lamboworld

The only change from the original dyno vs. this dyno was the switch from a ported OEM intake to a non ported MSD Intake. A gain of 16whp and 19wtq.

Next up is 125 shot of Nitrous that will be installed in late August.


One other item to note. About two months ago, I decided that my Corsa exhaust was too loud and I switched back to my stock exhaust and I had it dyno'd after that change. I lost 8whp and 14wtq going from the Corsa exhaust to the stock exhaust. I was pretty shocked that I got this much power out of the Corsa. I loved the Corsa at WOT and hated it when I wanted it to be more tame. My original dyno with the Corsa exhaust and the ported OEM intake was 566whp and 497wtq.

C6Z06C6

That loss from the exhaust is shocking. They are both 3 inch. Even if you went from no cats to cats that sounds way to much of a loss.

MTPZ06

Punch your OE exhaust out to a true 3" system... https://www.corvetteforum.com/forums...ht=muffler+mod

There's a guy on here that can do that for you.

lamboworld

I was pretty shocked as well. The only change was removing the Corsa cat back and changing back to the stock mufflers. The headers and the race cats were the same.

AzDave47

3" OEM mufflers neck down to 2.3" before the inlet to the muffler. It is a 3" connection to the H or X pipe, however.

A lot of $, but I went with the B&B Fusion Extreme III that have a full straight thru 3" with 3" flapper and have the closed side that is louder than stock but fine for highway cruising. Open it screams wonderfully.

dyno link for sound:

Must_Have_Z

Not really. Corsa has put out videos showing that much of a gain going from stock to their Sport system on a Z. Google is your friend.

Unreal

Actually it is shocking to me. Plenty of HUGE power stock muffler cars. On a <600rwhp car I find it hard to believe it was that big of a difference.

With that little of a difference, on different days, I would call that dyno variance, not lost power from lack of mufflers. Unless it was an hour later, after swapping on same day.

lt1z

I have not seen the stock mufflers hold back a H/C/I LS7 with the flaps open. Did three this week alone between 585-610whp. All with stock mufflers.

dcamick

Say hello to Kelly! Great work done in Mooresville!

cv67

8hp is nothing especially if it helps you enjoy your car again

64chevyII

Yup 603whp here stock mufflers.

Josh B.

Best mod I've ever done!! I can always whip up another set, I've done 3 now.

My stock to 3" Muffler Mod back to back dyno results were similar to the OPs corsa to stock results. When started the 3" Muffler Mod I made a gain of 4 rwhp and 12rwtq. There's definitely some torque hiding in uncorking the exhaust!!

Josh B.

I gained 4rwhp and 12rwtq. Depending on one's definition of "holding back", IMO, I am happy to have the additional torque. I was elated to make 549rwtq on my K501 combo. Generally, only the Torquer cams have gotten around 550rwtq on pump gas. Uncorking the exhaust allowed me to go to a more top end oriented cam, but without much of the associated torque losses through the mid range.

My .02.