how many people tell the truth about horsepower? do you?

[cold85]

Every where i go people ask how much horsepower i have in my charger 440 with intake headers msd box and distributor and cam i tell them i think around 390to 400hp. i had a 87 gn that dynoed at 439 rwhp and that is what i would tell people. But i have had a ton of people tell me about their 350 60 some model impala that has factory heads and a small cam have 600 horsepower and was built for 87 octane gas? and last night i was watching speedvision and a guy with a street acura said he had 500 hp at the front wheels and i know that from what he said he had there is no way he had that much at the wheels. I think this is the biggest lie people tell about their cars. i for onw tell to the best of my knowledge what my car has and if i dyno it i tell exactly what it did. What are some stories you have heard.

[SirNik73]

i agree, totally. i have friends who think they have all this horse power in their cars... and i know they don't. I've got a 400 in my charger and when people ask how much horse power i have and i tell them around 275, they flip pout and tell me that i have to be wrong. i think people are gauging their HP via the feeling they get in their @$$. what people don't get is that is Torque not HP. my mercedes kicks had and jerks the tires when it shifts... and its got like 130 HP in a 6000 pound car... it jerks because its a Diesel and probably has 200Ft/LB of torque.

[Blown70]

Every where i go people ask how much horsepower i have in my charger 440 with intake headers msd box and distributor and cam i tell them i think around 390to 400hp. i had a 87 gn that dynoed at 439 rwhp and that is what i would tell people. But i have had a ton of people tell me about their 350 60 some model impala that has factory heads and a small cam have 600 horsepower and was built for 87 octane gas? and last night i was watching speedvision and a guy with a street acura said he had 500 hp at the front wheels and i know that from what he said he had there is no way he had that much at the wheels. I think this is the biggest lie people tell about their cars. i for onw tell to the best of my knowledge what my car has and if i dyno it i tell exactly what it did. What are some stories you have heard.

I love the HP estimates.   Put her on a DYNO.   If someone tells me I have X amout of horse I ask for the dyno sheet.   Now most people do not have one and studder like a MOFO,  

The only issue I will have is the place that will build my engine the dyno max is 1,000hp....(I will have to talk tim into a bigger dyno) So I guess I cannot say I will have over that...

Tom

[firefighter3931]

Good topic Cold85. A lot of people guestimate their hp #'s based on data they read in magazines. Usually their power numbers are high based on the combination of parts in their motor. The magazines don't help because they create unrealistic expectations for their readers. The facility that dyno's engines for Mopar Muscle (Westech in Ca.) is notorious for having a "happy" dyno and they have so much as admitted that theirs is off 7-10% on the high side.

Unless the engine is dynoed, no one really knows how much power they're making. You can predict based on other engines that are running similar combinations, but it's a guess at best. Ultimately, the track will tell you how much power the engine is making...it is the true dyno. A 600hp motor that dips into the high 12's ain't no "real world" 600hp motor....and there are lots of those running around.   

As for me, mine has been dynoed so i know exactly how much power it made and where that power comes in and when it noses over. Makes picking a converter and gears so much easier when sorting out the car. The dyno experience is a great chance to learn and should be strongly considered for any performance build. Fine tuning can be performed while the engine is being tested to determine optimal timing and fuel curves....it is the ultimate tuning tool.

So, the answer to your question is yes, i tell the truth about power #'s if anyone wants to know and have the sheets to back up those results.

Ron

[bluesfool]

I don't need to impress anybody...I tell them what I have. Fortunately though, most people just say something like " I bet that thing is fast!", to which I reply 

[THE CHARGER PUNK]

we have not yet taken our car to the track but have had it rear wheeled dynoed at 610hp we will do an actual engine dynoe this summer b4 we take it 2 the track-MATT

[Smoke20]

So what's the bigger lie men tell..... Horsepower or inches! 

[ChargerSG]

That one was a good! Since i have a 318 in my Charger there is no need to lie....

