View Single Post
DonE DonE is offline
Wo ist die Rennstrecke?
 
DonE's Avatar
 
Join Date: Mar 2004
Location: Brooks, GA
Posts: 1,211
Quote:
Originally Posted by drmatera View Post
well, i have an update of sorts. Not more dyno figures but I did go back to the 1/4 mile track.

on 15psi with 20* total timing I ran 12.96 @ 113 mph 10.9 a/f
up from a 13.27 @ 111 on 13psi 11.6 a/f

question: do you guys that tune on a dyno see the same a/f on the street? So far that has not been the case for me. I had to pull fuel out to get my a/f in the 10.9/11.0 at WOT going down the track compared to the dyno runs. This further reinforces why i do not like dynos with turbo cars. With all the datalogging devices available I see no better tuning tool than a flat straight stretch of road with no cops on it. But then i see that as a good thing while tuning or not
If the temps and altitude are the same, then yes I see the same AFR on dyno and street. But then again, I do not use a dynojunk, sorry, dynojet dyno - they do not put a load on the engine so its impossible to tune most of the important fuel cells simulating real world driving. Being one cell off with fuel can mess with the AFR when the ECU interpolates between the two. You must find a dyno that applies a load for any given RPM and manifold pressure/throttle position/or whatever your ECU uses as the X or Y axis. Using a proper dyno also allows you set one of the most important items - total timing. Without a dyno, you are shooting in the dark trying to get peak torque, and without managing the torque, you're leaving money on the table.
Old 01-21-2010, 04:51 PM
  Pelican Parts Technical Article Directory    Reply With Quote #36 (permalink)