How much HP at rear wheels?

[G Force]

As a guide to see if my car is perfroming to its potential.. I would appreciate if the Pros (moderators) could
Give me their  Best guess as to how much Horse power and torque I should have at the Rear wheels on my 70 charger + - 3,700 lbs.
and what my 1/4 mile run times should be.
Thanks in Advance!


Here is what I have:

440 ci
.040 bore
10.2-1 compression ratio
Kieth black flat top pistons
Eagle 2 piece connectiong rods
Edelbrock 84 cc aluminum heads intake valve size 291  exhaust valve size 214
Comp cam 274 intake  286 exhaust
                intake 31 open    63 close
                exhaust 77 open  29 close
comp cam roller tip rocker arms
Stock 6 - pac carbs with stock six pac manifold (I think its 1,350 cfm. Is that correct?)
The carbs have been jetted (dont know the size) and the Champion RJ plugs are burning at correct tempeture.
K&N air filter
93 octane gasoline
hughes stall convetor speed 3000 rpm
MSD 6AL ignition (900 -  6,000 rpms)
MSD billit distributor
727 transmission (with street shift kit valve body)
3.90 rear gear ratio
25.9" high rear tire height
Hooker headers with 3" collectors
3" straight out exhaust
Did i miss anything?

PS Are there any simple or single items that stand out to you, that could or should be changed to create a stronger set up?

Thanks again.

[firefighter3931]

That's a nice combo G Force  Assuming the heads are stock (unported) i would expect it to make in the 480hp range. With good traction and chassis tuning you have enough power for low 12's and maybe a high 11 on a very good day. 

More power comes with head porting and a bigger camshaft. 


Ron

[aifilaw]

agree with ron, 450-500 at the rear depending on how its tuned and losses through the drive-train. Gobs of torque around 4k and keep the RPM's up and you'll have a good day, if its strip only I would bump up the converter and definitely have the edels maxed out with a bigger cam. But very nice

[G Force]

Wow  I'm excited to hear those numbers.. We are talking at the rear wheels, Right?

Here now lies the problem,  When I brought my engine to be rebuilt, I spoke at lenght about what kind of performance I was looking for. ( keep in mind I have very limited knowledge of engine workings)
I knew I wanted an agressive street set up ( to follow the Muscle car theme).
The engine builder provided and reccomended the set up listed on my post.
The engine builder calculated that the engine should produce approx. 500 HP with 470 Ft Lbs at  approx. 5,000RPMs, What this transitions in rear wheel HP I am not sure.
The car is not performing anywhere near those numbers and I am not sure why 
Any insight would be Greatly appreciated as to Where I may be losing my engine Power.
As a foot note: My engine creates 8" of vacuum on idle and 10-15" on rev up. Comp cam says it should be in the 12-14" range at idle.
Is this a tell tale as to what the problem my be?
Thank you both again!

[aifilaw]

the engine should be producing well over 500 at the flywheel, when I said 450-500 I was accounting for driveline loss et cetera... so I would expect at least 550hp from a flywheel brake dyno.
If you aren't getting those and its falling far short, then I would start checking on the basics, ensure the timing is right, check the plugs and the A/F ratio. Ensure the cam has its full lift and the valve train is where it should be, after that do a compression test.
The vacuum seems just a little low, but that's an off-the-cuff response since I'm pressed for time.

My only real question on the build is the valve, are you sure about the valve sizes, and what lift on the cam, those are some detirmining factors, and that's all best-case scenario, which few get without luck, and a lot of tuning

[firefighter3931]

G-Force....the numbers i quoted would be at the crank. It takes 600+ flywheel hp to make 500 at the rear wheels. Based on similar 440 builds with hydraulic cam profiles in the 230*@.050 range with unported heads and a dual plane manifold. With some porting on the heads, a little more compression and a big solid cam/roller you can make another 70hp or so.

For example ; my 446 has a big solid with 30* more duration@.050, a single plane intake manifold and ported E-heads....that combo made 535hp/540tq at the crank. A solid roller cam is usually worth 25-30hp....all things being equal.


Ron

[70sixpkrt]

GForce your build is close to mine. I asked Ron, before I had mine dynoed, what he thought mine would be and he was right on the money. My engine dynoed at 491hp/535tq. I am very happy with the numbers. With street tires I ran 13.01 at 107.93 and it is a 4-speed.

440 bored .030=446
KB 237 pistons .003 deck height
Eagle 4340 H-beam rods
Comp is 10.25:1
Eddy heads 84cc with stage 1 and bowl blend
Straightline Cam 234/242@.050 540/525 solid with 112 lsa (4* built in) installed straight up
6-pack aluminum manifold with stock carbs.
forged crank .010 under
comp pro-magnum 1.5 rockers with 3/8 Smith Bros. pushrods
MSD 8546 dist.
Dana 60 with 3:54

[G Force]

Ron, Here is my BEST  Dyno results from a Mustang Dyno.
Is this where I should be... Or am I leaving alot on the table?

