# Intercooler Efficency Can Add 6 Inches to Your... Dyno Graph? **URL:** \ **Category:** NYSpeed Automotive\ **Created:** [December 10, 2007, 10:14am UTC](https://forums.speedlife.net/t/intercooler-efficency-can-add-6-inches-to-your-dyno-graph/40039 "2007-12-10T10:14:46Z")\ **Posts on this page:** 20\ **Page:** 1
**Author:** ![Zer0DazE](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/zer0daze/32/7624_2.png) [@Zer0DazE](https://forums.speedlife.net/u/Zer0DazE)\ **Post date:** [December 10, 2007, 10:14am UTC](https://forums.speedlife.net/t/intercooler-efficency-can-add-6-inches-to-your-dyno-graph/40039/1 "2007-12-10T10:14:46Z")
forgot i wrote this up… i don’t think i ever posted it up. it wasn’t totally finished, but i have become old and lazy. so enjoy For this to be of any real use you are going to have to know what the efficiency rating is for you intercooler. I am sure some digging on the internet, or a call to the people who made it will give you the answer you need. What’s that big shiny hunk of aluminum do? Its a heat exchanger just like your radiator. It pulls the heat out of the air passing through it thereby lowering your intake temps and giving you more dense/cooler air. It will actually lower boost?!?!!?!? oh no’ssss Yes, that’s right. The colder more dense air will actually be at a lower boost pressure. (that’s a good thing) Here is a quick example… If we take some cylinder (size is no matter) and fill it with air, and then cap it off, it will be at 14.7psi. Now if we were to heat that cylinder up 100\*C it would raise about 5psi (give or take). :shock: So figure the air coming out of the turbo to be the hot air, and the air from the intercooler to be the cooler air. That’s the pressure drop. Ok back on track. Lets say its a 60_F day, and your turbo is pumping out 10psi at a blistering 260_F. That’s a temperature rise of 260 - 60 = 200_F (that’s hot) and lets say that your intercooler is 60% efficient. That means it will remove 60% of the temp change. 200 x .60 = 120_ This leaves you with an intake temp of 200 - 120 + 60 = 140\* That’s cool and all, but what we are concerned with is the change in density. Change in density can be calculated with this formula Dc = [(Dt + 460) / (It + 460)] - 1 Where Dc = Density change Dt = Compressor outlet temp It = Intercooler outlet temp So in our example we would have Dc = [( 260 + 460) / (140 + 460)] - 1 Dc = ( 720 / 600 ) - 1 Dc = .20 In theory that means we will have a 20% increase in density, and a 20% increase in power…but that’s not going to be the case. The intercooler is a restriction, as well as the rest of the charge pipe. There is also the inherent pressure drop from the air being cooler after the intercooler. If your piping and intercooler aren’t total crap you shouldn’t see more than 10-15% pressure drop from the turbo to the manifold. How much power am I going to make with this hunk of aluminum? HPr = Dc + 1 – [(Ap + Bc) / (Ap + Bm)] Where HPr = Rise in HP Dc = density change from the intercooler Ap = Ambient Pressure Bm = Boost pressure at the manifold Bc = Boost pressure at the compressor Lets look at this with the data we have been looking at. We are getting a 20% (Dc) increase in density, Ap is 14.7 (we are at sea level), pressure in the manifold (Bm) is the boost pressure minus the 15% loss thought the pipes; so that gives us 8.5psi, and pressure at the compressor (Bc) is 10psi. lets fill in the equation. HPr = .20 + 1 - [( 14.7 + 10 ) / ( 14.7 + 8.5 )] HPr = 1.20 - ( 24.7 / 23.2 ) HPr = .14 That’s a 14% increase in power. That’s pretty good for a big hunk of aluminum. Just imagine what would happen if you shelled out cash and bought a real intercooler… Something that had say… 80% efficiency. ---
**Author:** ![cky89](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/cky89/32/4945_2.png) [@cky89](https://forums.speedlife.net/u/cky89)\ **Post date:** [December 10, 2007, 10:18am UTC](https://forums.speedlife.net/t/intercooler-efficency-can-add-6-inches-to-your-dyno-graph/40039/2 "2007-12-10T10:18:28Z")
Interesting read. Nice write-up. :tup: ---
**Author:** ![fairgentleman\_Z](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/fairgentleman_z/32/7263_2.png) [@fairgentleman\_Z](https://forums.speedlife.net/u/fairgentleman_Z)\ **Post date:** [December 10, 2007, 10:23am UTC](https://forums.speedlife.net/t/intercooler-efficency-can-add-6-inches-to-your-dyno-graph/40039/3 "2007-12-10T10:23:23Z")
Wouldn’t temperature need to be represented in absolute values? (Kelvin for metric, Rankine for English). ---
