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

justinfetalvero

New member
Hey guys,

I just got a Flowmaster Delta 50 welded on in place of the stock muffler the other week. Ever since I got it installed I have had lower torque and lower MPGs.

Does anyone have any experience why? They guy that welded it on for me told me there may not be enough backpressure anymore. I just have no idea about exhaust systems or how they work and wanted to know if anyone could help me out with this.

I did fine some leaks in the welds yesterday as I poured water over the welds and a section of the weld was spitting the water drops.

Could that leak cause the issues?

I am taking it back to the guy to reweld everything. The reason he couldn't weld it on good is that he couldnt drop the exhaust piping because my bolts were rusted.

Does anyone have experience getting rusty bolts off?

Thanks for all your help!

*I did do a search for a couple days and did not find any information related to this problem but sorry if this has been covered before.
 
Register to hide this ad
Others will know better than me. My guess is it may take some time for your computer to adjust to the new muffler.

Sent from my SM-N920V using Tapatalk
 
Hey guys,

I just got a Flowmaster Delta 50 welded on in place of the stock muffler the other week. Ever since I got it installed I have had lower torque and lower MPGs.

Does anyone have any experience why? They guy that welded it on for me told me there may not be enough backpressure anymore. I just have no idea about exhaust systems or how they work and wanted to know if anyone could help me out with this.

I did fine some leaks in the welds yesterday as I poured water over the welds and a section of the weld was spitting the water drops.

Could that leak cause the issues?

I am taking it back to the guy to reweld everything. The reason he couldn't weld it on good is that he couldnt drop the exhaust piping because my bolts were rusted.

Does anyone have experience getting rusty bolts off?

Thanks for all your help!

*I did do a search for a couple days and did not find any information related to this problem but sorry if this has been covered before.

Do you have a V6 or V8? I was actually debating on the exact same muffler so I am anxious to hear what the deal is.
 
Others will know better than me. My guess is it may take some time for your computer to adjust to the new muffler.

Sent from my SM-N920V using Tapatalk
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
 
Replacing just the muffler should have no effect on fuel consumption. Minuscule exhaust leaks at the welds will not cause any noticeable higher fuel consumption either.


Sent from my iPhone using Tapatalk
 
its a flowmaster , you lose back pressure and gain sound. they make mufflers that make loud drone, I know when I had the super 44 and that thing sounded deep, but it did feel like I lost some low end torque. good thing I found a borla system on the cheap and got that put on right away, sounded milder and got the performance back.
 
Thanks for Althea responses. So I have a V8. I installed it to get a deeper sound. I wasn't looking for performance gains but I wasn't looking for performance loss either. It sounds really good but not worth it if it takes away your low end torque. That's why I got the V8. Anyway do you guys have any suggestion to create more back pressure so I can keep my exhaust sound and get back to ome performance?

I still have the stock muffler but don't want to pay the same price to put it back on. Any suggestions.
 
I agree with the earlier poster; changing only the muffler shouldn't have a noticeable effect on fuel consumption. I have a Flowmaster 70 series on my 2008 V8, with the resonator removed and a side-routed tip and noticed no change in low-end performance or fuel mileage.
No chance you're subconsciously stomping on the skinny pedal more now to hear the sound of the exhaust? That might have a negative impact on the MPG ;)
 
URD cross over Y pipe. Underdog Racing Development
Expensive, but that V8 will probably break your neck with the new found torque after you install it. The sound of that muffler will probably be incredible then. Can't speak of the computer learning new parameters, I have no real experience there.
Exhaust bolts? THEY are a PIA. Soak them in PB Blaster or another penetrating oil (not WD40 either). Soak em over night, hell soak em for 2 nights and be liberal with the spray. Then hit them with some heat from a cutting torch (get them glowing hot) on each bolt right before you put the wrench on them. Even then it's possible they won't break loose without snapping off. Buy some bolt extractors and replacement bolts/studs of the proper size before hand, in case you break one. They are always good to have around anyway. Also, agree with [MENTION=75195]OzarkRunner[/MENTION], I consciously have to stay out of the throttle because of how good my truck sounds lol. Good Luck!!
 
Last edited:
I agree with the earlier poster; changing only the muffler shouldn't have a noticeable effect on fuel consumption. I have a Flowmaster 70 series on my 2008 V8, with the resonator removed and a side-routed tip and noticed no change in low-end performance or fuel mileage.
No chance you're subconsciously stomping on the skinny pedal more now to hear the sound of the exhaust? That might have a negative impact on the MPG ;)

Hey, that is what I thought too. I didn't think it should have an effect. I kept the resonator on and only changed the muffler. I know I am not stomping on the gas more as I am very conscious about my driving as I live in Hawaii and gas is expensive as F***.

