old AFR flow numbers w/RPM air gap vs factory LT-1
08-30-2007, 05:05 PM
#1
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old AFR flow numbers w/RPM air gap vs factory LT-1
I just got back from the local speed shop and here are the numbers off the Super Flow 600. Old AFR 195 at 550 lift flowed 240 cfm. Bolt on the RPM Air Gap and the numbers drop to 231. Swap in the factory LT-1 and the numbers drop to 228. So I paid $213.00 for the Air Gap and only gained 3 CFM! WTF!! Additionally, according to AFR, I will only make max 365-370 RWHP wit the NEW ELIMINATOR 195's! I was really looking for closer to 400 RWHP out of a 10.25 to 1 384. I feel cheated!
08-30-2007, 05:35 PM
#3
Le Mans Master
Goes to show you what many have known for about 38 years...the factory LT-1 manifold is very good! BTW, those heads with the right set-up will make damn near 500 hp.
08-30-2007, 06:20 PM
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08-30-2007, 07:08 PM
#6
Race Director
That cam for a stroker motor is a little short on duration. Is it a roller or flat tappet. I'm way up in duration for a flat tappet. If I was going to a roller I would want to be in the mid 240 range on duration.
08-31-2007, 04:58 AM
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It's a hydraulic roller. I have just ordered a set of the new Eliminator 195's, the matching rev kit and a set of Jesel SS shaft rockers. Now I wonder if I should change the cam.
08-31-2007, 08:17 AM
#10
Race Director
If you are staying with a hyd roller this will produce very good torque in the mid range. You probably won't need to go beyond 6000 rpm because the power will fall off due to the cam. It won't produce high HP numbers but should produce a butt load of mid range torque and be a great street motor.
08-31-2007, 10:12 AM
#11
Team Owner
HP is a function of rpm. If you can't do higher rpm you are not going to make the bigger HP numbers. For such a mild cam and heads the shaft rockers are kind of a waste. If you are after HP. You need to get the max cfm of flow out of your heads. This requires higher lift. Every one of my 383's had .620 - .644 lift. I also would have purchased a minimum of 210 cc heads for 383+ cc motors
Last edited by gkull; 08-31-2007 at 03:59 PM.
08-31-2007, 02:18 PM
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I would recommend finding out what is wrong with your heads before I selected any other components. You are at least 30 CFM short of what those heads should be doing. (I'll assume they were tested at 28" H2O) Send them back to AFR for evaluation if that is what it takes, but IMHO unless you have all the components right, you aren't going to get results.
Also, at those low flow numbers there won't be much difference in manifold performance. Get up around 280 CFM and you might see the Air Gap start to really differentiate itself from the LT1 manifold.
Also, at those low flow numbers there won't be much difference in manifold performance. Get up around 280 CFM and you might see the Air Gap start to really differentiate itself from the LT1 manifold.
08-31-2007, 03:11 PM
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Another interesting trip to the flow bench. The new Eliminator 195's flow 260 @ .550. Thats exactly 20 cfm less than what AFR claims and interestingly enough the old 195 flowed exactly 20 less than what AFR claimed. So who really knows. I have seen him bolt several sets of Trick Flow heads onto the same flow bench and they flow almost exactly what is advertised. As for the shaft rockers, I was trying to address what was described as "valve train instability" above 4600 rpm. I thought with the lighter components in the new heads, an upgraded spring package and the rev kit I would cure the instability and also pick uo some additional flow/HP.
08-31-2007, 03:27 PM
#15
Another interesting trip to the flow bench. The new Eliminator 195's flow 260 @ .550. Thats exactly 20 cfm less than what AFR claims and interestingly enough the old 195 flowed exactly 20 less than what AFR claimed. So who really knows. I have seen him bolt several sets of Trick Flow heads onto the same flow bench and they flow almost exactly what is advertised. As for the shaft rockers, I was trying to address what was described as "valve train instability" above 4600 rpm. I thought with the lighter components in the new heads, an upgraded spring package and the rev kit I would cure the instability and also pick uo some additional flow/HP.
better priced heads.
08-31-2007, 04:05 PM
#16
Team Owner
Another interesting trip to the flow bench. The new Eliminator 195's flow 260 @ .550. Thats exactly 20 cfm less than what AFR claims and interestingly enough the old 195 flowed exactly 20 less than what AFR claimed. So who really knows. I have seen him bolt several sets of Trick Flow heads onto the same flow bench and they flow almost exactly what is advertised. As for the shaft rockers, I was trying to address what was described as "valve train instability" above 4600 rpm. I thought with the lighter components in the new heads, an upgraded spring package and the rev kit I would cure the instability and also pick uo some additional flow/HP.
With sub 600 lift I would be looking a Beehive valve springs. Things like stud girdle cure rocker shaft flex, but that is another thing only really required when you use enough spring pressure to deflect the stud. Go with the larger 7/16th rockers and studs and you would be fine.
08-31-2007, 04:13 PM
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With sub 600 lift I would be looking a Beehive valve springs. Things like stud girdle cure rocker shaft flex, but that is another thing only really required when you use enough spring pressure to deflect the stud. Go with the larger 7/16th rockers and studs and you would be fine.
08-31-2007, 04:20 PM
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I would recommend finding out what is wrong with your heads before I selected any other components. You are at least 30 CFM short of what those heads should be doing. (I'll assume they were tested at 28" H2O) Send them back to AFR for evaluation if that is what it takes, but IMHO unless you have all the components right, you aren't going to get results.
Also, at those low flow numbers there won't be much difference in manifold performance. Get up around 280 CFM and you might see the Air Gap start to really differentiate itself from the LT1 manifold.
Also, at those low flow numbers there won't be much difference in manifold performance. Get up around 280 CFM and you might see the Air Gap start to really differentiate itself from the LT1 manifold.
08-31-2007, 04:32 PM
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I'll repeat this again, I would not bolt on the heads until you get decent numbers. If your flow guy can't get close to AFR's numbers there are any number of potential issues. A big one is whether he is using a inlet flow guide, and if he is, what style and radius.
My 195 AFR Eliminators (Comp) version flow over 300 at .55 lift. We really struggled to get them fixtured correctly on the flow bench...including sending them back to AFR measure them. When it was all said and done, we measured within 3 to 4 CFM of what AFR measured. The flow bench was a SF600 as well.
If the heads are really that crappy, AFR should know. If they aren't, your head guy and you should understand why there is a discrepancy.
My 195 AFR Eliminators (Comp) version flow over 300 at .55 lift. We really struggled to get them fixtured correctly on the flow bench...including sending them back to AFR measure them. When it was all said and done, we measured within 3 to 4 CFM of what AFR measured. The flow bench was a SF600 as well.
If the heads are really that crappy, AFR should know. If they aren't, your head guy and you should understand why there is a discrepancy.
08-31-2007, 04:50 PM
#20
Team Owner
If you already have them use them. what ratio did they come with?