[69bananabeast]

I might fudge it  a little bit but not like other people would . I've got a built 440 and have heard from a few people that it has about 490 Hp . I've told a couple people it's 500Hp just to have a more sound #. When i actually do Run it/Dyno it  i'll round it slightly say if it ends up being 493 Hp  I'd tus tell people its 495 hp . I dont think it would hurt too much.

[hotrod98]

I always answer the same way..."how the hell would I know?". 

[yellowcuda]

The other funny thing is when people don't quote rwhp and you do, then they act like yours is so low.  We keep a dyno sheet on the hemi blower car, but then we explain that it is underdriven and etc. etc.  Seems like every 80's something mustang we run across has over 500 hp...yeah right

[ChargerRT440]

  well since all thats going into my dart is a built 318(I say built as in I built it myself) with port polished heads, a valve job, purple shaft with something like .500" lift, a eddy 4bbl manifold and a 4bbl carb. With stock flat top pistons and stock bottom end. Really I'm only expecting at the most 250 hp if I go with better pistons to reduce cc's I might get more like 300. I'm hoping to find a cheap way to make like 350-400 hp, but that seems a little hard to do in a 318. If anybody could suggest anything I'd really appreciate it.

Anyways how would I test the hp of this engine since the cars not close to ready to have the engine put in?

[Blown70]

::)well since all thats going into my dart is a built 318(I say built as in I built it myself) with port polished heads, a valve job, purple shaft with something like .500" lift, a eddy 4bbl manifold and a 4bbl carb. With stock flat top pistons and stock bottom end. Really I'm only expecting at the most 250 hp if I go with better pistons to reduce cc's I might get more like 300. I'm hoping to find a cheap way to make like 350-400 hp, but that seems a little hard to do in a 318. If anybody could suggest anything I'd really appreciate it.

Anyways how would I test the hp of this engine since the cars not close to ready to have the engine put in?

Engine shops around my have a DYNO,  Otherwise once in the car you would need a Chassis dyno,  Those are harder to find, at least by me.

[ChargerRT440]

Can anybody guess what my hp would be? the number isn't really important to me it's just a running motor in the car

[hemihead]

A lot of these people don't even know what a dyno is! LOL And they don't even use all that HP anyway just driving at 35mph to the local Spit and Shine Show.

[Troy]

we have not yet taken our car to the track but have had it rear wheeled dynoed at 610hp we will do an actual engine dynoe this summer b4 we take it 2 the track-MATT

Hmmmmmmmmm:

510hp to the rear wheels-MATT

i dont i just know it could waste the tires off the car in 3 blocks

the engine was originally dynoed by the last owner at 560hp we took off the 850 holley double pumper and swapped it with a 750 edelbrock and tweaked it a little and small changes to the engine .the guy who helped us with the engine is a charger fanatic/mechanic who told us that thse changes would increase our horsepower by 50.im not sure if it is all that but the car is alot faster then after we made the changes-MATT

Troy

[hemigeno]

I tell people that it has enough power to pass anything but a gas pump...

[426wedge]

I like to keep most things like that secret. They can find out when they see   my tail lights.   Actuallly I've only had one of my cars on a chassis dyno. It was a 440 in my 70 Cuda.   I had $400 invested in that motor and a lot of tuning.   With a 4spd and 4:10's it was sideways at almost any speed. FUN... It had 288 hp and 317 torque with a very flat curve. The funny part of the story was right after me was a 70 chevelle with a 454 4spd 4:11s. He had MEGA dollars in this car. He turned 244 hp (can't remeber the torque). He was MAD. He said that the dyno was broke. His car will go sideways in all 4 gears. More whining and crying. It was funny to watch.   I love it how most people think they have 500+ horse. Ya just gotta laugh.

[69charger2002]

so troy, would that be 510, 560 or 610??? 
lol
trav

[Ghoste]

I haven't a clue nor could I care.  Even if I did know, no one would ever find out.

Only my dyno operator knows for sure.

