Factory experimental

Jim Bailey · 01-20-2009, 02:07 AM

Bill, # 1.... yes I am kidding.... # 2..... Safety..... #3...... It's not about boost, it's about how efficiently you make the boost (ie:screw blowers). Point; which is better, If it takes 300hp (from the crank) to make 40# boost, or if it takes 150 hp (from the crank) to make 40# boost? How do you monitor that will a tell tale?

bill dedman · 01-20-2009, 07:57 AM

Quote:

Originally Posted by Jim Bailey

Bill, # 1.... yes I am kidding.... # 2..... Safety..... #3...... It's not about boost, it's about how efficiently you make the boost (ie:screw blowers). Point; which is better, If it takes 300hp (from the crank) to make 40# boost, or if it takes 150 hp (from the crank) to make 40# boost? How do you monitor that will a tell tale?

Thanks for the response, Jim; I appreciate it!!!

On #2, I am curious as to what the safety issue is with compressed air valve springs (or, did I get the numbers wrong?) Formula 1 cars race around CORNERS at 200 MPH and the F.I.A deems these springs as safe to use (they've been on all F-1 cars for years), so what's the problem with straight-line racers' safety isues with them? I don't understand what "safety issue" of concern is, here.

And on #3, your answer of "How do you monitor that will a tell tale?" relative to boost didn't really explain anything RE: why screw superchargers are banned. They have a reputation as being more efficient than Roots blowers, and I'm sure somebody's "blower dyno" has all the answers about how much power it takes to drive any of the popular configurations to X-pounds of boost, but the question was, "Why are they banned?" I'm certain NHRA doesn't ban them because they're inefficient...

I have my own ideas, but you having been "in the business," would have a much better idea than I would.

Thanks again for your response. Is your A/SA car a Stage III Wedge? Good luck in 2009!!!

Bill

Jim Bailey · 01-20-2009, 09:10 AM

Bill: this would probably be better addressed in a "new" Thread. Or if you want to PM me. Valve Springs are more of an issue with Alky than they are with Fuel Cars. And the mere Size/Mass of a Screw Blower,(Case and Rotors both), Filled with Almighty Nitro - BANG - You can't have that much energy flying around in specator seating. In an effort to Slow these Cars, NHRA has to really keep a handle on New Proto Type Parts. Today's Fuel Motors are more of a SPEC motor than any in drag racing. Including stock elim.
But, with that said, and the popularity of this thread....Give NHRA Tech just a little more credit, watch and see what happens, I don't look for the New Fords to be way outta line within current rules. It'll be when the Racers begin to "tweek" the combo (and rules), especially the supercharger, that we'll see an unfair advantage.

Greg Hill · 01-20-2009, 09:25 AM

If any of you have outlaw street cars at your local track take a look sometime. A lot of them run a procharger blower and absolutely fly. These are generally small block chevys and fords and routinely run low 7 seconds with 10.5" tires. The tech department has no clue how to monitor these cars. You talk about opening a can of worms.

Greg

Tim Kish · 01-20-2009, 10:26 AM

Based on the rotor profile and port geometry of a screw compressor there are areas within the supercharger where the air is compressed, this does not occur in a roots style supercharger which is purely a positive dispacement device with no internal compression. Introduce nitromethane to a screw compressor and you are trying to compress a volatile fuel - Kaboom

01-20-2009, 02:07 AM	#1
Jim Bailey Senior Member Join Date: Aug 2004 Posts: 674 Likes: 15 Liked 584 Times in 94 Posts	Re: Factory experimental Bill, # 1.... yes I am kidding.... # 2..... Safety..... #3...... It's not about boost, it's about how efficiently you make the boost (ie:screw blowers). Point; which is better, If it takes 300hp (from the crank) to make 40# boost, or if it takes 150 hp (from the crank) to make 40# boost? How do you monitor that will a tell tale?

01-20-2009, 09:25 AM	#4
Greg Hill VIP Member Join Date: May 2006 Location: Louisville , KY Posts: 1,995 Likes: 69 Liked 279 Times in 68 Posts	Re: Factory experimental If any of you have outlaw street cars at your local track take a look sometime. A lot of them run a procharger blower and absolutely fly. These are generally small block chevys and fords and routinely run low 7 seconds with 10.5" tires. The tech department has no clue how to monitor these cars. You talk about opening a can of worms. Greg __________________ Greg Hill 4171 STK

01-20-2009, 10:26 AM	#5
Tim Kish Member Join Date: Nov 2003 Location: Kalamazoo, MI Posts: 281 Likes: 2 Liked 11 Times in 4 Posts	Re: Factory experimental Based on the rotor profile and port geometry of a screw compressor there are areas within the supercharger where the air is compressed, this does not occur in a roots style supercharger which is purely a positive dispacement device with no internal compression. Introduce nitromethane to a screw compressor and you are trying to compress a volatile fuel - Kaboom __________________ Tim Kish 3032 SS/GS

01-20-2009, 09:10 AM	#3
Jim Bailey Senior Member Join Date: Aug 2004 Posts: 674 Likes: 15 Liked 584 Times in 94 Posts	Re: Factory experimental Bill: this would probably be better addressed in a "new" Thread. Or if you want to PM me. Valve Springs are more of an issue with Alky than they are with Fuel Cars. And the mere Size/Mass of a Screw Blower,(Case and Rotors both), Filled with Almighty Nitro - BANG - You can't have that much energy flying around in specator seating. In an effort to Slow these Cars, NHRA has to really keep a handle on New Proto Type Parts. Today's Fuel Motors are more of a SPEC motor than any in drag racing. Including stock elim. But, with that said, and the popularity of this thread....Give NHRA Tech just a little more credit, watch and see what happens, I don't look for the New Fords to be way outta line within current rules. It'll be when the Racers begin to "tweek" the combo (and rules), especially the supercharger, that we'll see an unfair advantage.