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...



https://cimg5.ibsrv.net/gimg/www.cor...9920cc358d.jpg

Nice video Josh, impressive, did the power stay that high after shut down and restarts?

Great results! What octane fuel in the vehicle? Do the ARH headers then go into high flow cats?

Best Regards,
Dave

Being knowone can tune these zr1s yet i was just curious whats the leanest afr youve seen on the dyno with these mods

That's the way to do it......put the car on the track follow by the dyno.

No secrets with what the ZR1 would be capable of with calibration. Staying excited and optimistic for access! Thank you for the questions.

Thanks... Signature Wheel SV501 with Hoosiers on the rear and SportCup2s on the front.

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.

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.

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*).

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.

Great power for the stock file.

93 oct, and there are no cats.

:lurk:

What did you do to not get a check engine light? I want to put on ARH headers and no cats but don't want to have a check engine light.

Code, CEL, is present. No major issue, visually an annoyance.