[RD]

my charger has 0 hp (no motor in it)

my duster has 0 hp (motor is in the machine shop, ahhh to wish to have money to complete it)

my ramcharger, well, I dont know, but it roasts the rear tires and well that is good enuff to me!

[Charger500]

the people that don't know much about cars only hear your horsepower and then immediatley judge your car.

[Smoke20]

I tell people that it has enough power to pass anything but a gas pump...

Ha! No Doubt, especially the way gas prices change daily these days.

[bluesfool]

the people that don't know much about cars only hear your horsepower and then immediatley judge your car.

Say it again brother!

[TheGhost]

I don't lie, because I have very little hp in my Barracuda.  180 hp, 260 tq is the stock ratings for a 273 2v in 67, I believe, and since my engine has never been rebuilt, I gotta be making a bit less than that.

[694spdRT]

we have not yet taken our car to the track but have had it rear wheeled dynoed at 610hp we will do an actual engine dynoe this summer b4 we take it 2 the track-MATT

Hmmmmmmmmm:

510hp to the rear wheels-MATT

i dont i just know it could waste the tires off the car in 3 blocks

the engine was originally dynoed by the last owner at 560hp we took off the 850 holley double pumper and swapped it with a 750 edelbrock and tweaked it a little and small changes to the engine .the guy who helped us with the engine is a charger fanatic/mechanic who told us that thse changes would increase our horsepower by 50.im not sure if it is all that but the car is alot faster then after we made the changes-MATT

Troy

Note to self...the search button on this site does work.   

[cudaken]

 Yea people seem to day dream to much and get caught up in the Mag trap. I have posted before what are Mopars made in real HP at the crank and most people want to hang me or there heads.

Bottom line, no matter what you claim what matters is who gets the win light.

Even the chassie dyno can be miss leading but great for tuning.

Bottom line, I have beat the shit out of more than one claimed 600 HP plus cars with a 11.8 68 Road Runner.

On the street a real 400 HP at the crank will get you in to the high 12's if you can hook up. Not numbers to impress people with, but the look of the 500 HP Bragging right losser? Pricless.

                  Cuda Ken

[69_500]

I have no idea what the horse power is in the 500. Its a pretty strong running 440, but it hasn't ever been torn down and it has 80K+ miles on it, so i'd say probably about 320.

But its  enough to make my son excited and its a Charger so that is all the matters to me.

[ChargerRT440]

lol it's liker my mechanics teacher trying to convince me that a hemi only had 375 hp(he's a ferd guy) And I just laugh.

[Silver R/T]

people can bs all they want but if they got dyno sheet I respect that

[Brock Samson]

  got mine dynoed at 503/510 with a leaky LS-6 Carb... but what it does in the car at the rear wheel is provide alot of fun! 
damn thing is slow in the quarter, wrong gears, a one legger,.. glove box popps open... but who cares?..  it sure sounds fast...  last thing i did was get a new tranny, bigger tires the rims and the Holly Street Avenger...
  still needs at least a dana and torque boxes...
ahhh,. the dream continues...
one day maybe even the duces, A/C and a OD... 
I just tell em 7.4.

[Lowprofile]

475 Cat putting 429 HP to the Wheels. Oh yea, about 1600 ft. lbs. of Torque. My daily Driver

[ChargerBill]

we have not yet taken our car to the track but have had it rear wheeled dynoed at 610hp we will do an actual engine dynoe this summer b4 we take it 2 the track-MATT

Hmmmmmmmmm:

510hp to the rear wheels-MATT

i dont i just know it could waste the tires off the car in 3 blocks

the engine was originally dynoed by the last owner at 560hp we took off the 850 holley double pumper and swapped it with a 750 edelbrock and tweaked it a little and small changes to the engine .the guy who helped us with the engine is a charger fanatic/mechanic who told us that thse changes would increase our horsepower by 50.im not sure if it is all that but the car is alot faster then after we made the changes-MATT

Troy

That's classic Troy...thanks for the laugh!

