UPDATE: NOT Disappointed
 

I have a manual 2014 ZL1 and had some mods installed yesterday. When I took the car in the pre-install dyno showed 509 RWHP / 497 RWTQ at 10.3 Psi AFR 11.3 The pre install run had a Roto fab CAI, VMAX 87mm TB and a catch can.

So, I had installed the ATI 10% pulley, ARH shorty headers (ceramic coated), Roto fab big gulp and tuning with HP tuners. End result was 550 RWHP / 540 RWTQ at 12.7 Psi AFR 11.9.

The temp during the runs was 68 F and 64% humidity at an elevation 765 feet MSL in Murrieta, CA on 91 octane, 98% injector duty cycle.

My question to the members of the forum is, do these number seem low for the mods completed?

Just curious, why no LTs since you where going with tune anyways. Is it a inspection thing? What about hi flow cats? Or you still running factory cats?

Yes it was an inspection thing. ARH shorty are CARB approved. Factory cats on the car.

See I don't think there will be much gains from the short tubes, but the 10% and the tune will be your gains. So 41 rwhp I don't think is all that bad, and that 91 octane will also be a limiting factor when you start to up your boost.

But the big question is how does it feel, if it pulls hard and puts a smile on your face, enjoy. Don't worry about dyno numbers.

Also with your stock injectors being maxed out that's probably as far as they could take it. Seems about right. A 10%lower isn't much of a boost increase. I would add a 2.55 upper and port snout at same time, Id850, and some 200 cell high flow cats. You would see a nice increase. But 550 with those mods on 91 is about right.

Yep, going to the ID 850's for now. Porting and upper pulley will be later down the road.

I knew the shorties would yield little to no power. They do sound way better than stock. Twice as loud at very least. Tuner said the same, 91 and duty cycle are limiting. He said I could get another 25 with 93 octane. It does pull much better all around. Just a little disappointed as most are getting gains of 75 RWHP with the same mods, mostly on 93. I'm going to get injectors and a retune. Had a one piece driveshaft but gforce sent the wrong adapter. Hope to get a new one that fits the ZL1 and finish it off for now.

Most get that 75 with long tube headers and high flow cats. I think that's a good gain considering stock cats and 91 and shorty headers.

Most Zl1's avg around 480, 490 rwhp. You've increased your output 60 - 70 Hp , that's dam good.

Understand, but the vendors on this site advertise 75 RWHP with the 10% OD pulley, CAI and a tune. My numbers reflect no where near that. I do understand 91 octane will lower that a bit. The 125 RWHP kits from vendors advertise 125 with long tubes,high flow cats, injectors,10% od pulley, CAI and tune.

My increased output is 41 RWHP, not 60-70. Maybe your quoted numbers reflect an automatic? I am a manual. By your metrics I am 19-29 RWHP short.

The first set of mods added probably 25hp and the second set probably another 40. Seems pretty decent to me considering the cost

Looks like its time for some fuel system upgrades...

my car was an A6 with a 10% lower and headers. With a conservative tune for the road course, it was only 508rwhp/540rwtq. It sill ran 11.37@119 like that so don't sneeze at "only 550rwhp". The dyno doesn't mean a lot, but the good thing is that you can get a larger lower pulley like a 9.17" or 9.55" and really enjoy the power. It would be in the 580rwhp range with a larger diameter lower pulley with 91 octane. I bet it feels great on the street so don't dwell on the #s so much!

i agree don't let the numbers bug you, my car has long tubes with high flows, intake, 2.55 sc pulley, id 850's, dyno tune. after reading lots i was really thinking it would make 600 but only made 574.

you need 93 octane