Vr6 exhaust dyno: 2.5" vs 3" back to back.

[skydaman]

Care to elaborate?

He pretty much summed it up:

It might be what's wrong with import modification as a whole. Too much internet, too much unfound logic, too much bench racing. No real world testing.

Things like:
-small cams are good for boost
-restrictive exhaust systems are needed for "back pressure"
-cai's don't make power
-20w50 is good for a vw

[root beer]

[brobs is back]

It might be what's wrong with import modification as a whole. Too much internet, too much unfound logic, too much bench racing. No real world testing.

Things like:
-small cams are good for boost
-restrictive exhaust systems are needed for "back pressure"
-cai's don't make power
-20w50 is good for a vw

yes, your engine benefitted from a bigger exhaust.. but what about a stock one?

20-50 is recommended for an 8v right in the owner's manual

[root beer]

Stock, i'd do 2.5". I def wouldn't do 3" on a stock stock motor.

These lifters aren't designed for 20w50. Excess valvetrain friction. No good. But if we're talkin 8v, they'll run forever anyway.

Edit, but i think it's important to notice that i had no torque loss going to 3". Should tell a story about exhausts on these motors.

[RoamFreely]

Ordering my 2.5 system today...thanks for that video and graphs... well done to the both of you...

[LA7VJetta]

you aren't going 3"?

[RoamFreely]

you aren't going 3"?

Well no, if you read the post he has a good amount of mods done to his car, headwork etc.. when they did the test, I only have a chip, cai, nothing else done to my car other then that so I wont see that kind of horse power gain that he had, So ill go with a 2.5 for now till i have the same kind of mods to my vr or more then install the bigger free flowing exhaust.... hense 3"

[aphythiate]

Why get a 2.5? You don't have the need for 3 yet, but why do an upgrade that you'll just have to do again? It seems counterintuitive. Just keep what you have now until you have a better head/cams setup. Otherwise you're just wasting money.

[RoamFreely]

Why get a 2.5? You don't have the need for 3 yet, but why do an upgrade that you'll just have to do again? It seems counterintuitive. Just keep what you have now until you have a better head/cams setup. Otherwise you're just wasting money.

In this case would make sense but, after I no longer need the 2.5 exhaust and need the 3" i can take the 2.5 and throw that on my other VR... works either way... still will need to buy 2 exhaust systems. Still will spend just about the same.

[aphythiate]

Valid point. One VR is never enough. And stock exhaust just won't do!

[Ubermark]

Thanks for all the hard work on this to all those involved. MUCH appreciated. We've been arguing 2.5" vs. 3" for a long time over on the Corrado forum:

http://forums.vwvortex.com/showthrea...exhaust-on-VR6

[root beer]

I would never say that 5whp is worth $400. It's just something to think about. Price a TT kit and a test pipe though, and compare. If you're making that choice, knowing that a 3" exhaust could yield more power might sway a decision when picking an exhaust from the get-go.

I would still recommend TT kits over all others for most cars. Anybody with fany type of forced induction though....this is the kit you want.

[1337cshacker]

Neuspeed 2.5 catback

Good test.

[dankvwguy]

i sure do love the sound of a n/a 12v VR6

[olong_us]

any graphs yet? would like to see them overlayed

[root beer]

No, i haven't had a chance to get up there with a flashdrive. Tomorrow at the latest.

[root beer]

Updated the first post with a graph

[LA7VJetta]

id say thats an increase all over.

[pubahs]

I havent been following the 12v NA scene much but I did see those very nice new headers that were made.

Id like to see those thrown on this car with the 3" exhaust and see what kind of numbers it produces

Good testing

[root beer]

word!

[JstADub]

I wonder what different exhaust sizes would do to a NA built 2.slow...

*flamesuitengage*

[PettR]

What would happen if you used a 2.25"? less power than a 2.5"?

[root beer]

Eh, i'd assume so. Maybe comparable on an all stock motor. Not worth testing for me.

[Kiyokix]

I wonder what different exhaust sizes would do to a NA built 2.slow...

*flamesuitengage*

Take that flamesuit off.

I can say without hesitation that many many people wonder about this, but they're 'all' afraid to say it around here for fear of some kid making jokes about them on the internet. I wish I was still sitting at the same money as I was a year or so ago, I'm really into testing different ideas especially the ones that others seem 'pointless'.

