Help My Understand The Exhaust System :p

[Midol]

Let me stress I am VERY new to car modifying.

Reading up on the exhaust which from what I can gather is a very important mod.

So, from the turbo you have your dump pipe, right? This goes into a front pipe then to the exhaust or is the front pipe a part of the exhaust?

So if I wanted to throw a full replacement system on my car I'd want the Legalis R, a dump (which I have not even started researching) and then what else? I want to hit that entire system in one go.

Excuse my newbyness

[pyro-ns]

for a full kit, i'd buy an off-the-shelf kit for stageas. i know Just Jap have a couple here, so they can be had. finding the right one is a little difficult though.

generally, for turbo cars, you can't go wrong with a full 3" mandrel bent system with some form of high flowing catalytic converter (or you could just put in a de-cat pipe, but it will fail emissions, should you ever get checked, you might blow a few flames too and it'll be louder).

a full exhaust system generally consists of:

1. dump pipe - comes out of the back of the turbo, generally has the O2 (oxygen) sensor in it

2. front pipe - goes from the dump pipe, down to the underside of the vehicle

3. the rest of the exhaust - made up of sections of pipe, mid-mufflers, resonators, catalytic converters and a final muffler with a tip (note, a legal exhaust system would be made up of these bits)

there are typically two different types of bends in exhausts, press bends and mandrel bends. mandrel bends are the same consistent diametre through the length of the bend, whereas press bends become smaller. a larger press bent exhaust will do the same as a smaller mandrel bent exhaust (i don't know the ratio's, but generally it's considered that a 4" press bent exhaust, will flow the same as a 3" mandrel bent).

all-in-all, an exhaust system isn't really a very important mod, unless it's done wrong. there is a science to it (like everything motoring related). to shorten it down though, a bigger exhaust will flow more gas, which in a turbo application, is what you want. unfortunately, a bigger exhaust has it's drawbacks, such as loudness and it will detract from your bottom end power (which is generally considered a lost cause in turbo cars anyway, so no great loss).

there are also different types of dump pipes. generally it'll come down to a split dump, or a bellmouth dump. most people choose bellmouth and i'm yet to see any performance gain from a split dump 9but i'm no expert).

jap brand name kits are also considered to be of better build quality with a better power output too, but will cost you more $$ than a generic kit. i'm yet to see any side-by-side comparisons though, proving one way or the other.

[andy65b]

I couldn't find any exhaust kits for the M35 on Jast Jap but give them a call if you want one from Japan, I am sure they could source one for you.

There are now a few good exhaust shops in Sydney (not sure where you live) that can build you a custom exhaust to your specifications. I used Charleston Exhaust in Blacktown as he has now done 5 M35's which in Australia makes him almost an expert on the car. (or as close as you can be)

There are also 3 exhaust shops in Sydney working on dump pipes and these should be available very soon.

I decided to buy local as you then have local help if you are to have any problems and I could not see any evidence that the Japanese systems would have any benefit over a local unit and cost with the yen was cheaper.

Cheers

Andy

[pyro-ns]

sorry, i didn'tt see the m35 in his profile and just assumed c34

[iamhe77]

I decided to buy local as you then have local help if you are to have any problems and I could not see any evidence that the Japanese systems would have any benefit over a local unit and cost with the yen was cheaper.

Cheers

Andy

Hot to know a local product as I think it is important to help the local economy... but your point about the local "help" if you have any problems is not relevant with Jap exhausts.

They are amazing quality (I had a group of 5 big HP GTR owners ogling my Legalis when it was being put on), include good quality gaskets and bolt straight up... even if you mix your manufacturers of use parts of the OE exhaust.

I will be going local for my dump as I want an 82mm dump as my Kakimoto front pipe is 80mm & I want to make the most of it (even if it makes sweet f*ck all difference).

Michael, yes a full exhaust is generally made up of 3 sections.

1. Dump pipe - from the turbo. Short and almost 'S' shaped in the M35.

2. Front pipe - from the dump (commonly contains that main cat). A bit over a metre in length with two 45degree(ish) bends which allow it to bolt up without modification.

3. Exhaust or Cat-back - these are you Fujitsubo Legalis's, Kakimoto R's etc and mainly dictate your exhaust note and how loud it will be.

[Midol]

I'm in Brisbane (well, the sunshine coast but brisbane is my capital) but I do go to Sydney twice a year or so, normally fly but I guess I could drive it I really had to

Okay, thanks you guys. Now I actually understand what makes up the full system (from front to back) I'll be able to research it a bit more thoroughly

[pixel8r]

I've had 3 exhausts put on 3 separate cars, all of them locally custom-made for the car (mandrel bends etc). The workmanship was fantastic, but if I were to do it again I'd be looking at an off-the-shelf one from japan - one that has been designed for the stagea.

