If hp is more important then trq, then why is it that peak VE happens at peak trq and not hp? Logic would say that if hp is more important to ET and to an engine, that an engine should produce peak VE at peak HP.
==============================

like you... i also use to think Peak Ve% always occurred at Peak Torque RPM

but in 15 years of dyno testing all different sorts and brands of engines... i don't remember one time when peak Ve % occured at Peak Torque after engine was tuned for its best overall combination of Peak Torque and Peak HP


Peak Ve% typically occurs midway between Peak Torque point and Peak HP points...usually "closer" to Peak Torque RPM
as you stated.

The reason Peak Ve% in overwhelming majority of tests does not occur at Peak TQ point,
is that after Peak TQ point, pumping and friction losses "reduce" Torque values from their best Peak,
... even while the Cylinder is continuing to benefit from Inertia Ram/Wave tuning effects increasing the VE% values until Ve peaks later in RPM range.

 

http://www.maxracesoftware.com/WJ_Shift_Graph_2.jpg

the above 1st Link ..is old 1994 "best" ProStock run
at that time
796 to 800 Torque at 7500 RPM in 1994
1200 to 1220 Peak HP at 8700 RPM in 1994

notice WJ is only seeing Peak Torque points
for total amounts in hundreths of a second worth in time !
The rest of the entire Run is well over Peak Torque RPM point

and Shift and Cross RPMs are higher than the Peak HP RPM point as well !

============================================

the next Link, is another old Graph of an NHRA C/ED Dragster
of Joey Tanksley with 304 cid SBC engine
Peak TQ was at 7800 RPM
and
Peak HP was at 9200 RPM (720 HP @ 600 Rpm/Sec)
ran 7.56 ET which at that time was faster than C/ED NHRA record

notice the 8200 Stall converter
10,000 rpm shift point
10,000 rpm + finish line cross RPM

http://www.maxracesoftware.com/Tanks...ift_Points.jpg

that was with 2-Speed PowerGlide just before trying the 3-speed

--------------------------------------------------------------------------
Tanksleys currently running B/ED and qualified #17 at
17th annual O'Reilly NHRA Spring Nationals at Baytown, TX this weekend

most Pro Cars never see Peak Torque RPM down the DragStrip,
yet set many records

 

Thanks for the info and the graphs, Larry. It looks like the 10 yr old PS was in the 2500-3000 rpm/sec in the lower gears and near 650 rpm/sec in the top. Trans ratio steps are about 1.2:1.

Torque @ 8700 with 1200-1220 hp is about 735, within 8% of peak, so the engine was operating in a nearly flat torque range which makes the acceleration plots near a straight line with very little slope change. The last 40 mph or so (above 150 mph) comes in about 2.8 seconds. That's .65g or so in top gear which is about what a 2.20 60 ft time feels like for acceleration.


Yep. Intake and exhaust tuning is the key. Phillip H. Smith would be impressed with today's appplications of his research.

 

Master,

What is your engine's torque peak?

What RPM do you launch at?

What is preventing you from launching at a higher RPM?

Traction?

 

mastrdrver,

TQ is not a measure of work. The units make it look that way but it's just a force unless you muliply it by revolutions of radial dustance. Then divide it by time as in RPM times TQ and you got work/time and now you have power from which we can make meaningful estimations on acceleration ability. TQ by itself doesn't tell you much except how big your engine is or if you are running a power adder.

 

the above 1st Link ..is old 1994 "best" ProStock run
at that time
796 to 800 Torque at 7500 RPM in 1994
1200 to 1220 Peak HP at 8700 RPM in 1994
====================================

Current ProStock technology ; (2004)
808 to as much as 835 Peak Torque
1300 to 1330+ Peak HP

835(year 2004) - minus 800 (year 1994) = 35 TQ gain

1330 (year 2004) - minus 1220 (year 1994) = 110 Peak HP gain

9000 (year 2004) - minus 8700 (year 1994) = 300 RPM gain

***Notice the very much larger gains in HorsePower -vs- gains in Peak Torque..and moving power curve higher

with Peak Torque basically "locked into " CID engine size and Compression Ratio,...the only way to make more HP per CID and more HP / Weight Ratio is to find a way to move Peak TQ and HP curve higher in RPM range !
This method has been the predominate way in all forms of MotorSports to go faster since MotorSports racing has begun
in last Century .
============================================

More info from the past => remember the Dodge Boys in ProStock rumors of using/cheating with Nitrous ??
...at that same time i was Dyno testing Troy Coughlin's ProStock engine on my dyno.....Kip and Terry at Cam Motion were supplying both teams with camshafts, the Dodge Boys were claiming 1200 HP at 8200 RPM at same time WJ was claiming
1200 HP at 8700 rpm with 797 Peak TQ @ 7500 rpm
the Dodge Boys were using entirely different Lobe designs than anyone else .

the Dodge Boys were slightly faster at that time and were mostly dominating ProStock.....so Kip was pretty impressed with the way they were making Peak HP a whole bunch lower than anyone else in ProStock he was grinding Cams for !!

sort of thought the Dodge Boys were the "Einsteins" of ProStock, and that we would try to make Peak HP and Peak TQ in same RPM points as Dodge Boys ..for Troy Coughlin 's engine .

we made some gains moving Peak HP and Peak TQ downwards
..but basically the 1st 4 weeks was a waste of time .
then the news broke all over the Internet of the Dodge Boys breakin and Nitrous rumours. i finally ran a computer simulation
from the incremental times, and couldn't see Nitrous being applied during the Run....so they must have applied Nitrous from starting line ..thats why some of HoodScoop fires/explosions were occurring at starting line.
but during the computer simulation..it calculated that the Dodge Boys had to be making at least 850 to 860 Peak Tq to run the numbers they were.... i told Kip this was impossible to do and they were most likely using Nitrous !