[Ghoste]

If the truth can't be told in a thread about telling the truth, then you have to really wonder.  I guess with so many dragstrips closing up and so many smaller shops with dyno's, it's become the new way of claiming how fast your car is.  Remember when everybody claimed their car went 12 flat?

[Just 6T9 CHGR]

we have not yet taken our car to the track but have had it rear wheeled dynoed at 610hp we will do an actual engine dynoe this summer b4 we take it 2 the track-MATT

Hmmmmmmmmm:

510hp to the rear wheels-MATT

i dont i just know it could waste the tires off the car in 3 blocks

the engine was originally dynoed by the last owner at 560hp we took off the 850 holley double pumper and swapped it with a 750 edelbrock and tweaked it a little and small changes to the engine .the guy who helped us with the engine is a charger fanatic/mechanic who told us that thse changes would increase our horsepower by 50.im not sure if it is all that but the car is alot faster then after we made the changes-MATT

Troy

DOH   ....Its possible he could have added some power adders to his latest dyno run HP #....no?


Anyhoo.....heres my #'s   I was kind of surprised at such a low # after hearing all the high #'s on here.   Im happy with it though.  It starts on the first crank, idles nicely, sounds great, can run on 93 octane, averaged 15mpg down to Carlisle and can still dust a few Mustwangs & ricers locally and my frineds '69 Z/28 Craparo 396 4 speed at the track!!

[firefighter3931]

Anyhoo.....heres my #'s     I was kind of surprised at such a low # after hearing all the high #'s on here.     Im happy with it though.   It starts on the first crank, idles nicely, sounds great, can run on 93 octane, averaged 15mpg down to Carlisle and can still dust a few Mustwangs & ricers locally and my frineds '69 Z/28 Craparo 396 4 speed at the track!!

Those are very respectable #'s that represent a measured power level, for that dyno, on that day with that particular operator. Different dynos will produce different results so comparing from one to the other is really pointless.....too many variables. I'd be willing to bet that yours is as strong or stronger than most on this board who've posted higher #'s...just my opinion. The combination of parts in this motor should produce an honest 420 crank hp and 500+ ftlbs of torque. I'm sure it's a blast to drive.  

Ron

[cudaken]

lol it's liker my mechanics teacher trying to convince me that a hemi only had 375 hp(he's a ferd guy) And I just laugh.

Hum, it closer to being right than you think. 67-71 Street Hemis stock not super tune made between 390 to 410 HP. Guess that is why he is the tracher.

That is from the old DC Racing manual.

                                                                                      Cuda Ken

[Brock Samson]

ok,.. your comments got me thinkin so I dug out my printout from 2/6/97.

     high torque   534.4  at 376.5 H.P.         3700 RPM

     high H.P.      418.7  at 439.8 Torque.    5000 RPM


                         

is that good?..

[Smoke20]

.....heres my #'s     I was kind of surprised at such a low # after hearing all the high #'s on here.     Im happy with it though.   It starts on the first crank, idles nicely, sounds great, can run on 93 octane, averaged 15mpg down to Carlisle and can still dust a few Mustwangs & ricers locally and my frineds '69 Z/28 Craparo 396 4 speed at the track!!

Those numbers arent bad, Chris. Besides HP is BS anyway. Torque is what moves the car and it looks like you have about 300 lb-ft of it.

[Jon Smith]

I tell people around 550hp at the flywheel but its a guess really
it runs low 12s with no traction, full weight car

[Ghoste]

Hey Chris, at least you've posted a scan of an actual dyno sheet instead of just making it up.   And no, I'm not implying that anyone here is liar.  Unless of course you are, in which case we are all on to you.

[Chargerguy74]

lol it's liker my mechanics teacher trying to convince me that a hemi only had 375 hp(he's a ferd guy) And I just laugh.

Hum, it closer to being right than you think. 67-71 Street Hemis stock to super tune made between 390 to 410 HP. Guess that is why he is the tracher.

That is from the old DC Racing manual.

                                                                                      Cuda Ken

What is all that closer to 500hp talk going around? Wonder what kind of dyno those numbers were from.

