Horsepower factors

[bill dedman]

Does the IHRA use the NHRA horsepower factors that are listed on the NHRA (Classification Guide) website to classify Stockers (when applicable)??? I know there's nothing on the NHRA site about crate motors, but for conventional Stockers, does IHRA use the factor numbers, down the line, so-to-speak?

Thanks for any information...

Bill

[Doug Blackley]

Yes but IHRA does not refactor based on NHRA adjustments. This is where the factors are different; ex 1985 Camaro/Firebird 305 150/258 combo in NHRA is still at 250 in IHRA.

[bill dedman]

Thank you, Doug, for that complete answer. That was precisely the information I was looking for.

Is there an online site with the IHRA Classification Guide horsepower factors that we can access (like the NHRA site?)

Bill

[Doug Blackley]

IHRA doesn't have a class guide persay. There is a section on IHRA's site that lists all the hp adjustments. If the combo you're looking for isn't on that list then it is still at the original NHRA factor.

[X-TECH MAN]

When I worked for IHRA in the 70's they had thier own class guide. As the years passed by and IHRA was sold several times they just used the NHRA guide. Then as some of the HP factors we noticably out of wack IHRA made some changes slightly different than NHRA's. As far as the production S/S cars are concerened IHRA had a guide that contained the lighest car shipping weights for that part of a seperate S/S catagory called "Formula S/S" as car counts decreased over the years they were combined into regular S/S eliminator based on cubic inches to shipping wts. Now you have "Production S/S" (same class structure) and they just use the lighest shipping wt listed in the NHRA guide per cubic inch to obtain the class. Along the way the multi carbed cars in the old formula S/S were discontinued. Now before someone wonders what a "Bastard" class Production S/S is....its a take off on the old AHRA formula S/S cars (cubic inches to factory shipping wt) only they look much better today and not much different than single carbed modifed cars running in NHRA.....lol.

[bill dedman]

Thanks for the explanation. I was discussing an NHRA car that was heavily factored by the AHFS, that has shown up running IHRA and was curious if the factor was used in both associations.

It made no sense to me that IHRA would use one (original) set of HP numbers, but would not follow through and assign AHFS-generated factors as they were accumulated.

But, apparently, that's what they do. I guess they have their reasons, but it would seem to complicate things to a very large (and, unnecessary) degree.

I appreciate the explanation, guys....


Bill