I was thinking today about the SuperRam/AFR setup with a large cubic inch Small Block Chevy - flow qualities in particular.

In an earlier thread a few guys were discussing the fact that the SuperRam should flow a slightly greater cfm ratio of air in relation to the heads for things to operate at their most efficient levels.

The point was made that the AFR 190 or 195 heads were probably best matched with the SuperRam because of the flow numbers available from that intake (260-300 cfm).

My perceptions probably need honing, but I'm thinking that a large cubic inch small block such as a 427 would be best suited by a pair of the larger AFR heads such as 215's or 225's. How does this factor reflect against the available flow from the SuperRam intake? Is this simply the wrong intake for this application, or are there other factors that I'm not taking into consideration? TIA!

 

I too would like to know!
I have a 350 block being bored .060 over + stroker recip assy =ing 396 CID
AFR 210's sitting here
and a superram also sitting here. Unported.
I have a 242/248 .050 110lsa cam sitting here too.
Too much lift/head/cid for the unported SR?
Not sure if I should assemble all these together.

 

Here are flow numbers that I have copied from previous posts on the CF.

Here goes (peak numbers without head attached; 28" Hg):

TPI, stock base, stock runners, 48MM - 185 cfm
TPI, Accel base, large tubes, lots of porting, 52MM - 212 cfm
TPI, Accel base (cheater), large tubes, lots of porting, 52MM - 226 cfm

SR with unported Edelbrock base, 52MM - 224 cfm
SR with unported Accel base, 52MM - 233 cfm
SR with heavily massaged E base, mild port runners, 58MM - 256 cfm
SR with heavily massaged A base, mild port runners, 58MM - 259 cfm
SR with heavily massaged A base, massive work throughout - 278 cfm

stock MRII with 1204 (AFR 195) ports, 58MM - 265 cfm
stock MRII with 1206 (AFR 220) ports, 58MM - 281 cfm
MRII clean-up, 1206 ports, 58MM - 292 cfm
MRII cut, weld, port, ect, 58MM - 321 cfm
MRII (same as above with mono blade) - 322 cfm

My heads flowed 308 cfm @ 0.550" lift, so I felt I had gone far enough with the intake. Yes, you are correct that a good ROT for NA applications is 15% more flow from the intake than the heads. Very few FI intakes flow to that level, but the better ones work well with the factory type D-ports.

Lessons:
- Cheater intakes (connected cylinders) work well on very mild combos. Higher flows yield lean cylinders in real world apps.
- Flows above 230 seem to benefit from a 58MM TB.
- The monoblade (MB) seemed to show no appreciable difference at the 320 cfm level. I would suspect that it would show gains at higher levels.

My new heads (18°, 2.18" intake, 1.68" exhaust) flow in the 380 cfm range. Imagine the intake flow required to support them. (Sheetmetal w/ MB)

Good Luck,
Aaron