imstimpy

My VTEC engagement is at 3650 currently, dyno-verified to be the ideal point of engagement with my current tune. I have a Berk 70mm HFC, 70EM single, FPIK, and my own tune.

On a stock car you can pull VTEC down to ~5500. Once you free yourself of the stock cat, you open up a large RPM window for VTEC. A test pipe would net you the most gains, however it isn't fit for a public road.

odb812

I'll ask again, do you have any experience actually tuning an s2000 with a flashpro and HFC? Can you please explain to me exactly how "the cat alters the vtec response?"

Car Analogy

Search for posts by Gernby. He did extensive research on Cats and vtec engagement point. He found that stock Cat has some sort of resonance issue where lowering vtec below around 5.5k lost lots of power. But with a test pipe you could lower it to 3.something k with no issue. He also found a right-sized HFC (bigger not better, must size it to rest of your system), you could get almost as good a gain.

He found it wasn't Cat restriction, it was Cat resonance. So then he built his own cone shaped Cat thing to capitalize on this resonance, and was able to get signifigant gains above a test pipe. He now offers his Cat as part of a full system. Its arguably considered THE best exhaust you can run for S2k power.

06s2kid

Hey if i have a hfc and flashpro, and i lower my vtec to 4k, do i have to mess with my AFR too? Or do i leave it alone and just lower vtec without a problem?

Grilla

You need a tune.

Chuck S

While you can set your VTEC to just about any rpm you want with FlashPro there's a lot more involved than my tuning skills can accomplish.

I got a Gernby FlashPro road tune. Took 3 weekends (2 hours per weekend) and probably 30 "pulls" to accomplish and mid range power is now astounding compared to the stock tune and revs climb so fast I installed a red line alarm to keep from hitting 8400 rpm fuel cutoff on the interstate on-ramps all the time. Highly recommended. My VTEC engages at 3600 rpm under WOT. I can cruise at 85 mph on the low cam and VTEC is right under my right foot without dropping down two gears.

-- Chuck

Kakarot103

That sounds amazing!

Chuck S

It is. Caused a buddy to buy a supercharger!

-- Chuck

s2000Junky

Yeah, it will run too lean if you dont. You will need to add fuel to run safe, and a little timing as well if you want the full power benefit.

Mugen_is_best

What I gather from the op question is that running the Mugen I/H/E calibration works best for only having an intake and hfc.