Maximum rated horsepower allowed in factory stock cars
 

I was just looking through the year end HP adjustments and saw they upped the 590hp COPO combination to 630hp, this effectively makes it unable to run in stock due to the weight it would have to run at it would need to be 3,635lbs which is over the limits of the cage specs. I was curious and decided to check, basically if any new car(COPO, cobra jet, drag pak) gets rated over 623 they will be no longer able to run that combination in stock with the current weight breaks (3,600-170=3,430lbs, 3,430/5.5=623.6hp).

The 580hp COPO combinations is getting close too, it was upped from 580 to 617 in November. I also see the 2016 Cobra jet 575hp combo is at 600hp, so if someone hits them hard the way the 580 COPO got hit they'll be up against the limit too.

The FS/AA class which is what these cars are meant to run (other than FS/XX) doesn't have weight breaks that will keep these cars legal if they keep adding horsepower.

Re: Maximum rated horsepower allowed in factory stock cars
 

So, what do you want to bet that NHRA ups the max wt. limit on the cage before February? I would guess that 3600 is just a number that someone arbitrarily came up with anyway.
I'm a bit more concerned about the first Racer that shows up with a Hellcat in A/S at 4700 lbs..

Re: Maximum rated horsepower allowed in factory stock cars
 

It's an SFI specification, for any car faster than 8.50 (running 7.50 to 8.49) you need an SFI 25.5 spec cage, SFI specifications list a maximum weight of 3,600lb. Now if the SFI spec means a maximum car weight or car and driver weight of 3,600 I don't know, I'm sure there's someone with more knowledge about how they interpret that. I interpret that they mean car and driver weight. If they just mean car weight, then with the NHRA driver weight of 170 the cars would then be ok for another 170 lbs. Which would put their max hp possible at 654hp

Re: Maximum rated horsepower allowed in factory stock cars
 

I brought it up with Tech and was told a few different things that did not make complete sense to me. But Tech thought it was legal and there was not a 3600 lb limit and I was misinformed. I would think it would help to bring it up with tech in your Div.

Re: Maximum rated horsepower allowed in factory stock cars
 

NHRA does not have the authority to change or override an SFI chassis specification. SFI is an independent motorsports industry entity that serves all types of motorsports, not only in the USA but also worldwide. Doing so puts a liability on NHRA in the event of a crash.

The current applicable specs are as follows:

SFI Spec 25.3C: Full Bodied Car with Aftermarket Body Shell and Tube Frame, OEM Body Shell and OEM Frame with OEM or Modified Floorpan and Firewall, or Uni-Body with OEM or
Modified Floorpan and Firewall Roll Cage – 6.50 to 7.49 Seconds ET;
3,600 lbs. Maximum

SFI Spec 25.5D: Full Bodied Car Stock or Modified/OEM Floorpan and Firewall with OEM Frame or Uni-Body Construction – 7.50 to 8.49 Seconds;
3,600 lbs. Maximum

SFI Spec 25.6: Full Bodied Car Stock / Truck or Modified/OEM Floorpan and Firewall with OEM Frame or Uni-Body Construction – 7.99 to 8.49 Seconds;
5,000 lbs. Maximum

SFI 25.3C and 25.5D is limited to 3,600 lbs. maximum.
Although SFI 25.6 allows up to 5,000 maximum, is limited to a 7.99 ET.

Re: Maximum rated horsepower allowed in factory stock cars
 

Interesting how the SFI got those numbers? Did they take a 3000, 3600 and a 4000 lb car, wreck them, then see how they faired? I know there's math involved, but in my opinion, way to many variables unless there's one cage fits all. If pushing the limit of 1-5/8" cm, go to 2", more than doubles the strength. There are ways around this dilemma, look at NASCAR. Over 4000lbs and those cars hit a few walls time to time. Amazing when you're been at the top for a long time, after awhile questions don't get asked.
Like I said, my opinion, Mike

Re: Maximum rated horsepower allowed in factory stock cars
 

?^^^^^^?

Re: Maximum rated horsepower allowed in factory stock cars
 

I mean a simple solution is to create a FS/AAA with weight breaks of 5.00 to 5.49, either that or lower the index time for FS/AA and retroactively take off the horsepower that was added for running too far under the old index time. I don't know what else they could do to keep these cars legal?

Re: Maximum rated horsepower allowed in factory stock cars
 

I see what you say about the 25.6 being good up to 5,000lbs but only 7.99ET, but in the rule book NHRA says stock cars running faster than
8.50 must have an SFI 25.4 or SFI 25.5 cage, no mention of 25.6, and these cars are becoming capable of 7.99

Re: Maximum rated horsepower allowed in factory stock cars
 

SFI uses actual crash data and analysis to come up with the specification. In addition, many of the top chassis builders are also consulted.
It is not an arbitrary number.

Re: Maximum rated horsepower allowed in factory stock cars
 

NHRA can opt the use of the SFI 25.6 for the Hellcat and hope they don't go faster than 7.99

Re: Maximum rated horsepower allowed in factory stock cars
 

I know this is a old thread, but has anyone got any clarification on this? Thanks, Todd

Re: Maximum rated horsepower allowed in factory stock cars
 

Nothing has changed.
This is the only SFI Guidance applicable to drag racing stock body cars:

SFI Spec 25.5D - Full Bodied Car Stock or Modified/OEM Floor Pan and Firewall with OEM Frame or Uni-Body Construction
– 7.50 to 8.49 Seconds; 3,600 lbs. Maximum
Effective Date: May 5, 2018

SFI Spec 25.6 - Full Bodied Car Stock / Truck or Modified/OEM Floor Pan and Firewall with OEM Frame or Uni-Body Construction
– 7.99 to 8.49 Seconds; 5,000 lbs. Maximum
Effective Date: August 26, 2016

Re: Maximum rated horsepower allowed in factory stock cars
 

Does 3600 include driver? Ive seen plenty of 2018 and up copo's and cobra jets running FS/AA .