i was just wondering if anybody here has 3 inch piping all the way through. i bought a bunch of 3 inch bends and i am making my own intercooler setup. i would appreciate it if i could get some "ups and downs" from people who have had it or has it. please dont respond with... i heard or i read. i could use real experience here please... thanks

This is what im assuming. If you dont have a large turbo pushing a lot of cfm's then your going to have a great deal of pressure drop. Blow through a straw (evo 3 persay) into a coffee can. There's a noticible difference in pressure. Idk how else to explain it....branis not working right now. but i think 2.1/4 or 2.5 would be plenty for most turbo setups.

i know what your saying dude. dont worry, i have very good knowledge of turbo physics . i was just wonderin if anybody has tried it? most people go with 2.5 because other people tell them so. that doesnt mean that its the best. so i just want to hear it first hand from someone who has used 3 inch piping. i have a 50 trim so i think that it can handle filling up that much piping... i dont really know though, thats why i ask.

My buddies civic (regardless of what car its pretty much the same) has a 14b on it. His dumb ass went with 3inch piping. The actuator is set around 8-11 right, his boost gauge (remember he has NO boost leaks) read a max of 5
Although a 50 trim might fill that gap, you will still have some sort of pressure drop

i am not saying this from experience, but if you have bigger piping wouldn't the turbo have to work harder just to fill it up, you might end up getting a 3" pipe full of hotter air. just my 2 cents

yea, i know what you mean. it would definitely be a little more laggy than now. but i think that huge amount of air being moved will be good.

oh by the way, i think that your buddy has his actuator set at 5lbs or 6lbs, it just would take it a while to fill up those pipes...

91-gsx said:

i am not saying this from experience, but if you have bigger piping wouldn't the turbo have to work harder just to fill it up, you might end up getting a 3" pipe full of hotter air. just my 2 cents

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i was wonderin that too. but maybe a 50 trim can handle that much pipe.

a 50 trim isnt that much bigger than an evo 3 honestly. Id say go for it, but you may be hurtin yourself in the long run

i am in no way an expert, but the way i think turbo work the best is when they are not pushed to the limit or for a long period of time. when you have larger pipes the turbo always has to work harder to fill it whether it is a 50 trim or not. when you have smaller tubing the area filled is smaller and that means the turbo will spool faster and it will also push out air with not too high of a temp. just like getting a bigger exhaust makes the turbo work less and your motor work less as well, to push the exhaust out. so basically what i am trying to say is try to make your turbo work as little as possible and get colder air which of course in turn makes you faster. this would be my other 2 cents

In that case..... make your piping....... 1.5 inchs............

Personally my setup is as follows....

from side mount IC 2.5" to 3" to 2g throttle body elbow....

I really dont kno how my setup came to be... I just had pipe laying around so i made it...

Someone will probobly have somthing bad to say about my setup... but my boost gauge holds the right psi, spool is excellent like 3psi at about 2500 rpm.

3" all the way may be too big.... but give it a shot an tell us how it works.


G

I've seen a person switch from 2.5" to 3" piping and pick up a few tenth's when he was running low 10's.

that would make sense if you had a big turbo in which the tubing becomes a restriction if it is too small. but then again the whole point of a turbo is create pressure, not reduce the back pressure like you do when you get a bigger exhaust, right? i guess it could go a lot of ways, if you have like short route piping 3" would not be bad but if it is really long and 3" then you might have a issue. i guess as they all say here, try it or find someone that has gone to 3" tubing and then make up your mind, tell us how it goes.
later

I am going to agree with 91-gsx. If you are going to do a 3inch, it better be a short route. If you think about it, the difference in cubic inches from 3inch short route to 2.5inch long route, its got to be about the same overall cubic inches. In-turn, the same amount of pressure should be applied to the engine.

let us know how it works...

ok guys. i am going to do it. i have a bunch of aluminum 3 inch pipes and bends. i will definitely let people know how it goes.

on another note, i dont neccessarily agree with saying that you want more pressure with a turbo. i believe you want to flow as much air. psi is a turbos restriction to flow. if i put bigger piping, the turbo doesnt have to push hard psi to get that cfm flowing.. i dont know for sure if it is true, but it makes a little sense to me. wisemen, please enlighten me if you see fit. thanks again guys.

I went from 2.25" to 2.5" and noticed an increase in throttle response. I could also hit full boost slightly sooner. I recieved NO gains in top end flow (lb/min) as calculated by DSMlink. I only gained in throttle response. Personaly, Im satisfied with 2.5" piping. I have no experience with 3" piping. I dont think it will hurt you too much, but I really dont think it will help you either. Im sure you are not having problems with throttle response so 3" may be a little over kill.

