Masterl1nk

Hello buddies,

I'm helping out a friend whom is doing a K24 swap into a Civic EG. Due the lack of the stock ecu, and the highly prices for a kpro/related ecu here in our country, we will use a standalone ecu which does not control VVT/VTC, so we are looking for opinions on locking the VTC mechanism to a fixed angle. As per I've read, a 25-35-40 degree angle will do the biz on this engine.

Took a look at this Hondata write up: https://www.hondata.com/tuning_k24a2_tsx_engine.html that seems super interesting to me. They just fixed the vtc up to 45 degree all way long?

Note 1: We do not have any problems nor restrictions on emissions control.
Note 2: We do not care if there is a lack of power/torque on low RPM.

Which angle will do more power and/or torque? It's a stock k24a1 engine,with a race exhaust header and a 68-70mm TB.


Thanks in advance!!

JRCivic1

If you are not worried about maximum midrange torque, there is no reason to advance the camshaft that far... because it will not make maximum power up top with 45' if the engine is N/A. VTC tables at WOT are typically bell shaped... slightly above 0' initially, advancing toward maximum advance (45-50') throughout the midrange, and then retarding back toward/approaching 0' above 6000 RPM. Don't think of it like a single static setting because that is NOT what VTC is about. The ability to advance/retard the camshaft is what creates a condition in which maximum torque/HP can be created at ANY given point in the RPM range.

Masterl1nk

Hi! Thanks for the reply

Yes, I'm aware of that and I know it's not a static setting but due the limitations on the ECU we'll use, we have no choice at all.

Thanks again!

Chance EG

May want to ask on K20a.org to see if anyone there has ideas. I know manufactures like Hytech and TracTuff offer mechanical limits to "pin" the VTC gear beyond a certain angle, but I don't know about having both an upper AND lower limit to keep it completely locked. I know you can also electronically set VTC limits, but according to your post that's the entire problem you're facing by being limited by ECU.

What standalone system are you using? May want to consider just eliminating the VTC gear entirely and taking out that feature from the engine, but not sure and won't currently look into what that would take for your engine.

Masterl1nk

Thank you sir! I will.

We're using a Megasquirt 2. PWM control isn't a problem on this ecu, but closed loop PWM is.

JRCivic1

Why not simply use a mechanical adjustable cam gear in place of the VTC gear ???

Skunk2 cam gear set part number: 304-05-0300

Masterl1nk

Hi!
Yes that was my idea, sorry about that, I was unclear at my first post. For locking the vtc angle I mean, a fixed angle (not 0 or fully advanced, but some angle which does the best hp/torque curve).

Thanks again!