The dyno test posted was taken at a Speed shop in my area AFTER  they did some Rejetting and timing work.
The previous Dyno test on the mustang (before the Rejetting and timing work) resulted in 266 HP @ 4700 rpms and 349 LBS torque @ 3700 rpms.

70sixpkrt Thanks for the comparison! Do you have Rear wheel dyno reports Or 1/4 mile time slips for your car? If so I would love to continue to compare.
I have the utmost respect for Ron and know he has help many members over the years!    Thank you Ron 

I am a person that has High expectations (usually too high and somtimes unrealistic )  and just want to know if my car is performing at it optimal level.

[aifilaw]

mustang dyno's show the lowest numbers of them all, but not that low, I'm still of the mind that you should be seeing 375-400 RWHP on a mustang dyno

[70sixpkrt]

GForce here is a time slip that I did a couple of months ago. Remember my car is a 4-speed and I'm running BFG street tires and they were spinning. I'm in the left lane.

[firefighter3931]

Ron, Here is my BEST  Dyno results from a Mustang Dyno.
Is this where I should be... Or am I leaving alot on the table?

The dyno test posted was taken at a Speed shop in my area AFTER  they did some Rejetting and timing work.
The previous Dyno test on the mustang (before the Rejetting and timing work) resulted in 266 HP @ 4700 rpms and 349 LBS torque @ 3700 rpms.

70sixpkrt Thanks for the comparison! Do you have Rear wheel dyno reports Or 1/4 mile time slips for your car? If so I would love to continue to compare.
I have the utmost respect for Ron and know he has help many members over the years!    Thank you Ron 

I am a person that has High expectations (usually too high and somtimes unrealistic )  and just want to know if my car is performing at it optimal level.

G-force,

Chassis dyno numbers can be all over the place....and there can also be issues with the operator and correction factors. I don't place too much weight on those numbers....chassis dynos are good for sorting out the ignition and fuel curves. 

Take it to the track and post some numbers....the MPH will tell us how much power it is, or isn't making. 



Ron

[G Force]

Thank you all for the replies.

After Thrity 1/4 mile runs in one day, this is the best I could do.
I am having difficultiy getting off the line quickly. My six pac has mechanical linkage... No vacuum pods. 
I was told I would be better perfomance without the pods, Is that true?
If I accelerate too quickly may car will hessitate (bog down) before going.
Out of the thirty runs the highest speed accomplished was 104 mph and a time of  13.3.

[G Force]

Here are the attachments

[aifilaw]

your car is pretty close to where it should be, as ron mentioned, the dyno and dyno operator are indicative of numbers that mean nothing, and in this case he was dead-on. The dyno was reading much lower than it should, and it looks as though the car is doing well, and with some practice and minor changes in driver habits you should be able to break into the 12's with the current setup.

[firefighter3931]

G-force, Based on the ET's it's safe to say the chassis dyno results were off. It's hard t analyze the timeslip because you're having so much trouble launching due to carb issues. The 60ft short times aren't bad but there is definate room for improvement there. Once you get the fuel system sorted out it will pick up a lot of speed and the ET will drop.

I like to use the Moroso power speed calculator which is a slide rule that calculates HP based on weight and elapsed times. For example: a trap speed of 103mph should show an ET in the mid-high 12 range and yours is running 13.30's. Basicly the slide is confirming that the combo is working poorly at launch but still making descent power on the top end. 

Like Aiflaw, i believe this car will ET in the 12's easily once the fuel system and chassis are sorted out. 


How much does the car weigh with the driver ?
Any wheelspin at launch ?
what type of leafsprings ? shocks ? pinion snubber ?



Ron

[G Force]

How much does the car weigh with the driver ?                 + - 3,900 LBS?  (I weigh 200 lbs)
Any wheelspin at launch ?                                                Yes
what type of leafsprings ? shocks ? pinion snubber ?           Mopar perfromance HD Leafs  (extra leaf on passanger side)   Edelbrock IAS classic shocks.  Yes it has a Pinion Snubber.
Ron                                                                                 G Force

[firefighter3931]

How much does the car weigh with the driver ?                 + - 3,900 LBS?  (I weigh 200 lbs)
Any wheelspin at launch ?                                                Yes
what type of leafsprings ? shocks ? pinion snubber ?           Mopar perfromance HD Leafs  (extra leaf on passanger side)   Edelbrock IAS classic shocks.  Yes it has a Pinion Snubber.
Ron                                                                                 G Force

Well the car is heavy (4100 race weight) and the mph is being skewed by the poor launch....but even at that it looks to be in the 350 rwhp range. I'm sure that number would be better if you could launch well and make a clean pass. 

Hope that helps. For sure the Mustang dyno numbers are off.



Ron