How much will different sized intercooler piping flow?

[dsm-onster]

I'm going to paste in everything that member Vigge PMed me yesterday. His real world testing says exactly what I would speculate through theory. So there's no need to insert mathematical aphorisms.

Noted there is a pipe size related topic on the forum and here is some measurements which relate to that issue.
The reason for doing these measurments where to point out to a "bigger" audience in the saabscene that majority who invest in larger pipes are just wasting money and worsening their set-up since there aren that many saabs around in which the bhp level would be so high that the original 2" (45mm I.D.) would become restrictre even though some tuners on their website say the opposoite.

Anyhow here is a old post of mine where I compapred the spool and responce with the original stuff vs. 2.5" shiny stuff. Used that same 2" IC-TB pipe in my last viggen set-up also which produced around 600bhp/650Nm

--------------------

The aim of the following test was to come to the bottom if a shiny 2.5" delivery pipe among with a redone TB bend will lead to improvements. The normal claims in fawor of the pipe have been
-smoothner power delivery
-better/improved response
-smoother transition from under pressure to boost
-more power
aso.

Today I covered the responce testing with both T5 orig delivery and aftermarket and here are the the discoveries. Prior to all test the car was driven on highway to "normalize" the conditions. In all logs solid lines = after market stuff, dashed T5 OEM stuff

Response test 3000rpms 4th gear
www.stcf.net/viggen/pipe3000.pdf
TB plate opens slitly later with OEM stuff, but regarless of this the OEM pipe outperforms the aftermarket stuff. Speed difference in the beginning 0.6km/h and 4.3 km/h once at full boost. Difference mainly from lower rpm spool with OEM pipe

Responce test 3500rpms 4th
www.stcf.net/viggen/pipe3500.pdf
more or less the same as above but devieance not as big

Responce test 4000rpms 3rd
www.stcf.net/viggen/pipe4000.pdf
again more or less the same but roughly equal

The above tests where repeated several times to rule out the normal run to run variation, but regarless of it the results are as posted above.

Conclusion, the pipe for sure will do nothing in terms of improved response and I perosnally would vote for the opposite. Smoohter power delivery can be written as slitly delayed power delivery.

 

[gstryyder]

Knochgoon, That is some great info and some very good calculators. I will have to bookmark that. It is always good to expand upon what calcs you have and what knowledge I can gain. I will look over that more thoroughly when I get off work.

Thanks Matt! -This is the kinda stuff I was hoping you had up your sleeve. Real world testing is all I want yet, cannot do. I wanted to find a way to prove smaller pipe is better, Yet with all the math it sucks. Real world testing is what it is all about. Yet, that is the hardest true evidence you can find ( Being that someone actually has the time and capability to do it. For me now it is trying to do the math, but this is what I wanted!

Real world testing is the best you will get! The biggest difference between END RESULT and me crunchin numbers would be that I cannot calculate (with my puny brain) how on/off throttle in variance, and how partial boost and all that stuff will react when you are actually in driving conditions.

The key point i am looking at per his testing is the efficiency of the real life testing. knowing that we can put "some true number" values to stuff so people can look at it and go. rather then doing all the guess work. My goal was to prove that/ and where smaller piping is still more efficient than upgrading. So people have a base to start with instead of guessing they need to upgrade and can go from there. I find it rather depressing to see someone with a 5-600hp car that feels they NEED to run 3" piping to be efficient. When they don't believe the words that come out of my mouth. I could throw some "correct" math at them to try and indulge upon and let them figure it out themselves. I would rather the people that care enough to get over the shiny pipe that are looking for true results to be able to help them achieve that goal. We all like to see how far we can push our turbo's and be effiienct. Why not every other part also. .

