SLP Loudmouth Exhaust

[Mikemedic66]

I have an '09 Torch Red GT, and I am considering applying SLP Loudmouth Axle-Backs. American Muscle seems like a reputable distributor, just want any other opinions other than screened reviews. Thanks in advance!

[PureVenom]

SLP belongs on a F-body so they can sound like ass.

Borla's, bassani, or magnaflows would be my recommendations.

[lowflyn]

SLP is the same as running straights...if you want a loud, raspy, popping, in your face exhaust then go for it. Let us know when you decide to buy a true exhaust system in about 6 months after driving around with that one lol.

[SpectorV]

go with the ford racing mufflers (the ROUND ones) they are the SAME as the borla stringers but cost less and have Ford Racing on them instead of Borla.

they sound quite good

[ThaBear14]

Quote: Originally Posted by PureVenom SLP belongs on a F-body so they can sound like ass. Borla's, bassani, or magnaflows would be my recommendations.

What about flowmaster?

[PureVenom]

IF you want to replace them every couple of years, go for it. Hottcobra had them on his, just got 2 years out of those piles of turds, then they started falling apart inside and rattling.

Chokemasters belong on classics and 5.0's....unfortunately they sound good there. Other than that, they are just piles of turd.

[ThaBear14]

Oh well good thing I didn't go down that path.. I was considering it.

[SpectorV]

bang for the buck goes to ford racing (the little round ones not the oval shaped version)

[mrevilracing]

SLP's are LOUD. Take your cats off and they are REALLY LOUD. I have them on my Mach. Someone mentioned longevity....I've had them on for approximately 92,000 miles with NO problems. An MRT catted H will keep that deep sound and will quiet them down some.

This is with the MRT:

This is with the MRT but I pulled the cat innerds out:
Car sounds WAY better with the cats than without. But I'm making 306hp and 330tq with minimal mods and a tune.

In-car with cats:

In-car without:

Dyno(this was Saturday):

But remember, they are LOUD. You can't even hear the dyno turning and most were covering their ears, hehe. Even I did!

I think this is the Ford Racing exhaust with no cats: It's quiet enough that you can hear the dyno.

[PureVenom]

THat's about all the SLPs are is loud. That's their only claim to fame.

[ThaBear14]

Well that seems right considering it's how they were named

[PureVenom]

Yeah, but no where in the name do they describe that they have no depth to the sound, no quality to their sound, no nothing. THey are just loud and sound raspy, poppy, and shitty.

[ThaBear14]

Someone should sue

[mrevilracing]

With no cats, they sound like shit, I agree. But they do make good power. WITH cats in, I have had dozens of spectators tell me how much they love that sound. But I'm hesitant to put the cats back in because I'll lose hp/tq. More importantly the tq.

[SaleenFiend]

Quote: Originally Posted by mrevilracing With no cats, they sound like shit, I agree. But they do make good power. WITH cats in, I have had dozens of spectators tell me how much they love that sound. But I'm hesitant to put the cats back in because I'll lose hp/tq. More importantly the tq.

I don't see how cat's would allow you to lose horsepower... sheets for proof?

[mrevilracing]

The combination of the Accufab throttle body and the cats being removed did a net change of +11.64hp/+18.66. If I add the cats back in, the exhaust flow would be reduced. I am certain there would be a loss in hp/tq. Maybe only 2 or 3 but a loss never the less.


Dyno with cats and stock throttle body:
Note: Tune installed is the 008 pull - 294.97hp/312.06tq


Dyno 1 year later with no cats and an Accufab throttle body.


This car doesn't have an aftermarket CAI. Factory exhaust manifolds are used. 1/4" PHP intake spacer installed prior to dyno pull last year.

[SaleenFiend]

Interesting I was under the impression that our cars made better bottom end torque with a catalytic converter bc they rely on back pressure highly, but I guess the difference is so signifigant up top not to worry about it. Nice to see. BTW how big is your piping? 2 1/2 ?

[mrevilracing]

Quote: Originally Posted by SaleenFiend Interesting I was under the impression that our cars made better bottom end torque with a catalytic converter bc they rely on back pressure highly, but I guess the difference is so signifigant up top not to worry about it. Nice to see. BTW how big is your piping? 2 1/2 ?

Yes, 2.5". I don't know where I'd start to lose tq. Maybe with a CAI or 1 5/8" headers. All I know is I certainly don't want to lose it. Many times I am down around 3k or lower in some turns and you can see I am at about 275tq at 3k. This car makes really good power. And, yes, it's was on the dyno with about 6 other Machs so the comparison is pretty good. Not to mention the motor has 97k on it. I am truely amazed that it's doing this well so far into the clock on the mileage. When it goes, it goes. I'll be in Street Mod next year, HOPEFULLY, because it's now become not fast enough. With wider tires, say, 315's, I could really destroy the ESP records but my eye is on the SM races next year.

[SaleenFiend]

Quote: Originally Posted by mrevilracing Yes, 2.5". I don't know where I'd start to lose tq. Maybe with a CAI or 1 5/8" headers. All I know is I certainly don't want to lose it. Many times I am down around 3k or lower in some turns and you can see I am at about 275tq at 3k. This car makes really good power. And, yes, it's was on the dyno with about 6 other Machs so the comparison is pretty good. Not to mention the motor has 97k on it. I am truely amazed that it's doing this well so far into the clock on the mileage. When it goes, it goes. I'll be in Street Mod next year, HOPEFULLY, because it's now become not fast enough. With wider tires, say, 315's, I could really destroy the ESP records but my eye is on the SM races next year.

Good luck. Sounds like you have a stout running car.