Tsp stg 2.5 5.3 vs afr 205
07-28-2009, 06:19 AM
#82
Usable Power, you can't drive a dyno sheet! ...lol im not going for the highest hp or track times i just enjoy driving the car.... saving money is great too! Hopeful Goal of 430+rwhp (adding 40 or so rwhp) with heads, intake, and ud pulley maybe injectors added to my setup and high 11's or consistant low 12's at the track...partly a problem with my 60ft lol im workin on it.
So why all the rambling on, I would trade 15 RWHP less at 6500 rpm for 50 RWHP more at 2500 rpm any day of the week. My hypothesis is that my car would still be quicker in the quarter mile than a car which makes 15 RWHP more at 6500 rpm but had less horsepower than mine from say 5400 rpm.
but even if it wasn't quicker my car would be way more fun to drive around town.
P/S the gas mileage should be better as well.
Ed
Last edited by BRD-PREY; 07-28-2009 at 06:21 AM. Reason: spelling
07-28-2009, 09:05 PM
#83
This is what I'm saying, I know we all have different uses for are Hobby! No one gives any kind of part throttle power or response data. To me that makes up a large part of the driveability factor. That along with where in the power curve your power lies are hugh factors.
What if a known surface area was representative of 25% throttle opening? Dyno tests from 1500 rpms to 4500 rpms should tell us a lot about how much power is available at "part throttle". Good luck getting the aftermarket to all use the exact same size hole, or preventing vendors from doctoring the restrictor for the best possible air flow, yet appearing to fall within the guidelines.
As for where in the power curve, at least we know why some graphs start at 4500, completely omitting the "area under the curve".
OMG, don't you know we're not supposed to talk about fuel economy here? Now everyone will tell you you shouldn't have a LS1, and if you care about mileage, you should have bought a honda...
07-29-2009, 06:38 AM
#84
Standards One problem would be finding a way to quantify that data and standardize a system for testing it.
What if a known surface area was representative of 25% throttle opening? Dyno tests from 1500 rpms to 4500 rpms should tell us a lot about how much power is available at "part throttle".
As for where in the power curve, at least we know why some graphs start at 4500, completely omitting the "area under the curve".
OMG, don't you know we're not supposed to talk about fuel economy here? Now everyone will tell you you shouldn't have a LS1, and if you care about mileage, you should have bought a honda...
What if a known surface area was representative of 25% throttle opening? Dyno tests from 1500 rpms to 4500 rpms should tell us a lot about how much power is available at "part throttle".
As for where in the power curve, at least we know why some graphs start at 4500, completely omitting the "area under the curve".
OMG, don't you know we're not supposed to talk about fuel economy here? Now everyone will tell you you shouldn't have a LS1, and if you care about mileage, you should have bought a honda...
I would think that if Horsepower(torque) is higher in CAR A in a given RPM range and throttle position is less then CAR B then CAR A would be more efficient in that RPM range. So it would use less fuel if load (mph) was the same. That assumes a lot of variables are constant for comparision purposes such as displacement, fuel composition, timing, cam, of course all of the environmental factors and a whole host of other things. Remember were talking which head is better. So inorder for that to be comparable everything else must be constant.
2. Standards, If the load a dyno puts on a car was set to some standard wouldn't that solve the issue. I know thats not going to happen but hey who that GM would be gov't owned. If the load was set to some value then the car was brought up to some set speed. This would yield a throttle position or (AIR Volume) given the different heads had the same A/F ratio the more air the less efficient. The MAF values would probably be a more accurate comparision of Air Volume. If several different load points were used a curve could be established that would represent efficiency at various RPM's/loads.
Now with all that being said, lets for this discussion only assume the AFR head with higher port velocities yielding more flow at lower demands and the TSP 215's flow better at WOT. The efficiency graph would show less throttle required for all the low and middle load settings for the AFR head to reach the desired speed(mph) on the dyno but as the load settings reached the higher and finally max setting to reach the set mph
the TSP 215's would require less throttle or at max the dyno load applied would be higher. REMEMBER the above was just an example would and doesn't apply to anybodys products.
I know that a variable load dyno is not common. The above procedure would be I think a fairly accurate way and best way to compare 2 heads and as long as its done on the same dyno on the same vehicle it should yield consistent results.
Remember daily driving is important to me so to restate my desires in a head. Head A producing 50 more horsepower at 2000 rpm but but having 10 horsepower less at 6500 rpm then Head B makes HEAD A the choice for me!
Your ultimately right though it needs to be independent tests.
The restrictor NASCAR thing isn't quite right as it attempt to limit air volume right? I'm not a fan of the round de round thing.
Ed
Please point out any errors in my above logic (but only if you take the time to explain where you think I came to the wrong conclusion.
