I think I noticed a slight improvement when I installed mine - took several passengers for a spin - they all felt there had been a bit of an increase in low end torque. No dyno to prove it though.

 

Thanks for all the helpful input !

It's been almost 200 miles since I did the install and it appears that the computer is starting to recover .

It revs better than directly after the swap and it's getting more responsive overall but it still seems to be hunting. In the upper rpm range it had a crisp throttle response previously and would rev out the back door before I knew it . . . hitting the rev limiter in the process . Now it seems somehow metered, like it's not sure if it should let loose .

I know this is a nebulous synopsis but I'm calling it like I see it :bang:.

I passed the CHP litmus test (for now) this evening by letting off and clutching as I passed by the oncoming Officer with his windows down on a small country road .

Another 160 mi. tomorrow should cinch it as far as the "But 'O Meter" is concerned.

 

Wrong. And I'l leave it at that.

 

I am on the verge of ordering a set of SLP Loudmouths but you guys all have me worried about power loss. I guess no one really knows the real answer here huh???

 

Then why do Stock Cars in NASCAR not run mufflers?

 

just ignore what he said, he has no clue what he is talking about.

 

Jordan
So the tell me do you still like the SLPs. I think I am going to order them tonight but I am looking for something that is loud and tough.... like of like an old school muscle car sound!!!!

 

SLPs look and sound great, and I haven't experienced a difference either way (loss or gain). Very mean. I get comments about it all the time from gas station attendants and such... May add a bassani x-pipe (keeping stock cats). If I do, I'll try to load a sound clip. Have heard it makes a noticeable difference.

 

heck YEAH!!!

 

I love em..
Funny story - when I went in for the strut tsb last week - my slps reverberations in the high bay garage set off the car alarms in the ford garage on the cars being worked on. When they moved it to the alignment bay - they went off again and when they pulled it out of the garage - once again.. it was pretty humorous to see the mechanics running around shutting off the alarms...

 

I am ordering them... I want some noise!!!! Hopefully they don't take too long to come in!!!

 

I didn't think the car computer monitors the mufflers (shouldn't there be a sensor by the mufflers if it is monitoring it?
What people mentioned here is true, back pressure comes from exhaust manifolds, cats and mid pipes, not the mufflers. By the time the exhaust gas reaches the mufflers, the back pressure is already created, removing the mufflers won't affect it or if it does, it should be minimal. The computer has no way of knowing whether you have a muffler in the car or not, there are no sensors around there, but anyhoot, what do I know...

 

Are you sure about that? I swear I have read several times that mufflers have an impact on backpressure. If they didn't why do some street/strip cars mod the exhaust so they can quickly make a change that bypasses the mufflers all together. I know it just isn't for noise.

 

So what your saying is that just about everyone that has changed their exhaust didn't need to get a tune or reset the computer? Then please write to Magnaflow and inform them that in their instructions they can remove the line that tells the customer to disconnected that battery before installing the new exhaust and that there is no reason to reset the computer.

 

I mean, if there are no sensors around the muffler, what difference does it make!?!? I can understand the computer getting errors on readings (and calcs) if you mess with the O2 sensors, but the mufflers? I don't know... someone that knows should help us out here!

 

It's back . But O' Meter and right foot agree that all is well again . I can't say that I notice any performance gain and I really didn't expect much if any.

It took almost 300 miles for the computer to relearn the fuel trim and other settings after the battery disconnect .

We all obviously have differing opinions and understandings about the effect of muffler removal on back pressure and possible resulting A/F ratio changes .

I guess the only way to know for sure would be to run it up on a dyno, monitoring with a wide band O2 sensor in stock form and then without resetting the computer, do the swap to the SLPs and run it again. If the A/F ratio differed between runs then we'd have our answer.

I disconnected the battery to reset the computer with the hope that if there were any minor performance gains to be had with the SLPs this would be the way to realize them.

Right or wrong, at least now I know how long it takes for the computer to relearn its stuff.

And of course now I have that awesome SLP bark .

 

Bob
How are the loudmouths treating you?? Does it seem like your car is starting to find its lost power again??

 

Jonathan,

It's all good . . . it's back .

I had NO IDEA how long it would take for the computer to relearn its stuff and became concerned after the first 30 miles or so .

Honestly, they are awesome .

I caught up with some of my buddies last night at our local adult beverage establishment. They knew I had them but had not put them on yet. When I pulled into the parking lot the whole place emptied out and surrounded me. They all had very positive comments but the most telling was from a guy who I had taken for a ride with the stock system. He said "now it sounds like it looks"

 

Just ordered a pair :dance: , can't keep reading everyone enjoying the sweet sound of SLP Loudmouths and me not having any... They are here in FL (LMPerformance), so shipping shouldn't take that long!

 

Rony
That is the same thing that happened to me. I've read all these stories about them and how great they sound and couldn't resist not having them. Then only thing is I am in WA so it will take a week to get them..... looks like they are in TN right now.