2.5 downpipe or 3 inch downpipe... which is best???

[squeak10686]

does it matter which size downpipe i am using into my car?????


i have a 16g tubo,
mbc,
k&N fipk
and am getting a safc


is it alright for me to use a 3 inch downpipe???

 

[CanadianTSi]

3 inch will be fine.

 

[TSIfreek]

Alot of guys say that they run into boost creep with a 3" DP. I would recomend porting your 02 housing concentrating on the WG passage in the housing. The more easyer the exhaust gas is removed from the WG the less boost creep you will have. I would run a 2.5" DP with no cat and a 3" cat back. This set up is great for a 16g and will support 400+HP.
The reason behind using a 2.5'' is that the gases out the turbo wont out run the gases coming out the waistgate. If you out run the turbos exhaust gas you will run into creep at the higher rpms.
That 16g will only put down 350hp at the max any way so the 3'' is not needed and will not benifit from doing so.
I would have FP or SBR port your 02 they both do great port work.

 

[squeak10686]

but, my car is in the shop getting custom fabbed right now for 3 inchw ith both, will it still work fine? the 3 inch that is

 

[TSIfreek]

Just watch for boost creep at high rpms. Porting your 02 housing will help alot with preventing this.

 

[DSMeclipse4G63]

I have ported evrything...manifold, turbo, o2 housing and I have a 2.5 into 3in downpipe then a 3in cat back and it works great for me....other then the creep as the rpms go up.
Andrew

 

[reese]

i have a 2g ported 02 housing, 3 inch down pipe no cat into 3inch custom mandres bent exahust into a generic 3 inch muffler and it creeped hella until i got the new 02.

when my car gets the new shortblock in it i now have a ported 2g exh mani to throw on as well.

id go with a 3 inch so that way the potential of supporting more hp is there, and i noticed a substgantial rise in the ass dyno test.

 

[Turblown]

it creeped hella until i got the new 02.

Meaning that when you got the ported 2g 02 housing ("new O2") it stopped boost creep completely? Did you port the turbine housing at all? Just wondering.

 

[reese]

that is correct. the ported 02 worked wonders. after that install i only creep about half a pound...so not shit.

just my .o2

 

[coltboostin]

ort the Turbine housing like a man and run 3inch DP. YOu wont have creep issues and will not need to upgrade later.

 

[Talonman]

I got teh exhaustdepot.com dp, starts off 2.5" to a 3" flex then 3" back no cat, good welds, good flex and full stainless for $169. Thats what I figure a bent piece of pipe should cost, these shops charging 250+ for a ss dp are raping us. Look at exhaust system price for domestic v8 cars, cheaper than ours and twice the pipe/labor.

Mine would have fit perfectly with a standard catback, I had a Buschur 2.5" and the flange met perfectly with it. I later found a used ATR 3" SS catback on a used car lot off a totalled Talon for $125 ( I had to unbolt it). ATR is slip fit and measured differently, I had to cut the flange and about 3" off of my exhaust depot dp and then it slipped right into the ATR.

Most say 2.5" off the 02 is better for oil filter clearance and not heating up the oil and filter.

 

[Turbo Monk3y]

I got teh exhaustdepot.com dp, starts off 2.5" to a 3" flex then 3" back no cat, good welds, good flex and full stainless for $169. Thats what I figure a bent piece of pipe should cost, these shops charging 250+ for a ss dp are raping us. Look at exhaust system price for domestic v8 cars, cheaper than ours and twice the pipe/labor.

Mine would have fit perfectly with a standard catback, I had a Buschur 2.5" and the flange met perfectly with it. I later found a used ATR 3" SS catback on a used car lot off a totalled Talon for $125 ( I had to unbolt it). ATR is slip fit and measured differently, I had to cut the flange and about 3" off of my exhaust depot dp and then it slipped right into the ATR.

Most say 2.5" off the 02 is better for oil filter clearance and not heating up the oil and filter.

How did you order off their site it takes me to a Yahoo sign in place and asks me for a password. All i want to do is order a freakin downpipe not sign up for yahoo.....

 

[GSX_RCR]

How did you order off their site it takes me to a Yahoo sign in place and asks me for a password. All i want to do is order a freakin downpipe not sign up for yahoo.....

http://www.exhaustdepot.com