Just trying to mull this over, i installed woodruff keys (from sideways) a while back i went with -1 intake, and +2 exhaust with will change overlap.

I was told it would increase torque and power and in my mind i thought it would alter the curve and give increase torque and power. It seems initially the woodruff didnt do a great deal only added a small amount of power, it could maybe be because the chain has stretched with mileage.

I have a 63mm singlepipe exhaust with decat and a good tracysports manifold on my CTSC+AC supercharged setup, i expect them both to not really strangulate the power by much at my boost levels ~10 psi.

Rewind before fitting them, I cant say for sure but it seemed to drop peak torque (couple of lb's) but increase max power BHP at the top end by a small amount (7 ish BHP) and the power at the top end didn't seem to dip like it did prior to fitting the keys, it was just flat with the keys so the car didn't really drop power until probably the last 50rpm! if anything. I cant really comment on the curve but I'd expect it to change maybe shift higher up?

I've been thinking about removing them but its a bit of PITA and wondering if i should.

Question is depending on the curve shift what's best for a road/street car? and what have my settings likely done?

I don't do launches or 1/4 mile stuff.

thanks in advance

 

This is worthless without a before and after dyno comparison.

 

I don't have have the graphs but just told you the differences.

 

Increasing cam overlap as you have done, all else being equal, will shift the powerband up in RPM. Seems about right.

 

So it just depends on what you want. Seems for a street car that sees regular low/mid rpm roll on’s, would be more satisfying to shift the power curve down, add some more grunt to an otherwise top end power band set up and might even save a little gas if thats a benefit you wouldnt mind seeing. I'm not convinced you can’t have a bit of both however given the right boost amount and exhaust/tune set up. Sideways seems to have made nice gains throughout his entire rpm range if I’m not mistaken. I think it really needs to be analyzed further. Dyno graphs with related engine hardware and tuning for comparison would really be helpful. Just starting from simple things first, id like to see how the afr changes relative to cam key mods and stock and in what rpm, I think that should offer some insight into where improved breathing is being made. Technically where the curve leans out would be an indication of improvement areas.

But the idea with the keys I understand is to close the valve overlap to allow less boost escape, letting the engine see more pressure and thus netting more power. The cam profile doesn’t change as far as lift and duration so I’m not sure how the power band would shift up or down per say, but I’m not an expert in this field either. Just seems like if the right overlap is chosen, the net should be improved power throughout the entire rpm. The overlap on our engine from the factory is based around NA principals and there is a lot of it, so seeing some benefit to altering/closing the overlap with boost in mind seems likely. How much and on which cam is what I don’t know and I don’t think sideways does entirely either, its still being experimented on what the thresholds are one way or another.

 

I am going to install these sometime this year and re-tune my 10psi supercharger.

I'll post an overlay of the dyno charts to see the differences.

 

^I just watched that pit change 20 times, just insane, sorry this has nothing to do with the thread