A/FD Power and Torque?

How much Power and Torque has a competetive A/FD engine have and at what rpms?
Ballpark figures...

///chris

 

I understand that it takes 3500 to 3700 hp to run 270 mph with a 2100 lb car.
Sure there is someone out here that can calculate what you are asking for though.

 

Here is a link to a calculator that figgers this stuff out for you, by the way A/F mph record is 280.66, http://www.speedworldmotorplex.com/calc.htm

 

Thanks guys!
Assuming they run un 36" tires(no growth) and 2.9 ratio final drive, the speedtrapp rpm would be ~7600rpm, for a 280mph. And ~8400rpms with a 3.2 final drive ratio

hmm it takes a lot of torque to make 3500hp@7600, ~2400lbsft

And thats with 420-430" engines right?
Is it possible to run these monsters on dynos?

///chris

 

With the right Dyno you can!!!

 

Yep, it`s called, The Asphalt 1320.

 

Is there such a dyno that can take both the torque and the rpms?

///chris

 

http://www.10000rpm.com/ Probably others too. Alternatively, put a torque transducer in the driveline, and turn every run into an instrumented pass/pull.

 

Thats it, The Asphalt 1320. GET IT,???

 

Yes, a Digilog Testmate control system with a Henan/ Froude F-33 Brake will hold a constant 3100 foot pounds @ 10,000rpm. Oh, and a 450gpm 25hp water pump to feed the brake. Its about a $250,000.00 Dyno, but it will safely do it!!

 

ChrisR

On the track with 36 inch tire with growth the actual rpm with a 2.90 gear is about 6600. At 280 mph would be around 6850 rpm. About the only one who could verify the 280 rpm would be Gunderson!

 

Bill Reichert holds the record @ 280.66

 

a-fuel speed

You're right eli. Didn't mean to slight Bill. He is the best today. Just typing and not thinking.

 

Are these engines genarally big bore/short stroke or vice versa?

///chris

 

Most of the engine combo's are 3.5 X 4.375. This is 421 cid. However there are some other comb's that are like 426 and 433 cid. Maybe even a couple up to around 450 cid. At the present weight of 2105 the ideal engine size is 421 cid if you don't want to add weight to the car. For every cubic inch of displacement over 421 you are required to add five lbs. of weight to the car.
Some would argue that the larger engine size is offset by the theoretical increase in power. Some of the best et's this year have been by the larger engine combo. but most of the top 10 best cars run the 421 combo.

 

Thanx nitrohawk!

I suppose with a short stroke like that you can have the benefit of a really long conrod in a Hemi?

Is the evolusion like most other natural aspirated race engines, toward bigger bore, shorter stoke, lower deck hight blocks and higher revs?

///chris

 

I always thought that because of the slow burn rate of Nitro that a long as possable stroke was favored. I quess the minumum bore diameter is limited because of the valve size and arrangment.

 

Hey nitrohawk, thanks for the bore/stroke post. Do you have some rough numbers for deck height and rod length? Just curious what the norm is for such an A/FD motor. Compression? Do they rev very high?

In a situation where there are no governing rules or weight penalties, which variable does A/FD nitro tend to respond more favourably to in terms of engine geometry?

 

Tol

Yes I can give you rod lengths for both std. deck and .500 short deck motors, but will depend on the compression height of the piston. If you are interested in more information give me a private email @ bobholley33@yahoo.com
Also if you are considering the no rule best situation for the afuel motor that would mean running the nitro out of the 100% drum uncut.

 

You will shortly have mail. Thanks.....