what size exhaust for t25???
 

Sorry to post this again if it's already been answered already.

I have a 97 Civic HX and i'm almost ready to put the kit i have put together on, but i need to get exhaust and i'm not sure what size.

I'm running:

HF manifold
T-25
Ported 02 housing
2.5in downpipe
random FMIC i found
1st gen DSM BOV
VAFC
450cc DSM injectors
8-10 psi

is 3in exhaust to big or should i be just using 2.5in?

What muffles are available for each???

THANKS for any help ahead of time guys.

PauL

Re:what size exhaust for t25???
 

2.5 will be just fine, just be sure to forget to put the cat back in ;)

Re:what size exhaust for t25???
 

don't worry about that. ;) i'm gonna put an 02 simulator in..hehe. thanks for the help!!!

PauL

Re:what size exhaust for t25???
 

obd1 ownz jo0, and a 3" exhuast will make more power even on a t25. Ignore the ruls of scavenging, because you can make more power with faster spool and less backpresspressure across the entire rev ramnge instead of tuning for maybe 4hp within a certain rpm range.

Re:what size exhaust for t25???
 

Cars can easily make 4-500 hp on 2.5 downpipes, its not like you will see a huge performance gain from 2.5 to 3.0 on a stock T25 (d series) setup running 8-12 psi.

Our Z6 hatch has a very nice 2.5 mandrel exhaust system, no cat, and a Apexi N1 turbo muffler, it spools incredilby fast.

T-25 exhaust wheels alone are probably not bigger than 1.75 inchs

https://www.homemadeturbo.com/adam/adyno.jpg

Jeff

Re:what size exhaust for t25???
 

i was thinking 2.5in downpipe and 3in exhaust. i guess i'm getting such mixed opinions..that's why i'm having trouble deciding. thanks for all the info so far guys...keep it coming!

PauL

Re:what size exhaust for t25???
 

Bigger = better. 4" will make more power than a 3" on a t25. No exhaust will make the msot maount of power. Turbos get soem of their power from diffusion. The higher the pressure difference, the more power the turbo has. Highest pressure difference = no exhaust. But larger is always better. I'm sure you could make 400 hp on the stock exhaust too..

Re:what size exhaust for t25???
 

I'm not saying bigger downpipes dont make more power, I'm just saying for this specific setup, running 8-10psi on a stock D-series with a 2.5 downpipe is plenty, and that you wouldnt even feel a difference in a 3in downpipe over the 2.5

Also 3 inch isnt exactly the easiest piping to work with on hondas, its a bit tough to tuck it on some areas. But manageable, You can look at it this way, 3 inch would be great if have big plans with the car, and plan boosting into the teens. Other than that I wouldnt worry about it.

2.5 DP and 3in exhaust is very common on setups.

JEff

Re:what size exhaust for t25???
 

that's what i'm thinking. 2.5in downpipe for sure!!!! i'm pertty sure i'll go with 3in for exhaust... i'm not looking for monster power though....and 2.5in would be quieter for exhaust...

see...there i go again not being able to decide. LOL at least i've decided 2.5in downpipe

Thanks for all your help!

Re:what size exhaust for t25???
 

go for 5 inch dia ;D