3.4L engine dyno results

Maybe I'll do it with both sets on it. The main reason is to get a good accurate friection loss percentage. I think that would be done best with stock. For an extra $100, I might as well use both sets of wheels to compare them too.

 

I've spent more time on dyno's then I care to remember, dyno's are not all equal and there are soo many variables at play that it would be misleading to say compare dyno A to dyno B. even comparing dyno A to itself can be tricky, I've spent literally all day straight on a dyno many many times and have watched the variation over the day change as temps, barometric pressure and the engine itself fluctuate. Fuel is another one, fuel varies too in the blends and additives and how 'fresh or stale' it may be. accurate vehicle weight on the rollers is another one, use scales don't guess.

Yes the dyno companies all tout their corrective software, but how many operators are constantly adjusting and calibrating the dyno every hr? eddy brake dyno's also suffer from core saturation, I'll spare everyone the physics behind magnetic core loss from saturation and reduced permeability, but suffice it to say it's not linear nor a fixed scalar field.

the more consistent dyno uses a fixed mass roller, great for comparative runs but not accurate to real world conditions, however that's not the point of a dyno. The dyno is a tool to measure and track changes when tuning, not a gauge to compare against another engine. that's a marketing ploy that somehow gained traction and people have run with it.

Just keep in mind that there is no reasonable way to calculate the two dyno results to each other. It'll be interesting to see what the results are but I would not hold them as accurate or within 'X' percentage.

I'll offer this tip, air movement and engine bay temps CLIMB on the ferrari's when on a dyno and suffer from a lack of proper airflow. the majority of vehicles on the dyno are front engine and the shops fans are all setup for front air flow, I like to get additional fans pointed at the rear 3/4 of the vehicle to assist in drawing air out of the engine and supplying air to the intake. If the dyno is at the back wall of a shop, it'll never have the proper airflow and I would avoid that dyno shop, ideal shop layouts have the dyno positioned with a bay door behind them to help keep exhaust gasses from building up in the shop and allow for proper flow. shops that use 'hoses' attached to the muffler tips should also have in-line exhaust fans that flow near the CFM of the exhaust or the back pressure in the hose will effect the engine performance, if it's just a hose with no exhaust fan in the line, find another facility.

hope that helps...

 

bingo!