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.[CODE]

Bo White

iTrader: (59)

Good comparison dude. Very realistic #s.

verbs

I don't think it's a good comparison at all. Apples to Oranges. Completely different heads flowed on different bores.

Mr 35th

Like I said in my post.. just a comparison for me. I just wanted to pass the information on to you guys. At least you get to see what the AFR's are doing on other flow benches. The numbers are a little off from AFR's website, but I am not dissapointed. Its good information if you ask me. Anyway its my comparison because if I didn't buy those AFR's then I would have the absolutes on my 408.

Beast96Z

iTrader: (21)

I'm glad you posted it. It really lets me see how my AFR/TEA heads shine against the 225's. Mine flowed almost exactlly the same on a 3.905 bore fixture. Thanks for the info, you should have a stout set-up.

Jason99T/A

iTrader: (21)

Shawn, I'm glad to see the email went through. I'm looking forward to getting your motor built!

I can post of the AFR 225 flow numbers on a 3.900" bore tomorrow when I find some free time for those interested.


Jason

Mr 35th

I am sure there are a few people that would be interested in those numbers as well.

DAPSUPRSLO

iTrader: (14)

Wow, do all heads seem to stall out after .600" lift?? Good comparison by the way. I too am looking at heads for a 408.

JS

iTrader: (4)

U need to flow them on the same bore size..
This proves nothing...

BrentB@TEA

I agree with Verbs. I would have comparred them on the same bore. To see what head would have worked best with your combination.
Either way though I am sure your 408 will be killer.

jrp

iTrader: (16)

i dont think this was meant to be a direct comparison. he had them flowed on a 4.030 bore because thats what his engine is, no reason to do the 3.905 unless for informational purpose.

im interested though if you can do the smaller bore jason.

Tony Mamo @ AFR

iTrader: (13)

Actually, it is good information and the numbers are right on in my opinion. We advertise flow numbers on the larger 225 head on a 4.125 bore, hence the intake flow being slightly softer than our "advertised" numbers. As far as the exhaust, its obvious that you didn't flow the exhaust with a flow tube. A 1.875 pipe will add 25 CFM+ to the numbers you recorded (with the AFR exhaust port) putting the exhaust #'s exactly where we advertise as well.

I'm going to start a thread touching on why flowing exhaust ports with a pipe (that is curved downward to simulate a header) is so important, and how an incredible amount of information is LOST without doing so. Does ANYONE run an exhaust port blasting into the open air without a header?....then why would you develop a port that way and check it that way as well. This is a little "off topic" and If I find time today I will address it in a seperate thread. By the way, this information isn't being "aimed" at the creator of this thread....It seems pretty common place and thats why I am addressing it.

Also, I would have preferred the same bore size in a "comparison" as well, seeing that is how it was presented in the first place, but trust me when I tell you that shrinking the bore another .050 per side is not going to eat up the significant advantage you currently have. Depending on the lift point, you might see an additional 1-5 CFM drop. At .600 lift, our equipment shows about 312-314 CFM on a 3.900 bore.

Enjoy the AFR's.....I'm sure they are going to work out well.

Thanks,
Tony M.

ONEBADWS6

iTrader: (22)

Your reasons stated for flowing with a pipe on the ex side is the same reason I've been trying to get across about flowing a head with the intake attached. What is the point of having a hogged out race head with crapy low and mid lift #'s just to hit 320cfm if you cant get more than 285cfm through a ported 90mm LSX?

Tony Mamo @ AFR

iTrader: (13)

Agreed....Its the same reason I spent so much time developing the 225's "under the curve" numbers (knowing some of the gains found there cost me some peak number advertised "bragging rights")....Id rather brag about how much power I make or how fast the car goes....and 320 "Legit" CFM at .600 is still very respectable at that port volume and cross section.

DanZ28

iTrader: (5)

I think the ABS heads held up pretty well considering the different bore tested and the different valve sizes. At any rate, AFR have some killer heads and you should have a stout 408...

Dan

YsoFast

I take it that those AS heads were stage2 because my stage2.5 flow numbers were better than that.

ONEBADWS6

iTrader: (22)

offaxis

iTrader: (19)

Those AS heads are 5.7 s2 heads. His car made excellent power with a 224 cam those heads and a 12bolt. 432/400

There is no doubt the new motor with the afr`s will be a killer. I cant wait to see the results.

GTOtoGO

iTrader: (1)

I just had my AS 241 stage 2 heads flowed. Below are the results.

Intake Exhaust
150 79 78
200 156 121.6
300 224 156
400 274 174.7
500 292 184
600 292 190

This was on a 190 bore.
This was without pipe on exhaust (add 10-15 CFM)
The machine shop was very impressed and had lots of questions on who did the work. Awesome job Jay!

Kelly

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