Hondata s200 tuning woes

[SiRGodfather]

I have a 2000 civic Si(R) with Comptech I/H/E, CTR cams, ITR valve springs, AEM cam gears, and Hondata s200. I took my car to one of the authorized Hondata dealers in your list of dealers, and was somewhat disappointed with the results. My set-up is not a very complicated one, and Hondata was certainly not neccessary. After 4.5 hours of dyno tuning and 2-3 hours of road tuning, my car is plagued by a power dip right around the VTEC engagement point. By the recommendation of the guy tuning my car, the VTEC x-over is currenty set at 4800 RPM, with a redline of 8400 RPM. Below is the dyno plot of my car in it current condition. The intake cam has been advanced 3 degrees, and the exhaust cam retarded 2 degrees.



From what I understand, the VTEC x-over was set to engage at 5300 RPM and 5800 RPM, only to produce the same results, with a shift in the dip ever so slightly towards the right. Thoughts and or ideas?

[Spunkster]

Post the dyno plots with the vtec set at the higher points. This probably needs a high vtec point of 5800-6200 rpm on a smaller displacement engine to acheieve the same intake velocity speeds as a larger displacement engine.

[Carchitect]

Usually B16s make more power at the top end but seeing how your torque curve falls after 7200 RPMs you will need to elliminate what your restriction maybe. The stock cats on the 99-00 civics are very restrictive. I had a Vortech 00 SI on 10 PSI only put down 225
Deleting the stock cat and some fine tuning we got the car upto 275. A 50 HP increase at the wheels!!

I would recommend replacing the stock retainers with a set of Crower Titanium retainers made for the stock type-R valve springs. Now you can rev till 8700 safely. The B16 use a lot slower piston speed, largely from the better rod ratio and the short stroke. Make sure you dont have any exhaust bottle necking going on. Might also want to check the ignition timing.

Joe.