AFR 195 or Trick Flow 23*
Burning Brakes
Joined: Oct 2001
Posts: 1,146
Likes: 0
From: Milford NH
Re: AFR 195, Trick Flow 23* or Edlebrock (snb73)
It is all about the numbers. Cylinder head make power & torque by flowing air. Looking at the flow numbers of the AFR 180,190,195 & Trick Flow 23 heads (all as cast), the AFR 180 & Trick Flow heads flow very similar. AFR 190 & AFR 195 flow very similar. Here are the average of the intake flow numbers from 0.200-0.600 lift:
AFR 195: 220 cfm
AFR 190: 217 cfm
AFR 180: 216 cfm
Trick Flow: 213 cfm
Now, when it comes to torque, the cylinder heads with greater port velocity perform better. Usually as the intake port size increases, port velocity decreases. I like to look at how much cfm a cylinder head flows through a given port size. More cfm per cc the better. Here is the average cfm/cc for the cylinder heads:
AFR 180: 1.20 cfm/cc
AFR 190: 1.14 cfm/cc
AFR 195: 1.13 cfm/cc
Trick Flow: 1.09 cfm/cc
The AFR 195 head and the trick Flow head both have the same intake port size yet the AFR head flows 0.04 more cfm which must mean more velocity. AFR 180 is the clear winner here.
Finally, you have to look at how well the exhaust port flows. LPE uses a ratio between the intake port and the exhaust port flow. Here are the averages:
AFR 180: 77%
AFR 190: 77%
AFR 195: 76%
Trick Flow: 72%
AFR 180 wins hands down by the numbers. The smaller port AFR 180 heads flow as much as the larger port Trick Flow heads (better cfm/cc) with better exhaust flow also. If you can spend the money, I would go with the AFR 180 heads.
Aren't engineers wonderful? :crazy:
AFR 195: 220 cfm
AFR 190: 217 cfm
AFR 180: 216 cfm
Trick Flow: 213 cfm
Now, when it comes to torque, the cylinder heads with greater port velocity perform better. Usually as the intake port size increases, port velocity decreases. I like to look at how much cfm a cylinder head flows through a given port size. More cfm per cc the better. Here is the average cfm/cc for the cylinder heads:
AFR 180: 1.20 cfm/cc
AFR 190: 1.14 cfm/cc
AFR 195: 1.13 cfm/cc
Trick Flow: 1.09 cfm/cc
The AFR 195 head and the trick Flow head both have the same intake port size yet the AFR head flows 0.04 more cfm which must mean more velocity. AFR 180 is the clear winner here.
Finally, you have to look at how well the exhaust port flows. LPE uses a ratio between the intake port and the exhaust port flow. Here are the averages:
AFR 180: 77%
AFR 190: 77%
AFR 195: 76%
Trick Flow: 72%
AFR 180 wins hands down by the numbers. The smaller port AFR 180 heads flow as much as the larger port Trick Flow heads (better cfm/cc) with better exhaust flow also. If you can spend the money, I would go with the AFR 180 heads.
Aren't engineers wonderful? :crazy:
Safety Car
Joined: May 2001
Posts: 3,758
Likes: 3
From: Surrey
Re: AFR 195, Trick Flow 23* or Edlebrock (69stingray)
69stingray,
Good post, thanks. I was starting to think that I was missing something in thinking that the 180's might be the best choice for what I want (lots of low down torque).
:cheers:
Good post, thanks. I was starting to think that I was missing something in thinking that the 180's might be the best choice for what I want (lots of low down torque).
:cheers:
Burning Brakes
Joined: Oct 2001
Posts: 1,146
Likes: 0
From: Milford NH
Re: AFR 195, Trick Flow 23* or Edlebrock (BeaterShark)
I'm not really sure about the 180s, but the 190s recommend a FelPro 1204 gasket and the 195s recommend a 1205 gasket.
The Performer manifold recommends a 1204, while the Performer RPM a 1205.
If you put 190 heads on a Perf RPM manifold, the intake port on the intake will be bigger than that of the head. This is not good for flow.
The Performer manifold recommends a 1204, while the Performer RPM a 1205.
If you put 190 heads on a Perf RPM manifold, the intake port on the intake will be bigger than that of the head. This is not good for flow.
For street engines wanting low speed torque, consider Edelbrock heads. They have 170 cc iintake ports.
Average CFM from 0.200-0.600 lift: 202 CFM
Average CFM/CC from 0.200-0.600 Lift: 1.20 :)
Average Intake/Exhaust Ratio: 75%
Price: approx. $1,000/pair :rolleyes:
Drifting
Joined: Sep 1999
Posts: 1,411
Likes: 1
From: Wylie TX
Re: AFR 195, Trick Flow 23* or Edlebrock (Ryan77)
I ran the AFR 195's vs the 190's on Desktop Dyno. Both with the competition package, on a 388ci (it's the same motor as the 500hp 383 on AFR's website, just 5 more ci), and the 195's made only 1 more ft/lb and 3 more hp than the 190's :yesnod: . The 190's will give better throttle response and more port velocity, so I'd take the 190's hands down, and that's what AFR recommends too :thumbs:
[Modified by Ryan77, 5:58 PM 3/20/2003]
[Modified by Ryan77, 5:58 PM 3/20/2003]
69Stingray, I agree with most of what you are saying, IF all you care about is low end torque. At some point, the extra torque is useless as it just smokes the tires. I prefer to have an engine which makes good torque down low and flat out pulls at 6k.
I'll leave this with a few notes about what GM is doing now with their stock intake sizes. All of this is taken from the Chevy High Performance flow to go tests:
Heads: intake cc, ave intake flow, flow/cc, E/I
L98 ('87 - '91) : 163cc, 172, 1.065, 75%
LT1 ('92 - '96) : 170cc, 190, 1.12, 67%
LT4 ('96 only) : 195cc, 213, 1.09, 69%
LS1 ('97 - 03) : 204cc, 207, 1.02, 70%
I know heads aren't everything when it comes to power, but from top to bottom, each new head made a faster 'vette.
If I had a choice of which GM head to use on an engine I was building, I'd go for the LS1 even though it has the worst intake flow/cc.
Drifting
Joined: Sep 1999
Posts: 1,411
Likes: 1
From: Wylie TX
Re: AFR 195, Trick Flow 23* or Edlebrock (69stingray)
Ensuring the intake port / gasket / intake manifold AND header / gasket / exhaust port match is very important. Having good flowing heads then a mismatch at the port kills your power.