The reason is that local exhaust places are great at welding and bending a nice 3" piece of pipe. And to quieten it down they know how to put some mufflers or resonators (=drone in a wagon) in. Dont get me wrong, they do a fantastic job for a lot of cars, but with a wagon, noise / acoustics play a huge part.

The jap ones that are designed specifically for the stagea are actually engineered to produce a nice sound, sometimes a quiet sound. A lot of testing goes into it and what you're buying is not just a pipe, its a piece of performance and sound engineering, blended into one. Also when you buy one of these, the manufacturer can show you exactly what the car will sound like, and exactly the performance gains to expect when installing on a stock stagea. And they dont just make it quiet. They focus on making it quiet across specific rev ranges so that you can still hear the exhaust when you belt it but not when cruising.

A lot of them also have twin pipes out the rear muffler - which produces the same airflow but with less noise.

There really is no comparison between the way they sound. Even the jap ones sound different to each other. Have a search on youtube for "VQ25DET engine" or something like that. There's a clip on there that just shows the exhaust tip on a white M35 and it just sounds awesome!

One last thing, if you get an exhaust, you might want to also check out an aftermarket ecu. Thats my view anyway.

Edited July 23, 2009 by pixel8r

[zei20l]

dont forget to mention that a jap exhaust designed for that car will literally just bolt on. no mods necessary.

[Midol]

I've had 3 exhausts put on 3 separate cars, all of them locally custom-made for the car (mandrel bends etc). The workmanship was fantastic, but if I were to do it again I'd be looking at an off-the-shelf one from japan - one that has been designed for the stagea.

The reason is that local exhaust places are great at welding and bending a nice 3" piece of pipe. And to quieten it down they know how to put some mufflers or resonators (=drone in a wagon) in. Dont get me wrong, they do a fantastic job for a lot of cars, but with a wagon, noise / acoustics play a huge part.

The jap ones that are designed specifically for the stagea are actually engineered to produce a nice sound, sometimes a quiet sound. A lot of testing goes into it and what you're buying is not just a pipe, its a piece of performance and sound engineering, blended into one. Also when you buy one of these, the manufacturer can show you exactly what the car will sound like, and exactly the performance gains to expect when installing on a stock stagea. And they dont just make it quiet. They focus on making it quiet across specific rev ranges so that you can still hear the exhaust when you belt it but not when cruising.

A lot of them also have twin pipes out the rear muffler - which produces the same airflow but with less noise.

There really is no comparison between the way they sound. Even the jap ones sound different to each other. Have a search on youtube for "VQ25DET engine" or something like that. There's a clip on there that just shows the exhaust tip on a white M35 and it just sounds awesome!

One last thing, if you get an exhaust, you might want to also check out an aftermarket ecu. Thats my view anyway.

Thanks a ton, I think I am definitely leaning towards the Legalis but I just need to decide on the dump and front pipe? Any suggestions of which Dump would suit me? Looking at mid-upper range gear.

With the ecu, I was planning on doing that in my "second stage" of mods. Keeping in mind I am an uber noob so this is subject to change:

Stage 1: Full exhaust (including all pieces), new panel filter.

Stage 2: High flow turbo, new ecu/some ecu mod, new wheels.

After that I'll just go through one at a time. By "stage" I mean everything listed under that will be done in one hit. First I need to get my alarm and cruise control done though...

[iamhe77]

I've had 3 exhausts put on 3 separate cars, all of them locally custom-made for the car (mandrel bends etc). The workmanship was fantastic, but if I were to do it again I'd be looking at an off-the-shelf one from japan - one that has been designed for the stagea.

The reason is that local exhaust places are great at welding and bending a nice 3" piece of pipe. And to quieten it down they know how to put some mufflers or resonators (=drone in a wagon) in. Dont get me wrong, they do a fantastic job for a lot of cars, but with a wagon, noise / acoustics play a huge part.

The jap ones that are designed specifically for the stagea are actually engineered to produce a nice sound, sometimes a quiet sound. A lot of testing goes into it and what you're buying is not just a pipe, its a piece of performance and sound engineering, blended into one. Also when you buy one of these, the manufacturer can show you exactly what the car will sound like, and exactly the performance gains to expect when installing on a stock stagea. And they dont just make it quiet. They focus on making it quiet across specific rev ranges so that you can still hear the exhaust when you belt it but not when cruising.

A lot of them also have twin pipes out the rear muffler - which produces the same airflow but with less noise.

