Does the power this car is putting down seem right?

[FTT843]

Heres all the mods done to the car at a shop before we bought it. Dyno graphs included. Ill follow up with more information tommorow. What do you think this would run in the 1/4?  (383,4spd,3.91)





Sorry about the size ill fix it tommorw im way to tired and about to fall out at the keyboard.   

[Chryco Psycho]

looks about right for rear wheel HP , I didn`t hAVe time to read through the parts list though

[PlumCraZRT]

I forget what the losses are, but rear wheel drive has a lot of losses.  Definately not what you would expect to see at the fly.

[kudakidd]

I forget what the losses are, but rear wheel drive has a lot of losses.  Definately not what you would expect to see at the fly.

HP will be approx. 15% less at the rear wheels.

[HP2]

Almost 100 hp and 60 lb ft increase with a change in intake, heads and cam, not bad until you look at the price for the 100 hp. I'd guess that would be around 450 horses at the crank in ideal conditions. I assume that dyno run did not include the NOS shot.

Actual RWHP usually suprises people quite a bit. Losses through the drivetrain as well as ajustments to atmospheric conditions can really put a damper on those 500 horsepower claims. Where I am at, a 465 horse Hemi will only put down 200 rwhp through an automatic. You want to see some long faces at the dyno...

[nivvy]

Ive seen 500HP cars lay down 400 at the wheels.... which is 20% loss...

so I would say a 465HP Hemi would be 372RWHP ..... I cant believe it would be 200RWHP

Ive also seen stock 425 HP Hemis make 345RWHP which is about 20%

[Carlwalski]

I'll be getting the 528ci built to basically stock spec, I want it as mild as they can come.
Tim said around 600hp is the absolute minimum due to the nature of the engine and I should expect 615-630hp.

With around 615hp I'm hoping my RWHP would be around 510-520hp. The car is manual so I'm figuring around 15% in drivetrain loss. For arguments sake it worked out at 490hp @ -20% for an automatic car, some 30hp less.

[matt63]

Actual RWHP usually suprises people quite a bit. Losses through the drivetrain as well as ajustments to atmospheric conditions can really put a damper on those 500 horsepower claims. Where I am at, a 465 horse Hemi will only put down 200 rwhp through an automatic. You want to see some long faces at the dyno...

I don't understand that.  If the 500 hp doesn't include losses from the alternator, ps, fan, water pump then the real flywheel hp will be much less and perhaps the rear wheel hp numbers would be understandable.  After that, lost hp is going to heat.  100 hp is equivalent to 250,000 btu's in heat!  As a previous post on another topic said, you would be boiling the tranny and diff oil if that was the case. Interesting topic!

[360 'CUDA]

Heres all the mods done to the car at a shop before we bought it. Dyno graphs included. Ill follow up with more information tommorow. What do you think this would run in the 1/4?  (383,4spd,3.91)

I think a E-body should go low 13s pretty easy but 12s would be alot harder without slicks.  One of the limiting factors is the 3:91 gears. You would have to keep the slicks pretty short and that limits traction.

For consistancy and lower times an automatic with a good converter, low gearset and a 4:56 rear gear with 30" tall slicks would be a hooking monster and the rearend and tranny would last longer then with a 4 speed

Your way would be more fun though

[Carlwalski]

For consistancy and lower times an automatic with a good converter, low gearset and a 4:56 rear gear with 30" tall slicks would be a hooking monster and the rearend and tranny would last longer then with a 4 speed

Your way would be more fun though

I agree an auto would be more consistent and win more rounds overall but I feel a manual car would set the fastest time, say, if they had 10 goes each and recorded the fastest time. In other words the manual will still set a faster 1/4 mile, just not every round like an auto. It's good to have both!

[360 'CUDA]

I just can't recommend going 12s or faster with the 4 speed and a 8 3/4.  If you don't hook up you don't go fast enough and if you do hook up real well parts just start to fly off. First the U-joints go and the front one usually takes out the tailshaft.  When you bulletproof the driveshaft then the rear gear goes. If that holds together the axle housing will bend ect

With a heavy E-body and a 1.7 second 60 foot time or lower your gonna hurt drivetrain parts real fast and I doubt you could get 10 runs total without destroying something back there.

As far as 4 speeds being faster not everyone is the late great Ronnie Sox  .............

[Carlwalski]

I just can't recommend going 12s or faster with the 4 speed and a 8 3/4.  If you don't hook up you don't go fast enough and if you do hook up real well parts just start to fly off. First the U-joints go and the front one usually takes out the tailshaft.  When you bulletproof the driveshaft then the rear gear goes. If that holds together the axle housing will bend ect

With a heavy E-body and a 1.7 second 60 foot time or lower your gonna hurt drivetrain parts real fast and I doubt you could get 10 runs total without destroying something back there.

As far as 4 speeds being faster not everyone is the late great Ronnie Sox  .............

LOL! True but Ronnie (RIP) is not the only one in the world who can drive. You don't need to be a "pro" to run fast or know how to powershift @ WOT. Ronnie was the man, no question. If he had a Dana 60 things would be different. But I agree kind of that anything below an 11 second ET should consider converting to an auto, perhaps. If not for consistency then perhaps for a tenth or two.

[FTT843]

The car has a hardened yoke already it ate right through the pinion snubber the first day we got it and doesnt have a scratch... so think the drive line should hold up pretty well. We have done many good launches and hooked VERY hard through all the gears.

Someone mentions the use of an auto tranny. But that for sure wont be nesecery, My dad can outshift the 4spd most of the time catching the gear before its even ready. He can lay rubber easily through all 4 gears with drag radials. 

[FTT843]

.. sry made a double post

[Chryco Psycho]

It depends what type of dyno is used , I know different dynos will read as much as 15% different
 test on a Mustang dyno if you want to see disappointment , I watched a Mopar 528 Hemi pull 350 hp on a mustang
 I generaslly use the Mustang dyno to test on & the owner says it is X1.6 to get a 1970 Gross Hp rating on his dyno