Hondata

Can Hondata confirm that the 02-04 reflash picks up 20 HP on an unmodified 02-04 RSX-S (K20A2 engine), whereas the 05-06 reflash nets 10 HP with a CAI installed on a K20Z1 engine? The links to your dynos are:

http://www.hondata.com/reflash_rsx.html for 02-04
The details section of this page specified that this is an inmodified RSX-S.

http://www.hondata.com/reflash_05rsx.html for 05
The modifications section of this page suggests that the stock airbox was not used, so I presume a CAI was used.

Both tests were done on a Dynapack. I assume that the difference lies in the 10 HP improvement that Honda made to the K20Z1 engine, so that the benefit of a reflash and a CAI aren't as great as they are with earlier RSX-S models. Just trying to understand before I buy a bunch of stuff....

Both dynos were made with the stock intake. It is only suggested to use a cold air intake because that is very good bang for the buck.

Generally the K20Z1 will make more power than the K20A2 because of the cams. Note that there is a lot of variation between engines - on the same dyno our stock 03 RSX made 180 hp stock, 199 hp with ECU tuning, and 213 hp with KPro and cold air intake (about 10% more than the vehicle which we used for development). The difference was that I owned the RSX from new and broke the engine in correctly.

Hey, thanks! I appreciate the thoughtful and thorough response. And I hadn't considered the importance of properly breaking in an engine. Good point and something that is seldom mentioned on other sites.

broke the engine in correctly - what does this mean? How should one do this correctly?

In the first miles of an engines life it requires moderate to high load to force the piston ring onto the cylinder bores.

The only break in required for a modern engine is the piston rings. The rings get lapped smooth by the rough cross hatch pattern on the cylinder bore. If the rings do not get enough cylinder pressure to lap them before the cylinder bore is worn smooth, then the engine will make less power and burn more oil.

In short - as few cold starts as possible, avoid idling, and give the engine around 1/3 to 1/2 throttle, varying the rpm from 2500 to 3500 or so in a high gear (5th or 6th). A long trip actually works very well.

thanks