n/a exhaust
- Thread starter Needboost
- Start date
Well, I finally got my Raptor Racing exhaust put on last weekend. It took some fiddling to get it so it didn't bump against the car, but it wasn't too bad. I did have to get some more flange gaskets because it wouldn't seal against the ancient and rusty cat flange at all with just one.
It's certainly louder than the cheap Bosel cat-back I had, but it doesn't seem so loud you can't hold a conversation with the passenger even at moderate throttle with the windows closed. It's quite a bit louder to the driver with the windows open. It seems strange to me that most of the sound seems to come from the middle of the system around the resonator, rather than out back. When idling or almost coasting it's really quiet. The tone is low and decent.
I drove around town for 20 minutes or so. My butt dyno said it really didn't add any power, but it's hard to tell. The engine is now happier from 1500-2000rpm, but I really never run it there. I'll know better when it gets cooler and I start driving it more, especially if the gas mileage goes up any. It should add some power at the higher RPMs.
Anyway, I did buy it partly to play, so I didn't waste my money at all. It does look nice.
It's certainly louder than the cheap Bosel cat-back I had, but it doesn't seem so loud you can't hold a conversation with the passenger even at moderate throttle with the windows closed. It's quite a bit louder to the driver with the windows open. It seems strange to me that most of the sound seems to come from the middle of the system around the resonator, rather than out back. When idling or almost coasting it's really quiet. The tone is low and decent.
I drove around town for 20 minutes or so. My butt dyno said it really didn't add any power, but it's hard to tell. The engine is now happier from 1500-2000rpm, but I really never run it there. I'll know better when it gets cooler and I start driving it more, especially if the gas mileage goes up any. It should add some power at the higher RPMs.
Anyway, I did buy it partly to play, so I didn't waste my money at all. It does look nice.
Asterix;1616501 said:
yea i made a custom exhaust using this muffler and the resnator it does sound good but in certain gears at a certain speed it is a constant drone sound. i love the exhaust driving tho and at WOT. just need to get some sound dampner for the rear. love to see some pics. mines on page 4
I'll take some pictures this weekend when I'm under there checking for leaks again. The resonator is as long as it can be. The tail end looks just like the one in post #40.
It certainly would drone at certain throttle positions. I'll find out... WOT is nice and not super loud. I didn't seem to be turning heads in traffic, so it can't be too loud.
It certainly would drone at certain throttle positions. I'll find out... WOT is nice and not super loud. I didn't seem to be turning heads in traffic, so it can't be too loud.
Asterix;1616501 said:
A free flowing exhaust will make a car run leaner.
This is because of less back preasure makes for less residual exhaust gass in the cylinder to mix with the next incoming charge.
Get yourself a S-AFC, and an A/F ratio gauge, and dial in the fuel delivery to match your mods.
Then your but will feal the force luke.
(and so will a dyno)
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Which is well within the realm of the O2 sensor doing it's job. It's a computer controlled fuel injected car, it doesn't need to be retunedfrom such minor changes. Not to mention Toyota tuned them rich as hell from the factory...
*not to mention back pressure is a myth, and exhaust gas is inert, which is why it's used for EGR...*
*not to mention back pressure is a myth, and exhaust gas is inert, which is why it's used for EGR...*
After driving it to work today, since my summer car is down with a flat tire, I can say on the highway it's quieter now than it was with the Bosel exhaust. That's running 3000-3200rpm (about 70mph). There's no drone at all. It's loudest from 2k-3k with moderate throttle, but that's no surprise. I do still think it didn't add any power except maybe over 4k, but I didn't have much chance to try that this morning due to traffic. That's no real surprise either, since the flow matters more over 4k.
Now, I need to check and make sure my ACIS is working properly. I thought I felt a bump in power over 4300 the one time I checked.
More testing is in order!
Now, I need to check and make sure my ACIS is working properly. I thought I felt a bump in power over 4300 the one time I checked.
More testing is in order!
Poodles;1617254 said:
Except under full throttle, when the system goes open loop.....
Hm, never seen a GE 'rich as hell'. Especially since max HP is abtained around 12.5:1 A/F ratio.
Seldom seen on a factory fuel map on anything.
Poodles;1617254 said:
Well, for one, the EGR pumps in CO in at low speeds/partial throttle to cut down the combustion temp in order to reduce NO emmisions,
That's it, period !
And the more you have trapped in the next charge when trying to make power, dilluting the incoming fresh charge, the less HP you make.
Try plugging off half of your exhaust pipe, and see what it does to A/F readings, and 1/4 mile times.