The numbers that your friend gave you and the results show most of the necessary information needed to determine how efficient the setup is without all the number crunching. Would you mind asking him exactly what tools it is that he used to get those readings? I would really appreciate it. Those are some that I would like to be able to gather. . Especially when it comes to maximizing my track car's potential, but also when it comes to work related stuff. Also, is there any way you could ask him if he happened to log the temps his setup was reading as far as pre/ or post intercooler? or was he running a turbo to its MAX ( just to get an idea of how hot that air was along with the pressure. So I can work to put some sort of number value's to this? All I can say is thank you for posting that. THAT IS KEY INFO! And thank your pal for sharing that and for taking the time to do testing like that. It is the only way to tell for sure what is going on is how it realistically affects performance. You can't really calculate every variable. Only other question I would have is, do you have a link to his profile, or have a an idea of his mods; and also what car this is in reference to?

This is going to turn out as a key thread for this forum if we can get some actual helpful info out of this mass of good stuff people are throwing around. Exciting! I will indulge myself more into this stuff after work, But I have got to start getting ready to leave. LoL

Thanks for the info and help guys! You are helping me out just as much as any other person on this forum or that will read this stuff. Except I am going to enjoy figuring all this out as far as numbers go (before real world experience has been done to test) so hopefully people can just just reference to it rather then the guess n test and all that stuff.

Fun Stuff. Gotta love this forum. LoL

 

[dsm-onster]

Just know that Vigge deserves the credit. I could sit down and spend all day doing the math and then the next morning too. But it would say the same thing that his results spell out very plainly. He gets the credit for effectively sinking the putt without all the theoretical analysis. I'm sure he'll pm me with the tools used.

Point is, you're more right that you showed with your math. There's SOO much less an effect piping diameter has on total flow than initially infered. There's no need for anyof us to require any more than 2.5" piping. Except for instances that such a diameter favors a resonance sought, as resonance CAN occur in the intercooler piping. But WRT laminar flow: 740cfm (2.5") is far beyond a 50-trim or 20g in flow and that is at 0.4 mach. Operating at 0.5-0.6 mach, you can see that 2.5" piping is plenty for a gt35r, s362, hx40 or even bigger.

 

[92AWDHX40]

Yep for my set up 2.5 is efficient ill be happy this was a very informaive thread lots to read though.

 

[romeen]

FWIW, I am using 2" pipe pre-IC and 2.25" piping post-IC (matches the inlet and outlet of my HRC SMIC which is rated for 400hp). On stock 1G cams my car pulls HARD all the way to 7K. I'll be the first to admit that this is purely anecdotal and not real proof of anything but I do feel that there is at least some implication that the pipe size seems to be well matched to my setup. Again, take it for what it's worth.

 

[KiNg MaRtY]

Thank you all for the information. Very nice read. I now feel confident that my ETS pipes are plenty for my 50trim setup. Happy I didn't go for the 3".

 

[dsm-onster]

The PTE intercoolers have no more than a 2.74" inlet/outlet and they have garrett core rated to 825whp with even denser fin structure than ETS.

 

[pneumo]

Here is the calculator for pressure losses in a typical throttlebody:

Throttle Body Sizing Calculator | REVTRONIX

Take it for what its worth.

I'll make this quick. Off my spreadsheet, given an airflow of 45 lb/min, turbo outlet temp of 375*F, turbo outlet pressure of 25 psig the following pipes will drop the listed psi:

2.25" O.D. straight tubing: 0.17 psi per foot
2.5" O.D. straight tubing: 0.10 psi per foot
3" O.D. straight tubing: .04 psi per foot

Using a (bend radius/pipe diameter) ratio of 1 which is a pretty tight bend and the worst you will see or the tightest you can bend a tube without rupturing it, the K factor (loss coefficient for a 90* bend) is roughly .25-.4. Using K = .35 I get for the following:

2.25" O.D. 90* bend: 0.27 psi per bend
2.5" O.D. 90* bend: 0.17 psi per bend
3" O.D. 90* bend: .08 psi per bend

Various pipe step ups or step downs will yield various additional K loss factors and you'd need to consult a Fluids text for the appropriate charts.

