Fuel Flow vs. IAT/FWT

[Harpo]

In the interest of investigating WAI, I captured some numbers this week on five day drive to work trip. Idle Fuel Flow only, No AC.

I was lucky to have a few days of cold engine/warm IAT, a few days of Cold engine/cold IAT, and a day of warm engine/cold IAT. Some ranges, I just couldn't arrange. I tried to get all the readings at the top of the temp ranges in each set. They were very reproducable. With spring approaching, I'm hoping to fill in the blanks some. I see why the block heaters are popular.

I guess it's not shocking the linearity of it all. I was pleased to see the >185°°F FWT and 115°F IAT. Makes me want to make a adjustable WAI. Getting dynamic, non-idling numbers are near impossible. I'm hoping there will be some coupling with fuel flow up to 1.5-2.0 gpm or so.

[jerij]

Hmmm....
I'm surprised no one responded to you on this. I just arrived at this site today and have been looking over the FWT/CAI/WAI/IAT controversy trying to decide which direction to take my vehicles. The data looks very interesting.

Do you have any more data since you created this graph? Have you noticed any changes in your information? Could this be extrapolated (in your opinion) as a generalization to other Civics or other cars?

Thanks

jerij

[DifferentPointofView]

I'm guessing this is proving that warmer intake air is better? (atleast for civics?)

[tjts1]

Originally Posted by DifferentPointofView

I'm guessing this is proving that warmer intake air is better? (atleast for civics?)

At idle under zero load, no question about it. I would be more interested to see what happens when the engine is under load on the threshold of of detonation. Can you measure ignition timing under load with cold and warm air intake?

[Harpo]

No more logged quantitative data except idle conditions. I've been only logging trip data, and when in those trips FWT/IAT get to ideal. Obvioulsy FWT and Block Temps have the most impact. That's why we always try to drive a warm car, or use block heater.

I had the pleasure of driving my STD trip to work Saturday and was able to simply to a "stop and go" to return home. In that trip, my startup was at 75° OAT, and it took approximately 5 minutes to reach 180°FWT. IATs were at 75° same as OAT. After about 15 minutes, the IAT begain to climb, but only reached ~ 85° before that leg was over. Traffic conditions were quite similar and I minimized my full stops as usual.

The return trip had startup at 80°OAT, IAT at 100° and FWT at 180°. The IAT climbed to 105° within the first 3 miles due to underhood heat soak. As compared to my normal cold startup after work, similar WX conditions from the last week, the avg FF was lower by around 6%.

I believe this was mainly due to operating hot engine, and having manifold air near perfect for the entire trip. There's nothing flat, straight or predicatable enough to test FF / MPG reliably on my trips. You can look at my return trip data, last two entries.

I've blocked most cold air entry from right adjacent to air inlet pickup and have upper grill block, thus forcing the intake to pick up more underhood air. I have noticed this week, with rising temps (88° OAT) that the IATs have gone as high as 120° and FF at idle has dropped to as low as .20gph when at a dead stop at the end of return trip home.

I'm very keen on hearing ping, since I've dealt with many high compression (10.5cr-11.0cr) pump gas motors making over 700hp with advances as high as 38°BTDC. It's a fine line between success and failure in a big inch stroked motor. I guess I can start looking at timing changes compared to IAT during isolated load conditions to develop a timing curve between changes in IAT.

[DifferentPointofView]

What exactly does an engine ping or knock sound like? An actual ping or knock, or are they just named that? Cause I've never experienced those sounds from an engine before.

[OfficeLinebacker]

Originally Posted by DifferentPointofView

What exactly does an engine ping or knock sound like? An actual ping or knock, or are they just named that? Cause I've never experienced those sounds from an engine before.

It sounds like someone banging on a tin pan under your hood.