oh right. i was never one to complain too much about the top end feeling. A lot of others did though, to the point where they thought VTEC wasn't working!!

I've always mentioned too, it's just the feeling of power loss, the dyno plots all show HP still rising.

for Giles, sounds like a great tuner!! I really want to know what he did to stop the crazy spiking. That would likely benefit all the rest of the greddy kit owners who have been experiencing this.

 

it feels like we are losing steam up top because we hit peak torque so early!

im not sure how he fixed it either

 

The small black valve you moved to the black bracket that greddy provided. It should now have a stock vac hose and a blue hose coming out of it. Swap the hoses. The valve only seats in one direction.

 

My AP1 on the base map feels the best from 8-9K ever since I freed up the exhaust. (Well besides the 4-5K torque bump)
I'm sure it has something to do with my boost creeping up there also.

 

Nope, no laggy feel. However, again, since the torque peaks earlier, it seems like the car is running out of steam. The reality is that it just comes earlier.

 

nice numbers, i will need to contact you when its time for my tune ap1 to get tuned, i have fam in MA, and i plan to make a trip from md, to ma on the 9th or 10th of this month,, can you give me your tuners info???

 

here you go:

http://www.holyrollerdyno.com/Index.html

 

The larger cam lobes have more overlap, duration, and lift. That's great for making power NA, but falls down with a restrictive exhaust. Log manifolds cause high pressure at the exhaust valves. Because the pressure in the exhaust manifold is higher than in the intake manifold, that contaminates the incoming charge of fresh air and prevents the extra overlap, duration, and lift from actually adding more fresh air/fuel mixture. Moving the VTEC point up in RPM increases the speed the exhaust and intake gasses are flowing and overcomes the additional exhaust pressure from the log manifold.

This also explains why superchargers like really low VTEC engagement. The low VTEC engagement helps cram even more fresh air/fuel mixture into the engine. The positive pressure on the intake side adds to the inertia of the gasses to overcome and expel spent gas into the exhaust system.

Efficient turbo setups also need a lower VTEC engagement. Tubular manifolds, such as the one from Full Race, result in lower pressure at the exhaust valves and are more effective at transporting spent gasses from the cylinder, which also makes the entire intake cycle more efficient. Some very efficient turbo setups can even approach the point where pressure at the intake valves is higher than pressure at the exhaust valves.

Make sense?

Tim

 

So basically the air stacks up, velocity goes down, and that slows the turbo?

 

This is why I want my VTEC moved higher when i get a tune..

Now I got to find out of the tuner can do the rewire or if I got to do it myself. (And figure out which wires to do what with) I hate wires though!