So we have seen and heard some chatter online about the pros and cons of going with our Kooks 2” headers vs the Kooks 1 7/8” headers on an NA build. We all know that when boost is concerned, “bigger is better” is typically the recommended way to go. But what about the rest of us who want to gain some power on our NA builds? Does that rule still apply?
We wanted some real world answers and results, so we decided to do a test for ourselves (Test done on a 17 SS N/A). These dyno runs were done just 11 days apart, at the SAME location, using the SAME Dyno. We have ZERO connection with this shop.. it is just a local reputable import tuning shop in the area. (You can look them up Procom Racing).
I asked if there were any changes made to the dyno in between the runs, or any corrections for weather, etc, and they said they do not run any weather, or other corrections whatsoever… They give you exact numbers on the day you bring it in, with whatever the current conditions are.
The only change in the setup was the headers. We even ran the same fuel (pump 93). I did not drive the car hardly at all since the first dyno and had about 1/8 tank when I brought it in for the results run. There was absolutely NO TUNING changes made.. just the header swap!
The 1 7/8” kooks headers were removed and our 2” Kooks headers were installed right after the first dyno run (within a day or so) — I only waited this long to get back on the dyno due to the shops availability.
As for the weather (since I know this might come up) — The weather this time of year is pretty much the same every day.. on the original run at 9am it was about 75* out.. and today is just about the same (see photos) — also, we are pretty much at sea level here, give or take.
- -VCM Intake w/LS7 MAF
- -Ported Throttle Body
- -RCR Ported Manifold
- -RCR Ported, polished and milled LS3 Heads
- -RCR Dominator Pro Cam
- -Kooks 1 7/8” Headers (First runs)
- -SSOnly/Kooks 2” Headers (Todays Runs)
- -SOLO 3” Catback w/Catless connection pipes
- -RCR Tuned
Original run is the Solid line.. later 2 runs are the dashed lines.
Original Runs Results
- Eng Power @ 484
- Eng Torque @ 457
Todays Runs Results
- Eng Power @ 509
- Eng Torque @ 490
If you look at the graph you can see we DID NOT lose power or torque ANYWHERE in the band.. and instead picked it up across the board. The band follows the same path as before.. just more power!
I know a lot of you have combatted these claims in the past.. but this is pure unedited data ran at an independent shop with no other changes but the headers.. you dont have to agree.. but you cannot deny.
And before anyone starts with doubts or trying to call us out for fudging the numbers or weather, etc, etc, — just stop.. dont waste your time.. the numbers dont lie!
Some might say they dont believe my car makes this much power.. or that it should make more.. all that is nonsensical..this test was simply done to see a real life comparison before and after the header install.. I dont care if the numbers read 300 hp to start.. gains are gains!
If you are interested in purchasing these headers (retail or wholesale) please feel free to contact us with any questions or comments.