I had duals2.5 magnaflows and a vmp tune for it, I went down to a 3 in single and a y pipe and a single 3 in. magna flow to get some low end torque back for pulling my boat.

Does anybody have an educated guess on how much it richened the air fuel ratio?I am still running the vmp tune.

I do not have a air/fuel gauge.

 

it should not have have changed anything...

 

I'm guessing this means" it should have not changed anything"

clarify for me please

 

Nothing a/f changed. You added no more air into the motor or fuel. Exhaust doesn't change either.

 

nothing changed with the motor...



and if spent money re-doing your exhaust then you wasted it as you gained nothing but a lighter wallet

 

Well, I pull my boat in the lower rpm range and with the exhaust change (to a 3 inch single)it pulls my boat better. I could tell it was better the first time I stepped on the throttle, and the first time I pulled the boat with the 3 in compared to the dual exhaust, so I think its money well spent.


I'm happy and it's my truck so I'm the one that matters.

btw the question was not about the money spent on the exhaust its already done and I am not going back to duals so why was that brought up?All I wanted was an answer to the af question.

 

well that's something you need to take up with Justin, and send him some datalogs...


but then again, it's your motor and if you were really worried about it you've have done that (talked to your tuner) before you did any changes to the truck

 

I'm going assume you haven't seen an increase in boost???

 

I actually thought that it would not hurt anything,when I did it. I just wanted some other opinions to confirm or deny , if there was anything to worry about.

I'm not like some people who think they know everything the more questions that I asked the more I learn.

I was waiting on justin to email me back when I make the post and he confirmed that the exaust does not affect the a/f ratio.

I did learn something from this thread though...........................

 

I went from a 2.5 SI/DO muffler and I did notice going true dual 2.5 (again) that I did lose a little down low. WOT top of 2nd and all of 3rd is alot stronger. A/F on my wideband did not change at all.

 

I have 2.5 dual to a single 3" and when i removed my muffler the lose of tork was pretty noticable. I put the magnaflow back on and got all my tork back. My AF never changed but I did see my boost go up about a #