Like it was said earlier, there are FAR too many invisible internet dyno results floating around...and not NEARLY enough actual real life testing going on. You see it every day someone will ask about a 2.0 mod, and you get 50 different responses of varying 'low and slow' or 'drive it downhill' garbage. I remember the days when you did a mod and gained 2-3hp and it was a GOOD thing. Now, it seems that unless you can possibly make 300whp it's not worth doing? Seriously...it's just a kid on the internet making jokes, man up and get back to real testing...they'll go away eventually anyway when they find the new 'in' thing.

This VR6 test/study is awesome, I really hope more like it appear in the short future.

Kei

[MBSPE]

What would happen if you used a 2.25"? less power than a 2.5"?

i'd assume so. But it highly depends on your set-up at the moment my personal VR6 is running the 2.25 magnaflow set-up that came on it with the rear muffler deleted. because of my future plans for the car i will most likely be installing my own 3" system shortly but i feel at the moment the car is doing just fine with a 2.25 exhaust. it went 14.7 in the 1/4 last week on a basically bolt on motor. Like i said though it all depends on your set-up and what your looking for out of your exhaust system.

I wonder what different exhaust sizes would do to a NA built 2.slow...

*flamesuitengage*

no flame suit needed. if we had a car we could regularly test on we would be all for seeing what different set-ups do on an NA 2.0 car. Everyone is into different things thats what makes the car world so interesting. if we all did the same thing over and over again it would get boring

I havent been following the 12v NA scene much but I did see those very nice new headers that were made.

Id like to see those thrown on this car with the 3" exhaust and see what kind of numbers it produces

Good testing

I had heard great things about that particular header you are speaking of. it would be very nice to try and get one of those to do some testing on mated up to our 3" system. If we could find one we would be all for it.

id say thats an increase all over.

Yes it is. We couldn't be happier with the results of this test. I myself was actually very impressed with how well the system did.

Thanks for all the hard work on this to all those involved. MUCH appreciated. We've been arguing 2.5" vs. 3" for a long time over on the Corrado forum:

http://forums.vwvortex.com/showthrea...exhaust-on-VR6

I promised i would get this done sooner or later and i am a man of my word. I'm just glad we got a chance to do some real dyno testing to finally put the argument to rest

Stock, i'd do 2.5". I def wouldn't do 3" on a stock stock motor.

Edit, but i think it's important to notice that i had no torque loss going to 3". Should tell a story about exhausts on these motors.

Once again timmy. Thank you so very much for your support through all of this and further helping the MK3 and VW community. None of this would be possible with out you man

Now to touch on the opinions of 2.5 VS. 3" I completely agree that on a stock car there is absolutely no reason to be running a 3" system and i would most certainly put a 2.5" system over the 3" system. Which is also the reason that the 2.5" system from us has been developed for the MK3 platform cars and will be released and available shortly

This VR6 test/study is awesome, I really hope more like it appear in the short future.

Kei

Thank you Kei. We plan on dyno testing as many of our products as possible now that we have access to a local dyno. We are all about proving power and not just going with what everyone else says or making up some number. Keep an eye out for more exciting products in the future!

[epic d]

good info Tim

To the man with the 2.5TTw/borla, What are you using for a downpipe?

[root beer]

You mean my exhaust that i was running? It was a ported stock downpipe and manifolds/42dd test pipe/tt borla

[epic d]

awesome man, that's exactly what I was planning on doing to replace my magnaflow junk. With the exception of your headwork and lack of lightened pulleys that will be my exact setup.. Just under 200whp is a lot better than I expected

[root beer]

All in the details homie, good luck. Pm me if you catch a dilemma.

[LowLife]

Good deal, glad you took the time to dyno this out. So does any company out there offer a 3 inch system? Or is something that has to be custom made? Dreaming of a Vrt with a 3 inch system...

[1337cshacker]

Does exhaust size of that much difference effect back pressure on turboz? I would look up numbers on different size exhaust on vrt's. One I know where I live uses his stock muffler and has good numbers 80hp of boost

http://www.tercelreference.com/terce...st_theory.html

[JohnStamos]

Does exhaust size of that much difference effect back pressure on turboz? I would look up numbers on different size exhaust on vrt's. One I know where I live uses his stock muffler and has good numbers 80hp of boost

http://www.tercelreference.com/terce...st_theory.html

Stop talking.

[root beer]

This is all i have to say about turbo exhaust systems

[son of planrforrobert]

Being up this early on a Saturday blows

hai Timmy

[WannabeVWguy]

i've got a S2 metalwerks header on my car. Noticable difference throughout the rev range but i did lose a tad of low end...mid range and upper rpm though definitly show improvements but i've yet to get it on the dyno.

I might have to invest in a 3inch and see what it does with that