new to tuning ls1

[EagleMark]

I can only imagine the convience of a load baring dyno and how much time could be saved! Man you'd have good data points to build a fuel map off of. But like mentioned above it's only a tool and only as good as the person using it.

That throttle follower trick works sweet on manual trans, but the first time I used same settings on an Auto it had drivabilty issues at slow speed in traffic and did not idle down quick enough, little tweaking and had it dialed in.

Even if you did the entire tune on a dyno, it stills need some street tune IMO, not just tranny. If it does not start and drive cold or has any other drivibilty issues your only going to find them by driving, starting, stopping, trying to make it stall etc.... Keeping vehicle over night, doing cold start, driving cold etc... bottom line, does it start and run and drive with no issues? OK done!

[mekkis]

Keeping vehicle over night, doing cold start, driving cold etc... bottom line, does it start and run and drive with no issues? OK done!

I offer to do cold startup for everyone as part of the tune, but surprisingly few people every take me up on it. Too impatient. Hondas and DBW Ford I don't have to do that with as I know them well enough or they simply work, but the cable throttle Fords, Chevy, and standalone stuff I'd want cold startup and drivability tuning done if it were my car.

[Fast355]

Steady state loading on a dyno is great to hit the individual cells of a VE map and play with ignition timing, idle stuff not quite so well, but I can still approximate most on/off throttle quirks a big cam has while on the dyno. But the REALLY big cams tend to be a pain.

The best thing in that situation is to not bother fighting the idle, and use the throttle follower like Ford's Dashpot function. It saves a LOT of time. Add in a lot of air across the TF, throw in some TF decay delay, and reduce the TF decay rate so that the air you've added in comes back out slowly. The IAC will act proactively and slow the engine's natural decel down, hold idle a few hundred rpms above target for a second until the TF decay lapses and idle trims kick back in, and then she falls right into target idle with no static.

Much of this can be alleviated on cars that do not have drive by wire. On all my older GM/Chrysler stuff with the base idle adjustment screw, I like to plug off the IAC, and set the idle to a certain RPM. Most big cam cars, I set around 700-800 rpm and command a 750-800 rpm. Set the hot idle about 50 rpm lower than you are commanding. After that the stock IAC settings often can handle the cam just fine. My 4.7 Dakota has crane ground 218/224 @ .050" cams on a 112 LSA. ZERO issues getting them to idle flawlessly despite only having Superchips can program and a Split Second PSC-1 piggyback MAP adjuster. With the newer 08+ flex fuel 4.7 injectors, I was able to put my Innovative LM1 on both banks and dial in the WOT air/fuel ratio across the board. I manipulated the voltage at part-throttle to Zero out the LT fuel trims. Sounds crude, but works surpisingly well.

20-60 FIRST GEAR pull on uphill ramp

http://www.youtube.com/watch?v=D1_xHMvoW48

http://www.youtube.com/watch?v=ciDFZahmEUc

http://www.youtube.com/watch?v=LutcPUvgcJk