Intake tube upgrade
08-01-2013, 01:54 PM
#86
Bump. I just ordered the 5inch to 6inch elbow for my 70mm turbo that has a 4 inch inlet. I will be running the 4 to 5 insert sleeve to make up the difference. Also ordered the 6inch Dia x 10inch long filter. These elbows are nice pieces.
As far as dyno comparison when I was at New Era we did pulls with the reg 4 inch filter right on the front of the turbo vs no filter and it made no difference. I will compare this huge intake elbow and filter vs no filter the next time I go to the dyno. I'm guessing it won't change on the dyno. Im thinking It will make a small change when cruising down the road w the hood down or at the track. Based on decreasing the iat being pulled into the turbo from behind the rad to the fender.
Either way, great company and quality pieces
As far as dyno comparison when I was at New Era we did pulls with the reg 4 inch filter right on the front of the turbo vs no filter and it made no difference. I will compare this huge intake elbow and filter vs no filter the next time I go to the dyno. I'm guessing it won't change on the dyno. Im thinking It will make a small change when cruising down the road w the hood down or at the track. Based on decreasing the iat being pulled into the turbo from behind the rad to the fender.
Either way, great company and quality pieces
08-07-2013, 08:14 PM
#87
On The Tree
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2001Z methods aren't correct and he is simply repeating second hand information. First superchargers and turbos both are negatively effected by intake restriction. The fact that a SC is belt driven changes nothing. A turbo impeller will spin at the same speed regardless of intake restriction just as a SC. The intake restriction has no effect on the power side of a turbo, the only thing that will effect impeller speed is boost. No intake, no boost, impeller is free to turn. Next to add to this SC and turbo's are primarily designed to boost pressure, there not designed to create vacuum. This is why there effected so much by restriction, there design is to force feed air, not to eat it through a straw.
With that in mind this is where large intake tubes (volume) help. When you have a large amount of unrestricted air (volume after the filter) it makes it easier for the FI system to create velocity or siphon effect to get the air moving. It's the same effect as priming a fluid pump if that's a better visual to understand. Once the unrestricted air begins moving it creates a low pressure zone for the air to enter past the filter. This all amounts to a more efficient intake charge which in turn creates a more efficient discharge resulting in higher boost pressures and more power.
Lastly lower iat before the turbo results in more power period. When you have cool intake temps it helps to fight off heat soak through out the entire system. Pre turbo temps are important due to the fact that when you compress air it multiplies the temp by x amount each pound. For example (not the actual formula) we'll say every 5lbs of boost doubles the temp. So 90 degree IAT pre turbo by 10#boost would equal 270 degree IAT after turbo. A 10 degree drop in preturbo IAT would be a 40 degree drop after turbo. I'd much prefer 240 over 270 pre intercooler temps.
With that in mind this is where large intake tubes (volume) help. When you have a large amount of unrestricted air (volume after the filter) it makes it easier for the FI system to create velocity or siphon effect to get the air moving. It's the same effect as priming a fluid pump if that's a better visual to understand. Once the unrestricted air begins moving it creates a low pressure zone for the air to enter past the filter. This all amounts to a more efficient intake charge which in turn creates a more efficient discharge resulting in higher boost pressures and more power.
Lastly lower iat before the turbo results in more power period. When you have cool intake temps it helps to fight off heat soak through out the entire system. Pre turbo temps are important due to the fact that when you compress air it multiplies the temp by x amount each pound. For example (not the actual formula) we'll say every 5lbs of boost doubles the temp. So 90 degree IAT pre turbo by 10#boost would equal 270 degree IAT after turbo. A 10 degree drop in preturbo IAT would be a 40 degree drop after turbo. I'd much prefer 240 over 270 pre intercooler temps.
Last edited by damianldaigle; 08-07-2013 at 08:15 PM. Reason: Space paragraphs
08-07-2013, 11:37 PM
#88
Your boost temp bit is more confusing than the real thing...
To actually find it, use the isentropic compression equation with your turbos compressor map (to identify comp efficiency point).
T2=t1+(t1*(p2/p1)^((k-1)/k)-t1)/eff where p is in absolute pressures, k is ratio of specfic heats (1.4 for air), t is in absolute temps, and eff is compressor efficiency.
t2= air coming out of turbo
t1=ambient air
So by your example
t1=90f=549R ,p1=14.7, p2=24.7, eff=70% so t2 would be 215 degrees f. Yes it really is that hot coming off a turbo. If the process was 100% efficient it would still be 178f, at 50% its 265f. This is why its important to size a compressor properly.
80f t1 @10psi boost @70% eff would be 203f, so 10 degrees before is 12 after.
To actually find it, use the isentropic compression equation with your turbos compressor map (to identify comp efficiency point).
T2=t1+(t1*(p2/p1)^((k-1)/k)-t1)/eff where p is in absolute pressures, k is ratio of specfic heats (1.4 for air), t is in absolute temps, and eff is compressor efficiency.
t2= air coming out of turbo
t1=ambient air
So by your example
t1=90f=549R ,p1=14.7, p2=24.7, eff=70% so t2 would be 215 degrees f. Yes it really is that hot coming off a turbo. If the process was 100% efficient it would still be 178f, at 50% its 265f. This is why its important to size a compressor properly.
80f t1 @10psi boost @70% eff would be 203f, so 10 degrees before is 12 after.
Last edited by Atomic; 09-05-2013 at 11:42 PM.
08-07-2013, 11:43 PM
#89
Your boost temp bit is more confusing than the real thing...
To actually find it, use the isentropic compression equation with your turbos compressor map (to identify comp efficiency point).
T2=t1*(p2/p1)^((k-1)/k)/eff where p is in absolute pressures, k is ratio of specfic heats (1.4 for air), t is in absolute temps, and eff is compressor efficiency.
So by your example
t1=90f=305.4k ,p1=14.7, p2=24.7, eff=70% so t2 would be 532k or 498 degrees f. Yes it really is that hot xoming off a turbo. If the process was 100% efficient it would still be 210f, at 50% its 880f. This is why its important to size a compressor properly.
80f t1 @10psi boost @70% eff would be 480f, so 10 degrees before is 18 after.
To actually find it, use the isentropic compression equation with your turbos compressor map (to identify comp efficiency point).
T2=t1*(p2/p1)^((k-1)/k)/eff where p is in absolute pressures, k is ratio of specfic heats (1.4 for air), t is in absolute temps, and eff is compressor efficiency.
So by your example
t1=90f=305.4k ,p1=14.7, p2=24.7, eff=70% so t2 would be 532k or 498 degrees f. Yes it really is that hot xoming off a turbo. If the process was 100% efficient it would still be 210f, at 50% its 880f. This is why its important to size a compressor properly.
80f t1 @10psi boost @70% eff would be 480f, so 10 degrees before is 18 after.
errr.... WTF..... You really need to lower your expectations on what us simpletons understand around here....
08-07-2013, 11:53 PM
#90