[Afflyer]

When I show the "Mistress", I tell people when they ask about the horsepower of my 440, I tell them that when it rolled off the line, it was 350 horses.  Take 15 horses off for the power steering pump and it's basically 335 horses- but I've yet to dyno the engine for a true number.  I won't dyno it until the engine is completely rebuilt.

As you all here may or may not know, my 440 has never been rebuilt.  It had new freeze plugs installed when it was placed in my Charger, before I bought her, but that's all.  I don't know how much or when I'll be able to do a really good rebuild.  When I do, I want to keep the stay with a mild or "purple" cam.  I just love the stock 440 sound with my Flowmasters.  I get more comments on the sound of my old 440 at the car shows, compared to some of the guys who beef up their engines with monster cams, etc..

Bradley 

[Baracda]

It would be a lot more useful for people to post thier car weight and thier MPH in the quarter.  Work over Time as they say...

jim

[cudaken]

 Chargerguy74, guess it was from the guys that said they had 450 HP and got there theeth kicked in my a Hemi. I as well have heard about the Hemi making 475 HP and all that happy stuff, but not stock as a rock. Well tuned and every thing perfect I could see 435 HP and may be a little more.

Seen the road test of Ronnie Sox's in a 69 and 1/2 440-6 Pack, 4.10 gears and 4 banger and I think ran a 12.8 stock? Give me a break, that sucker was blue printed and tune beyone anything most of us could dream about.

All well, drunk, wifes friend is over and no 440 to work on so I will post some real numbers. This is a spread. Take a 440 Highs will be 67-71 440's, lows will be after 71. Take it from there, these are the OLD DC Numbers not mine. At the flywheel and no Alt, PS or fan.

318 2 barrel 150-170 Hp
340 4 barrel and 6 barrel 275-290 Hp
360 4 barrel 225-245 Hp
361 4 barrel 240-270 Hp
383 4 barrel AFB, AVS and Holley 260-290 Hp Made me sick owing a 68 Road Runner rated at 335 HP
400 4 barrel TQ 240-270 and right with the 383
413 4 barrel AFB 280-305 Hp and does not count the Maxie
426 Wedge 4 barrel AFB 290-320 HP
426 Maxie Wedge S/S 475-500 HP, 11's stock out of the box, no warranty. Wonder why?
440 4 barrel AFB, AVS, TQ, Holley 270-330 HP
440 6 barrel 3 Holleys 340-370 HP
426 Hemi 8 barrel 2 AFB 390-410

Now a little math. Say you have a 4000 pound car and want a 101 trap speed you only need 340 Hp. If you are hooking good, not great, you will cut 13.20's. That is a little worked with snubber, clamps on the springs and 10" slicks. Power to weight is .085.

Let take a real 500 HP engine with the same rear end set up and it will hurt and 4000 pound car. Power to weight is 0.125 =116 MPH and that is 11.40's

If you look at the math, it is easy to see how a 270 383 can get into the 14.9's. You don't need as much real HP as you do bragging rights HP.

Besides, want to tell the bench racer next to you you run 13.2's with only 340 HP I do

Math may be off a little, few cam 2's where used during the math but will be pretty dam close.

                                Cuda Ken, wanting to kick some more 500 HP Chevys in the ball bearings again

  

[ChgrSteve67]

I am shopping for a Dyno shop to put my rebuilt drivetrain on to get it tuned and tested.

How much is it going to cost me to have my Charger strapped to a Chassis Dynamometer?

[HeavyFuel]

cudaken, you are my idol.   

['CUDA360]

Right cudaken....You beat me to it

In the back of the old direct><connection engine book is the drag strip dyno   The formulas work great as long as you know the weight of your car with you in it and the trap speed at the dragstrip

On my '72 'CUDA the W/P number according to the book is 10.4   That is a mopar car with an automatic transmission that goes 106 mph in the traps.

