Power-House

Alright so I just ordered a slp catted x pipe and slp lm1's for my 2005 mustang gt. Now I got people saying that lm1's make you LOSE hp?? I didn't believe them but they seemed pretty sure of it. I also have people telling me if I didnt have a tune I would lose hp but because i got one ill be fine. Then there is other people saying no all this is wrong there's no way possible you could lose hp from adding an axle back due to better air flow or something, i'm not quite sure but could somebody please tell me if this is going to make me lose hp or not! Thanks in advance

parchisi

I don't think you would LOSE any HP. Lower backpressure should free up a few in fact. A tune on top of that would help even more, but you won't really notice any difference with just an axleback and high-flow cats.

alkemist

Tune will help with the overall performance of the car and wake it up. As for having a tune written specifically for the use of the SLP's, it's not required.

SpartaPerformance

You can't lose power freeing up exhaust but changing mufflers.

Power-House

Thanks for the replies guys. But just for good measures, is there anybody that is using the slp loudmouths and can surely say that they did not lose any performance?

alkemist

I didn't notice anything except the nice sound the SLP's make. I do have a couple performance mods though.

ADK2012GTCS

My father-in-law is the general manager at SLP. If you have any issues let me know. They're not supposed to make you lose hp.

Power-House

Appreciate your concern ADK2012GTCS, I'll never know if i lost any power though because my mustang is sitting in barn right now in stock form and all parts are going on at same time. Can not wait till the snow leaves! lol

Ford-a-tude

When I had my 93 5.0 I had to have an off road H Pipe. The guy that installed it for me asked me if I was sure because my car might feel slower. I was like, "Pffffftttttt, whatever that's impossible!" Turns out he knew a lot more then me about back pressure, over scavenging, loss of low end torque. So while it might not effect your car, be warned that reducing back pressure in your exhaust CAN be felt in the seat of your pants.

ADK2012GTCS

Sent my father-in-law an email expressing your concern and asked if there was any insight that I could pass along to you. When he gets back to me, I'll definitely let you know.