**Author:** ![Zer0DazE](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/zer0daze/32/7624_2.png) [@Zer0DazE](https://forums.speedlife.net/u/Zer0DazE)\ **Post date:** [December 10, 2007, 10:52am UTC](https://forums.speedlife.net/t/intercooler-efficency-can-add-6-inches-to-your-dyno-graph/40039/4 "2007-12-10T10:52:43Z")
[quote=“fairgentleman Z,post:3,topic:40039"”] Wouldn’t temperature need to be represented in absolute values? (Kelvin for metric, Rankine for English). [/quote] whats wrong with Fahrenheit as a unit of measure in these examples? use whatever unit of measure you like. we are dealing with percentages here. as an example 20% of anything is always going to be the same. if there are 10 apples and take 20% of them you have 2 apples. i don’t care what you call that apple, a 蘋果, pomme, Apfel, or a mela. it is still a pretty red apple. unless of coarse i miss understood your question. ---
**Author:** ![91MR2](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/91mr2/32/7217_2.png) [@91MR2](https://forums.speedlife.net/u/91MR2)\ **Post date:** [December 10, 2007, 12:06pm UTC](https://forums.speedlife.net/t/intercooler-efficency-can-add-6-inches-to-your-dyno-graph/40039/5 "2007-12-10T12:06:00Z")
Good read. ---
**Author:** ![justa4door](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/justa4door/32/7259_2.png) [@justa4door](https://forums.speedlife.net/u/justa4door)\ **Post date:** [December 10, 2007, 12:06pm UTC](https://forums.speedlife.net/t/intercooler-efficency-can-add-6-inches-to-your-dyno-graph/40039/6 "2007-12-10T12:06:46Z")
:tup: ---
**Author:** ![VANDIT](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/vandit/32/4977_2.png) [@VANDIT](https://forums.speedlife.net/u/VANDIT)\ **Post date:** [December 10, 2007, 1:55pm UTC](https://forums.speedlife.net/t/intercooler-efficency-can-add-6-inches-to-your-dyno-graph/40039/7 "2007-12-10T13:55:39Z")
[quote=“Zer0DazE,post:4,topic:40039"”] whats wrong with Fahrenheit as a unit of measure in these examples? use whatever unit of measure you like. we are dealing with percentages here. as an example 20% of anything is always going to be the same. if there are 10 apples and take 20% of them you have 2 apples. i don’t care what you call that apple, a 蘋果, pomme, Apfel, or a mela. it is still a pretty red apple. unless of coarse i miss understood your question. [/quote] how much money do you want me to send you??? lol, great write up! just did the math on my v-dub :bloated: how sad… lol ---
**Author:** ![Devioustsi](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/devioustsi/32/7406_2.png) [@Devioustsi](https://forums.speedlife.net/u/Devioustsi)\ **Post date:** [December 10, 2007, 6:45pm UTC](https://forums.speedlife.net/t/intercooler-efficency-can-add-6-inches-to-your-dyno-graph/40039/8 "2007-12-10T18:45:52Z")
Thank you John. Good write up. ---
**Author:** ![neonglh](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/neonglh/32/4951_2.png) [@neonglh](https://forums.speedlife.net/u/neonglh)\ **Post date:** [December 10, 2007, 7:10pm UTC](https://forums.speedlife.net/t/intercooler-efficency-can-add-6-inches-to-your-dyno-graph/40039/9 "2007-12-10T19:10:07Z")
Just turn up the boost, it all evens out in the end 🙂 Really though, nice write up. ---
**Author:** ![fairgentleman\_Z](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/fairgentleman_z/32/7263_2.png) [@fairgentleman\_Z](https://forums.speedlife.net/u/fairgentleman_Z)\ **Post date:** [December 10, 2007, 7:39pm UTC](https://forums.speedlife.net/t/intercooler-efficency-can-add-6-inches-to-your-dyno-graph/40039/10 "2007-12-10T19:39:05Z")
[quote=“Zer0DazE,post:4,topic:40039"”] whats wrong with Fahrenheit as a unit of measure in these examples? [/quote] Actually, nothing, you added 460 to it to convert to Rankine. I was thinking that it would be needed for the Eff equations as well, but sense you are dealing with a percentage of a delta T it doesn’t matter (you would just convert to get the same amount of “stuff”). ---
**Author:** ![MOBOOST4U](https://avatars.discourse-cdn.com/v4/letter/m/f4b2a3/32.png) [@MOBOOST4U](https://forums.speedlife.net/u/MOBOOST4U)\ **Post date:** [December 10, 2007, 10:28pm UTC](https://forums.speedlife.net/t/intercooler-efficency-can-add-6-inches-to-your-dyno-graph/40039/11 "2007-12-10T22:28:56Z")
Great read but… [quote=“Zer0DazE”"] Dc = [(Dt + 460) / (It + 460)] - 1 [/quote] Call me stupid but why 460? ---
**Author:** ![cky89](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/cky89/32/4945_2.png) [@cky89](https://forums.speedlife.net/u/cky89)\ **Post date:** [December 10, 2007, 10:51pm UTC](https://forums.speedlife.net/t/intercooler-efficency-can-add-6-inches-to-your-dyno-graph/40039/12 "2007-12-10T22:51:37Z")
[quote=“MOBOOST4U,post:11,topic:40039"”] Great read but… Call me stupid but why 460? [/quote] [quote=“fairgentleman Z,post:10,topic:40039"”] you added 460 to it to convert to Rankine [/quote] That help moboost? ---
