Measure Back Pressure
03-02-07, 10:54 PM
#16
Lead Lap
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More planning
Supra and JBRADY,
I will post it all when I get it done. Part of my motive is payback to this incredible forum and the people that make it work.
To further add cred to my personal experience I will also document my RWHP and torque before and after every thing I do. This slips my time table as I still need the instarment to make those measurements. Coming soon! I also had a dickens of a time getting a good boost gauge locally. I ended up with one that reads up to 30 lbs of boost, got a good price and have to wait for it to make its way from CHINA. They didn't say which province. It is a new and different world!
Please tell me what rpm's at which I should take my measurements. I want the data to be of the most use to the greatest number and I will stretch here.
I expect to hold it at the rpm selected with the brake and record the WOT pressure and then move to the next rpm as quickly as possible. Copilot will document. Sound ok?
Stay tuned. Don't forget: the older we get, the better we were. I'm near Godlike in my youth at this point.
John
I will post it all when I get it done. Part of my motive is payback to this incredible forum and the people that make it work.
To further add cred to my personal experience I will also document my RWHP and torque before and after every thing I do. This slips my time table as I still need the instarment to make those measurements. Coming soon! I also had a dickens of a time getting a good boost gauge locally. I ended up with one that reads up to 30 lbs of boost, got a good price and have to wait for it to make its way from CHINA. They didn't say which province. It is a new and different world!
Please tell me what rpm's at which I should take my measurements. I want the data to be of the most use to the greatest number and I will stretch here.
I expect to hold it at the rpm selected with the brake and record the WOT pressure and then move to the next rpm as quickly as possible. Copilot will document. Sound ok?
Stay tuned. Don't forget: the older we get, the better we were. I'm near Godlike in my youth at this point.
John
03-04-07, 11:49 AM
#17
Lexus Champion
John,
The higher the RPM the higher the flow requirements of the system. Engine displacement X RPM = flow (simplistic as if the intake chokes flow prior to peak test RPM then peak flow would be more or less the same from choke point up).
I would not bother with brake to hold rpm for testing. Simply have your test pilot record pressures as you call out RPM. Check at say 3000, 4000, 5000 and 6000. Peak will be at 6000 (or more if you choose to test to redline).
Pressure is just one part of the equation but is good data to know. Notice that at low RPM there will be minimal back pressure. Kind of kills the argument that backpressure is needed for low RPM power
Muffler wise I am not sure about the Flowmasters. Try and see. May be louder than expected. I would have probably suggested the Dynomax Superturbos as they are a three pass good flowing muff with internal flow directors. The best flow are the side-in/side out. The also maintain internal diameters where many mufflers use substantially smaller internal passages than the end fittings suggest.
The higher the RPM the higher the flow requirements of the system. Engine displacement X RPM = flow (simplistic as if the intake chokes flow prior to peak test RPM then peak flow would be more or less the same from choke point up).
I would not bother with brake to hold rpm for testing. Simply have your test pilot record pressures as you call out RPM. Check at say 3000, 4000, 5000 and 6000. Peak will be at 6000 (or more if you choose to test to redline).
Pressure is just one part of the equation but is good data to know. Notice that at low RPM there will be minimal back pressure. Kind of kills the argument that backpressure is needed for low RPM power
Muffler wise I am not sure about the Flowmasters. Try and see. May be louder than expected. I would have probably suggested the Dynomax Superturbos as they are a three pass good flowing muff with internal flow directors. The best flow are the side-in/side out. The also maintain internal diameters where many mufflers use substantially smaller internal passages than the end fittings suggest.
05-01-07, 11:12 AM
#18
Lexus Test Driver
For sound purposes only-- I pulled up behind an LS400 the other day that had a nice quiet but distinct rumble-- I noticed that the muff's weren't stock but they didn't look crazy or anything--
I followed the guy and they turned out to be Flow 40's --
What a sweet sound-- The guy had an Injen intake too-- All exhaust was kept stock besides the mufflers--
I bet you could delete the center resonator and maybe the rear two and retain the stock mufflers for a really good throaty sound--
I love the odd firing pattern sound of the 1UZ -- same as the 4.4L bayerische motoren werke pattern-- Which I happen to love the sound of with a nice Dinan exhaust--
I followed the guy and they turned out to be Flow 40's --
What a sweet sound-- The guy had an Injen intake too-- All exhaust was kept stock besides the mufflers--
I bet you could delete the center resonator and maybe the rear two and retain the stock mufflers for a really good throaty sound--
I love the odd firing pattern sound of the 1UZ -- same as the 4.4L bayerische motoren werke pattern-- Which I happen to love the sound of with a nice Dinan exhaust--
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