CLASS RACER FORUM - View Single Post - to all 85-92 efi racers

Fred Popov · 10-03-2008, 02:02 PM

Jeff,
Thanks for the Turbo/Transmission explanation. What you said makes sense that keeping a consistent boost pressure on launch would be more difficult.
The 350 TBIs also have bigger valves so flow should be better than the 305. But giving them horsepower just because some 305s are rated at about 260 is not the way to do it. Based on your theory, using year 1990, rating of horsepower the 350 should be: 241/305 = 0.79 Therefore 350x 0.79 = 277 hp
Bumping up the horsepower to 277 for the 350 TPI seems like a fair number, but that's not how NHRA arrives at these ratings. They would have to completely revise the way they factor engines. If they did that nobody would be happy. Just think if they rated the 302 based on the 327s or the 350's.
I think that the way it's done now is the best way to make it fair. If it runs too fast, give it horsepower and make it run in the next higher class. The problem is the people that intentionally run slow just to stay in their class.

Also, the Corvette has a 350 TPI but that one has aluminum heads and more compression. It was also rated at 260 up until this year. This year the automatic was bumped up to 273 hp, manual version is still 260 hp.

10-03-2008, 02:02 PM	#46
Fred Popov Junior Member Join Date: Sep 2007 Location: Chesapeake, VA Posts: 64 Likes: 0 Liked 0 Times in 0 Posts	Re: to all 85-92 efi racers Jeff, Thanks for the Turbo/Transmission explanation. What you said makes sense that keeping a consistent boost pressure on launch would be more difficult. The 350 TBIs also have bigger valves so flow should be better than the 305. But giving them horsepower just because some 305s are rated at about 260 is not the way to do it. Based on your theory, using year 1990, rating of horsepower the 350 should be: 241/305 = 0.79 Therefore 350x 0.79 = 277 hp Bumping up the horsepower to 277 for the 350 TPI seems like a fair number, but that's not how NHRA arrives at these ratings. They would have to completely revise the way they factor engines. If they did that nobody would be happy. Just think if they rated the 302 based on the 327s or the 350's. I think that the way it's done now is the best way to make it fair. If it runs too fast, give it horsepower and make it run in the next higher class. The problem is the people that intentionally run slow just to stay in their class. Also, the Corvette has a 350 TPI but that one has aluminum heads and more compression. It was also rated at 260 up until this year. This year the automatic was bumped up to 273 hp, manual version is still 260 hp. Last edited by Fred Popov; 10-03-2008 at 02:07 PM.