NHRA Horsepower Factors. How?

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  • #9681
    jrstk
    • Total Posts: 32

    Always wondered how they do it. An example being a old 340 Dodge factory rated at 275 hp is refactored by the NHRA to 310 hp. Where or how did they come up with 310?
    Doug

    #18452
    dino
    Keymaster
    • Total Posts: 11503

    This looks like a job for Storm King

    #18453
    storm-king
    • Total Posts: 453

    You want me to take a shot at the unpredicatable, maniacal thoughts of the NHRA? Right.
    I don’t know, I guess they just pulled nubers out of their collective asses that sounded like enough of a “factor” to help GM products win races in something other than junior stock classes. That’s all I could ever figure.
    NHRA factored Chrysler right out of pro stock racing because of one man…Ronnie Sox. The other Mopars weren’t running anywhere near what Ronnie was, he was fast because of his driving, primarily. In truth, Greg Anderson won more than Ronnie, but did they factor the Ponchos? No. It’s OK as long as GM is winning. So it’s a pretty convoluted process they must use. Look how many times they factored Ford when Glidden was the only non-GM car in pro stock! One guy, one car, one combination, no other racers to get info from, and yet he held back the GM hords all by himself all the while NHRA “tinkered” with new formulas to screw him up.
    I know, I’m ranting, aren’t I?
    I just never understood why we go away from cubic inch to weight.
    To the question, it was well known that Mopar under rated their true horsepower output, while Gm wildly over rated it for advertising purposes.

    #18455
    jrstk
    • Total Posts: 32

    To this day in the non professional categories they use the same factor system but I can’t for the live of me figure how they come up with their numbers.
    Doug

    #18456
    bobby-s
    • Total Posts: 700

    That’s a great question for Joe DeMarzo or the Morehead boys to answer 😮
    they know the system real well, from what I understand the faster you get a car to go
    NHRA has a system to adjust the estimated base ET index factor ❓
    not sure how it works but they have something
    (as storm said to give GM the brake)if anyone else can get their race car to go as fast.
    Come’s down to the old saying you got the $$$$$ to go fast 😉
    and can hit the tree right you WIN. :mrgreen:

    sure this helped to screw up everyone’s mind 🙄
    Paul you might know this system, ❗

    #18463
    storm-king
    • Total Posts: 453

    Certainly someone who is racing today wouold be more qualified to answer. I obviously still hold a great deal of bitterness for the way they screwed Mopar. But to validate my point to some degree, it’s why Joe Kenny switched from Mopar to GM. You couldn’t get a fair break.

    #18478
    xchamp1317
    • Total Posts: 4

    Talk about complicated, but I will do my best. Every class in stock and super stock have an index. The index is the min amout a car “should: run. Take my class G/SA, the index is 12.30. The car has a horsepower rating from the factor, I run a 72 Nova, 350 rated 200 from the factory. It is a smog motor with a dish piston. It is currently rated 270 by NHRA. NHRA tracks all runs at national events and if any car with that motor (350 dish psiton) runs faster than -1.15 under the 12.30 index (11.14) the combination is then reviewed. If the average runs for that combo is greater than -1.0 under the index than NHRA adds HP. Usually 3-4 HP. NHRA reviews the average 2x a year, November and July. Now the kicker, if you go faster than -1.4 under anywhere (10.89 in G/SA) you are automatically hit with HP. Usually 10-15 HP depending on your current NHRA rating. They talk all runs throughout the country at National events and average the runs regardless of the body style. So camaro’s nova’s and chevelle’s that run the same motor are averaged together. If the aveerage of the engine combo is greater than -1.0 than you get HP. There are many other MHRA enhancements but this the basics. You can request HP off but have to prove the combination is not competetive, has become obsolete becasue of to much HP or your average runs are less than -.5 under the index. It has become a hugh game and not about performance unless you have a heads up that is meaningful. Heads up in class in no longer about bragging rights but about protesting your HP rating. That is probably as clear as mud but ask away and I will try to answer as best I can. Go to NHRA and you can read the policy on their website. It is not clear to all of us who play so reading it may not help.

    P.S. I did have a heads up run recently at a divisional race and we both went all out. My opponents car was faster 11.27 to my 11>30 but I won the race becasue I had him at the tree .011 to his .052.

    #18482
    dino
    Keymaster
    • Total Posts: 11503

    Got me confused…wonder why Heads Up Pro-mods are so poular with Spectators…they can figure it out …also why they only show the pro heads up classes on TV. ….Ah the old days …A/S …4-speeds… heads up and whoever put on the win light …got the trophy..no excuses …see ya next week…..try again .

