GT-40 vs. AFR HEADS

[94GTcobra]

What is the difference of afr heads and gt-40 heads with the same port sizes? will it really make a difference.

 

[2slo95fiveoh]

they might have the same port size but what they flow in CFM is crazy different.
in a 5.0 mustang and super fords test on a 393 stroker, only switching from GT40 aluminum heads
to AFR 185s they picked up 75 hp. that was the only change between the two tests, and the difference in power
speaks for itself.

 

[quickstang_1994]

it depends on the set up and which heads (afr-165,185,205)(gt40-p,y,x,z)

 

[94Pro-5.0]

only switching from GT40 aluminum heads to AFR 185s they picked up 75 hp. that was the only change between the two tests

:

 

[jpajkos]

AFR hands down. IMO I believe AFR's flow alot better then the GT-40. I had both set ups with my old fox.

 

[scott5]

i LOVE my afr 185s

 

[95Grandtouring5.0]

Afrs ftw

 

[Hybrid Freak]

AFR's will outflow GT-40's all day everyday.

 

[94gtstang50]

AFR's ftw.

 

[Stangbangin]

AFR's WILL flow alot more.. but doesn't mean you can't be in the 12's with gt40's. GT40's is a great budget head.. AFR's are like top of the line..

 

[94GTcobra]

I know afr's are super better that gt-40's, lets say you have some gt-40p heads ported to the same flow as some afr's 165cc heads, what would be the difference.

 

[Lightning Struck]

how is the longevitiy of the AFR's ?

 

[OnyxCobra]

I know afr's are super better that gt-40's, lets say you have some gt-40p heads ported to the same flow as some afr's 165cc heads, what would be the difference.

After everything is all said and done the AFRs have awesome resale value. Thumper ports GT40 heads and apparently they flow awesome afterwards but I saw some ETs and wasn't overly impressed.

 

[Stangbangin]

I know afr's are super better that gt-40's, lets say you have some gt-40p heads ported to the same flow as some afr's 165cc heads, what would be the difference.

After everything is all said and done the AFRs have awesome resale value. Thumper ports GT40 heads and apparently they flow awesome afterwards but I saw some ETs and wasn't overly impressed.

well say you port the gt40's to flow the same as afr's. You'll still have the weight savings, and the heat dissipating capabilties of the aluminum heads. With the right intake and cam you can make 300 to the wheels with gt40s and run in the low 13's and high 12's.

 

[OnyxCobra]

Ported GT40s would still be a lot heavier than aluminum heads and will still hold heat. People have run 12s with stock GT40 heads, i just couldn't justify spending the $600 or w/e to have my GT40s ported just to put old heads back on my engine. The AFRs are factory CNC milled and are a lot lighter, plus they have proven their potential time and time again. The flow numbers on Thumper GT40s is quite impressive but like I said the ET numbers didn't impress me.

 

[Downshift]

I know afr's are super better that gt-40's, lets say you have some gt-40p heads ported to the same flow as some afr's 165cc heads, what would be the difference.

After everything is all said and done the AFRs have awesome resale value. Thumper ports GT40 heads and apparently they flow awesome afterwards but I saw some ETs and wasn't overly impressed.

well say you port the gt40's to flow the same as afr's. You'll still have the weight savings, and the heat dissipating capabilties of the aluminum heads. With the right intake and cam you can make 300 to the wheels with gt40s and run in the low 13's and high 12's.

x2

 

[quickstang_1994]

Dont forget it will always depend on the setup. But I would go with the best deal. But i run low to mid 7's(in the 1/8) on street tires (goodyear) with gt-40x heads.

 

[Hybrid Freak]

I know afr's are super better that gt-40's, lets say you have some gt-40p heads ported to the same flow as some afr's 165cc heads, what would be the difference.

If a budget is in mind then I say go for it. If not AFR FTW for the weight loss.

 

[2slo95fiveoh]

I know afr's are super better that gt-40's, lets say you have some gt-40p heads ported to the same flow as some afr's 165cc heads, what would be the difference.

GT40-p are the worse gt40 head. they have the straight exhaust port, and i've heard you can only run Mac?? headers
with them. they also supposedly flow less than the standard gt40 iron.
if you didn't have the $1300 for a pair of AFRs 165s, then i would look into GT40 aluminum (also called GT40X)
heads and port them.

 

[Schiffy]

Don't forget now, that if you're going to compare those 2, Patriot Performance offers a new "Freedom" series head that flows pretty well... I think i have the flow sheet somewhere, but i'm at work and can't post... They are uner $900 fully assembled.

they go like this.... Cyl 1 INT CFM @ .100 lift 83.7cfm/@ .200 lift 152.7cfm/@ .300 lift 209.5 cfm/@ .400 lift 237.9 cfm/@ .500 255.7 cfm/@ .550 lift 261.8 cfm/ and lastly @ .600 lift 268.4 cfm

Cyl 1 EXH CFM @ .100 70.7 cfm/@ .200 lift 120.6 cfm/@ .300 lift 160.6 cfm/@ .400 lift 185.5 cfm/@ .500 lift 198.0 cfm/@ .550 lift 201.3 cfm and lastly on the EXH side @ .600 lift 204.2 cfm

those came off the flow sheet i was sent by a patriot representative when i was asking about them... they dont' flow bad, and with a P&P they will flow even better... they are 185 based heads by the way.