Nice music..

Maybe I need to have you fix my exhaust ports because I only made 1115 hp with their "bad design", Smitty

" I think Tyler did some back to back dyno testing on the stock Darts vs. CNC AFR's."

Tyler was pretty impressed with the power my motor made on HIS dyno with My AFR 315's, when and how did he compare afr's to darts? Smitty

Smitty, The flow numbers are real, you can belive them or not. And yes I would be happy fix your AFR exhaust ports too. (:

I believe he compaired them on a hp 500 efi na. Afr cnc'd to a stock set of 325's. The results were the afr heads made stightly more but not worth the cost. How much power, I don't remember the number. Maybe Tyler can answer

Which AFR head was it? Please be specific when making claims about product performance. It always bugs me when someone who is supposed to know what they're talking about makes very general claims without any factual data especially when trying to promote their business. Why would the AFR head that made more power not be worth it? I have always found AFR's prices to be cheaper then Dart. And why would you use a 325 head on a stock 500EFI if you were trying to optomize the combo? What year was that video taken? What head was that? Is it the current production design? If you can get that much flow out of an exhaust port I'm surprised you have enough time to post on this forum.. I have several set of AFR's in stock, why don't you send me one of your magic heads and I'll put it on an SF-1020 probench against an AFR and let everyone know how it turns out. I'll even pay the shipping. I am in no way disparaging Dart's products as they are all very high quality, just trying to get the facts.

Good post.....I would like some clarification as well.

I have tested just about every manufacturer's BBC cylinder heads on my flow bench and its my opinion the AFR exhaust ports are more efficient than most, and look especially good in the low and mid-lifts which is perfect for cams most performance boats would consider (with any type of longevity in mind).

And using a pipe for exhaust flow testing isn't "cheating"....it actually lets you see the true curve of the airflow exiting the port. No different than flowing an intake port with a radius plate helps the air enter the intake properly (a task usually handled by the intake manifold), a pipe helps replicate real word results helping the exhaust gas to exit the port properly. It doesn't make the port better or worse....just allows the gas to stay in a column just like it does in just about every engine assuming a header or tubular manifold is bolted to it.

I have tested alot of heads with and without flow tubes....some pick up a little and some pick up a lot. At the end of the day I could care less what an exhaust port flows without a pipe....what useful purpose does that serve?

Use the same applicable sized flow tube for all your engine family testing, then cc the port to see how large it is for a quick estimate of CSA comparison, and evaluate all the flow curves. Now you have something real world to chew on and compare notes....with most BBC applications (conventional 24-26' stuff) I use a 2.125 pipe which fits most aftermarket (AFR, Brodix, DART, etc.) as well as OEM head options.

Teague Marine seems like a very fussy shop.....I noticed he uses AFR heads on ALL his high powered (high dollar) boosted builds. I would imagine if there was a better or more cost effective option he would likely use something else, not to mention the countless other shops and individuals I have seen good results from from time to time with AFR product.

Jim V.....start flowing all your exhaust ports with the same flow tube (you will only need to make about 3-4 different sizes depending on what your testing) and I think you will see things you never saw before concerning the shape of the airflow curve and how different brands now compare when not emptying the port into the atmosphere (which doesn't give the short exhaust port an opportunity to work properly like it would in the real word). Ever notice how most exhaust ports just kind of die past .500 - .600 lift......test the same port with a representatively sized flow tube and watch not only the numbers change but the shape of the curve change dramatically as well (now the port keeps climbing past the liftpoint it started stalling without the pipe)....and once again some heads respond better than others but assuming the same tube and the same bench is used now you have more meaningful information to chew on.

JMHO

-Tony

The videos are real, that should speak for itself. I believe those are the facts.

i get same results with harley heads...they flow much more at high lifts with a pipe attached,with a lot less turbulence

So in summary... As a reputable business man you feel comfortable stating as a fact: All cnc'd AFR heads need their exhaust ports fixed. This conclusion was drawn from testing a head that you believe was a 325, even though the 325 is an "as cast" head, and you think it is probably the current design, and you think all AFR heads share the same exhaust port.. You also like to use the term "cheater pipe". Could you explain the benefit of designing an exhaust port that achieves optimum flow without a pipe attached? Would those magic ports be used on an engine without an exhaust manifold or header? Have you ever seen an engine run without an exhaust manifold or header attached? Who cares what a raw port flows, might as well see what it flows without valves in it too.. I do not think any of these general statements you have made are facts based on the amount of times you stated "I think", or "I believe". My kid "thinks" the tooth fairy left $2 under his pillow this weekend.. If you're going to make claims please have the facts to back them up, or state that it is "your opinion". That is my opinion..