I use the rule of thumb that every 1 psi drop is roughly 10-11 h.p. lost at the 450 h.p. level. So if I have a 2.25" lower I.C. pipe that has 2 90* bends with 4 feet of straights, I get a psi loss of about 1.22 psi loss. If I upgrade to a 2.5" pipe with the same configuration I get about .74 psi loss. For 3" I get about 0.32 psi total pressure loss. At best, the switch to the 3" pipe on the lower I.C. pipe is worth about 0.9 psi gained back in the intake manifold, or about +9.0 h.p.

Thanks for the info pboglio, I find it very useful, as always.

I have a quick question about the following paragraph. Could you clarify? I read this as if you're saying the turbo outlet bend will be sharper if a larger lower IC pipe is used, but it's not quite clear. This is the reason I avoid using cast outlet elbows on downflow turbo outlets- the bend is too sharp.

Also keep in mind when you switch to bigger I.C. pipes the transition off the turbo outlet has to be taken into consideration, which the psi loss actually increases as the pipe size increases, so the gains going to a bigger lower I.C. pipe are not as great as the case I just illustrated. Which is why you need to sketch out exactly the pipe configuration you have now and what you will have when you uprgrade for an accurate loss analysis.

You can play with the numbers all day long but you get the idea. There are gains to be had optimizing the piping size IF your turbo compressor is already dropping off boost at high rpms. Otherwise the turbo will simply command itself to spin up a little faster to compensate. When the turbo is pinned wide open at high rpms and your already seeing boost drop off due to the engine outflowing the turbo, THIS is where reducing pressure losses in the intake system pays off.

In my case, I saw a +1 lb/min increase and 10 h.p. gain swapping out my lower 1.675" j-pipe to a 2" j-pipe because I was already maxxing out my turbo compressor. Otherwise you won't see gains.

More good info. Good science = more power!

 

[pboglio]

I meant a diffuser transition, not a sharp 90* bend. Yep, those cast elbows suck with those sharp bends. I could easily imagine a 20-30 h.p. increase with a full 3" I.C. pipe upgrade and massive 4" thick FMIC core upgrade from Garrett just from the pressure loss decrease alone. When I see guys running straight methanol with no I.C. and yanking big psi numbers out of an EVO3 16g at redline, they have to be getting that boost from somewhere.

 

[fergulus]

I have to say that this plethora of information was exactly what I was hoping for in posting this question. This will save many people time and frustration trying to figure out what kind of piping they need for their particular setup. Thanks to everyone for your input!

 

[pneumo]

I meant a diffuser transition, not a sharp 90* bend. Yep, those cast elbows suck with those sharp bends. I could easily imagine a 20-30 h.p. increase with a full 3" I.C. pipe upgrade and massive 4" thick FMIC core upgrade from Garrett just from the pressure loss decrease alone. When I see guys running straight methanol with no I.C. and yanking big psi numbers out of an EVO3 16g at redline, they have to be getting that boost from somewhere.

This is why I'd like to rotate the compressor housing on my 16G so it faces downward instead of using a j pipe. This would eliminate the 180 degree bend and shorten the pipe by 1 foot. But the wastegate wouldn't fit anymore, so it would have to be converted to an external wastegate, which isn't a bad idea anyway. That should free up some power.

I totally agree that a thick IC core is the way to go. A thicker and taller core has more flow area, which reduces pressure drop. Now if I could find a core that isn't so long there would be room for a better endtank design.

 

[pboglio]

Yeah, clocking would help out and clean things up nicely. Every little bit helps out. I've seen the new Garrett 3.75" cores (25"x12.5"x3.75") in person for the EVO9 and it simply is hugenormous. The advantage I see with 3" tubing is that since the flow velocity is much reduced going into/out of the end tank, the pressure loss would also be reduced. Or the DVDT style endtanks would be something to consider, never was partial to the stock foglamps anyways.

