jwolf8604

I have a gm stage 2 with 2.9 pulley, zzp shorty header, and K&N intake. I have STOCK exhaust. Do you think I am getting the power that I "should" be getting from those mods without a performance exhaust? When I get my exhaust am I gonna notice a huge difference in power because I haven't been getting the real benefits of my mods so far? I don't know if this is even logical, I'm just wondering how I lost to a turbocharged integra (not type r). When I am assuming by my mods, that I have about 260 whp.

NJHK

I highly doubt you're making 260 whp

I'd take it a dyno to find out for sure.

arng22

look at the mods in my sig..i have about 260..

88cobaltSS

I don't see you having 260 whp even with your mods and full exhaust. But with a new exhaust you would see a good bit of gains.

Are you guessing or do you know for sure?

NJHK

not being rude but how do you have "about" 260. Did you actually dyno?

an0malous

upgrading the exhaust might get you to 250whp

arng22

just kind of assuming and having a 106 trap time is about 260.

jwolf8604

with the K&N and stage 2 I dynoed 241 on a mustang dyno. Now I have headers and 2.9 pulley. I figured I was at about 260. OUch, guess not.

firemanfrank

An exhaust system will net you 4 things:

• about 5-7whp
• a headache from the additional noise
• angry neighbors
• more attention from your local police dept.

Not worth it in my opinion ...

LopsidedJester

i disagree a little. With increased mods, the more the increase from an exhaust you'll feel. I would say up to 10whp and possibly slightly more is attainable. If you have the right exhaust it should sound robust and shouldn't give you a headache, otherwise why would you upgrade if you don't even like it. You'll also get attention from more people period and its not all that bad.

firemanfrank

LOL

Was just my opinion.

Before I purchased my SS/SC I had an '06 Focus ST. I had a custom exhaust installed on that car, and then regretted having put it on every single day thereafter.

Even though the the exhaust upgrade was not all that radical, it was still too loud (became very annoying after a while). Also, it only netted me a 1/10" reduction in 1/4 mile times (and less than 1mph increase in trap speed).

I'll never do another exhaust mod again ...

07 SS/SC

I dont think trap times are a direct relation to HP. I know there is a member here with just cooling mods, he has nothing done performance wise and he traps 102+.


To the OP I think your ass-o-meter will feel a good gain from changing your exhaust!

Edubs

If you dyno'd 241whp on a mustang w/ those mods, the dyno operator was giving you "adjusted" or "corrected" numbers. That number is pretty close to what someone would dyno on a dynojet w/ those mods.

Back to the original topic, the stock exhaust is restricting enough that you will see some gain. How much gain depends on which type of exhaust you use, how large, whether you tune for it and maybe a few other factors I'm not thinking of. It's up to you, but an upgraded exhaust will always be louder. Some people like it, some don't...

joeworkstoohard

a header and cat might get you a little more juice, but iif you expect any real power from an exhaust, you are fooling yourself.

I don't want to rain on parades, but a cat back is 95% for show.

Area47

if you're at 260. im at 300.

UmeNNis

sweet... real helpful, seeing as how we don't know your mods....

Area47

you just have to know where to look.

QuikSilverSS

I dyno'd 257whp with AEM CAI, GM Stage 2, 2.8" pulley and Zex plugs (on a really cool day with 94 Octane) with stock exhaust, at sealevel. My dyno sheet is in the VBgarage, I have since added downpipe and catback, and made a nice difference, will update in a few weeks as I am due to go to the dyno.

aj_92rs

They are (assuming we're talking about trap speed), more so than ET.

ET is dictated by traction, as I'm sure a lot of you are well aware of. A ZO6 will only run mid 15's if it can't hook up.

jwolf8604

Yea, I do know that the 241 reading I got WAS adjusted. I think I was in the mid 230s w/o the adjustment. I'm being flamed for assuming that headers and a smaller pulley gave me 19 hp. I don't get it. Header was rated at 15 hp and who knows how much a pulley gets....... My point is, I wasn't calling attention for my "260" hp comment (which I was apparently wrong about, but I am not contesting it) , I was asking if I am suffering from having a stock exhaust.

LopsidedJester

I think your HP numbers will suffer slightly more from the stock DP. HP can only increase so much from increasing the flow through your whole exhaust, but its not like you can add horsepower for every mod. Since you already have a header i believe that the gain from a catback will be slightly less of an increase than what you woul feel without a header because you have opened up some of the potential already.

Your overall HP increase with the header and the catback would be higher, but for every potential increase in exhaust, the less you will feel (basically, the first exhaust mod you do will produce the most potential HP increase).

For example, if you change your DP and keep stock exhaust, you'll probably feel a small increase, but after that a catback would probably add on even less potential gain and you probably wouldn't even feel a difference from the header + downpipe combo. Overall though, you would make the most potential HP with every exhaust piece changed to a better flowing aftermarket piece.

Also, on another note, The DP and Header are more essential to flow. It has been proven that restrictions in the beginning of the exhaust effect flow and HP more than restrictions towards the end of the exhaust.

an0malous

huh?
i think 10whp from an exhaust is pretty reasonable "real power" from a catback.
and that number has been proven many times. sometimes more.

I dont see how thats 95% show?

IamTvor

I say get a megan racing cat-back. Its cheap, sounds nice and well made. IMO
I think you can get anywhere from 5-10 whp.

joeworkstoohard

i'm just looking at the overall math, you're a smart guy, so my point is basically that when just about anyone says "10whp' they're usually referring to the point of the most gain. generally, it's about a 1-2 hp gain over most of the powerband, that's not all that much more power.

i agree with the previous poster that a DP is prolly a better bang for the buck hop up.

moonboom10

I'm not quite sure where you're getting your information, but if you're talking about a 2006 or newer Z06, expert drivers can run low twelves and crappy drivers run high twelves.