 100% truth answer, that will put this topic to rest, and clear all confusion and Myths... maybe i am asking the impossible...

[Hybrid]

That's never going to happen until someone buys 5 stock sierras, dynos them, then does a few different exahsut variants, then dynos them again. Maybe buy a 6th just so they can do a hiclone test......

[Fatzook]

whincup wrote:

if i can afford it, im going to see about getting mine on a dyno run (no tuning, just on the dyno and do the test then off) before i get my exhaust changed, then again after. depends on what they charge for a single run...

btw, i think im getting the 2"...

The only possible way this could work is if you had all the different variant exhausts made up already an just bolted them on one after the other whilst on the dyno. Just as important as the mods themselves are the operator ( use the same one) ambiant temp and relative humidity, correction factor on the dyno, even tyre temp can play its part ( although I doubt it would be seen on any car less than 500HP )

So what I am really saying here is don't waste your money.

Pete