Ok, I've had 'em a while and finally put 'em on today. The install was everything everyone has said . . . easy. Prior to beginning the install I disconnected the battery to prepare the computer for the change.

I took my time and fiddled with some other projects on the side, it ended up taking me an hour and a half from start to finish. The only reason I mention this is to give you an idea how long the battery was disconnected. It really is just a 45 minute deal at the most.

I reconnected the battery and then prior to taking a ride I ran through the instructions/procedures in the manual for a battery disconnect event, they're quoted below.

"Because your vehicle’s engine is electronically controlled by a computer,
some control conditions are maintained by power from the battery. When
the battery is disconnected or a new battery is installed, the engine must
relearn its idle and fuel trim strategy for optimum drivability and
performance. To begin this process:
1. With the vehicle at a complete stop, set the parking brake.
2. Put the gearshift in P (Park) (automatic transmission) or the neutral
position (manual transmission), turn off all accessories and start the
engine.
WOW! :cop:
3. Run the engine until it reaches normal operating temperature.
4. Allow the engine to idle for at least one minute.
5. Turn the A/C on and allow the engine to idle for at least one minute.
6. Drive the vehicle to complete the relearning process.
• The vehicle may need to be driven 10 miles (16 km) or more to
relearn the idle and fuel trim strategy.
• If you do not allow the engine to relearn its idle trim, the idle
quality of your vehicle may be adversely affected until the idle
trim is eventually relearned."

So I took off for a spin around the block.

Let me say that they are LOUD when you're on it, but can be controlled when needed. Anyway, I drove about 20 miles before I put it on the But O' Meter. I live out in the country and have some great roads to put this car through its paces so I hit my favorite sections and started testing.

My first impression is that the car is currently less responsive to throttle input than it had been and seems down on power overall.

Previously, I could easily steer it with the gas peddle . . . bringing in a nice drift to square up the turns, not anymore. It feels lethargic, doesn't rip from a stop like it did and grabbing second is now much less rewarding .

Sorry for the long winded thesis . . . my questions for those who have 'em are . . .

Did you experience this?
Does is take longer than I gave it for the computer to sort out the change?
If yes, how long?
Does it ever get BETTER than stock, performance wise?

Any insight would be greatly appreciated. Even though I REALLY like the sound , if I can't resolve this I'll have some slightly used SLPs for sale :notnice: .

 

I felt a small loss of torque on the low end after installing SLPs. I didn't disconnect the battery, though. Thinking about doing it now - wonder if it would help.

How exactly did you disconnect the battery? I tried, but couldn't really figure out how. Thought I had disconnected it, but the radio and AC and stuff still worked when I turned the key in the "on" position. I basially just unscrewed the red line into the battery.

 

no muffler = loss horsepower, loss torque...... thats what I was under the impressions with any vehicle

 

Thanks for the reply Jack, I pulled the (black) ground cable.

Yeah, thanks Paul . . . but it's interesting to me that the rest of the folks who have installed them haven't reported any ill effects.

 

I tossed my slp's on without doing any battery disconect or computer reset and have experianced the exact same performance I experianced with stock mufflers on, however much louder. My buddy swears it "feels" like it's quicker but to me it feels the same.

The amount of back pressure in the stock exhaust will be nominal at best and why most cars do not bennifit a great deal from just free'er flowing mufflers. Most of the back pressure will come from your exhaust manifolds, cats and mid pipes.

Unless someone posts actual dyno numbers I have a really hard time believing any axle back will have much if any affect on tq/hp numbers. Full cat back I can believe but just mufflers, doubt it.

 

Yup, mine is louder alright .

I wasn't expecting any gains, especially due to all of the neutral press on minor exhaust mods . . . . wasn't expecting any losses either :angry: .

 

Since nobody has posted dyno results yet from the loudmouths yet, I E-mailed SLP for results from their findings. Hope to hear back from them soon

 

Thanks! I should have considered that.

It will be interesting to see what they have to say. I doubt they'll come back with anything like . . . .

"Our product delivers 20 less horse power and 35 less ft. lbs. of torque than Ford's stock mufflers but . . . . darn they sure sound great and are a breeze to install! Just a side note, we designed our product so it's easy to uninstall too when you get tired of the sound without the stock performance."

Giving SLP and all those who have installed them the benefit of the doubt, I'm counting on it being that my computer just has a REAL SLOW learning curve :bang: .

I'm going on a 160 mile drive tomorrow through all sorts of driving conditions so hopefully it will relearn and I'll get back what I had .

 

You seem pretty Smart Figure it out on your own. :notnice:

 

Well, I was waiting for a post like this to come up. All I can say is that there was one guy on here who said he gained a HP or two and everybody else who swears it is either excatly the same or faster. I personally think it is exactly the same as stock. I put the car thru its paces before I put my SLPs on and again after, and I noticed no difference, besides the awesome sound. My $0.02

 

Thanks Mike. I know you have the answer but I don't hold it against you for keeping it to yourself and your humor here doesn't escape me .

 

Hey Jordan . . it's me . . "Find your Db meter yet?"

I love the sound but miss the performance. I'd be happy if it were a no gain/no loss situation. Hopefully the computer pull pull it head out tomorrow on my 160 mile commute to work. If not, no great loss . . . it was a learning experience.

You won't loose your job at SLP if I take them off will you?

Thanks for the input bro!

 

This is my old dyno sheet with just the SLP. I don't have a baseline before hand but I am very sure the SLP did not hurt peformance and if anything I gained in the torque department. Either way it was not enough of a change to be noticeable.

I never disconnected the battery and I wonder if that might be related to the problem you are experiencing.

 

I haven't noticed any difference in the seat of my pants test for the SLP. I think sometimes I get caught up in the sound and it feels faster.

 

Darn! That's what I get for reading all these tech tips!!

I'm with you . . . I think the computer has a STEEP learning curve and that the 30 miles or so that I put on it aren't enough. I'll put 160 miles on her tomorrow and report back.

Thanks for the dyno sheet . Great numbers!!!

 

You had to disconnect the battery to install a pair of mufflers?!?!

 

Thats my thought too. Makes no sense to me, but what do I know.

 

I didn't disconnect it for safety reasons if that's what you're getting at.

I've seen it suggested on this and other forums that it should be disconnected to let the computer relearn any required changes in fuel trims that might result from intake or exhaust system alterations of any kind.

 

I got 'em and I noticed a def. increase in low end torque

 

any time you change something that has an effect on what the computer reads (such as mufflers) you need to reset the computer. Yes, the darn thing is that sensitive.