 

[pneumo]

Here's a pic I took of a stock 1G intercooler outlet. My intake tract was very oily at the time, and the oil left some interesting patterns. The pic shows how air swirls as it goes through a 90* bend. It's interesting because the IC core should straighten the airflow, similar to the honeycombs on a maf, but when the air needs to go around a bend it doesn't stay straight. Maybe this is why the pressure drop through a 90* bend counts for nearly twice as much as a straight pipe of equal diameter. If you look at the left side of the pipe you can see that the swirl pattern isn't consistant. There's a line where the swirl changes direction, and that overlap area is most likely turbulent.

You must be logged in to view this image or video.

 

[DSMunknown]

http://www.dsmtuners.com/forums/tur...ake-14b-into-downfiring-turbo-instead-up.html

 

[92EagleAWD]

Ok, so im going to revive this thread here, becasue ive been reading through it and im loving all of this info im absorbing! I have an intercooler i want to have piping made for, but its not a typical FMIC, at least in the routing sense. The core i have is THIS!(both end tanks facing same side) and i have a e316g with an internal gate. I want to make this as efficient as possible, even though i know this intercooler is overkill and will probably hurt me a bit compared to a smaller one, its what i have so its what im working with. I just want some help with making the best route with the fewest bends/reduced angles as possible! Im using an e316g ATM, but plan to upgrade to an HX40 the near future, so from what ive read 2 1/4 piping should suite me well correct? I just cant find an efficient way to get from the turbo to the intercooler without making a near 180* bend, or maybe i could just make the bend larger, im not sure.

 

[pneumo]

Ok, so im going to revive this thread here, becasue ive been reading through it and im loving all of this info im absorbing! I have an intercooler i want to have piping made for, but its not a typical FMIC, at least in the routing sense. The core i have is THIS!(both end tanks facing same side) and i have a e316g with an internal gate. I want to make this as efficient as possible, even though i know this intercooler is overkill and will probably hurt me a bit compared to a smaller one, its what i have so its what im working with. I just want some help with making the best route with the fewest bends/reduced angles as possible! Im using an e316g ATM, but plan to upgrade to an HX40 the near future, so from what ive read 2 1/4 piping should suite me well correct? I just cant find an efficient way to get from the turbo to the intercooler without making a near 180* bend, or maybe i could just make the bend larger, im not sure.

That intercooler works best when the pipe coming out from the turbo follows the stock routing, then makes a 180 degree bend and goes into the lower IC inlet. The IC outlet should have a sharp 90 degree bend that goes through the radiator support where the overflow container sits.

Here's a similar install- RRE 2G  Griffin

 

[92EagleAWD]

Yeah, thats what i was thinking, just making the 180* go around the outside so it wont be so sharp, and running back up through the rad support. Just wanted to be sure i wasnt missing something.

 

[magik95]

Ok my question is I have a big fmic with 3" inlet and outlet. I run 2.5 ic pipe befroe and after the ic. I run a n/t tb which is obviously bigger than a turbo tb. Is this set up causing restrictions and or turbulance in my airflow path?

 

[92EagleAWD]

Well, the NT Throttle body is the same size as the turbo. The only difference is that you need an elbow to bolt on to the Turbo TB and the NT one has a small partition to put a coupler on. But if you are running a stock turbo i would say 2.5 piping is a bit much, the stock piping size is perfect for the stock turbo, but you could probably reduce or eliminate some of the bends to help.

If you look at the pic of the SMIC and the swirls coming out of it you will see that the air swirls in a bend and creates turbulence, which isn't a big deal unless your running over .3 mach or are near the max airflow of your turbo. Smaller piping would benefit you but its probably not cost effective for you. I myself would switch the pipe, but most would not find the minimal gain worth the cost. You might gain minimal HP depending on your MODS, HP level, and turbo, better response from the engine, and less pressure drop from the turbo to the TB. So yes its hurting you a little, but not much at all, so you shouldn't worry about it. But you wont need to be upgrading that pipe unless you plan to run over 650-700 whp

 

[magik95]

Thanks. I was palnninig on rerouting the ic pipes to do away with some of the bends i have in the system. I plan on upgrading to a big 16.