I will try and fix the leak and see if that fixes the problem.

Another way I tested it is a week before changing the muffler I went up Haleakala here on Maui. Very steep hills. Had no problems going up. But then I went back up this past weekend and had to really press on the gas to get it to go up the hills vs before of lightly pressing the pedal.

I also calculate my mileage by resetting my odometer everytime I fill up and I run my tank until the low fuel light comes on.

Thanks for all the help everyone.
 
URD cross over Y pipe. Underdog Racing Development
Expensive, but that V8 will probably break your neck with the new found torque after you install it. The sound of that muffler will probably be incredible then. Can't speak of the computer learning new parameters, I have no real experience there.
Exhaust bolts? THEY are a PIA. Soak them in PB Blaster or another penetrating oil (not WD40 either). Soak em over night, hell soak em for 2 nights and be liberal with the spray. Then hit them with some heat from a cutting torch (get them glowing hot) on each bolt right before you put the wrench on them. Even then it's possible they won't break loose without snapping off. Buy some bolt extractors and replacement bolts/studs of the proper size before hand, in case you break one. They are always good to have around anyway. Also, agree with [MENTION=75195]OzarkRunner[/MENTION], I consciously have to stay out of the throttle because of how good my truck sounds lol. Good Luck!!

Thanks for the recommendation man! I will def check that out. And thanks for the tips on getting the bolts off. I will pick up some PB Blaster tomorrow and start soaking it and pick up some replacement bolts and studs. And yes I do consciously stay off the gas haha
 
Come to think of it you might want some quality drill bits because these bolts are hardened, and a Tap to clean up the threads after you have removed the bolt. Drilling out and extracting a snapped bolt is tough with out the proper tools. You Tube has some video with several methods on how to get it done.
 
Thanks for the recommendation man! I will def check that out. And thanks for the tips on getting the bolts off. I will pick up some PB Blaster tomorrow and start soaking it and pick up some replacement bolts and studs. And yes I do consciously stay off the gas haha

A far better option for bolt loosening is a 1:1 ratio of acetone and brake fluid...outperforms the penetrating oils on the market to the public and literally makes bolts just loose...I use this in a little oil squirter tin bottle and it holds for along time and works better than PB Blaster and WAY better than WD40...just my $.02

Good luck!
 
Have you done anything..

to increase the flow of air into the engine? You might try a CAI, aftermarket filter and removing the H C filter..

Then remove and replace the ECU fuse to reset the ECU..:blah:
 
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.

to increase the flow of air into the engine? You might try a CAI, aftermarket filter and removing the H C filter..

Then remove and replace the ECU fuse to reset the ECU..:blah:

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?
 
I installed a super 50 on my v6 and i knew it had an exhaust leak, Then i re welded it with my tig and now it is 100% leak free and i regained power. It feels more powerful than stock now just make sure you do not have any leaks
 
I installed a super 50 on my v6 and i knew it had an exhaust leak, Then i re welded it with my tig and now it is 100% leak free and i regained power. It feels more powerful than stock now just make sure you do not have any leaks

YES! That gives me hope and what I wanted to hear. Thanks man! Now I'm just waiting on the guy to have the time to take my car in and patch up the leaks. Thanks man!
 
URD cross over Y pipe. Underdog Racing Development
Expensive, but that V8 will probably break your neck with the new found torque after you install it. The sound of that muffler will probably be incredible then. Can't speak of the computer learning new parameters, I have no real experience there.
Exhaust bolts? THEY are a PIA. Soak them in PB Blaster or another penetrating oil (not WD40 either). Soak em over night, hell soak em for 2 nights and be liberal with the spray. Then hit them with some heat from a cutting torch (get them glowing hot) on each bolt right before you put the wrench on them. Even then it's possible they won't break loose without snapping off. Buy some bolt extractors and replacement bolts/studs of the proper size before hand, in case you break one. They are always good to have around anyway. Also, agree with [MENTION=75195]OzarkRunner[/MENTION], I consciously have to stay out of the throttle because of how good my truck sounds lol. Good Luck!!

Thanks for the recommendation man! I will def check that out. And thanks for the tips on getting the bolts off. I will pick up some PB Blaster tomorrow and start soaking it and pick up some replacement bolts and studs. And yes I do consciously stay off the gas haha

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."
 
Last edited:

Members online

Forum statistics

Threads
278,312
Messages
3,554,089
Members
248,016
Latest member
Advally Service

Trending content

Back
Top