GTP Stage 2 Flow #'s?
05-16-2003, 08:48 PM
#1
Registered User
Thread Starter
Join Date: Jun 2001
Location: "Shoulda Gotton An LS1 Racin"
Posts: 872
GTP Stage 2 Flow #'s?
Anyone know what they are supposed to flow? I have a set that will be getting flowed soon by a local shop & wanted to get an Idea of what GTP claims...
Thanks
Eddie
Thanks
Eddie
05-17-2003, 08:58 AM
#5
Registered User
Join Date: Aug 2002
Location: Red Oak Texas
Posts: 1,509
Superflow SF 300 bench
28" of depression
4.155 bore
1/2 inch clay funnel on intake
NO pipe on exhaust
If you check with any one that has flowed these heads on an independant bench, they will have these #'s. Most Superflow benches will spit out these #'s. I have seen some other benches (Flow Data, Quadrant Scientific, etc) that will show different #'s. A good way to compare the portworkwould be to get flow #'s from a stock LT1 from the same bench tested the same way. The before and after #'s are important so you can see how much "gain" there is. It is impossible to compare only the "AFTER" #'s from different benches.
Most Superflow benches will show "about" 215/150 for a stock LT1. Some other benches show 230/180 for stock #'s so if the heads flow 280/220 on that bench, they will not flow that on my bench. Not that anyone is lying or inflating their #'s it is just that every bench is different.
NightTrain66
28" of depression
4.155 bore
1/2 inch clay funnel on intake
NO pipe on exhaust
If you check with any one that has flowed these heads on an independant bench, they will have these #'s. Most Superflow benches will spit out these #'s. I have seen some other benches (Flow Data, Quadrant Scientific, etc) that will show different #'s. A good way to compare the portworkwould be to get flow #'s from a stock LT1 from the same bench tested the same way. The before and after #'s are important so you can see how much "gain" there is. It is impossible to compare only the "AFTER" #'s from different benches.
Most Superflow benches will show "about" 215/150 for a stock LT1. Some other benches show 230/180 for stock #'s so if the heads flow 280/220 on that bench, they will not flow that on my bench. Not that anyone is lying or inflating their #'s it is just that every bench is different.
NightTrain66
05-17-2003, 10:32 AM
#6
Registered User
Join Date: Feb 2003
Location: St. Charles, Il
Posts: 641
Well I flowed my LT-1 and LT-4 heads yesterday on a superflow 600 but it was done at 10 inches and i got
Intake Exhaust
.100 35.1 / 41.1 35.1 / 44.0
.200 74.1 / 93.1 57.3 / 68.6
.300 96.6 / 121.5 74.0 / 81.8
.400 113.0 / 141.1 86.2 / 94.9
.500 115.1 / 154.5 93.1 / 102.4
.525 114.8 / 156.8 94.7 / 103.3
.600 114.0 / 160.2 97.1 / 103.5
What is the conversion factor ?
Intake Exhaust
.100 35.1 / 41.1 35.1 / 44.0
.200 74.1 / 93.1 57.3 / 68.6
.300 96.6 / 121.5 74.0 / 81.8
.400 113.0 / 141.1 86.2 / 94.9
.500 115.1 / 154.5 93.1 / 102.4
.525 114.8 / 156.8 94.7 / 103.3
.600 114.0 / 160.2 97.1 / 103.5
What is the conversion factor ?
05-17-2003, 12:02 PM
#7
Registered User
Join Date: Aug 2002
Location: Red Oak Texas
Posts: 1,509
The correction factor is 1.67. That will make a 10" # a 28" #.
This doesn't always work out. A port that doesn't go turbulent at 10 inches could go turbulent at 28" since there is more air moving through the port. The only way to know for sure would be to test at 28". If the shortside portwork is good, there will probably not be much difference. The higher depression will show more imperfections in the port and valve job. Alot of people test at alot higher depressions for this reason. The #'s are pretty much for their use only and can not be compared to other peoples 28" #'s but it serves their purpose for "maximizing" the port job and valve job.
NightTrain66
This doesn't always work out. A port that doesn't go turbulent at 10 inches could go turbulent at 28" since there is more air moving through the port. The only way to know for sure would be to test at 28". If the shortside portwork is good, there will probably not be much difference. The higher depression will show more imperfections in the port and valve job. Alot of people test at alot higher depressions for this reason. The #'s are pretty much for their use only and can not be compared to other peoples 28" #'s but it serves their purpose for "maximizing" the port job and valve job.
NightTrain66
Thread
Thread Starter
Forum
Replies
Last Post