Fair enough, but the question remains...even at 75% of capacity you are talking about 900hp, a number I will not be seeing without a lottery win, which would make this a moot point http://www.rllmukforum.com/public/st...t/eyebrows.gif
Fair enough, but the question remains...even at 75% of capacity you are talking about 900hp, a number I will not be seeing without a lottery win, which would make this a moot point http://www.rllmukforum.com/public/st...t/eyebrows.gif
You can transfer more heat with more heat transfer area. Ir-regardless of the choke point of the inlet outlet diameter, the inlet/outlet temperature is more critical as well as the time the liquid spends in the exchanger. I want it to slow down, which will result in a pressure drop. Tthe longer air(liquid) spends in the heat exchanger the greater the btu transfer.
The cores by themselves weigh 15lbs. That's a significant density. I learned a lot when I increased my radiator and intercooler to 3 times the stock capacity, weight, and density. The bigger core is what you want for performance, especially when your intercooler inlet temp is 450 degrees on little TD-04 turbos. A 3.5" core or a core weighing 5 lbs lighter with an effective CFM and btu exchange rate 20% less yields less power. The temp differential from the temperature alone is worth about 10% in horsepower.
585 cfm is where 2" piping is starting to be restrictive and flow losses are experienced.
its ok that the piping have a little pressure loss too. the cores are also rated at 900cfm@ 1 psig pressure loss across the intercooler core and a charge-air pressure of 10 psig .
'2" piping could flow about 720cfm or so with a pressure drop of about 1.1 psi' at compressor inlet conditions. sure the 2" piping would not be ideal if someone plans to push these cores to the flow limit, 2.25" or 2.5 piping would be about a perfect match in that case .
fiy to you all who wish to keep the stock piping and run more boost with it.
according to this calculator and remember this is just straight smooth pipe no bends.
Compressed Air Pipe Lines - Online Pressure Drop Calculator
ninja edit
even at low boost of 15psi and at low 360cfm flow our stock 1.5 " ID IC piping alone have a total pressure drop of 1.6 psi, it gets exponentially worse with more boost/flow!
now upgrade the piping to 2" 0.3 psi pressure drop at the same 15psi of boost and flow !
Yeah kinda... The calcuator you just linked to from engineering toolbox is absolute pressure based. Say its fairbto assume DR750R's or Billet Evo 16g's flow 750cfm at 25psi gauge pressure per turbo... At absolute of sea level you would add 14.7psi to the 25psi. . According to the calculator 11 feet of pipe flowing 750cfm at 40psi absolute has a pressure drop of 1psi. No big deal at all really. You lose like 15 horsepower. What you gain in 40 degree cooler ait from time in core and density scatter is 40 horsepower .. You want the big core.
EDIT: I used the following values in the imperical calculator:
q = 750 (cfm)
L = 11 (length of piping ft)
d = 2 (inside diameter of intercooler piping in.)
p = 40 (absolute pressure = 14.7psi + 25psi)
TOTAL PRESSURE DROP = 1.08psi
Love the idea of this, pity it's way out of my price range for now. Would need to sell my single core FMIC..And maybe an organ or two, would be worth it though :P
Using the same imperial unit calculator for stock intercooler piping and say 9b's at 15psi.
q = 360 (cfm)
L = 11 (length of IC piping in ft)
d = 1.5" (inside diameter in.)
p = 30 (absolute pressure 14.7atm + 15psi boost)
TOTAL PRESSURE DROP = 1.6psi.
When you increase the hose pressure the total pressure drop decreases because the weight behind it gets heavier.
There is a choke point but I really don't think you can hit it because you can make the power. I believe Ray P makes 750hp on stock intercooler piping and DR750's at 30psi.
yup I think your right. I wondered why I got such high pressure drops, lol
according to the calculator Ray P may have over 4 psi pressure drop in the piping alone if he really is using the stock pipes .
I wouldnt want to have anymore than 1,5-2psi max pressure drop in the IC piping.
according to this ( http://www.3sgto.org/turbo-engines-s...html#post69395 )
http://img827.imageshack.us/img827/6...ffffffffff.jpg
as early as at 320 cfm, and air tube diameter = 1.5 in the 1.5 piping reaches 0.395mach (0.4 mach is the point at which airflow meets increased resistance (drag) and flow losses are experienced) FWIW if going with Corky Bells recommendations from old school book maximum boost the stock piping would be good for about ~~640cfm or about ~~420 crank hp max.
the 2" piping would be then good for the ~~1,180 CFM or about 650 awhp, or about 780 crank hp max(as Ange mentioned before).
also if you consult Bell intercoolers(Gerhard Schruf) they will recommend larger piping than dual 2" even for 650 awhp or 1,180 CFM , i believe they still use this math and always advice to stay under .4 mach ...
Are there any piping kits in 2.25/2.5? running these w/ CX seems like a waste. I know of DN, but finding those are hard.