Sorry if this is the wrong section.

I have been getting a lot of interest in Toda VTEC Killer camshafts lately. And surprisingly I have found that majority of the customers who ask about them don't know what they really do. So here is a small tidbit on what their VTEC Killer actually is.

"The mid rocker cam is removed & both pins are changed, reducing the valve train mass for better response. Disabling the VTEC system removes fluctuations in the oil pressure system, securing a reliable oil feed to all the main moving components. Lost motion valve should be removed. For max performance, should be used in conjunction with TODA Sports Injection kit. "

Now most people would read that to mean the car isn't in vtec ever, and will be like an LS, and thus make more low end power. Hard as that is to believe, it've been dealing with it for a while. This is incorrect.

Notice where it says "both pins are changed"? Now if you know anything about how the VTEC system operates that should be a tipoff. Vtec isn't "killed" as the name would lead you to believe. VTEC is LOCKED in place, thus elminating the need to have variations in timing and oil pressure. Notice how they say the LMA is removed, but he center rocker isn't removed or replaced with a slug. By locking VTEC in place iwth the pins, what you are doing is locking the rocker arms together. The primary and secondary lobes on the "Vtec Killer" cams are the same size, and they push on teh outer two of three rockers. Since they are locked, they are all moving together.

Shorthand, you lock vtec in place, throw a VTEC Killer camshaft setup in and you are in VTEC all the time, so to speak. YOu are using the high cam characteristics of what would otherwise be a std 3 lobe vtec camshaft. You're increasing top end this way, then by adding the ITB (sports injection) you can tune the entire powerband to take advantage of the new power addition and it's placement in your range.

In a road racing situation, on a vtec powered car, you want to be in the top, where everything is being used to it's full potential. Short gearing to middle short gearing, and LSD, sprung clutch, great suspension, plus this combination would be very advantageous.

These camshafts were developed for road racing in Japan where dual camshaft profiles were illegal. if you had to pick between two profiles, why woudl you pick the smaller, shorter duration one for an endurance race? Toda said screw that and made these. Others went ahead and just switched the pins and ran a std vtec camshaft.

If you are brave enough and want to see what it's like . . . pull your rockers out and lock the pins, retune, and go drive. you're getting a similar effect. put iton the dyno and you'll see the difference in how the graphs look. I don't recommend you do this for an extended period of time lol. But if the mood strikes you and you wanna see what happens lol more power to you.

So yea, don't be mislead by the title that Toda gave their camshafts.

M.

ps - i accept paypal and reputation bumps. LOL.

Good stuff.

i read about these a couple years back. they sound kinda cool. but why hasnt anyone come out with a camshaft set with the same profile for the LS. If you lock in vtec, you basiclly running a standard single stage cam like any other non-vtec engine has right? so why not put that profile on an LS cam set and save the trouble of disabling vtec engagement on a vtec engine. maybe im just not picking up on what toda is laying down

(07-30-2009 11:30 PM)honduhboy Wrote:  i read about these a couple years back. they sound kinda cool. but why hasnt anyone come out with a camshaft set with the same profile for the LS. If you lock in vtec, you basiclly running a standard single stage cam like any other non-vtec engine has right? so why not put that profile on an LS cam set and save the trouble of disabling vtec engagement on a vtec engine. maybe im just not picking up on what toda is laying down

NO it's not like an LS. The toda set is designed to run at 9k+. I haven't seen any all motor LSs that rev that high. Even sleeved, I've never seen one. If they exist there are cams that can handle it.

Comparing a vtec to a non vtec in this situation is apples to oranges.

M..

gotcha, the magic is the high revs. i love the sound of a honda revin out to say......11k. so sexy. turbo could never sound that sweet.

what and where are the approx. gains? losses?

(07-31-2009 06:43 PM)S-LudeDan Wrote:  what and where are the approx. gains? losses?

Well it's all relative to the other modifications to the engine, the tuning package, etc. when you're in high cam on a vtec car for example, your power is doing most the work, not your torque (i know hp comes from torque, just follow me here for a min). but low cam, your hp and torque work together, the torque itself does more work to get the car in motion. once in motion the hp takes over. if you look at a std vtec graph you can see what i mean. now imagine if you're in high cam all the time.

follow me?

ps - im tired and cranky this may not amke sense.