 

[92EagleAWD]

Yeah, thats what im using, but im only running 10 PSI at the moment :/ because of the stock fuel system, getting too much knock above that. Waiting to order my AFPR, winebro pump, and injectors. So i thought i would mess with the intercooler system and perfect it a little while im waiting.

 

[v8s_are_slow]

Way too much technical crap in this thread for me. But I see a lot of people saying to stick with 2.5" pipes or, we made "x" amount of power on 2.5 inch pipes. I'm sure there's a lot to consider though. Size of the intercooler, length of piping, intake manifold used, turbo used, head, valves, etc.

Personally, I'm getting my car ready for a Holset HX-52 and the outlet on that thing is 3 inches alone. Wouldn't even think about downgrading to 2.5 inches from a 3 inch outlet. Also, I'm sure some people are saying that 3" piping is too big. Kind of like people were saying the JMF Drag manifold would be too big on a small turbo. Yet I think it was Evil_eagle that ran one with an E16g on an Evo if I remember correctly and his spool time was shortened and power was increased.

I'll be using my T-28 for a bit and will be adding the 3 inch piping in the mix with this turbo once I get the $200 I need. I'll run it with this teeny turbo until I can throw on the HX-52, but I'm curious to see if it's gonna hurt or help my performance. Sure it'd be something people would like to know. But overall, I don't think there's any good way to answer the OP's original question because there's so many variables that come into play. I'll post again when I have an update (for the ones not following my T-28 thread).

 

[92EagleAWD]

Well, this thread is about intercooler piping alone, if you look at some of the posts you will see that there are MANY variables to consider outside of the piping. Like the turbocharger outlet/inlet, TB, IM, ect... But this is just the piping thats being discussed here, and the only reason your turbo has a 3" outlet is because it was meant for a diesel engine with a lot of airflow. While your 3" outlet and piping causes you to lose airspeed. Bigger piping will mean less pressure drop, you lose airspeed and response, piping should be used according to your application. Such as how much power your looking to make with your holsett. 2.5" piping would work better for you, you would gain airspeed and response, but may see slightly more pressure drop. Which is where an efficeint IC comes in to play, if you have a good Intercooler then the minumal pressure drop you might see from the smaller piping wont happen.

Measure your piping and see how many cubic feet of air your turbo has to fill to catch up with the engine from vacuum with 3" IC piping, now do the same with 2 1/2" piping and see how much less volume your turbo has to fill to acheive "boost" or positive IM pressure. If you have the time you can calculate your airflow of your turbo and see how much less time it takes to hit "boost". Your losing airspeed, but have less pressure drop. If you have the time/money dyno your car, then switch to 2.5" piping and dyno again and see for yourself, belive me, as soon as i have time i will and i will be sure to post results.

 

[v8s_are_slow]

Well, if this thread is only about i/c piping, that'd be kinda stupid if you're gonna leave out all the variables. Since it's ALL about the variables. I mean really, 2.5 inches would make me spool faster? So I guess I should go with 1/2" piping to get the fastest spool possible? Lol. I mean we're only talking about piping and no variables anyway, right? It'd really speed up the velocity. If all this "smaller piping will give you faster spool" crap is true, then explain faster spool on a much larger than stock smim with the E16g. Anywho, I hate the whole debate threads that turns into bickering so won't go there. So I'll try out my 3" piping and see how it works. Maybe it'll kill my performance, maybe not. But if anything, my piping won't be a restriction by any means. And getting the shortest exhaust possible to make my turbo breathe as easily as it can. If it doesn't work, I'll downgrade. But personally, I just like seeing people's results, versus opinions. Cause there's a lot of haters on here that get proven wrong time and time again.

 

[92EagleAWD]

Ok, when i said variable i meant variable outside the piping, you dont have to try to be an ass because your ignorant and dont understand. If you went with 2.5" piping you would gain power and response, thats all im saying. By all means keep your 3" piping, you can go show it off to all the Honda guys and tell them how your 3" piping makes your car run 9's.