Hey hond-tech.....

So im boosting in a DA chassis, I was wondering if 3" charge pipes would be too big. Im asking because one of my friends is selling his charge pipes at a pretty good price. Or should i just find myself some 2.5" charge pipes?

So what would be better. 3" or 2.5"?

set up:
b16
8:1 pistons
eagle rods
turbonetis 60 trim
tial 38mm W/G
fab-works ramhorn
3" D/P
1000cc inectors
ported n polished
ITR valvetrain and cams

 

2.5" is all you need, I saw no difference in responce when I went from 2.5" to 3" but then again I had half the piping with the 3" setup.... just a cold side.

 

so will 3" hurt?

 

Probably takes the compressor longer to charge up the air to the IM.. decrease in spool time maybe?

 

crap. i wouldnt want that to happen.... makes sence though

 

my DA had 3" piping, 81mm lsvtec, gsr cams, gt35r(.63)spooled 18 psi at 5500

 

I doubt it would hurt response and it won't hurt power.

 

so 3" wouldnt hurt power or responce?
does anybody think otherwise?

 

Will hurt response.

 

just be a pita to route the pipes.

 

3" is just overkill, no need for it at all. think about it...

 

you will b fine with 2.5 with you setup....Why so low of a compression.

 

I got the bottom end for dirt cheap, I had the turbo kit at home so i figured why not give it a shot. Is the compression really too low?

 

So some of you guys think its too much?
I was going to do 2.5" charge pipes but thats going to run me about $700 with the intercooler. A friend of mine is sellin a 3" set up with a nice intercooler for $275.

But if its going to hurt power or responce i will spend the couple extra bucks and pay the $700

 

hope this can help you.

https://honda-tech.com/forums/forced-induction-16/when-does-2-5%22-intercooler-piping-start-become-restriction-2409417/

 

wow that link had alot of useful info in it, worth everyone reading for sure...

 

i fit the sparco 750HP core under my 91 da bumper. all 3" piping

 

why not get the 3" intercooler for cheap, then just buy the 2.5 piping and reducer couplings

 

i'm using 2" from turbo to the intercooler, and then 2.5 up to the intake manifold. 3" for my setup would be overkill.

 

Its pretty low, def no need for it to be that low, but you will be ok.....

 

Same deal as 2.5" vs. 3" charge pipes...you won't ever feel any signifigant difference between 9:1 and 8:1. Tons of people run that CR with good results.

 

This setup is just asking for some serious boost with that compression ratio and those big charge pipes!

 

just buy the 3inch piping/IC and save youelf the money.

 

You're going to increase spool time and make less torque with 3" piping versus a 2.5" setup. This is due to the larger volume in the piping which must be filled before the IM can see boost pressure. Also, the larger piping will move a given volume of air with less speed than a smaller diameter pipe which will decrease your torque numbers. You want to maintain air velocity and flow without incurring mass turbulence by running too small a pipe. There is a great thread in the FAQ regarding this...it shows the CFM needed to make a certain amount of power and how that equates to flow speed and turbulence. You should check it out before moving forward...

EDIT: Here's the thread...

https://honda-tech.com/forums/showthread.php?t=2409417

 

^^^^ that thread really goes in no specific direction IMO.....