Stand Alone Engine Management Systems

[SickLude]

how exactly do they work? for instance, after I do my swap for the H22, I want to install the Hondata system. but what i have a question about is, when you get the Stage 3 you can change, with the flip of a switch, the Redline, am I correct? how is it possible, without any prior bottom end work, that your redline can change from 7200 to 8000 or 9000?? Isnt the redline a prescribed set of numbers that exist simply because when you go anywhere after that, your car becomes vunerable to breakdown?? and i know that you can change when the VTEC kicks in too, correct? help me out.

[91zc]

You have the "ability" to change the redline but if you don't have the modifications to let you rev that high then yes the car will breakdown. I believe the hondata system does let you change the vtec crossover point. I forget which stage lets you do this, so I would suggest you check out Hondata's website for more info.

www.hondata.com

[fritz_269]

You're confusing "redline" and "rev-limiter"

Redline = The maximum RPM number where all engine parts are within their design parameters. Exceeding the redline will stress parts beyond what they were meant to take. To increase the redline on a stock engine, you will have to replace or modify the weakest parts. On a H22A that is generally considered to be the connecting rods and the valvetrain.

Rev-Limiter = A control mechanism which attempts to keep the engine from going beyond a pre-set RPM. It does by either cutting off fuel or spark at that point. It's often set just a little beyond the engine's accepted Redline; generally this is a fail-safe feature for idiot drivers and missed shifts. Note that this cannot prevent you from over-revving the engine from a bad downshift.

The Hondata, and most other aftermarket ECU systems will allow you to adjust the Rev-Limiter to any value you wish. If you have a stock H22A, the Redline is at 7400 RPM, and I wouldn't set the Rev-Limiter any higher than 8000RPM. No ECU will change your engines Redline.
:smoker2:

[SickLude]

thanks for your help. i do appreciate it. i do have one other question though. Fritz, you and Drift were discussing how the H22 can be desleaved to gain somewhere in the mists of 240 horses...to the crank, im assuming. is that really true? and if it is, how come it isnt that popular??

[buh_buh]

Originally posted by SickLude
thanks for your help. i do appreciate it. i do have one other question though. Fritz, you and Drift were discussing how the H22 can be desleaved to gain somewhere in the mists of 240 horses...to the crank, im assuming. is that really true? and if it is, how come it isnt that popular??

lots and lots of $. It would probably cost less to find another method of getting to 240hp

[fritz_269]

drift was mentioning that JG Engine Dynamics was working on a destroked version of the H22A. By using a shorter stroke, you lessen the high RPM loads on the crank, rods, rod bolts, wrist pin, and piston. It also increases the rod/stroke ratio which permits better airflow at those high RPMs. This combination, along with a lot of stronger parts and reworked head will allow you to run a much higher redline; I think that drift was talking about 9000 rpm. The good airflow will keep the torque up, and the hp will follow (remember that hp ~= torque * rpm ).

buh_buh is right though - doing this right will force you to replace nearly every moving component of the engine. A new, custom forged crank alone will probably ring upwards of $3k. My very uninformed guess is that this would be at least a $10-$12k engine.

Look into a turbo.

[SickLude]

fritz and buh buh, thank you very much. i do appreciate it. i didnt know exactly how that worked and i was wondering about it. damn dude. i had another question to ask you of you Fritz, but i forget now. ill think of it later.
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