Tibo

iTrader: (15)

Well, I am finally taking my Camaro to a dyno with constant load features to finish tuning the MegaSquirt 3 Extra. I have been looking through some old posts but hadn't found much info about tips and strategies for tuning an engine on a dyno with constant load capabilities. So I am hoping that a few members can add in their two cents and say what would be good to bring, or try or a strategy to adhere to. I have the vehicle driving pretty well with reasonable and constant air:fuel ratios and a sane spark map.

If anyone needs to know details of the engine:
355 sbc, 10.1:1 Compression Ratio, Ported Trick Flow heads, 1.6 aluminum roller rockers, LT4 "hot" cam, Hooker Super Competition 1 3/4" long tubes to 3" primary to 2 1/2" pipes to a Y to a 3.5" resonator dumped, Accel Pro Ram with the Accel 4 barrel progressive 1200 cfm (i think could be 1000cfm) throttle body, 30 lbs/hour Bosch III injectors, AFPR, MSD ignition componets, MegaSquirt 3 Extra ECM with Wide band O2.

Any advice appreciated, I've never had the car on the dyno for more than one "run."

efiguy

iTrader: (2)

Who's wideband are you using?
One tip, if he can load it anyway you need then make sure you do some steady state low rpm high load tuning. That'll help when calibrating revving from neutral or in gear.

Tibo

iTrader: (15)

I will be using my own wideband sensor which saves me a bit, its an innovate sensor.

Orr89RocZ

iTrader: (20)

Yup if you can load the car hard on the dyno, do so! Most dyno jets tend to not load cars as hard as the street does so we leave them slightly rich on dyno and maybe deg less timing or so. Once on street or track under real load it leans out back to optimal air fuel for the combo

Try to hit various areas of the map like low rpm heavy load, high rpm low load etc. more data points you hit the better the fuel map will be.

Also for wot tuning try doin some rapid back to back pulls. This builds heat in chambers and really will test how close to detonation/knock you are with the current setup and leads to a safer tune. One pull when motor is fairly cool may not show signs of detonation or knock and be fine. If you did 2 more in a row immediately after it may start getting hotter in the chamber and intake air temps, and may start to enter a detonation zone requiring spark retard. This will help you find how close to the edge you are with your tune and how to set it up for more safety if you need more. Like a drag car may be fine with one pull. Road race car may see multiple wot pulls in rapid succession so simulate your driving style on the dyno at the highest loads to verify how safe tune is

efiguy

iTrader: (2)

Well good luck with that, Innovates' suck. Probably the most inaccurate and slowest on the market.
You might try using theirs as well if they have something other than an Innovate.