The formula looks like this....2850# (the car's weight) divided by 10.4 = 274 HP

So my 'CUDA goes 12:45 @106 mph with a 274 HP   

You can work the formula backwards like this
274 HP divided by 2850=.096            .096 is on another chart as a car that goes 106 mph with an automatic

Maybe not the most accurate but it works for showing improvement.
As the car gets faster by making changes like jets or even a whole engine change you can keep redoing the formula for each run to find out what is working and what is not.

Also, if you have friends with similar cars you can all go down to the track to find out who has the most horsepower according to the charts
Here are copies of the charts below. Try it on your car

[cudaken]

 360Cuda, I want my bible back

You must be a old timer like me to remember the old DC Racing program. I got my first bible around 1975 or so. When I got to the back and saw the numbers they posted I was pissed and knew there number's where wrong! Then I started to go to the strip with the then stock 68 Road Runner, hum 15.2 at 92 MPH? Started to read and learn and watched the ET drop and MPH go up. What I did went hand in hand with there math.

People just forget or don't realize the advertised HP is just that, advertisement to sell cars. When  our cars where made the big 3 where in a HP War, bigger HP numbers sold cars. Same with the car Mag's rag's, would you buy a Mopar mag that said a 440 only made 320 HP

What year is your DC Manual 360Cuda, my last one is 1978.

                         Cuda Ken

[MOPARHOUND!]

In the latest issue of Mopar Collector's Guide, Ray Barton rebuilt a 71 426 Hemi from a GTX to stock spec's (I'm sure he did some blue printing, and dyno tuning) and it made 498 horsepower at the crank.

Many a story out their about 426 Hemi's off the show room floor running poorly.  Talked to Mr. Norm of Grand Spaulding Dodge at this year's June www.hpacmopar.com club Mopar show in Kansas City, and he said getting the timing right and tuning the carbs made a world of difference on the car's new.  He said his dyno was one of the greatest investments he ever made.

[cudaken]

In the latest issue of Mopar Collector's Guide, Ray Barton rebuilt a 71 426 Hemi from a GTX to stock spec's (I'm sure he did some blue printing, and dyno tuning) and it made 498 horsepower at the crank.

Moparhound, I don't think Ray Barton remembers what a stock Hemi is . With his rep as a racing engine bulider he had to make thoses kind of numbers. Sure he used is 25 years plus of tricks that would pass as stock to the naked eye. More than likely played in side on the intake, messed with the runners. Match poreted everthing, maybe just a little pocket work, blue printed deck height, custom cut push rods, had the stock manafolds hogged out a little.

Don't get me wrong, I never said a Hemi could not make well over 425 HP. But not the way they where made at the factory. Same with the other egines I listed, but we are talking about the way they from the factory.


                        Cuda Ken

                       

[Jon Smith]

An engine built by a top race engine builder is not the same as one built on a production line by someone who's not interested and is probably thinking about the few beers he's gonna have later on

[Blown70]

I think for ray barton to build to hemi specks he would have to use the equipemnt from the era.... I am sure the tolerances on his equipment is NOT the same as 30+ years ago.  Parts esp metal are made better today than yester year....

Also, define stock specks,  as pointed out above Friday at 4:30 as a shift would end well do you really think the same attention was paid?

[firefighter3931]

Right cudaken....You beat me to it

In the back of the old direct><connection engine book is the drag strip dyno   The formulas work great as long as you know the weight of your car with you in it and the trap speed at the dragstrip


Here are copies of the charts below. Try it on your car

Interesting charts Cuda, thanks for posting them. Using the formula provided and comparing power to weight ratios with MPH using my own car i come up with 119 mph which is good for low 11's.

4000lbs/535hp = 7.47lbs per hp (auto trans)

As per the chart, that falls between 118 and 120 mph in the 1/4 mile. I haven't run it yet but will next season....should be interesting to see how close the chart is to reality. I know it has plenty for mid 11's but low 11's would be a pleasant surprise.

Ron

[MOPARHOUND!]

In the latest issue of Mopar Collector's Guide, Ray Barton rebuilt a 71 426 Hemi from a GTX to stock spec's (I'm sure he did some blue printing, and dyno tuning) and it made 498 horsepower at the crank.

