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Dyno results: ZR1 w/headers, American Racing Longtubes
The ZR1 wrapped up the track season, with stock manifolds, a few weeks back. Very fast, consistent, and always a blast to drive no matter the venue. We opted to try and further the ZR1 even more.
A set of American Racing 2" long tubes are now installed. We fully anticipated more power across the chart. Sometimes, there are surprises. Check out the results...
You mention the car is actually adapting to the headers. The dyno results seem to back up that statement. Is it the oxygen sensor that is gradually changing or what is it that is capable of “learning” what the engine needs?
Last edited by Steve Garrett; 11-26-2018 at 10:02 PM.
No secrets with what the ZR1 would be capable of with calibration. Staying excited and optimistic for access! Thank you for the questions.
Originally Posted by SilveradoSS500
Nice work! What wheels and tires are those?
Thanks... Signature Wheel SV501 with Hoosiers on the rear and SportCup2s on the front.
Originally Posted by Rinaldo Catria
You mention the car is actually adapting to the headers. The dyno results seem to back up that statement. Is it the oxygen sensor that is gradually changing or what is it that is capable of “learning” what the engine needs?
The "learn" is change seen in the Timing and AFR.
Baselines without headers compared to the later runs with them installed, timing went up 1*. Peak timing was at 19.8* with the headers on. The 19.8* of timing does not appear until the last few hundred RPMS of the pull. Timing starts at 8* and gradually ramps up. The gradual increase is consistent with stock baseline pulls and dyno pulls with the intake and xpipe. The AFR delta was about a tenth, 11.38 to 11.46 peak. There was a .05 change down low. Leaner, bet very minor change overall but enough to make gains.
The change in peak boost appears to be almost 1psi lower from the headers being installed.
We are further reviewing data, and will be able to provide more insight soon.
Originally Posted by Too-Fast
Nice video Josh, impressive, did the power stay that high after shut down and restarts?
The power did stay. The following day it was dyno to check this and graphs were close to identical with the peak HP being 695. High 690s is where it stays.
Originally Posted by Bob U
What does the timing look like for both the X-pipe and headers?
Like mentioned above, peak timing is at 19.8. The timing is gradual, starting at 8* down low, and progressing towards the peak values. The 19.8* is (1) degree higher than the baselines without headers (18.X*).
Originally Posted by BlueDevilZ51
Being knowone can tune these zr1s yet i was just curious whats the leanest afr youve seen on the dyno with these mods
Leanest AFR is almost 11.5, with the headers installed. We will be leaning it out with a fuel blend in future, keep a look out for updates.
Originally Posted by Vernon
Nice documentation.
Looks like you’re making a good chunk over 800 at the crank.
Well done!
Great power for the stock file.
Originally Posted by Dave Schotz
Great results! What octane fuel in the vehicle? Do the ARH headers then go into high flow cats?
11-26-2018, 02:41 PM
Dyno results: ZR1 w/headers, American Racing Longtubes