THIS IS REAL LIFE EXPERIENCE... NOT SOME OF THE GUESSES STATED ABOVE.

Im sure other people have some real life experiences of their own that they can share. If you havent been there, dont post... you are making people stupid.

What will your intercooler setup be? Will it have 3" inlets? If your inlets are smaller in size than 3", the intake charge is going to speed up as it enters the intercooler. This is not desired as it will decrease the contact time with the intercoolers internal core.

Also, sudden changes in pipe diameter can cause eddy's within the intake charge. This will especially be a problem at the throttle body and turbo outlet. You want to keep the number of changes in pipe diameter to a minumum.

Well I'm no expert in this as I have no real life experience with 3" ic pipes but common sense tells me that unless your exhaust, head, intake manifolds, TB ....etc are all outflowing 2.5" IC piping, I seriously doubt it unless you're talking about 10 second cars, the only gains from 3" inch ic piping are probably slower spool, harder working turbo and more turbulence at the throttle body. It's like having a 3" DP is great but it does you no good if you still have the stock cat back.

yeah, i see exactly what you guys are talking about. im gonna try it anyway. if it is bad or good, at least i can let people know from experience.

and to answer the other guys question, i have an intercooler with 3inch inlet and outlet. and im gonna have 3 inch piping all the way through, from turbo to throttle body.

97gstnick said:

and to answer the other guys question, i have an intercooler with 3inch inlet and outlet. and im gonna have 3 inch piping all the way through, from turbo to throttle body.

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And then "BAM!", the 2g 52mm TB (2.0472 in). Let us know what happen.

Your turbo doesn't have a 3in outlet does it? It just seem like one would want to runn the same size pipe that the turbo outlet is unless the diameter of the size they are on is causing resctictions. That would make sure that there are the least ajmmount of diamter changes. I don't know. Just a though.

gamingguru said:

Your turbo doesn't have a 3in outlet does it? It just seem like one would want to runn the same size pipe that the turbo outlet is unless the diameter of the size they are on is causing resctictions. That would make sure that there are the least ajmmount of diamter changes. I don't know. Just a though.

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no, thats not really the case. after the outlet of the turbo, everything else gets filled up with air.

i am gonna upgrade the throttle body!! =) im just gonna put the piping on for now. what throttle body should i buy ? like one of the mustangs? 75mm?

oldman said:

And then "BAM!", the 2g 52mm TB (2.0472 in). Let us know what happen.

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, yea. trust me, im not gonna stay with that throttle body. i think maybe, just maybe... with that much pipe that boost would hit hard once it fills up the all the piping. ill let you guys know, dont worry.

Wouldn't it make sense to try to match what the compressor inlet and outlet are? And then, like oldman said, unless everything is that diameter, how could it help?

Hey, on throttle bodies I would suggest not to go with the accufab 75mm ones. The 1g throttle bodies are 60mm(2.36in) and B&M makes one that is larger; 75mm I think. Anyway, people always seem to have trouble with the shafts breaking on the accufab ones.

gamingguru said:

Your turbo doesn't have a 3in outlet does it? It just seem like one would want to runn the same size pipe that the turbo outlet is unless the diameter of the size they are on is causing resctictions. That would make sure that there are the least ajmmount of diamter changes. I don't know. Just a though.

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So, by your comment, you are saying I should run just 2" piping with my 60-1 just because it has a 2" outlet? WTF

And as oldman stated, you tb is only a little bigger than 2" so it is still only going to flow a given amount of air regardless of what size ic piping you run. Your $ would have been better spent on a 1g tb(close to 2.5"), a 2.5 tb elbow, and 2.5" ic piping. The 3" is going to create a severe pressure drop and you will be overworking your turbo to make the same power as someone else with 2.25-2.5" ic piping.

91-gsx said:

when you have larger pipes the turbo always has to work harder to fill it whether it is a 50 trim or not. when you have smaller tubing the area filled is smaller and that means the turbo will spool faster and it will also push out air with not too high of a temp.

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I'll agree that 3" piping probably won't help but it won't hurt either. Larger piping will not make the turbo work harder. Larger piping is less of a restriction and less restriction means more flow. That's the purpose of the BOV to keep the flow going and not build backpressure on the turbo. (this can cause surge) Turbo spool is more a function of exhaust side design rather than flow on the compessor side and temp increase is directly related to pressure rise. You could say that it has to fill more area and that will decrease spool time but atmospheric pressure can fill this void fast enough let alone something with a turbo.