Thanks for posting that up Ep. I had been looking for his plot for awhile now. I think he just ran out of turbo on this setup. I believe that this head flows so well it needs to have a higher flowing turbo on it. I had contemplated running a 35R on it, and I may still because I haven't purchased the GTX3076r yet. Of course it would be the GTX series.

 

I found this neato picture online comparing the 3076, 3582, and their gtx versions.


You're running around 2.5 pressure ratio (18-20ish psi after losses). The GTX3076 has about 5lbs more in it than the GT3076. There's 50hp more. The regular GT3582 is 5lbs more than that, and the GTX3582 is 5lbs more than that.

That all sounds great, but you'd never make it out to the 65lb area of the map if you're staying on pump gas (18-20psi max) and revving to 8500rpm. Take a look at that dyno plot. In the mid-band where there are no flow restrictions from the turbo and the VE is at it's peak, it's making 350-360tq. If the head can maintain that VE farther into the rev range, that is, if the tq fall-off is due to the turbo losses/restrictions alone, you'd theoretically have 350ish tq all the way out. Well, 350tq at 8500rpms is (350*8500/5252) is 566hp. The GTX3076 will flow that much at 2.5PR. This math isn't the traditional way to calculate, but if you did the flow math and corrected it based on the dyno plot and assumptions you'd wind up with similar numbers.

 

I had planned to run race gas occasionally, but after posting that up id never fully use the 35R to it's designed parameters. I'll stick with the 3076R. Even with the 3076R I'll make, or should make close to 600 on race gas which is what I am aiming for. Thanks again for those plots Ep.

 

E85 will be your friend

 

Yes, it would be however, i dont have any E85 pumps around here and I'm not driving to TPA to fill my tank.

 

is no e85 pumps in tampa , the closest on is in lakeland. I bought two 55 gallons drums to have it fill and storage at the shop

 

Yeah, well I'm not willing nor do I have the space to store 55gal drums... So pump gas is my friend

 

I'd agree with you, on the surface, but the point I was talking about, wasnt in reference to the actual lift/duration differences, as much as the P11 cams with the differences in timing on the high side vs the low side, compared to the P12, with either one you can change lsa with cam gears, the issue is that the low and high profiles have a different angle each, so if you get the low profiles in a good spot, the high side wasnt that great, and vice versa, with the P12 cams things were able to come out a lot closer to where the factory, and aftermarket cams put things.

 

You what you're saying Z28 is that it'll have to find a middle ground on the stock cams with gears? Meaning, If I optimize the high lobes, I'll have the low lobes out of whack?

 

Let's be clear from the start that we're talking about optimizing NA cams for an FI setup. I'd love to see it all play out, but I think the DE->VE advantage will be 10 times that of the P11/P12/LSA tweaks you add on top.