AA/S AAA/S and Class consolidation

LNorton · 09-15-2007, 04:21 AM

You also have to remember that this is a shoe polish race in the long run...

Chad Rhodes · 09-15-2007, 10:01 AM

Quote:

Originally Posted by LNorton

You also have to remember that this is a shoe polish race in the long run...

and thats the damn shame. Do aweay with the shoe polish and the AHFS will work itself out real fast, lol.

Stewart Way · 09-15-2007, 11:24 AM

Dick
You stated that an engine makes the same HP regardless of what car its in. Is that really true? I don't know but here is what I think. It varies. We have been doing dyno work lately and as you know if you rev the engine on an unloaded dyno it might make 60-70 hp. It takes resistance to develope torque. Now load the dyno for a 300 rev/sec pull and then a 600 rev/sec pull. Do you get the same hp numbers? No you don't. So if pulling at different rates nets different hp then doesn't it stand to reason that the same engine in a 3000lb car would make different hp than in a 4000 lb car because it will rev or pull at a different rate. Even a glide vs turbo 350 vs 4 speed could cause a motor to make different hp in the same car. No I don't think we need to consider all those factors in hp numbers but it does make a difference, I think.
I am no dyno expert for sure. These are just my thoughts and observations from the dyno and there may be something I'm missing that makes it worth about what you paid for it. I know I have gotten in trouble thinking before.

bill dedman · 09-15-2007, 01:21 PM

Stewart,

That's an interesting theory; certainly worthy of some discussion, I think!

I'd like to comment on that, if I may, and remember; this is only my opinion... I am no expert at anything, much less dynamometer engine testing, but it seems to me that...

If you're not specifically dyno-testing for just "peak" horsepower, but are testing for a horsepower CURVE, then the quicker you set the acceleration rate, the less horsepower will be left for the dyno to "see," because using a quicker acceleration parameter, the weight of the reciprocating AND rotating assembly will be creating more inertia-based parasitic drag, and will result in a smaller horsepower output number, as the engine accelerates its rpms.

BUT, I don't think that will be the case in a "peak horsepower-only" dyno test, using a static (peak) RPM, because there's no changes in the inertia at a steady rpm.

NHRA bases their factors on peak horsepower, probably because that's the way engines have tradirtionally been rated by the factories... the maximum output IS the rated horsepower. There's no easy way around that that I can see, insofar as assigning a factored horsepower rating is concerned.

So, the different accelerations in a dyno test, and the different output numbers they produce, probably wouldn't affect the peak rating, where the factors come from.

That's just my 2-cents... Your mileage (and, horsepower) may vary....

Bill

Bruce Noland · 09-15-2007, 01:49 PM

Jim,

There really is nothing machanical or automatic about Wesley's version. It has human hands all over it. We need to use the system the racers approved and maybe then allow human hands to influence the process but atleast some of the hands have to belong to actual racers. We all should know by now that the nhra staff is incapable letting the system function as originally designed.

You guys ever wonder why none of the nhra guys come out here to debate these AHFS problems? They are all over these sites on a daily basis.

Dick Butler · 09-15-2007, 02:43 PM

Thanks Stewart, I think the discussion by Bill is interesting one. Probably explains why one Dyno rates a motor concervatively and another seems higher for their motors. We used steady state before back to back so always had an idea going in if we gained.

Guys it will always be a Major calculation to take all the "factors " which can affect the deal into account. I do know this the bottom line of construction of a competitive S or SS car cannot be building a favorite motor or favorite body style. You have to research the aerodynamice, the HP rating as compared to others in class etc. I like different as much as other guys at a car show, at a cruise in but if you want to WIN in drag racing you have to be careful and plan ahead and use what is SHOWN to be a winner..Dont depend on bogus as that can go away quickly and then you have a Dog on your hands.
Look at AH. No risk takers there it is ALL the same stuff, you run one quick or slow its the same pieces.

AHFS. Weak by design. Needs more tuning using Air density at the time of runs. Needs to be tighter and without a reason to run fast more places it will always be weak. Bad if not documented to be legal at the time.

