Stage 2, GMPP Catback, GMPP Manifold, Injen CAI, TTR Engine Mount, Exedy Clutch + Flywheel

Consider a 350z, 280bhp (non stock) model put down 227hp on the dyno, a SL 500 (exhaust) rated 309bhp put down only 240hp, and audi TT (non stock) put down 159hp that day

GM Stage 3 pulley and dual pass intercooler end plate on the way.

 

Now thats a poopy dyno. Makes you feel like crap.

 

That's why you should use the same dyno to do a before and after. That way you can see the gains. Each dyno is different so it only works if you use the same dyno preferably the same day.

 

you have a sc ss cobalt with stage 2 and put down 220.9. that doesnt sound right at all. everyone elses dyno usually says 240 or so. weird huh?

 

I say it's the dyno. Look at what the other cars put down comparatively. I would keep that dyno sheet so when you beat some ricer you can show him that you only dynoed 220hp.

 

Man, I hope you didn't pay any money for the dyno.

 

Last time I dynoed 228hp before GMPP Manifold and Injen CAI, they couldn't give me AFR, so I went to a different one. This is the one I'll be using from now on. Its ok compared to what other cars where putting down.

 

i agree . the other cars looked low too , so your numbers were not bad

 

What downpipe should I choose, if at all, based on the current setup with the addition of the stage 3 pulley and dual pass which are in the mail atm. I'm need one with a CAT. Should I choose 3" or 2.5". Would 3" be a bit much since the rest of the piping is 2.25"?

 

i went with a 2.5" d/p with high flow cat, and the rest of my exhaust is 2.5" as well. i think 3" is too big unless you're goin turbo.

 

I made 228hp with an injen intake and custom exhaust. I plan on getting stage 2 shortly if I don;t trader the car in and get something else.

 

downpipes don't do anything

 

Me and my brother were looking at our downpipes and came to that same conclusion. They are decent in diameter. The only thing I plan on doing is ditching the cat. In fact the stock exhaust doesn't look that bad either except right before it gets to the fake rear. Then it necks down pretty small.

 

i found this out the hard way on my gxp i had.

i still have this catless dp from that car sitting in my garage. no one wants them. the stock cat flows enough, and the actual piping is good.

 

It doesn't matter to me if I see 1 horsepower from removing my cat. It's free and gets removed on every car I have I don't ever look at exhaust, intakes etc as power mods. Sure you can get some horsepower from them. I look at doing those mods as supporting mods for big additions like cams, heads, power adders etc, as it will be a restriction when you get into bigger mods. That's the way I always build my cars. So my conclusion is to save a buck on this and just ditch the cat, keep the dp, and maybe just replace the restrictions in the cat back.