Safe to run on a tuned ECU "basemap"?

[masospaghetti]

I'm getting a chipped ECU from Phearable.net with a basemap tune on it. Phearable says they don't recommend running on the basemap unless you have a wideband O2 sensor OR get it dyno tuned. I have neither.

Given that my setup is nothing radical would you just run the basemap? What would you do? Really the only thing out of the ordinary is the H22 pistons inside the H23.

Thanks

[Jarrett]

The H22A pistons in an H23A application can yield a pretty high compression ratio if the pistons are JDM P13 pistons or P5P Type-S units. The reason being is that the 95mm stroke and 141.5mm rod length require a piston with a 30.55mm compression height to bring it even with the deck at TDC. Installing an H22A piston with a 31mm piston will cause the piston top to sit .45mm higher in the bore and protrude about 0.020". This isn't the end of the world as the F20B has this scenario from the factory. However, USDM H22A pistons would result in a 10.7ish compression ratio and JDM H22A pistons would be over 11.0:1.

For that reason alone, I would be hesitant to trust a basemap. And honestly, unless large changes are made, I would be more apt to trust a Honda-engineered tune operating just outside its parameters than I would a mail-order generic tune.

The correct answer is that you should have your car dyno-tuned. You should also look into investing in a wideband. They're not expensive, and they can save your engine.

[illinois_erik]

the oem rom dumps can be downloaded, so if you just had a few bolts on's you could use a stock image, or one that suits the characteristics of the engine till you have an actual tune (like the f20b was mentioned), i wouldnt run someone elses tweaked bin, because its for that engine even though it may generically run yours. Im getting a chipped ecu and running an oem bin but w/ egr functions removed. I just have a header and port and polish so its more of the euro-r specs so i may try one of those accords roms. maybe get it tuned if i changed anything else however its unlikely thatll happen for some time.

[deevergote]

With USDM H22A pistons in an H23A1, you're looking at a compression ratio of 11.66:1.
With JDM H22A pistons in an H23A1, you're looking at a compression ratio of 12.47:1.
With JDM Type S pistons in an H23A1, you're looking at a compression ratio of 13.00:1.

With the USDM pistons, you MIGHT be able to get away with an H22A basemap, as long as you're absolutely sure to run 93 octane fuel. Pay close attention to the sounds your engine is making. If you hear pinging, shut it down.
I wouldn't feel comfortable pushing it with JDM-spec pistons. Type-S pistons in there would probably give it fits.

Get yourself on a dyno, or at least pick up a wideband and chip burner and give yourself a crash course in street tuning. You should be able to figure it out well enough to keep from blowing the engine up in a relatively short time.

Years ago, my buddy Antoine flew from Orlando to Philly to tune a guy's ECU. The dude went racing the night before, on a basemap, and blew his engine. Antoine tuned my ECU at a discount, because he suddenly had room in his schedule.
You put money and effort into your engine. Don't do something to jeopardize that now.

[gloryaccordy]

Not worth it man. So close, just get it tuned. Would be dumb to have the engine built and blow it up on a basemap

[masospaghetti]

Thanks guys. I'm sticking with the stock ECU for now until I can find a tuner or a get a wideband A/F installed.

[deevergote]

The stock ECU may not be much better than a basemap, given the high compression. Make sure your knock sensor is functional, and only run high octane fuel.