rtc1978

I know alot of CL members have an aftermarket or custom exhaust, I was wondering did anybody actually feel or notice any hp gain. I am asking because my car seems to be lacking top end power. Mods are T/C and SRT intake.(hollowed out my cats) My best 1/4 time is 14.29 at 95.....mph. My 60 foot time was a 2.01 with falken st-115 tires.(17inch stock rims) This run was at Englishtown N.J. about 50 degrees out, not really humid. But I ran the car in various condition and cant get a better trap speed than 95...mph.(The car has 71k miles on it) I will appreciate any advice out there, if anyone did notice performance with their exhaust please tell brand, or custom exhaust note the diameter, y-pipe or x-pipe, or straight daul exhaust.
PLEASE HELP!!!

redgs4

For me the sound alone was worth the change. And there was also the visual improvement of the dual grape fruit launchers. At this moment I have the Tanabe Hyper Medallion without the resonators.

I have heard the following but don't have personal, dyno-based facts to back it up. First: An aftermarket exhaust alone does not add more than 5-10 HP. Second: It's the combination of the exhaust with other power adders [SRT Intake, FI] that make more of a difference. While I have an aftermarket exhaust I failed to perform the apples to apples before and after dyno runs. And since I don't plan on going back to stock exhaust after I add an intake I won't be able to confirm number two.

JacobT

I'd say the visual and audio HP gain is worth the money. I have Greddy PE which is a 3" cat back straight thru system. I gain about 10 Hp at higher rpm but lose a little at low. The dual 4.5" exhaust tips are agressive, the deep sound from the exhaust gives you about 20 HP gain plus the shining stainless construction makes the statements that you are serious about performance.

fireballs gs400

you have the rear rod millen bumper? I have the greddy and have my pipes up as far as possible..the rear bumper is something i should think of with ltuned sides and tte front...anyone agree...btw...greddy rocks

JacobT

Yes. I have RMM rear bumper. I have my performance shop custom fit the exhaust to center the tips with 1/2" all around the bumper cut out. I also have them cut the tips to flush with the bumper.

BananaGS

Big intake, more intake air, more exhaust output, going into a restrictive exhaust, what you you think the ending result is?

MrSypher

Yeah I think you should definitely get the exhaust.. With the intake you have more air coming in but still are restricted with the flow exiting even with your hollowed cats.. And the Intake and aftermarket Exhaust go hand and hand for making more HP.. But only if it's tuned, like for example a piggyback ECU or a S-AFC.

bravo261

iTrader: (1)

my first mod was an exhaust and immediately i could feel the difference. i had almost no expectations from just an exhaust, and its not a "performance" one either, and walked away as happy as can be. and the sound is always worth it

Synergy

I have the RMM exhaust w/o resonators as well as new 4.5" tips and the sound is awesome! If anyone has aftermarket exhaust on the GS4, I challenge you to take off the resonators and listen to your V8 in it's true form