10+ years later...and still no ProStock Team is making 850 to 860 Peak Tq @ 600 Rpm/Sec

and no ProStock team is trying to make Peak HP at 8200 RPM

so we basically wasted 4 weeks of Dyno Testing chasing a "Lie"
the last 2 weeks of Dyno testing we started moving entire power curve upward ...and qualified for 1st time in ProStock
then Troy canned the whole deal and went with WJ program, later went out on his own, and to where he is now.

 

Is it not force that does the work and not revolutions? So:

trq=work done
hp=amt of work done over time

 

796-797 Peak TQ @ 7500 / 1200 Peak HP @ 8700
old ProStock record by WJ
60 Ft = 1.051
330= 2.924
660= 4.480 @ 159.06
1000= 5.819
1320= 6.948 @ 199.15
--------------------------------

approx 825 Peak TQ @ 7800 / 1330 + Peak HP @ 9000
2004 ProStock record
60 Ft = .999
330 = 2.795
660 = 4.293 @ 164.17
1000 = 5.582
1320 = 6.670 @ 207.18


6.948 - 6.670 = .278 ET reduction
207.18 - 199.15 = 8.030 MPH increase

29.0 Peak Torque increase
130.0 Peak HP increase

along with also advancements in chassis/traction/tires/clutch,
aerodynamics, hoodscoops,etc

 

Automotive Mechanics and Technology, Second Edition. Steckner.

Horsepower:

A measure of performance. It is the rate of doing work expressed
as work per unit of time. The term horsepower was introduced by
James Watt.

One horsepower = 550 pounds per foot, per second (550 ft.lbs./second).

or

1 HP =0.764 Watts

 

Again, many thanks for the info Larry.

Keeping it up (the torque curve, that is) at higher and higher rpm is the road to peak hp, as you said. Formula 1 (2003 BMW) is about 900 hp @ 18,200-18500 or so with peak rpm @ 19,200.

An interesting measure of air pumping or power production "efficiency" is to look at torque at hp peak rpm, per cubic inch. A 900 hp @ 18,300 rpm 183 cube F1 engine is at 1.41 lb-ft/cu. in. A 1330 hp @ 9000 500 cube PS engine is at 1.55 lb-ft/cube, or 10% more! PS is up from 1.45 in 1994. Trap speeds are up 4% from 10% more hp which just about what aero drag would require @ 200.

If we guess at a Nextel Cup engine at 820 hp @ 8700 from 358 cubes, that's 1.38 lb-ft/cube, right in there with F1!

Both the F1 and Cup engines are endurance engines which run over a million revs in anger. The PS engine runs about 1000 revs in a run, and then gets some attention to at least the valve springs.

All three of these engines are at the "peak" of gasoline NA engine development in both power and probably cost. I am continually impressed at the amount of air per cube pumped by all three, but especially by the two-valve per cylinder PS and Cup engines.


Most interesting story about the Dodge Boys. It confirms other stories I've heard. They should have quoted a higher rpm and you would have had a more difficult time figuring it out.

 

No... force does not "do the work". Work is a product of force over distance. Power is a rating of the amount of work done per unit of time.

trq=angular force
hp=amt of work done over time

 

Most interesting story about the Dodge Boys. It confirms other stories I've heard. They should have quoted a higher rpm and you would have had a more difficult time figuring it out.
========================================

funny....no more HoodScoop fires or explosions on the Starting Line


its been awhile ...hasn't it ???


hint=> ever since the "Breakin"

 

Nope, they won't. No matter how well it is explained (as it has been in this thread and in all the past threads just like this one). But like you initially said, that's OK--just take their money instead of trying to educate them. I don't feel that way with most subjects, but after arguing until I'm blue in the face over this one in years past, I make an exception.

Reading through this thread has brought back some good memories of the old days, though. Notably the thread exactly like this one here about 6 years ago that frustrated me so.

 

approx 825 Peak TQ @ 7800 / 1330 + Peak HP @ 9000

2004 ProStock record

60 Ft = .999
330 = 2.795
660 = 4.293 @ 164.17
1000 = 5.582
1320 = 6.670 @ 207.18
----------------------------------------------------------------------------

OldSStroker ,

you might be interested in these 1/4 simulation runs

http://www.maxracesoftware.com/ETA_Win_1.jpg

http://www.maxracesoftware.com/ETA_Win_2.jpg

http://www.maxracesoftware.com/ETA_Dos_1.jpg

 

I would have to agree with the comment that racer made a few post ago. I believe that horsepower is more a factor in drag racing than torque. Think about it. It doesn't matter how much peak torque you make down low between 2,000 and 4,000 rpm. When you go to the track most of us either have 3 to 4 thousand stalls or dump the clutch at 5,000. Now we are in that peak torque for what a split second then we are up in the power band from 5,000 on. this is were the car is running so this is were the horsepower is doing the pulling. Remember horsepower and torque is the same at around 5,250 rpm so the more peak horsepower you try to make then you will have more torque up top as well. Maybe not as much peek torque but you will have a good combination of good horsepower and torque. So I say build your motor for horsepower and the torque will fall in place. Think about it a do you think that those 3 second rail cars build for torque or horsepower? I know a dump truck makes a whole lot of torque along with school buses and semi-trucks but I dont see none of them running the quarter mile anytime fast.