I am wondering if anyone knows if it is better to go with a single in and dual out muffler with 2.5 pipes back from the muffler or should I go with true duals? What are the pro's and cons? I want to gain performance but not loose any low end torque. I read on the flowmaster website that they don't recomend going to true duals if you vehicle came with a single exhaust do to the computer will not be able to compensate for the extra amount of fuel needed. is this true? Thanks for any info.

 

i went true duals on my 8000lb van torque was my main concern-look at my gallery-i used magnaflow short body 4x9 mufflers and x pipe-i have improved torque from idle all the way to4300 rpms- stays near 300 ftlbs this range- tows my 6k lb trailer much better-phil

 

Phil,

When you went to "True Duals" did you lose or gain gas mileage?


Thanks,
Scott

 

I would like to know this as well

 

i drive my van conservatively so to speak,my van on the dyno put out 300lbs of tq at 2000 rpms annd stayed up to 279 lbs `at 4300 rpms-i keep it at about 2ooo rpms while city driving -hwy driving with my 3.73's is 65 -i try to lrt tranny shift into next the gear at 3000-3500 rpms if you get my point-anyways with this driving style-i CONSISTENTLY have gotten 1.25 as high as 1.5 mpg better- very pleased-the tq improvement impressed me most-phil

 

True duals will increase the flow and reduce restrictive drag allowing your engine to breath better, and if driven normally will ever so slightly increase your mileage bottom line.

 

true on that driven normally- when i first had it insatlled i was on it all the time to hear the sound-,but back to normal driving,gains are there mpg wise,navi- how's that tune treating you?-phil

 

If you're asking about performance, its great. The only problem is it is running richer than bill gates, and at 3.09 a gallon with a 30 gallon tank I get 300 miles. (you can do the math on that one.) Its also bellowing out black from the richness, but it runs like a sunuvabitch. I've got to do the datalogging and a/f this week!

 

Thanks guys for the info.

navi - Are you saying that when you went to True Duals that you started runnig rich?

 

No no, when I loaded the unfinished tune I started running rich. The first mod I did was the exhaust about a year ago. It still ran just like normal when I did the exhaust.

 

I put true duals on my truck last week... Got an x-pipe just before the 2 SISO original 40's flowmasters. I believe my mechanic used 2.25" piping, and all connections were welded. I have not noticed any low end loss, or really any gains, except for maybe the high RPM range.

I haven't had enough time to see a difference in gas milage, but I'll report back over the next few tanks of gas... Before the new exhaust I was getting ~15.5 MPG

 

I think the x/h-pipe is the key to increased low-end response. Plus, it's said to make the exhaust sound better.

 

so in the end what is better true duels or single to duel you would think that true duels messes up the computer

 

no it doesn' t mess up the ecm-phil