What size ic piping is better for 15/20psi boost because i cant find anything good about it.

 

2.5 should be fine. I got my kit from spoolinperformance, great quality!

 

But can some one tell me why 3" isnt better??

 

read the FAQ there is a link in there about intercooler piping sizes.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by v4lu3s &raquo;</TD></TR><TR><TD CLASS="quote">read the FAQ there is a link in there about intercooler piping sizes.</TD></TR></TABLE>
I already looked there butt coudnt find a thing there about it.

 

well its there, you just didnt look very well:

What size IC piping should I use? (thanks BlueShadow)
https://honda-tech.com/zero...02591

 

And if you read the end of the link, you will realize that the two opposing factors are pressure drop in your charge pipe vs. the lag time that it will take to fill a larger charge pipe volume.

If you are pushing 350 WHP with your setup, you'd be flowing somewhere around 400-500 CFM and should closely match the example in the link, and thus 3" charge piping would be better than 2.5". I already showed in the other thread that the lag will be hundredths of a second difference between 2" and 3" charge pipes - basically negligible (on the street, anyway - drag racers might argue the point) Meanwhile, pressure drop of a 2" system = 3.5 psig, 2.5" = 1.5 psig, and 3" = 0.6 psig . Nobody can argue than an extra 3 psig pressure drop on your intake side will be negligible - it will force you 3 psig higher on your compressor map at the same air flow, and thus definitely force an increase in exhaust manifold pressure and thus incur extra losses in trying to spin your turbine harder.

Obviously cost is a factor, but go ahead and calculate the pressure drops using the links to see how much reduction of pressure loss you can afford.

http://www.freecalc.com/gasfram.htm

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by turncoat &raquo;</TD></TR><TR><TD CLASS="quote">And if you read the end of the link, you will realize that the two opposing factors are pressure drop in your charge pipe vs. the lag time that it will take to fill a larger charge pipe volume.

If you are pushing 350 WHP with your setup, you'd be flowing somewhere around 400-500 CFM and should closely match the example in the link, and thus 3" charge piping would be better than 2.5". I already showed in the other thread that the lag will be hundredths of a second difference between 2" and 3" charge pipes - basically negligible (on the street, anyway - drag racers might argue the point) Meanwhile, pressure drop of a 2" system = 3.5 psig, 2.5" = 1.5 psig, and 3" = 0.6 psig . Nobody can argue than an extra 3 psig pressure drop on your intake side will be negligible - it will force you 3 psig higher on your compressor map at the same air flow, and thus definitely force an increase in exhaust manifold pressure and thus incur extra losses in trying to spin your turbine harder.

Obviously cost is a factor, but go ahead and calculate the pressure drops using the links to see how much reduction of pressure loss you can afford.

http://www.freecalc.com/gasfram.htm
</TD></TR></TABLE>

Thanks butt this is way over my head butt could you tell me what size is better for 400whp and remenber that i am gonna boost more in the future.

 

2.5" should be good enough for you then

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BlueShadow &raquo;</TD></TR><TR><TD CLASS="quote">2.5" should be good enough for you then</TD></TR></TABLE>

2.5 is a pretty universal size. hit me up if you want some ic piping kits.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by blackpearlcivic &raquo;</TD></TR><TR><TD CLASS="quote">

Thanks butt this is way over my head butt could you tell me what size is better for 400whp and remenber that i am gonna boost more in the future. </TD></TR></TABLE>

What I am saying is less pressure drop is better. If you can have almost 1 psig less pressure drop by going from 2.5" to 3", then go for 3". Obviously cost and fitment are factors too...but so are your future goals, and if you are going later for 400+ WHP, you should definitely go 3".

 

a friend of mine is running 650whp with 2.5 inch intercooler piping we made ourselves out of U-Bends....so I think 2.5 will be plenty

 

do not go with anything that is larger than either A, your throttle body, or B, your plenum inlet hole.

 

It's lovely how so many people have some rule of thumb they've learned from someone or maybe read here on the site that someone has made xxx whp with this setup, but never really thought about how it works, and possibly how to improve it. Oh well.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by adictionbass &raquo;</TD></TR><TR><TD CLASS="quote">do not go with anything that is larger than either A, your throttle body, or B, your plenum inlet hole.</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by quik sol &raquo;</TD></TR><TR><TD CLASS="quote">a friend of mine is running 650whp with 2.5 inch intercooler piping we made ourselves out of U-Bends....so I think 2.5 will be plenty</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by project dc2 &raquo;</TD></TR><TR><TD CLASS="quote">2.5 is a pretty universal size. hit me up if you want some ic piping kits. </TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Iceman05 &raquo;</TD></TR><TR><TD CLASS="quote">2.5 should be fine. I got my kit from spoolinperformance, great quality!</TD></TR></TABLE>

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by turncoat &raquo;</TD></TR><TR><TD CLASS="quote">It's lovely how so many people have some rule of thumb they've learned from someone or maybe read here on the site that someone has made xxx whp with this setup, but never really thought about how it works, and possibly how to improve it. Oh well.</TD></TR></TABLE>

i personally prefer

2 inch frolm turbo to intercooler
and 2.25 from intercooler to TB.

however people want 2.5 so i just serve what people want.

