dyno results

[metcoll]

just had my charger dynoed..what would be a guess at flywheel horsepower...my results were 327hp & 337tq..this is a built 440 with torqueflite tranny 4200 stall & 4.56 gears... I know gears & converter can throw numbers off a bit..

[c00nhunterjoe]

Figure on 15% loss for drivetrain roughly

[myk]

How is it "built?"  What are the 'specs?

[Kern Dog]

Figure on 15% loss for drivetrain roughly

15% would be on par with late model cars with tighter converters. I've understood 20-23% for a Torqueflite car and 15-18% for a manual trans.

[c00nhunterjoe]

Hence why i said roughly.

[oldschool]

at 20% driveline loss......408.75 hp @ flywheel.

[c00nhunterjoe]

Best way is take it to the dragstrip and get a mph number.

[fy469rtse]

Damn, would love it if only the 15%,
I know my figures on the engine dyno , once car on the road , chassis dyno mainly for tune ,
Will post on how much % I lost , hopefully very soon

[Challenger340]

just had my charger dynoed..what would be a guess at flywheel horsepower...my results were 327hp & 337tq..this is a built 440 with torqueflite tranny 4200 stall & 4.56 gears... I know gears & converter can throw numbers off a bit..

Hard to quote a definitive flywheel horsepower number from a rear wheel number, due to the mushy driveline disconnect on the auto/stall convertor ?
that said,
I'll guess that if it is a 10 inch torque convertor, "run of the mill" TCI or other lower priced units, and the 327hp occurred above 5,000 rpm ?, that the Flywheel Horsepower on an Engine Dyno would be around 395hp to 400hp.

IMO,
a basically stock 440 engine with a very mild Cam and 4 BBL ? In which case the 4200 stall and 4.56 gears may be redundant ?
Not trying to rain on your parade... just say'in....
that ain't much of a 440 ? for all that stall and gearing ?

   

[firefighter3931]

just had my charger dynoed..what would be a guess at flywheel horsepower...my results were 327hp & 337tq..this is a built 440 with torqueflite tranny 4200 stall & 4.56 gears... I know gears & converter can throw numbers off a bit..

Chassis dynos vary a lot....some read high, some low. The track will tell you how much power it's making....scale the car and run it at the track. Easy to figure out once we have a raceweight and 1/4 mile MPH number  


Ron

[metcoll]

How is it "built?"  What are the 'specs?

not a radical motor...six pack pistons, mild 452 heads, lunati cam (240/250@050,520/547lift) 13/4 headers,rpm intake with 780 holley double pump carb,& msd ignition...I was told motor should have 450-475 & the readings I am getting on the chassis dyno would be low because of the 4200 stall & 4.56  gears...

[Challenger340]

just had my charger dynoed..what would be a guess at flywheel horsepower...my results were 327hp & 337tq..this is a built 440 with torqueflite tranny 4200 stall & 4.56 gears... I know gears & converter can throw numbers off a bit..

Chassis dynos vary a lot....some read high, some low. The track will tell you how much power it's making....scale the car and run it at the track. Easy to figure out once we have a raceweight and 1/4 mile MPH number  
Ron

Like Ron said, the only way to know for sure  
Weigh it..... run it down the 1/4 mile and get a "mph" at the finish line.....  easy from there to calculate actual hp.

[BSB67]

How is it "built?"  What are the 'specs?

not a radical motor...six pack pistons, mild 452 heads, lunati cam (240/250@050,520/547lift) 13/4 headers,rpm intake with 780 holley double pump carb,& msd ignition...I was told motor should have 450-475 & the readings I am getting on the chassis dyno would be low because of the 4200 stall & 4.56  gears...

Like everyone said.  Chassis and engine dynos can be all over the map.  Dynos are tuning tools and can only be used for comparative purposes (motor to motor) if on the same dyno.  Using them for any other purpose is just a numbers game. 

Based on the parts, 450 to 475 seems reasonable.  But it is way more than parts that determine the actual power.  Using the rule of thumb, the 400 number seems right as well based on the chassis dyno.  Lots of variables though.

Don't know what your intentions are for the car, but you parts are a bit mis-matched.  If you go to the track and run a 1/4 mile (1320 ft) you won't make it to the end (figuratively).  You'll run out of motor at 1100 ft is my guess, unless you have 30" tall tires, or you're okay with trapping on the sunny side of 6500 rpm. 