There really is no comparison between the way they sound. Even the jap ones sound different to each other. Have a search on youtube for "VQ25DET engine" or something like that. There's a clip on there that just shows the exhaust tip on a white M35 and it just sounds awesome!

One last thing, if you get an exhaust, you might want to also check out an aftermarket ecu. Thats my view anyway.

So, I guess you work for the marketing arm of one of the bigger exhaust manufacturing companies in Japan?

That white Stagea on Youtube has the Takero's "Full Titan".

You can find the Youtube clip with the Takero's details in the M35 Aftermarket Exhausts thread. Hopefully that will give you some idea of the JDM cat-backs available.

dont forget to mention that a jap exhaust designed for that car will literally just bolt on. no mods necessary.

Did we?

Thanks a ton, I think I am definitely leaning towards the Legalis but I just need to decide on the dump and front pipe? Any suggestions of which Dump would suit me? Looking at mid-upper range gear.

With the ecu, I was planning on doing that in my "second stage" of mods. Keeping in mind I am an uber noob so this is subject to change:

Stage 1: Full exhaust (including all pieces), new panel filter.

Stage 2: High flow turbo, new ecu/some ecu mod, new wheels.

After that I'll just go through one at a time. By "stage" I mean everything listed under that will be done in one hit. First I need to get my alarm and cruise control done though...

Can't go wrong with the Legalis. Love mine (but if you find the "Zenki" M35 Nismo exhaust with the 2 square tips, I would be interested in trading). Quiet, but also gives off a beautiful burble and can certainly give a bassey scream when the car is booted.

Front pipes? Do you want de-cat? If so, Kakimoto and Freeway-Dolphin both do an 80mm de-cat front pipe (really enhances the Legalis' sound).

If you want the cat, I would suggest something local as there is nothing available that is JDM off the shelf stuff.

Edited July 23, 2009 by iamhe77

[Midol]

I want to keep a Cat I think, lower emissions and from my research a high flow cat/sports cat only slightly reduces power gains.

Will try and find a local shop that's "decent".

[pixel8r]

So, I guess you work for the marketing arm of one of the bigger exhaust manufacturing companies in Japan?

Haha, maybe they'll offer me a job?

I'm just comparing the exhausts I've had on my cars (basically a 3" piece of SS pipe, mandrel bent to fit in around the diff etc) sound with the youtube clips and manufacturer videos for JDM exhausts. The ones I've had always sounded a bit unrefined or droney, nothing like the sound of a kakimoto or fujitsubo exhaust.

Plus that Takero "Full Titan" one is the best I've heard. ever.

Performance wise you probably cant really go wrong with a 3" pipe, but I'd like to think the JDM ones are geared at maximum performance too.

[iamhe77]

Haha, maybe they'll offer me a job?

I'm just comparing the exhausts I've had on my cars (basically a 3" piece of SS pipe, mandrel bent to fit in around the diff etc) sound with the youtube clips and manufacturer videos for JDM exhausts. The ones I've had always sounded a bit unrefined or droney, nothing like the sound of a kakimoto or fujitsubo exhaust.

Plus that Takero "Full Titan" one is the best I've heard. ever.

Performance wise you probably cant really go wrong with a 3" pipe, but I'd like to think the JDM ones are geared at maximum performance too.

Completely agree with you Steve, which is why I have the combination I have on my car.

Could have gone with a local exhaust, but the prices I was quoted at the time were higher than getting my JDM front pipe and exhaust landed and installed.

... but that was when the dollar was about 95yen.

[loymclure]

1. Dump pipe - from the turbo. Short and almost 'S' shaped in the M35.

2. Front pipe - from the dump (commonly contains that main cat). A bit over a metre in length with two 45degree(ish) bends which allow it to bolt up without modification.

3. Exhaust or Cat-back - these are you Fujitsubo Legalis's, Kakimoto R's etc and mainly dictate your exhaust note and how loud it will be.

I'd put the CAT in its own catagory as it is can be upgraded and there isnt really any point in using your stock CAT with a turbo back system. It would be like holding a gooses neck while it was trying to swallow.

[iamhe77]

It would be like holding a gooses neck while it was trying to swallow.

hmm, sometimes your words concern me Clint..

[pyro-ns]

just reminded me of that insurance ad where the flock of geese decend and everyone crashes, then the goose swipes that woman's purse...

the wife and housemate's sitting in the lounge in silence, slightly amused and all of a sudden i go, "JUST SNAP THE BASTARDS NECK!" needless to say, they both shat themselves and i was promptly scolded

/off topic lol

Edited July 24, 2009 by pyro-ns

[DavisMurlock]

This is great. I am also looking at upgrading the exhaust system but have little knowledge about modding c34's, so Pyro-ns' reply was very helpful!!

thanks again