ok here is the question how much HP can be gained by going from a great CNC Stock LT1 head with 2.02, 1.60 valves. Let say it flows.....

.200---125/109
.300---179/148
.400---232/173
.500---265/189
.550---274/192
.600---283/196
.650---285/201

to a AFR heads 212cc, 2.10, 1.625 valves
flows:

.200---128 110
.300---191 152
.400---240 180
.500---282 201
.600---304 215
.700---307 223

ill be using the CC305 cam
220/230 .544/544



HELP ME! LOL

 

I have a set of AFR210 race ready out of the box on my set up.......more air = more power.....

 

going with the CNC lt1 heads instead of the AFR's, would be a little like losing .100" off of your cam, if you think about it. The lt1's are flowing a little less at .600" then the AFR's are at .500". do the AFR's hey i have some for sale

 

With only .544 lift, there's not much difference between those 2 sets of heads.

 

i think that would make sense n/a but not with boost...obviously car will make moer power with the nicer heads, the question is if its a big difference.

 

That's a pretty small difference in head flow. I would bet that they break even in power due to the fact that the AFR's have crappy shaped chambers and would make less power at the retarded timing required for FI use. The ported LT1's would flow slightly less, but make more power with retarded timing.

Think of it this way: you are stuck with, say, 25 deg of timing with either set of heads. The LT1's make best power at 34 deg while the AFR's need 38 to make best power. So, the AFR's are running 13 deg less timing than they want, while the LT1's are only running 9 deg less than optimum.

Mike

 

With that cam, I dont think you would see that big of a difference.

Besides, the extra money it would set you back for the heads, you could spend somewhere else and make a more significant gain ... Switching to a front mount intercooler, or something laong those lines ...

I say stick with the heads you have and mod somewhere else.

 

Bringing up an old thread, but can anybody confirm this?

 

i dont think the whole head plus boost thing is really needed. Sure it is proven that if you swap a head onto a car and change nothing, it will make more power, but I have had nothing but success with stock heads. Im going to try and get stock unported heads into the low nines just to show everyone that boost is king. if you want heads to flow more, turn the boost up 1 psi

 

Boost does change everything, that's correct. But obviously better heads = more power. But with LT1s this brings up a bit of a problem. LT1 intakes are very restrictive intakes. I think a fully ported LT1 intake will only flow like 265cfm or something crappy like that. So I don't think the AFRs will make that much of a difference unless boosted. OR! You get a sheet metal intake.

I think you'll see better midrange. A better bottom end... but nothing crazy up top.

 

Justin, I'd go with a set of LE fully ported TFS heads before LE3 stock castings. Better deck thickness, more options for combustion chamber sizes, and will flow more.

Definitely more airflow = more power. Another way to look at is more airflow equals the same power at less "boost".

 

i would love some ROADHEAD while boosting in my car...

 

your 227 afrs flow 274cfm at 500? wow
the flow number would make a difference for sure how big? probably not huge 30-50rwhp could be gained even more if you use a proper camshaft.

 

your thinking is wrong, boost is king but there comes a point where your YSI absoluty cannot get the boost past restrictive stock lt1 castings. If youre pushing in boost like me you will see that past about 17-19psi you will not make anymore power, you will make more boost and all its going to be able to do is widen your power curve.

 

The harder the compressor has to work the less efficient it is. Hotter charge = less power.