Mr 35th

Just recieve an e-mail from Jason at Thunder Racing with these flow numbers. Just making the comparison because I am building a 408 and swapping to the AFR 225 with a 72cc chamber. My Absolute Speed 5.7L Heads are for sale which made 430rwhp with TR224cam. The AFR's have a 2.08intake and a 1.60exhaust while the Absolutes have 2.02intake and 1.55exhaust. The Flow#s for the AFR were done on a 4.030 bore because thats what my iron block will be and the Absolutes were done on a 3.90 bore.

AFR Absolute
Int Ex Int EX
.100 67.7 56.7 68.7 56.9
.150 104.5 85.5 110.1 83.2
.200 145.6 121.7 145.8 112.5
.250 183.7 146.8 174.9 137.6
.300 214.3 173.8 200.9 154.6
.350 237.9 194.1 224.2 171.1
.400 258.4 206.6 246.2 182.6
.450 277.1 214.8 264.8 192.1
.500 294.9 221.2 281.2 198.5
.550 307.2 225.2 294.5 203.3
.600 315.9 228.9 286.4 206.6
.650 295.1 230.9 279.6 209.4
.700 294.4 233.0 282.5 211.2
average 230.5 179.9 219.9 163.05
I hope everyone likes this comparison. Like I said I did this because these are the sets that I own. Plus I wanted to know so I sleep sound at night knowing I spent my money well on a better set of heads. Let me know what you think about this comparison. Between .500 and .700 the AFR flowed and average of 16.66cfm more on the intake side and 22.04cfm on the exhaust side.

Mr 35th

sorry the numbers look bunched up I tried to spread them out, it looked ok in the edit but won't do it in the post.

verbs

Apples to Oranges comparison IMO, two completely different heads flowed on two different bores. The flow #s from the AFRs aren't that great. I'm assuming these are out of the box? I hope the velocity more than makes up for it.

BigTex

iTrader: (16)

Good info Neustrom, thanks for posting.

Bowtieman4life

iTrader: (1)

good comparison. What was the difference in runner size? I know AFR uses 225 and I heard that AS is know cutting them open to 245 to 250 cc like Lingenfelter. The smaller runner in the AFR should make more torque, while also creating better throttle response. I say money well spent. Lets see some numbers.

J-Rod

Whose bench were each test done on? A true test owuld be to have Jason at Thunder flow your Absolutes on the same bench with the same fixture. Otherwise the data doesn't really tell you much.

JZ'sTA

iTrader: (23)

I agree.
I am sure the AFR's will make more power then if you would have kept the LS1 heads. You heads wern't made for a big cubic inch motor which means smaller valve's.
As far as 245-250 cc runner's as stated in a earlier post that is crazy. I have never seen anything showing 245-250 cc runner volume from any Absolute speed especially a set of stage 2 LS1 heads.
240 is about top's and that is using the 6.0 or LS6 stage 3 heads and trying to make them work well on a huge motor.
That's just what I have read.

Thanks for the comparision, and I am sure you made the correct choice.

Mr 35th

I believe jason at thunder is gunna flow the AFR's on a 3.90 bore so we can get the true comparison. These numbers were just posted to give you guys some insight as to what each of these heads were doing. I would like to see the 3.90 flow#s as well even though my 408 will be a 4.030 bore

Brian2001SS

iTrader: (1)

If thats the case, my 5.3 AS heads flowed almost as good as the AFR heads at a fraction of the cost. I'll take it.

Lift intake exhaust
200 145 114
300 204 160
400 254 198
450 274 207
500 290 218
550 302 224
575 308 226

mikey

iTrader: (6)

I'm flowing a set of 72cc heads now on a 4.000" bore. I'll post up when complete.

Beast96Z

iTrader: (21)

If those are the numbers that are advertised, you might want to have them flowed locally. The heads in the original post are Absolutes and you see what they flowed.

Brian2001SS

iTrader: (1)

My heads are different from the heads posted above. Mine are 5.3, his later design, 2.04 intake valves, and stg.2 cnc/hand ported.

Bowtieman4life

iTrader: (1)

Then you really need to have them checked out. He was selling junk towards the end. Do a search and see how many people got screwed by Absolute. He even got booted of the board as a sponser because he was ripping people off. I would feel better if I owned his early heads before he started copying Lingenfelter. (per his statements.) AFR makes some if not the best SBC, BBC, SBF, BBF etc heads in the world.