Installed Flowmaster Delta 50 & Lower Torque and MPG...HELP PLEASE

I do know that improper back pressure in your exhaust system can cause power loss. I have experienced it on a Volvo I had where the pipes came loose on my exhaust system and I could barely back up my driveway. Once I hooked them back together it ran fine. A significant leak in your exhaust may indeed cause loss of power.


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Thanks for all the help guys. I really appreciate it. I will update on what I do to fix this issue just in case someone else runs into this same issue.



I'm not too sure what I am talking about as I am not a mechanic by any means. I do IT lol. But Since people were saying the cause could be because of lack of back pressure or scavenging, I was asking if anyone knew how to increase that without putting the original muffler back on.

Do you think I should reset the ECU since changing the muffler?

When tuning an open exhaust on harleys sometimes I've installed a 'lollipop' to help tune backpressure. It's a washer that fits in the opening 2x the pipes diameter in, and welded to a bolt than can be tightened when the reversion/backpressure has been corrected. (by rotating the washer inside the pipe to allow/block exhaust flow). If the exhaust is flowing too much, opening the intake will help, but it's a balancing act, too much on either end causes problems.

https://www.google.com/search?q=lollipop+exhaust+baffle&ie=utf-8&oe=utf-8

001.jpg~original


Just one way of doing it.
 
Just an FYI on the URD cross over Y pipe, if you do decide to get one make sure you understand and read the sorta disclaimer on URD's website at the link posted, this y pipe is not intent for road use, designed for strictly off-road and competition use and is not emission compliant, also it says for 2005-2009 4Runners, you never said what year you have.

Underdog Racing Development

"The URD off road Y Pipe was designed for off road use and competition events. The rear catalytic converters are eliminated. The URD off roadY Pipe is not for on road use and is absolutely not emissions legal anywhere on public roads."


Hey thanks for the clarification. I have an 2004 Limited V8. I live in Hawaii though and we have no emissions here. ;)
 
I do know that improper back pressure in your exhaust system can cause power loss. I have experienced it on a Volvo I had where the pipes came loose on my exhaust system and I could barely back up my driveway. Once I hooked them back together it ran fine. A significant leak in your exhaust may indeed cause loss of power.


Sent from my iPhone using Tapatalk

Thanks for the clarification man. I will patch leak ASAP and let you all know how it goes.

Thanks!
 
When tuning an open exhaust on harleys sometimes I've installed a 'lollipop' to help tune backpressure. It's a washer that fits in the opening 2x the pipes diameter in, and welded to a bolt than can be tightened when the reversion/backpressure has been corrected. (by rotating the washer inside the pipe to allow/block exhaust flow). If the exhaust is flowing too much, opening the intake will help, but it's a balancing act, too much on either end causes problems.

https://www.google.com/search?q=lollipop+exhaust+baffle&ie=utf-8&oe=utf-8

001.jpg~original


Just one way of doing it.

That is a very good idea. If patching the leak does not solve the problem I might do something like this. I was thinking about an intake but I like the stock intake as the filter is protected in the box from water/mud etc.

Whats your thoughts on the stock intake vs. Aftermarket in regards to water, dirt, and mud?
 
That is a very good idea. If patching the leak does not solve the problem I might do something like this. I was thinking about an intake but I like the stock intake as the filter is protected in the box from water/mud etc.

Whats your thoughts on the stock intake vs. Aftermarket in regards to water, dirt, and mud?

Personally? Anything more than a k&n filter is overkill. The stock system is already cai, and seems well protected . If you're doing deep water then maybe a snorkel.

Need to be honest with yourself about why you're doing a mod.

JMHO.
 
Basically

That is a very good idea. If patching the leak does not solve the problem I might do something like this. I was thinking about an intake but I like the stock intake as the filter is protected in the box from water/mud etc.

Whats your thoughts on the stock intake vs. Aftermarket in regards to water, dirt, and mud?

Just remove the HC filter from the intake and replace the OE air filter with a drop in K&N or equivalent. Then reset the ECU...
 
I have a v6 2007 with a 40 series and resonator removed. Got it put on back in January. Before the install I was getting 17/18. Right after the install I was getting 12 but it then rose to 13.7. cleaned maf and throttle body so I am sitting at 15.5 right now. In a damn v6. Jesus christ

Yeah same thing happened to me. Running about 17/20 before Flowmaster 44 install. After dropped to about 12 around town. Highway was still good.
 
Also concerning the ECU. There is no need to reset the ECU after a muffler install because the ECU has nothing to do with the muffler. Often if the battery was disconnected for longer than ten or so minutes during the install the ECU will reset automatically but the backpressure does not effect the ECU at all. I initially thought the same thing when I replaced my muffler so I reset the ECU a few times, it made no difference and upon further research I discovered that backpressure doesn't have any effect on the ECU.
 
Just remove the HC filter from the intake and replace the OE air filter with a drop in K&N or equivalent. Then reset the ECU...

Sounds good. Thanks!

I'm still waiting to hear back from the guy on scheduling to take my truck back to patch the welds.

Do you guys think JB Weld or Rapid Fix will be sufficient to patch welds?
 
I was talking about patching it temporarily since he can't do it until next thursday. What you think? Better or will that make patching it harder?

It will make welding it properly much harder, anything you put on it to seal it would have to be removed completely to achieve a proper weld, I'm sure he would be very displeased.
 
Update:

Yesterday, I removed the HC Filter from the air box.

I did notice an improvement in throttle response. Very slight improvement, but an improvement none the less.

I also ordered a K&N drop in filter. Have not received it yet though.

I also have not gotten my friend to patch the leaks in the muffler welds yet, that will get done this thursday.

I noticed that this last tank of gas lasted a little longer than normally. I always run my tank until it shows the low fuel warning light. Usually it comes on at 240 miles. Yesterday it came on at 255 miles. Not that much better but it is better than normal.

Also, on the 4Runner computer where it shows the average MPG, it now went up to 15. It never got above 14 before.

So I am not sure what made this last tank of gas last just a little longer than before as I have not repaired the leaks.

Was it time? Who knows.

But one difference is that I filled up with Costco's gas. I usually fill up at a different gas station. So as a test, I filled up at my normal gas station to see if the gas has anything to do with it. Both are premium BTW.

Long update, but figured I post it just in case anyone else was dealing with the same issue too.
 
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