 

We use 2 .25 flared to 2.5 from Turbo to intercooler , then 2.5 to the TB, Makes 600 no probs.
I don't know why you would need 3" on a street car.

 

Turncoat, i feel your frustration. lol

Listen to this guy, he knows what he's talking about!

Just cause your friend makes 700whp on 2" piping, doesn't mean it's optimal...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">Turncoat, i feel your frustration. lol

Listen to this guy, he knows what he's talking about!

Just cause your friend makes 700whp on 2" piping, doesn't mean it's optimal...</TD></TR></TABLE>

I don't think anyone even took the time to read through the thread to see what he is trying to say, lol. It's a little over my head, but I kind of understand what he is talking about. You are right though, the point everyone is missing is that just because a certain size piping worked for x amount of horsepower doesn't mean it was the best size piping for the setup.

 

Basically, there is a power difference as a result of pressure losses through smaller piping. You might not realize it, but it's there. Yes, you can cram 650hp worth of air through 2.5" piping, but it's easier to cram that same amount of air through 3" piping. Just like a bigger downpipe.

 

2 inch frolm turbo to intercooler
and 2.25 from intercooler to TB.

will this work ok for 450hp range?? or better off with 2.5??


Modified by eg:R at 4:20 AM 11/9/2005

 

I think it will make 450 but 2.5 would be a better choice, It's like a small turbo will make high HP but doesn't move the CFM of a large.

I would talk to the people that build and dyno cars , the ones which are real hands one which do this stuff for a living. It's like calculating injector size, I know which ones to use because I've seen which work and physically tuned it .

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by tony1 &raquo;</TD></TR><TR><TD CLASS="quote">Basically, there is a power difference as a result of pressure losses through smaller piping. You might not realize it, but it's there. Yes, you can cram 650hp worth of air through 2.5" piping, but it's easier to cram that same amount of air through 3" piping. Just like a bigger downpipe. </TD></TR></TABLE>

Yeah, I guess I should have just said it that way. It is a lot easier to comprehend, but I just can help explaining how I got to the answer. Besides, it's a lot more fun to calculate this stuff than the piping systems at the plant.

Oh, and I also realize now I made a mistake, too, but it was relatively minor. For fun here are the corrected and another examples...

For a 15 psig system, on a 2.0L motor, at 90% VE, flowing 300 ACFM (480 SCFM), aroud 400 whp:
2" piping: 3.0 psig drop
2.5" piping: 1.0 psig drop
3" piping: 0.4 psig drop

For a 30 psig system, on a 2.0L motor, at 90% VE, flowing 350 ACFM (725 SCFM), around 650 whp:
2" piping: 4.5 psig drop
2.5" piping: 1.5 psig drop
3" piping: 0.65 psig drop

If I was pushing the limits of the turbo, I would find it hard to resist going from a 2.5" to 3" pipe system and dropping 1 psig to maybe get into a better compressor efficiency range and pick up more power....

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by turncoat &raquo;</TD></TR><TR><TD CLASS="quote">Yeah, I guess I should have just said it that way. It is a lot easier to comprehend, but I just can help explaining how I got to the answer. Besides, it's a lot more fun to calculate this stuff than the piping systems at the plant.

Oh, and I also realize now I made a mistake, too, but it was relatively minor. For fun here are the corrected and another examples...

For a 15 psig system, on a 2.0L motor, at 90% VE, flowing 300 ACFM (480 SCFM), aroud 400 whp:
2" piping: 3.0 psig drop
2.5" piping: 1.0 psig drop
3" piping: 0.4 psig drop

For a 30 psig system, on a 2.0L motor, at 90% VE, flowing 350 ACFM (725 SCFM), around 650 whp:
2" piping: 4.5 psig drop
2.5" piping: 1.5 psig drop
3" piping: 0.65 psig drop

If I was pushing the limits of the turbo, I would find it hard to resist going from a 2.5" to 3" pipe system and dropping 1 psig to maybe get into a better compressor efficiency range and pick up more power....</TD></TR></TABLE>

The way you're figuring these examples it seems as though it would always be better to go with a 3" pipe because there will always be less of a pressure drop than with the 2.5". Is this correct? According to your calculations in the archived thread referenced above you also state that going from a 2.5" to 3" would only take an additional 0.019 seconds to get to 15 psi, so lag is negligable. Why would anyone not want to go with a big 3" charge piping?

 

going to 3 inch full IC pipping is the best thing I ever did!!!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RyanCivic2000 &raquo;</TD></TR><TR><TD CLASS="quote">
The way you're figuring these examples it seems as though it would always be better to go with a 3" pipe because there will always be less of a pressure drop than with the 2.5". Is this correct? According to your calculations in the archived thread referenced above you also state that going from a 2.5" to 3" would only take an additional 0.019 seconds to get to 15 psi, so lag is negligable. Why would anyone not want to go with a big 3" charge piping?</TD></TR></TABLE>

I guess I'm actually trying to find out for myself, too. By going bigger on the charge pipes, it will drop the pressure ratio on the compressor (at the same flow, assuming) and this will definitely help any turbo, in that you will have a cooler charge. And we are talking significant numbers, too, esp if you can drop a couple psig at the same compressor flow.

If anyone is building system from scratch, the cost of 3" from 2.5" wouldn't be much. I'd imagine anybody building a 500+whp motor would go 3" from the start anyway.