**Author:** ![Zer0DazE](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/zer0daze/32/7624_2.png) [@Zer0DazE](https://forums.speedlife.net/u/Zer0DazE)\ **Post date:** [December 11, 2007, 5:01am UTC](https://forums.speedlife.net/t/intercooler-efficency-can-add-6-inches-to-your-dyno-graph/40039/13 "2007-12-11T05:01:20Z")
for moboost > **[Rankine scale](https://en.wikipedia.org/wiki/Rankine_scale)** > > The Rankine scale (/ˈræŋkɪn/) is an absolute scale of thermodynamic temperature named after the Glasgow University engineer and physicist William John Macquorn Rankine, who proposed it in 1859. (The Kelvin scale was first proposed in 1848.) It may be used in engineering systems where heat computations are done using degrees Fahrenheit. The symbol for degrees Rankine is °R (or °Ra if necessary to distinguish it from the Rømer and Réaumur scales). By analogy with kelvin, some authors term the unit ... ---
**Author:** ![MOBOOST4U](https://avatars.discourse-cdn.com/v4/letter/m/f4b2a3/32.png) [@MOBOOST4U](https://forums.speedlife.net/u/MOBOOST4U)\ **Post date:** [December 11, 2007, 7:02am UTC](https://forums.speedlife.net/t/intercooler-efficency-can-add-6-inches-to-your-dyno-graph/40039/14 "2007-12-11T07:02:34Z")
[quote=“cky89,post:12,topic:40039"”] That help moboost? [/quote] Whoops, thats what you get for posting at 130 in the morning… thanks for further explanation zerodaze ---
**Author:** ![Zer0DazE](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/zer0daze/32/7624_2.png) [@Zer0DazE](https://forums.speedlife.net/u/Zer0DazE)\ **Post date:** [December 11, 2007, 7:04am UTC](https://forums.speedlife.net/t/intercooler-efficency-can-add-6-inches-to-your-dyno-graph/40039/15 "2007-12-11T07:04:31Z")
[quote=“Devioustsi,post:8,topic:40039"”] Thank you John. Good write up. [/quote] I would like to see a write up on injectors, spray patterns, and how they compare to carbs. I would even be willing to help write it if someone would like to work on it. ---
**Author:** ![Devioustsi](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/devioustsi/32/7406_2.png) [@Devioustsi](https://forums.speedlife.net/u/Devioustsi)\ **Post date:** [December 11, 2007, 1:56pm UTC](https://forums.speedlife.net/t/intercooler-efficency-can-add-6-inches-to-your-dyno-graph/40039/16 "2007-12-11T13:56:45Z")
carbs are ghey no write up needed 🙂 ---
**Author:** ![Zer0DazE](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/zer0daze/32/7624_2.png) [@Zer0DazE](https://forums.speedlife.net/u/Zer0DazE)\ **Post date:** [December 11, 2007, 2:10pm UTC](https://forums.speedlife.net/t/intercooler-efficency-can-add-6-inches-to-your-dyno-graph/40039/17 "2007-12-11T14:10:52Z")
[quote=“Devioustsi,post:16,topic:40039"”] carbs are ghey no write up needed 🙂 [/quote] they atomize better than injectors 🙂 excluding direct injection ---
**Author:** ![brent\_strong](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/brent_strong/32/7203_2.png) [@brent\_strong](https://forums.speedlife.net/u/brent_strong)\ **Post date:** [December 11, 2007, 2:23pm UTC](https://forums.speedlife.net/t/intercooler-efficency-can-add-6-inches-to-your-dyno-graph/40039/18 "2007-12-11T14:23:58Z")
They’re also further back in the intake path like showerhead injectors. 🙂 ---
**Author:** ![Devioustsi](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/devioustsi/32/7406_2.png) [@Devioustsi](https://forums.speedlife.net/u/Devioustsi)\ **Post date:** [December 11, 2007, 3:07pm UTC](https://forums.speedlife.net/t/intercooler-efficency-can-add-6-inches-to-your-dyno-graph/40039/19 "2007-12-11T15:07:49Z")
Thats the main reason they atomize better and the main reason they are hard to tune. ---
**Author:** ![Zer0DazE](https://yyz2.discourse-cdn.com/flex034/user_avatar/forums.speedlife.net/zer0daze/32/7624_2.png) [@Zer0DazE](https://forums.speedlife.net/u/Zer0DazE)\ **Post date:** [December 12, 2007, 5:04am UTC](https://forums.speedlife.net/t/intercooler-efficency-can-add-6-inches-to-your-dyno-graph/40039/20 "2007-12-12T05:04:21Z")
[quote=“Devioustsi,post:19,topic:40039"”] Thats the main reason they atomize better and the main reason they are hard to tune. [/quote] you would need to have a normal injector 4ft (give or take) down the runner to get the same atomization. i believe it should be discussed. just not in this thread [Next page](https://forums.speedlife.net/t/intercooler-efficency-can-add-6-inches-to-your-dyno-graph/40039.md?page=2)