What is a good or optimal Vtec crossover point for an LS/Vtec setup with B16a trans? I currently have it set at 5k and I think it should be higher. Does anybody agree with me or does anybody have any suggestions?

 

I was wondering the same thing, but for a CRVTEC with a B16 tranny and some 11:1 compression pistons. I don't think you can acuratelly tell someone a certain crossover point. All motor are built differently, especially frankentein motors. All I could say would be take it too a dyno, and TUNE TUNE TUNE!

 

Yup, depends on your setup and the tuning.

 

what cams , thats what really changes where your optimal x-over is gonna be

do this - on the V-tec controller do a pull with the x-over set as low as it goes , what is that like 3k
- next do a pull with the highest point avail.
- overlap the graphs and you will be close to the optimal point where they intersect , then fine tune on the dyno from there

 

how can you set the vtec controller to do pulls so you can overlap the graphs? I thought only dynos could graph this?

 

IMO: i would say stick w/ 5k if your rev-limit at about 8k. on the other hand, if you can rev up to ~9k redline at 6k would be optimal.

 

he meant pull on the dyno with ur controller set at lowest and highest points...then overlap

 

It's all about the tuning. Although the crossover might feel "strong" at 5,000 rpm, you could be giving up power that you didn't know about. Using a dyno to adjust fuel, cam timing, crossover, etc can have a HUGE impact on performance.

 

exactly what I was trying to say. Is this possible?

 

It's very possible. After tons of experimenting, the dyno showed that my ideal x-over was @ 5500 rpm.

It's different for every engine, though. No substitute for hard dyno #'s.

 

5500
stock crossover

 

What kind of cams are your running???

 

i have stock cams. I thank all you peeps for the feedback but what I was trying to say was, would the VAFC controller show the graphs and allow me to overlap? I'm trying to get some raw tuning w/o a dyno.