2g talon tsi downpipe size

[pnbdash]

how you doing people...
newbie here... this forum has been very helpful...
but i have a question my car is totally stock but I want to get a downpipe
I have a t25; which is a better size a 2.5 or a 3" downpipe...
Im concerned about boost creep...



thanks for your help

 

[Zdrummer15]

You shouldn't have any boost creep issues with the t-25. That being said, you don't need a 3" downpipe with it either. If you plan to extensively upgrade down the road and don't want to purchase parts twice, get the 3" one. If you don't, then you'll be fine with only a 2.5" downpipe. I'm also assuming you already have a cat-back because the downpipe won't benefit you at all without an upgraded cat-back.

 

[97-TSi-Hx35]

just do 3" if you ever do a 16g or bigger your gonna need it!

 

[jpmxrider489]

If you get a 3 inch with a t25 thats kinda overkill. If you upgrade to a 16g I would recomend a 2.5 because of boostcreep. But if you decide to go bigger you wont have a issue.

I have a 16g and 940cc injectors with a 2.5 catback and stock downpipe. Plus if you get a aftermarket downpipe, I was told you cant weld a bung for a wideband. But imsure people can. If you get a bigger downpipe i would get 2.5 but remember that you have to get a a o2 housing that matches unless you can port.

 

[bryanwheat]

If you get a 3 inch with a t25 thats kinda overkill. If you upgrade to a 16g I would recomend a 2.5 because of boostcreep. But if you decide to go bigger you wont have a issue.

I have a 16g and 940cc injectors with a 2.5 catback and stock downpipe. Plus if you get a aftermarket downpipe, I was told you cant weld a bung for a wideband. But imsure people can. If you get a bigger downpipe i would get 2.5 but remember that you have to get a a o2 housing that matches unless you can port.

WHAT? Why can you not weld a bung for a 3 inch pipe but you can for a 2.5? That makes no sense at all. Just get the 3 inch, and a 3 inch catback. If you have boost creep issues than port the o2 housing.

 

[Wild93GS]

^ he never said you couldn't for a 3 inch?

 

[miguelmcv]

Just go with 2.5 down pipe.

That will be more then enough for that T-25.

 

[bryanwheat]

Ok an aftermarket downpipe is what he said. regardless that is ridiculous.

 

[jpmxrider489]

I did not meant that you can weld in a 3 but not 2.5. I went and got a estimate for a bung installed since i can weld and they said they cant weld stainless. Sorry if that came out wrong. I have a 16g with stock downpipe. If you want a 3 then get one. There was a guy who actually tested when you should upgrade and the 2.5 came out almost the same as 3. I dont think youll actually notice the difference between 3 and 2.5 downpipe but a whole turbo back then you can notice. A lot of people think bigger is better and thats not totaly true. You have to base it off of you mod list/wants. If you do have a t25 i woulnt upgrade. If your going bigger than a big16g then you can upgrade to a 3 IF you want. But like I said it is not needed. I am happy with my stock downpipe.

 

[pnbdash]

yeah I'll be getting a 3' catback (luckily for free) ... which sites/brands do you guys recommend...
i should mention... i'll be keeping the t25 for as long as I can...

so basically having a 3' catback will work fine with a 2'5' downpipe....

 

[bryanwheat]

So because one person couldn't weld stainless steel that means that nobody can? There is no reason to not get a 3 inch downpipe other than the possibility other than possible boost creep which can be solved with porting. This way when you decide to upgrade in the future you won't have to buy another.

About the 2.5 dp with the 3 inch catback. Just get 3 inch for both in the same brand or else you will have to have one side cut and adapted to the other side. If you want to be able to bolt it together and not have to modify it than just get 3 inch in the same brand. Most different brands the flange will be at a different angle.

 

[hypergenesis]

I honestly just say go with the 3" if you ever plan to upgrade in the future. I got my 2.5" for free and I extremely want to just buy my 3" for my 16g that im about to install.

If you plan to upgrade its better to buy once than twice ya know?

Armin

 

[jpmxrider489]

I never said no one can. I said i got a estimate and he said he can do it. I said i cant do it. I got my exhaust from japanimport on ebay. Its good quality for ebay. Had it for a year and half and no problem.If you want a 3 catback and 2.5 downpipe then you would have to have a adapter or something because you will probilbly get creep if hit hits a wall. If you plan on t25 for a wile i would get 2.5. If you can port then thats good. If you dont want ebay then get hks megan or apexi but I think apexi has some fitment issues. My car is lowerd and my 2.5 used to drag some on bumps but thats cause i live in PA.

 

[pnbdash]

So because one person couldn't weld stainless steel that means that nobody can? There is no reason to not get a 3 inch downpipe other than the possibility other than possible boost creep which can be solved with porting. This way when you decide to upgrade in the future you won't have to buy another.

About the 2.5 dp with the 3 inch catback. Just get 3 inch for both in the same brand or else you will have to have one side cut and adapted to the other side. If you want to be able to bolt it together and not have to modify it than just get 3 inch in the same brand. Most different brands the flange will be at a different angle.

.... i'll keep this in mind even thou i said i will keep the t25 i know for a fact in the future i'll get a bigger turbo...

 

[bryanwheat]

The 3 inch will be fine. I've built and installed 20+ 3 inch full exhaust setups on cars with t25's. IT will be fine.

 

[jpmxrider489]

I actually have a 3 inch cat back with a stock downpipe. But the cat is built for the difference.

 

[bryanwheat]

There is no reason to have a big catback and a small downpipe. We all know that exhaust gasses will condense as they get further down the pipe requiring less diameter to move the same amount of gas. There is really no performance gain in that at all. You need it to be the biggest right out of the turbo.

 

[97-TSi-Hx35]

I have a 3" pipe right off my turbo flange that goes down past the oil filter and around the oil pan to the front of my t case and my exhaust is 3.5" from there back, works great. but if you don't plan on going big then run a 2.5" to 3" and you will be fine

 

[pnbdash]

I have a 3" pipe right off my turbo flange that goes down past the oil filter and around the oil pan to the front of my t case and my exhaust is 3.5" from there back, works great. but if you don't plan on going big then run a 2.5" to 3" and you will be fine

thanks for the feedback

 

[ConcowTSI]

not exactly a question about downpipe size but def. related... i am going to get an electric cutout and bolt it between the downpipe and cat, i have a 14b turbo, 1g bov, k&N, msd wires, denso iridium plugs... thats it. for now.
my question is:
will the turbo / boost level be effected when i have the exhuast cutout open? ( i realize it's alot noisier than it needs to be, but i live in the middle O' nowhere and i love the sound and responsivess of an engine with open exhuast.) plus later when i really up the boost i dont want to have a loud exhuast all the time. I just want it stock, then when im gettin down ill just open the electric cutout.
would this work OK?

 

[beendenied]

It'll boost quicker, but the t25 already boosts so fast hehe. Less resistance in the exhaust is almost always a good thing. But what is your second question, will it work? yes

You pretty much described what one would get a cutout for

 

[ConcowTSI]

actually its a 14b turbo, 1g bov (ebay intercooler and intake piping kit on the way. seems to spool fairly slow but it is my first turbo so i dunno. the second question was: will having the exhuast cutout open have ANY kind of negative effect on performance? thanks for the reply.