afr or prc heads ?????
Flow Numbers Heres my 853 casting ported heads flow numbers
.100-69 cfm intake 54 cfm exhaust
.200-125-109
.300-187-144
.400-243-162
.500-277-178
.600-299-189
.650-306-194
Just for comparison
.100-69 cfm intake 54 cfm exhaust
.200-125-109
.300-187-144
.400-243-162
.500-277-178
.600-299-189
.650-306-194
Just for comparison
TECH Senior Member
Joined: Mar 2004
Posts: 14,620
Likes: 17
From: BFE
Guys, no offense, but when will you get through your heads that comparing flow#'s from different flowbenches doesn't give you any comparison picture?
I challenge any of you to take the same heads to 3 different benches and get exactly the same output.
I went from 11.62 to a 11.14 swapping to PRC's 5.3L/2.5 (Both were tuned for nitrous), and they still gave me very decent gains. an average ~ .45 Et decrease is very respectable in my book for the $1400 I spent on those heads.
I challenge any of you to take the same heads to 3 different benches and get exactly the same output.
I went from 11.62 to a 11.14 swapping to PRC's 5.3L/2.5 (Both were tuned for nitrous), and they still gave me very decent gains. an average ~ .45 Et decrease is very respectable in my book for the $1400 I spent on those heads.
Here's a flow sheet from a PRC Stage 2.5 done independently on Thunder Racing's SF1200. Jason @ Thunder said the typical set of AFR 205s flows about 288-291 on this bench...
We've now got a even better flowing setup that flows alot better on the .400 & lower numbers, but it atleast gives you guys some independent info.
SF1020 bench, 3.900" bore, Radiused entry on intake side, exhaust port flowed open
Intake Exhaust
.050 36.1 30.0
.100 70.0 57.2
.150 103.9 83.6
.200 139.1 110.4
.250 168.3 130.0
.300 198.0 150.1
.350 222.9 165.3
.400 244.4 177.3
.450 262.1 194.1
.500 276.7 202.2
.550 288.4 208.5
.600 298.8 213.3
.650 304.7 216.9
.700 278.4 220.1
We've now got a even better flowing setup that flows alot better on the .400 & lower numbers, but it atleast gives you guys some independent info.
SF1020 bench, 3.900" bore, Radiused entry on intake side, exhaust port flowed open
Intake Exhaust
.050 36.1 30.0
.100 70.0 57.2
.150 103.9 83.6
.200 139.1 110.4
.250 168.3 130.0
.300 198.0 150.1
.350 222.9 165.3
.400 244.4 177.3
.450 262.1 194.1
.500 276.7 202.2
.550 288.4 208.5
.600 298.8 213.3
.650 304.7 216.9
.700 278.4 220.1
__________________
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
Great results Predator Z!! 
__________________
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
Everyone keeps talking about what is coming down the road. Well, anyone who has been in the LS1 game for at least a few years knows that no matter when you decide to buy, six months or year later someone will offer a better head or same quality head that is less expensive than what you just bought . The battle over heads looks a lot like Computer Chips...every 18 months another set comes out that kicks *** and other competitors are forced to either keep improving theirs or cut their price in order to compete.
If you want heads in 2005, buy what is proven to work today and don't worry about what might exist in 2006. If you wait untill 2006, I guarantee you that something better or cheaper will be looming on the horizon for 2007 and you'll be facing the same dilemma as to buy or wait. The only difference is that you will have gone another 6 months or more without enjoying 30 - 40 rwhp.
If you want heads in 2005, buy what is proven to work today and don't worry about what might exist in 2006. If you wait untill 2006, I guarantee you that something better or cheaper will be looming on the horizon for 2007 and you'll be facing the same dilemma as to buy or wait. The only difference is that you will have gone another 6 months or more without enjoying 30 - 40 rwhp.
My PRC's shipped yesterday!
Ragtop 99 makes a very good point. I remember when your header choices were Mac's or the original Grotts. Buy a set of quality heads. You can't go wrong with either the PRC's or the AFR's. Talk with each vendor about your goals and buy from the vendor that you feel comfortable, fits your goals and wallet.
Good luck.
The pissing contest regarding "how vendor X heads flow" stops on the street or track. I don't care what they guy next to me head's flow. I just want to win.
Ragtop 99 makes a very good point. I remember when your header choices were Mac's or the original Grotts. Buy a set of quality heads. You can't go wrong with either the PRC's or the AFR's. Talk with each vendor about your goals and buy from the vendor that you feel comfortable, fits your goals and wallet.
Good luck.
The pissing contest regarding "how vendor X heads flow" stops on the street or track. I don't care what they guy next to me head's flow. I just want to win.
Originally Posted by equandt
I remember when your header choices were Mac's or the original Grotts.
LS1 Tech Stories
The Best V8 Stories One Small Block at Time
Topdon ONE vs. Artidiag 800 BT2: Which is the Diagnostic Tablet For You?
Pouria Savadkouei
Gas Monkey Built a 6-Wheel Ferrari Testarossa With a Corvette LT4 Engine
Verdad Gallardo
7 Most Reliable High-Performance Engines GM Has Ever Built
Verdad Gallardo
Amazing '71 Camaro Restomod Is Modern Muscle Car Under the Skin
Verdad Gallardo
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Pouria Savadkouei
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Verdad Gallardo
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Pouria Savadkouei
Top 10 Most Powerful Chevy Trucks Ever Made!
