Heading to the Chassis Dyno - any input ahead of time? (1 Viewer)

[zerotreedelta]

I've always been curious to gather some data and see what self-tuning leaves on the table, or what I might be leaving on the table for timing as I just mimic'd OEM dizzy curves. So...I've got a timeslot booked on the local chassis dyno for an afternoon of twiddling. Currently it runs well, especially around "normal" part throttle driving. Above that, it seems a bit "flat", so I suspect I'm either fat-rich or possibly pulling too much timing...but time will tell. Any thoughts or input ahead of time might help get the most from the session, and I'm also happy to share the config file after.

The current setup:

• Stock 2F
  • relatively fresh rebuild .030 over (3000 miles)
  • '76 domed pistons, stock valves
  • factory cam
• Headers + 2.5" all the way back
• Holley Sniper + Hyperspark
  • Mostly OEM timing curve, aside from running 10* as base
• Planning to tune for 87 (although it would be interesting to see what it likes on 91)

For those with the Holley/Hyperspark, I'd be curious how your maps compare. Or for those who have tuned the mechanical/vacuum-advance distributors, how much did you push the curve in the higher RPMs?

Or for anyone else, feel free to ride along and live vicariously...and what's the over under on if we get 150 to the wheel?

 

[charliemeyer007]

Wow I guess there are racing tractors. Myself I'd rather tune for mpg than trying to push a box threw the air a little faster, but hey its your rig and money have fun and enjoy yourself YOLO

 

[zerotreedelta]

Realistically, it will be more of a driveability tune, I'm not expecting too much from the ol 40.

I actually suspect I'm leaving both power AND MPG behind. And I'm sure one could get close with road tuning and a friend in the passenger seat, but that's a bit more time consuming.

 

[Its me shaneus]

Very cool! Hope you share what recipe ends up making it happy. I’ve got a pretty fresh 2F and fuel injection (Fitech) and will be watching with great anticipation!

 

[Skreddy]

Unless your compression is a bit higher than stock, I think the only thing running 91 octane will get you is maybe a little more timing.
Looking forward to seeing what you find out. Interesting to see the 15.5 target afr. I have mine set to 14.5 cruise, 14 idle and 12.5 or 13 WOT.

 

[zerotreedelta]

Yeah, 91 would really only buy a little timing.

I did lean it out a little bit extra down at lower MAP, was dabbling with mpgs and it didn't mind it at the lower power there.