Intercooler Pipes
04-03-2003, 08:42 AM
#16
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Boostguy,
When I was at the dyno a long time ago with the stock pipes, LBE, CV, etc. and wasn't getting the boost curve I wanted, I decided to do a run without all that extra mechanical/electrical crap and as it turns outs, my stock 100k+ wastegate with a weak spring topped out at 18psi with a acceptable air/fuel ratio. So no brainer there, I just left it that way. So you are right, the pipes I put on later did not have a banjo bolt.
Luke,
You are correct, the O.D. of the intercooler tanks are 2.5" but that is a pretty thick wall casting, the I.D. measures close to 2" and that's all that matters. My pipes are only .029" wall thickness so that's practically nothing...
When I was at the dyno a long time ago with the stock pipes, LBE, CV, etc. and wasn't getting the boost curve I wanted, I decided to do a run without all that extra mechanical/electrical crap and as it turns outs, my stock 100k+ wastegate with a weak spring topped out at 18psi with a acceptable air/fuel ratio. So no brainer there, I just left it that way. So you are right, the pipes I put on later did not have a banjo bolt.
Luke,
You are correct, the O.D. of the intercooler tanks are 2.5" but that is a pretty thick wall casting, the I.D. measures close to 2" and that's all that matters. My pipes are only .029" wall thickness so that's practically nothing...
04-03-2003, 08:41 PM
#19
Nordschleife Master
That reminds me, I really need a new coolant tank. Last year someone said they got a really good price from some place in California? I think I'm ready to buy...
04-09-2003, 01:13 AM
#20
Three Wheelin'
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I decided to consult my Copy of Maximum Boost . Not sure why I didnt do that in the first place, but here it goes:
Mr. Bell States on page 61:
"There is probably a magic number that airflow velocity in a tube should not exceed, for reasons of rapidly increasing drag and consequent flow losses. I suspect that number is around Mach .4 or around 450 feet per second, since drag, and therefore flow loss, increases significantly after this."
Following Mr. Bell's directions... <img border="0" alt="[typing]" title="" src="graemlins/yltype.gif" />
"Tube size can easily be checked by calculating the maximum airflow attainable, dividing by the area of the tube in square feet, and dividing again by 60 to convert to ft/sec. An approximate value for maximum airflow can be obtained by multiplying the desired BHP by 1.5"
OK, with all of my modifications done, I hope to make somewhere around 400 RWHP. Lets use 15% drivetrain loss, so 460 FWHP.
460 * 1.5 = 690 CFM
Lets use 2.5 inch pipe, which in the gauge I have laying around the garage, has a inside diameter of 2.35 inches.
Pi * (R)Squared
3.14 * (1.175)Squared = 4.335 square inches
Converted to Square feet: .0301 Square Feet
690 / .0301 = 22923.588 feet per hour
Convert to minutes: 382 CFM
This is well under the 450 CFM limit set by Corky Bell. So I'll be using 2.5 inch pipe.
Mr. Bell States on page 61:
"There is probably a magic number that airflow velocity in a tube should not exceed, for reasons of rapidly increasing drag and consequent flow losses. I suspect that number is around Mach .4 or around 450 feet per second, since drag, and therefore flow loss, increases significantly after this."
Following Mr. Bell's directions... <img border="0" alt="[typing]" title="" src="graemlins/yltype.gif" />
"Tube size can easily be checked by calculating the maximum airflow attainable, dividing by the area of the tube in square feet, and dividing again by 60 to convert to ft/sec. An approximate value for maximum airflow can be obtained by multiplying the desired BHP by 1.5"
OK, with all of my modifications done, I hope to make somewhere around 400 RWHP. Lets use 15% drivetrain loss, so 460 FWHP.
460 * 1.5 = 690 CFM
Lets use 2.5 inch pipe, which in the gauge I have laying around the garage, has a inside diameter of 2.35 inches.
Pi * (R)Squared
3.14 * (1.175)Squared = 4.335 square inches
Converted to Square feet: .0301 Square Feet
690 / .0301 = 22923.588 feet per hour
Convert to minutes: 382 CFM
This is well under the 450 CFM limit set by Corky Bell. So I'll be using 2.5 inch pipe.
04-09-2003, 03:50 AM
#22
Nordschleife Master
Boostguy,
I think you have your units mixed up...
At the begining Bell mentions air velocity in feet per second.
Later on, you mention CFM, cubic feet per minute.
Am I missing something?
I think you have your units mixed up...
At the begining Bell mentions air velocity in feet per second.
Later on, you mention CFM, cubic feet per minute.
Am I missing something?
04-09-2003, 10:34 AM
#23
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His 382 is ft/sec not cfm. And 2.5" is probably good for that much hp but you should be using another more effecient intercooler because the stock one will be choking your flow, the I.D. of the tanks is not much over 2." Your stock throttle body is probably a big restriction by then too. And the manifold doesn't really go by Corky's recommendations either...
04-09-2003, 10:50 AM
#24
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</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica">Originally posted by SamGrant951:
<strong>Perry, Luke. Do you still have Sean's email address? Id like to email him about a set if he even still makes them.
thanks</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Please share as I am in the market also.
<strong>Perry, Luke. Do you still have Sean's email address? Id like to email him about a set if he even still makes them.
thanks</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Please share as I am in the market also.
04-09-2003, 11:46 AM
#25
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It is on my page with my pipes.
<a href="http://home.fuse.net/Porsche951/icpipes.htm" target="_blank">http://home.fuse.net/Porsche951/icpipes.htm</a>
I am not sure if it still works, or if he still makes them.
<a href="http://home.fuse.net/Porsche951/icpipes.htm" target="_blank">http://home.fuse.net/Porsche951/icpipes.htm</a>
I am not sure if it still works, or if he still makes them.
04-09-2003, 04:37 PM
#26
Three Wheelin'
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Yes, you are right, I got my units mixed up. 382 CFM should be feet per second. I just measured the ID of the IC inlet tank and got 2.1 inches.
A 2 inch pipe is going to have a ID of at most 1.8, so I am still gonna go with 2.5, which has a ID of 2.35. Maybe I could get a larger Gauge 2.5 inch pipe to cut the ID down to closer to 2.1. I am gonna check on that.
A 2 inch pipe is going to have a ID of at most 1.8, so I am still gonna go with 2.5, which has a ID of 2.35. Maybe I could get a larger Gauge 2.5 inch pipe to cut the ID down to closer to 2.1. I am gonna check on that.
04-09-2003, 04:52 PM
#27
Nordschleife Master
SAM,
i think he's asked alot more $ now, and he's on par w/ other middle men.
There's a REALLY good chance I wont be albe to use mine n/e more....
if you wait a week or two I'll know for sure.
i think he's asked alot more $ now, and he's on par w/ other middle men.
There's a REALLY good chance I wont be albe to use mine n/e more....
if you wait a week or two I'll know for sure.