[firefighter3931]

not a radical motor...six pack pistons, mild 452 heads, lunati cam (240/250@050,520/547lift) 13/4 headers,rpm intake with 780 holley double pump carb,& msd ignition...I was told motor should have 450-475 & the readings I am getting on the chassis dyno would be low because of the 4200 stall & 4.56  gears...

That's a nice combo.....cam & converter are well matched. It might be slightly overgeared depending on the tire diameter. It should pull nice to 5800 rpm and ET well into the 12's with good traction. I would expect somewhere around 108-110 mph if the car weighs 3900-4000 lbs 

As for power it is well north of 400hp....probably 440-450 depending on how well the heads flow and how well it's tuned. 



Ron

[BSB67]

I would expect somewhere around 108-110 mph if the car weighs 3900-4000 lbs 

As for power it is well north of 400hp....probably 440-450 depending on how well the heads flow and how well it's tuned. 

I think 108 to 110 is 400-ish hp.  I would expect 112-113 in decent air with those parts in a well tuned engine.

[1974dodgecharger]

I would expect somewhere around 108-110 mph if the car weighs 3900-4000 lbs 

As for power it is well north of 400hp....probably 440-450 depending on how well the heads flow and how well it's tuned. 

I think 108 to 110 is 400-ish hp.  I would expect 112-113 in decent air with those parts in a well tuned engine.

I can do 12.8 with 400HP to the wheels and 395ft-lbs at 105....I can also do 14secs..if I can get my shift right also...so I tell people 13.3 secs

[BSB67]

I can do 12.8 with 400HP to the wheels and 395ft-lbs at 105....

And the numbers game begin.

MPH & weight do correlate to hp.  et, not so much.

You could have 400 hp at the flywheel depending on the car weight and the atmospheric conditions.

If the car ran a 12.8, I would not sell it short by telling people 13.3.  For a car that is a real driver on the street, 12 sec. ets are good IMO. Making some assumptions about car weight, you probably had a 60 ft of about 1.85.  If not, there might be something else going on down track keeping your mph down.

[69wannabe]

How is it "built?"  What are the 'specs?

not a radical motor...six pack pistons, mild 452 heads, lunati cam (240/250@050,520/547lift) 13/4 headers,rpm intake with 780 holley double pump carb,& msd ignition...I was told motor should have 450-475 & the readings I am getting on the chassis dyno would be low because of the 4200 stall & 4.56  gears...

Are the 452's running stock valves or oversize valves??? Like Ron said above the amount of flow in the heads means alot. It made a big difference on my 440 when I had the bigger valves installed and mild port work done. With that size cam and the rpm intake with good flowing cast iron heads you should be close to the 450hp range I would guess. May be time for some good eddy rpm heads!!!

[1974dodgecharger]

I ran it twice in my life...just wanted to see....didn't really care just for fun and adrenaline rush.  I wont run it again due to parts breaking.....guys who do this and chase the numbers have lots of money for broken parts to fix which I don't.  My tranny blew up.....lets put it at that....well weakened it afterwards.

I can do 12.8 with 400HP to the wheels and 395ft-lbs at 105....

And the numbers game begin.

MPH & weight do correlate to hp.  et, not so much.

You could have 400 hp at the flywheel depending on the car weight and the atmospheric conditions.

If the car ran a 12.8, I would not sell it short by telling people 13.3.  For a car that is a real driver on the street, 12 sec. ets are good IMO. Making some assumptions about car weight, you probably had a 60 ft of about 1.85.  If not, there might be something else going on down track keeping your mph down.

[BSB67]

I ran it twice in my life...just wanted to see....didn't really care just for fun and adrenaline rush.  I wont run it again due to parts breaking.....guys who do this and chase the numbers have lots of money for broken parts to fix which I don't.  My tranny blew up.....lets put it at that....well weakened it afterwards.

I can do 12.8 with 400HP to the wheels and 395ft-lbs at 105....

And the numbers game begin.

MPH & weight do correlate to hp.  et, not so much.

You could have 400 hp at the flywheel depending on the car weight and the atmospheric conditions.

If the car ran a 12.8, I would not sell it short by telling people 13.3.  For a car that is a real driver on the street, 12 sec. ets are good IMO. Making some assumptions about car weight, you probably had a 60 ft of about 1.85.  If not, there might be something else going on down track keeping your mph down.

Yeah.  Not an inexpensive hobby.

[c00nhunterjoe]

I never understood the guys who wont go to the track, but thrash their cars on the street.    unless you are running slicks, the only difference between the track and the street is the track's legal.

[1974dodgecharger]

I never street race and never have I may accelerate fast, but not race per say.  Im more about crusing..........