Many a story out their about 426 Hemi's off the show room floor running poorly.   Talked to Mr. Norm of Grand Spaulding Dodge at this year's June www.hpacmopar.com club Mopar show in Kansas City, and he said getting the timing right and tuning the carbs made a world of difference on the car's new.   He said his dyno was one of the greatest investments he ever made.

Just the messenger.  Thought it an interesting angle to add to the debate/discussion.   

[MOPARHOUND!]

An engine built by a top race engine builder is not the same as one built on a production line by someone who's not interested and is probably thinking about the few beers he's gonna have later on

Hence, they run poorly when new.

I've heard one story of a guy so frustrated getting his hemi to run, he pulled his hemi back in the day for a 440.

Same Mopar Collector's Guide, page 128 concerning a 70 Hemi Challenger, "Then, to Jose' and Gus' absolute horror, they discovered what a number of new Hemi owners found out quickly - the car was a dog!   As delivered, the Challenger with the big Hemi was getting spanked by small block Chebbies. ........ The Challenger went through the full dyno treatment at Mr. Norm's within a few months of being new, after which it performed like the lion it was supposed to be."

Cool thing is they show the March 31, 1970 dyno receipt from Grand Spaulding Dodge, $13.65 for parts and $56.95 for labor.  Roughly $80.00 for a dyno session, that would be sweet.

Wish they would have listed the dyno numbers.     

[Baracda]

Its not working right now for some reason but there is a really nice website at www.prestage.com that has a number of active plug n play formulas for everything from dyno-generated shift points to piston speed to HP/MPH calculations.   The site has been around for 8 years or so, be patient with it and it will be up again soon I hope.

Whats interesting about this HP discussion is how it relates at the track.   Its funny how many bench racers use the ET as the generator of HP and its nice to see the old DC charts developing the actual HP relationship based on Work/Time.   Thanks for posting them.   Moroso used to make a really neat paper slide rule calculator that did the same thing but I dont have one anymore.   

The suspension plays into this so much that you can get strange anomolies of an ET with a car thats not set up "right" for the track.   My car has a tight suspension both front and rear and runs a nice MPH but the ET is way way off.   A typical slip reads as folows:

60ft - 1.643
1/8 ET - 6.789
1/8th MPH - 107.37
1/4 ET - 10.606
1/4 MPH - 131.67

My ET is way off what the MPH would indicate.   This is with a 3200 stall convertor which doesnt allow enough stall to let the motor move up into the power band when I hit it.   The front only comes up about 5 or 6 inches but the front suspension doesnt drop, it carries it with the front end.   The car weighs 3720 lbs with a 540" with 9.3:1 compression.   And the irony?   The only time I took the car to a dyno it made a max hp of 480 and a max torque of 510.   Thats why I dont trust a dyno.   The track NEVER lies.

jim

[Jon Smith]

theres a spreadsheet here with all kinds of calculations just click on where it says auto math on the left hand column
http://www.dodgechallenger.co.uk/

[Ghoste]

Keeping the hp numbers out of it just for a moment, something to consider when hearing stories of how poorly Hemi's ran when new is this.  Virtually every performance engine of the supercar era began life as a regular duty engine and it was hopped up to make it run hotter.  The Hemi was a race engine that was detuned to make it streetable.  When the ordinary performance mill falls out of tune, it still can perform adequately on the street.  When a Hemi falls out of tune, it's screwed.  And yes, they can be brand new and still be out of optimum tune.

[MOPARHOUND!]

Its not working right now for some reason but there is a really nice website at www.prestage.com that has a number of active plug n play formulas for everything from dyno-generated shift points to piston speed to HP/MPH calculations.   The site has been around for 8 years or so, be patient with it and it will be up again soon I hope.

Whats interesting about this HP discussion is how it relates at the track.   Its funny how many bench racers use the ET as the generator of HP and its nice to see the old DC charts developing the actual HP relationship based on Work/Time.   Thanks for posting them.   Moroso used to make a really neat paper slide rule calculator that did the same thing but I dont have one anymore.   