09-15-2007, 04:21 AM	#1
LNorton Senior Member Join Date: Apr 2004 Location: RacerTees.com Posts: 505 Likes: 0 Liked 4 Times in 2 Posts	Re: AA/S AAA/S and Class consolidation You also have to remember that this is a shoe polish race in the long run... __________________ Lee Norton - N229 STK IHRA H/FIA - NHRA O/SA RacerTees.com

09-15-2007, 11:24 AM	#3
Stewart Way Member Join Date: Aug 2003 Location: Atlanta Posts: 476 Likes: 20 Liked 70 Times in 22 Posts	Re: AA/S AAA/S and Class consolidation Dick You stated that an engine makes the same HP regardless of what car its in. Is that really true? I don't know but here is what I think. It varies. We have been doing dyno work lately and as you know if you rev the engine on an unloaded dyno it might make 60-70 hp. It takes resistance to develope torque. Now load the dyno for a 300 rev/sec pull and then a 600 rev/sec pull. Do you get the same hp numbers? No you don't. So if pulling at different rates nets different hp then doesn't it stand to reason that the same engine in a 3000lb car would make different hp than in a 4000 lb car because it will rev or pull at a different rate. Even a glide vs turbo 350 vs 4 speed could cause a motor to make different hp in the same car. No I don't think we need to consider all those factors in hp numbers but it does make a difference, I think. I am no dyno expert for sure. These are just my thoughts and observations from the dyno and there may be something I'm missing that makes it worth about what you paid for it. I know I have gotten in trouble thinking before.

09-15-2007, 01:21 PM	#4
bill dedman VIP Member Join Date: Feb 2002 Location: Conway, AR Posts: 1,739 Likes: 0 Liked 6 Times in 4 Posts	Re: AA/S AAA/S and Class consolidation Stewart, That's an interesting theory; certainly worthy of some discussion, I think! I'd like to comment on that, if I may, and remember; this is only my opinion... I am no expert at anything, much less dynamometer engine testing, but it seems to me that... If you're not specifically dyno-testing for just "peak" horsepower, but are testing for a horsepower CURVE, then the quicker you set the acceleration rate, the less horsepower will be left for the dyno to "see," because using a quicker acceleration parameter, the weight of the reciprocating AND rotating assembly will be creating more inertia-based parasitic drag, and will result in a smaller horsepower output number, as the engine accelerates its rpms. BUT, I don't think that will be the case in a "peak horsepower-only" dyno test, using a static (peak) RPM, because there's no changes in the inertia at a steady rpm. NHRA bases their factors on peak horsepower, probably because that's the way engines have tradirtionally been rated by the factories... the maximum output IS the rated horsepower. There's no easy way around that that I can see, insofar as assigning a factored horsepower rating is concerned. So, the different accelerations in a dyno test, and the different output numbers they produce, probably wouldn't affect the peak rating, where the factors come from. That's just my 2-cents... Your mileage (and, horsepower) may vary.... Bill __________________ Bill Last edited by bill dedman; 09-15-2007 at 01:25 PM. Reason: forgot a word

09-15-2007, 01:49 PM	#5
Bruce Noland VIP Member Join Date: Jun 2002 Posts: 1,855 Likes: 83 Liked 444 Times in 145 Posts	Re: AA/S AAA/S and Class consolidation Jim, There really is nothing machanical or automatic about Wesley's version. It has human hands all over it. We need to use the system the racers approved and maybe then allow human hands to influence the process but atleast some of the hands have to belong to actual racers. We all should know by now that the nhra staff is incapable letting the system function as originally designed. You guys ever wonder why none of the nhra guys come out here to debate these AHFS problems? They are all over these sites on a daily basis. __________________ Bruce Noland 1788 STK

09-15-2007, 02:43 PM	#6
Dick Butler VIP Member Join Date: Oct 2002 Location: Richmond Indiana Posts: 1,196 Likes: 5 Liked 32 Times in 19 Posts	Re: AA/S AAA/S and Class consolidation Thanks Stewart, I think the discussion by Bill is interesting one. Probably explains why one Dyno rates a motor concervatively and another seems higher for their motors. We used steady state before back to back so always had an idea going in if we gained. Guys it will always be a Major calculation to take all the "factors " which can affect the deal into account. I do know this the bottom line of construction of a competitive S or SS car cannot be building a favorite motor or favorite body style. You have to research the aerodynamice, the HP rating as compared to others in class etc. I like different as much as other guys at a car show, at a cruise in but if you want to WIN in drag racing you have to be careful and plan ahead and use what is SHOWN to be a winner..Dont depend on bogus as that can go away quickly and then you have a Dog on your hands. Look at AH. No risk takers there it is ALL the same stuff, you run one quick or slow its the same pieces. AHFS. Weak by design. Needs more tuning using Air density at the time of runs. Needs to be tighter and without a reason to run fast more places it will always be weak. Bad if not documented to be legal at the time. Last edited by Dick Butler; 09-15-2007 at 02:45 PM.