Hennessey's New Supercharged Silverado ZR2 Has 700 HP
Verdad Gallardo We just finished up flowing our newest version of the Stage 1.5 5.3l cylinder head.
The Precison Race Components 5.3l Stage 1.5 cylinder head features a 2.02 intake valve & stock exhaust valve. The valve setup on these cylinder heads allows customers with large camshafts (like the MS3) the ability to get a great flowing cylinder head without needing to cut valve reliefs!
Here's a flow sheet from the set of 1.5 cylinder heads going to a customer with a MS3 camshaft The 1.5 5.3l cylinder heads will retail for $1350!!! Like the 2.5 cylinder heads the 1.5 heads will feature complete hand finishing & detailed tweaking until the head meets Freddie's strict standards. The cool thing about the 5.3l casting is customers can also get a bigger exhaust valve & still clear large camshafts!
The Precison Race Components 5.3l Stage 1.5 cylinder head features a 2.02 intake valve & stock exhaust valve. The valve setup on these cylinder heads allows customers with large camshafts (like the MS3) the ability to get a great flowing cylinder head without needing to cut valve reliefs!
Here's a flow sheet from the set of 1.5 cylinder heads going to a customer with a MS3 camshaft
The 1.5 5.3l cylinder heads will retail for $1350!!! Like the 2.5 cylinder heads the 1.5 heads will feature complete hand finishing & detailed tweaking until the head meets Freddie's strict standards. The cool thing about the 5.3l casting is customers can also get a bigger exhaust valve & still clear large camshafts!
__________________
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
Jason
Co-Owner, Texas Speed & Performance, Ltd.
2005 Twin Turbo C6
404cid Stroker, 67mm Twins
994rwhp/902lb ft @ 22 psi (mustang dyno) www.Texas-Speed.com
Originally Posted by Jason 98 TA
We just finished up flowing our newest version of the Stage 1.5 5.3l cylinder head.
The Precison Race Components 5.3l Stage 1.5 cylinder head features a 2.02 intake valve & stock exhaust valve. The valve setup on these cylinder heads allows customers with large camshafts (like the MS3) the ability to get a great flowing cylinder head without needing to cut valve reliefs!
Here's a flow sheet from the set of 1.5 cylinder heads going to a customer with a MS3 camshaft The 1.5 5.3l cylinder heads will retail for $1350!!! Like the 2.5 cylinder heads the 1.5 heads will feature complete hand finishing & detailed tweaking until the head meets Freddie's strict standards. The cool thing about the 5.3l casting is customers can also get a bigger exhaust valve & still clear large camshafts!
The Precison Race Components 5.3l Stage 1.5 cylinder head features a 2.02 intake valve & stock exhaust valve. The valve setup on these cylinder heads allows customers with large camshafts (like the MS3) the ability to get a great flowing cylinder head without needing to cut valve reliefs!
Here's a flow sheet from the set of 1.5 cylinder heads going to a customer with a MS3 camshaft
The 1.5 5.3l cylinder heads will retail for $1350!!! Like the 2.5 cylinder heads the 1.5 heads will feature complete hand finishing & detailed tweaking until the head meets Freddie's strict standards. The cool thing about the 5.3l casting is customers can also get a bigger exhaust valve & still clear large camshafts! 
Originally Posted by PREDATOR-Z
Guys, no offense, but when will you get through your heads that comparing flow#'s from different flowbenches doesn't give you any comparison picture?
I challenge any of you to take the same heads to 3 different benches and get exactly the same output.
I challenge any of you to take the same heads to 3 different benches and get exactly the same output.
i feel what J-Rod brougt up a while back still rings true about bench comparisons and power.
https://ls1tech.com/forums/showpost....92&postcount=2
TECH Senior Member
Joined: Mar 2004
Posts: 14,620
Likes: 17
From: BFE
That is exactly what I'm trying to say:
Originally Posted by J-Rod
On the flow bench, the Brand Ys actually flowed better from .100-.550, while Brand X flowed slightly better past this. Same thing on the exhaust side. This just goes to show that a flow bench is an excellent tool, but not something that should be used as the determing factor in how a head will perform when put on a motor
TECH Fanatic
Joined: May 2003
Posts: 1,292
Likes: 6
From: RainbowCity,Alabama
It was alrerady offered to compare the AFR vs. PRC heads on the same car.The latest R&D stage 2.5 head from PRC is the best 5.3L head available,period!Freddie and I have worked very hard in making the heads the best available.
Last edited by Terry@RacetechSpeed; Sep 16, 2005 at 10:44 AM.
The AFR kills the PRC 1.5 on the exhaust side..There's no comparaision and u guys fall slightly short on mid lift on the intake side too?
I understand that your only running a 1.55 but thats a big difference...Whats your 5.3's runner CC too..
I understand that your only running a 1.55 but thats a big difference...Whats your 5.3's runner CC too..
Personally I will take my LPE ported/blended 59cc 2.02/1.60 heads over either of them. Numbers are numbers, it all boils down to the performance you get with the setup you have, everybody likes one thing or another. The nice part about it is we can make our own choices as individuals!!