From the net: (where there is some good info, if you look)
"EGR is considered a `metered intake leak' and was developed to reduce the combustion temperatures to below 2,500 degrees, the threshold where NOx is created. Not unlike putting a brick in your lavatory to lower the volume of water used, the EGR valve meters a readily available inert gas (actually exhaust gas which contains a lot of very inert Carbon Dioxide) into the combustion chamber to effectively reduce the volume. Smaller effective displacement means less fire, and less heat and thus lower temperatures, thereby controlling NOx emissions.
Obviously we don't want to `reduce' the volume of the combustion chambers (effectively reduced engine displacement) during hard acceleration, so EGR is turned off when you need full power (WOT (Wide Open throttle) conditions). At idle, the engine is very sensitive to air/fuel mixture ratios and swirl in the combustion chamber, so introducing EGR at idle is not on either. However at cruise the Fuel/Air mixture is set as lean as possible for maximum economy and this in turn generates the highest temperatures"
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gofastgeorge;1532641 said:
i doubt you run a SET of headers... that would mean two and you have a straight 6 not a v6 so theres only one header......
Poodles;1617843 said:
You evedentally have never did anything with a 7MGE, (other than replacing it with a GTE)
and are making things up as you go along.
And you evidently have no idea how the TCCS works. I'll remind you that this is the tech section and disinfo isn't tolerated.
Poodles;1617876 said:
Then explain you posting here.......
Fact is, I have worked on several 7MGEs for friends, and it is always the same.
Free flowing exhaust, better intake, and the things run lean under acceleration.
(using an innovate to tune with, not some cheap lean-rich A/F meter from autozone)
I then dialed in the A/F using more fuel pressure, and some type of piggy-back such as an Apex S-AFC,
and they all run better/faster after compensating for the lean condition caused by the bolt-on mods.
So maybe you should get your facts strait, mr. forum master.
Completely unnecessary as you can tune the flapper in the AFM if you need to (though I have yet to see a single one need to be tuned RICHER). Go ahead, sell your friends hundreds of dollars worth of piggybacks and tuning...
Poodles;1617926 said:
Old wives tale........
The flapper meter feeds a varying voltage to the ECU.
The ECU doesn't look for a set voltage, it looks at change in voltage.
So you loosen the spring, and it idles at a higher value, and at full throttle, it swings the same amount further open.
(due to spring rate)
Thus the change in voltage is the same.
You really don't know crap about the N/A, do you.
Old wives tale that has been done since the flapper AFM's were introduced and it works. You must really like selling tuning to people that don't need it...
CT26smoker;1617861 said:
I think you will find that should read "You evidently have never done anything with a 7MGE" although still not grammatically correct.
Perhaps your grasp of mechanics is on a par with you spelling and grammar and should be left to those more capable.
Don't feed the trolls. This guy obviously does not understand how an EFI system works but that's no reason not to be civil.
Update for those interested:
The car definitely has more power, but the in-cabin resonance around 2200rpm got to me. It was too loud, and I started to worry about my hearing. While it wasn't too bad on the highway around 3k rpm, it resonated under bridges enough to tell me it was too loud. My gas mileage didn't change noticeably from the Bosel cat back that was on there before.
So, I bought a Hushpower II resonator to replace the straight-through one supplied by Raptor. That quieted it down, and got rid of the almost all the resonance that was most annoying. I can't yet tell if I lost any power. The Hushpower II is back-to-back perforated cones inside a chamber lined with fiberglass. While it has to have more restriction than the old resonator, I'm willing to make that sacrifice to reduce the volume. It's still not quiet, but isn't like the open pipe that was in there.
I left the Magnaflow muffler alone. It still sounds nice, with a low tone that's not harsh or farty at all.
The Hushpower resonator I bought is 12512400, 17" long overall. It fit right in with little trouble.
The car definitely has more power, but the in-cabin resonance around 2200rpm got to me. It was too loud, and I started to worry about my hearing. While it wasn't too bad on the highway around 3k rpm, it resonated under bridges enough to tell me it was too loud. My gas mileage didn't change noticeably from the Bosel cat back that was on there before.
So, I bought a Hushpower II resonator to replace the straight-through one supplied by Raptor. That quieted it down, and got rid of the almost all the resonance that was most annoying. I can't yet tell if I lost any power. The Hushpower II is back-to-back perforated cones inside a chamber lined with fiberglass. While it has to have more restriction than the old resonator, I'm willing to make that sacrifice to reduce the volume. It's still not quiet, but isn't like the open pipe that was in there.
I left the Magnaflow muffler alone. It still sounds nice, with a low tone that's not harsh or farty at all.
The Hushpower resonator I bought is 12512400, 17" long overall. It fit right in with little trouble.