    #18484
    bossguy
    • Total Posts: 544

    I’m with you on that Dino, when they started slamming on the brakes at the finish, and all Funny cars had the same engine is when I started losing interest

    #18489
    dino
    Keymaster
    • Total Posts: 11503

    How ’bout All the Funny cars have the same BODY…decals for lights -grill and have to letter the windshield to tell ya what it is 😯 ……..pitaful

    #18490
    jrstk
    • Total Posts: 32
    quote XCHAMP1317:

    Talk about complicated, but I will do my best. Every class in stock and super stock have an index. The index is the min amout a car “should: run. Take my class G/SA, the index is 12.30. The car has a horsepower rating from the factor, I run a 72 Nova, 350 rated 200 from the factory. It is a smog motor with a dish piston. It is currently rated 270 by NHRA. NHRA tracks all runs at national events and if any car with that motor (350 dish psiton) runs faster than -1.15 under the 12.30 index (11.14) the combination is then reviewed. If the average runs for that combo is greater than -1.0 under the index than NHRA adds HP. Usually 3-4 HP. NHRA reviews the average 2x a year, November and July. Now the kicker, if you go faster than -1.4 under anywhere (10.89 in G/SA) you are automatically hit with HP. Usually 10-15 HP depending on your current NHRA rating. They talk all runs throughout the country at National events and average the runs regardless of the body style. So camaro’s nova’s and chevelle’s that run the same motor are averaged together. If the aveerage of the engine combo is greater than -1.0 than you get HP. There are many other MHRA enhancements but this the basics. You can request HP off but have to prove the combination is not competetive, has become obsolete becasue of to much HP or your average runs are less than -.5 under the index. It has become a hugh game and not about performance unless you have a heads up that is meaningful. Heads up in class in no longer about bragging rights but about protesting your HP rating. That is probably as clear as mud but ask away and I will try to answer as best I can. Go to NHRA and you can read the policy on their website. It is not clear to all of us who play so reading it may not help.

    P.S. I did have a heads up run recently at a divisional race and we both went all out. My opponents car was faster 11.27 to my 11>30 but I won the race becasue I had him at the tree .011 to his .052.

    Complicated for sure. Ive been to the NHRA site and I agree, it can be confusing. Let me see if I have this correct; the NHRA would have taken the minimum shipping weight for your car, plugged in the factory horsepower rating to determine what times the car should run? If it runs quicker, then the car is factored, re; horsepower factor increased? In your case, it has been factored over time, I guess since ’72 to the current 270 horsepower?

    #18491
    john-sachs-sr
    Participant
    • Total Posts: 430

    You ain’t seen nuttin………Wait till they finish with Pro-Stock bike.The Harley’s will be down to 1 cylinder,and weigh 900 lbs. 🙄
    John

    #18494
    storm-king
    • Total Posts: 453

    Come on, look where H-D started in PSB, running less weight and almost TWICE the displacement of the ricer’s! When V&H first began lobbying NHRA with H-D strong arming them at the same time, ricer’s ran stock blocks, cranks, heads, etc, with just a big block kit on them. Now, not one engine part will fit a stock H-D. V&H’s mills are all billet, and the ricer’s were forced to escalate their parts and cost to keep up.
    Incidently, back in the early days of AMA racing, Harley made the rules and the English bikes could only run a 500 cc single against the 750 cc H-D twins, and they still kicked H-D’s ass a good part of the time. For years I read about these “great battles” not knowing how H-D controlled the rules and were racing against bikes with 1/3 less the displacement and only one cylinder.
    I still think the V&H bikes have an MSD controlled traction device. I’ve listened and listened to them leave, and something just doens’t sound right. I know NHRA makes them allow tech to test the MSD units, but who supplies NHRA with the testers? MSD, and V&H run a unit exclusive to their combination which requires a tester just for their bikes.
    Creepy conpiracy theorist? I don’t think so.

    #18495
    paul-ceasrine
    • Total Posts: 528

    Horespower Factors,

    Sling-Shot Bobby,
    Still can’t kep up with what the NHRA is doing. Lost interest a long time ago.
    Last time I remember was back in 71′, the 340/275 was re-factored to 299HP.
    Classes were F/Stock or SS/I.
    I think now, they have (2) different HP ratings, (1) for Stock and (1) for S/S. Go figure.
    Gary of Storm King is right, NHRA really penalized the Hemi’s, virtually right out of Pro
    Stock.
    The real story of NHRA re-factoring is on the Ronnie Sox website. All you have to do is look at the wins he posted, and then you can understand the NHRA philosophy.
    I think the NHRA changed their moniker to “GM” HRA back in 73′.
    XCHAMP1317, said it all in one page. If anyone can figure that out, give them a case of
    Barilla pasta. HP factors, class index’s, weight breaks, go too fast, go too slow, bi-yearly
    class reviews, HP challenges through documentation. Looks like the U.S. Congress is involved. Aren’t they re-factoring the Health Care System.

    Paul

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