The suspension plays into this so much that you can get strange anomolies of an ET with a car thats not set up "right" for the track.   My car has a tight suspension both front and rear and runs a nice MPH but the ET is way way off.   A typical slip reads as folows:

60ft - 1.643
1/8 ET - 6.789
1/8th MPH - 107.37
1/4 ET - 10.606
1/4 MPH - 131.67

My ET is way off what the MPH would indicate.   This is with a 3200 stall convertor which doesnt allow enough stall to let the motor move up into the power band when I hit it.   The front only comes up about 5 or 6 inches but the front suspension doesnt drop, it carries it with the front end.   The car weighs 3720 lbs with a 540" with 9.3:1 compression.   And the irony?   The only time I took the car to a dyno it made a max hp of 480 and a max torque of 510.   Thats why I dont trust a dyno.   The track NEVER lies.

jim

Welcome to the site Jim.  540" with 9.3 compression, runs on pump gas I bet.  You have a PM.

['CUDA360]

360Cuda, I want my bible back
What year is your DC Manual 360Cuda, my last one is 1978.

                         Cuda Ken

I'm not sure what edition this book is because I read it so much it fell apart so I put it in a book binder. I can tell you the date on it is 1989 so it's at the end of the direct><connection program when it became Mopar performance.

Hey Firefighter
You might be right on your performance estimates but it should take a while before you get to the 11s.
The 60ft time is a great tool for this. Pick the right converter/gears, slick size and suspension mods.
My friends and I spent time playing with the clamps on the front of the rear springs as well as shocks and some ballast. The low gearset in the 904 transmission helps too.
I got my 60 ft down to 1:59/1:60   against Camaros and Chevelles with 1:80 and above 60 foots.
Those cars had faster times at the end but I left on them so hard I might have rattled them a bit as I pulled the front wheels a little off the ground   

I could just picture them sitting there waiting for their light to come down as they watch my 12 second small block car run away like a bat out of hell.

[firefighter3931]

Hey Firefighter
You might be right on your performance estimates but it should take a while before you get to the 11s.
The 60ft time is a great tool for this. Pick the right converter/gears, slick size and suspension mods.
My friends and I spent time playing with the clamps on the front of the rear springs as well as shocks and some ballast. hell.

Thanks, i've settled on a suspension package as well as converter and gears. Based on the dyno data, i decided on a 4500 stall and 4.10's. The engine made peak torque at 4400. Peak hp came in at 6000. Doing the math : 6000 rpm with 4.10 gears and a 28in tall tire is 120 mph....pretty much where i want to be. The suspension is a set of 3800lb b-body SS springs and Comp Engineering adjustable drag shocks front/back....i've seen this combo work well for many years. I expect it will 60 ft somewhere in the 1.50 range with the 28 x 10.5 Hoosier's. I'm not sure if the car will reach 120mph before it eats up 1320 ft but i bet it'll be close. I had done the math previously and your chart backed up my own calculations....i hope we're both right....

Ron

['CUDA360]

Cool 

[cudaken]

 Mine is still in pretty good shape, the first one along with a dealship manuel feel apart from reading and re reading.

Does anyone know if the current MP program have a manuel like it? If they do it is a must read, or see if you can find a old one. It would really cut down on some of the silly post like from me

One of the cool things in the Mopar Bracket Racer Science (360 Cuda that is what my chapter is called) helps you know where you want to start, slecting body, engine, yearly mileage, # of trips to the track a year, Acceptable Free Way speeds, Fuel Economy (seems funny now when talking old Mopar) number of cars you have (means when you break the one you are working on ) and the list goes on. Kind of lets you know up front what you are getting your self into.

Best 869 pages of writing I have ever read.

                                   Cuda Ken

[Ghoste]

Very much so Ken.  Only now they split it up over several manuals.  There is a chassis one, a Hemi one, a big block one, and so on.

[cudaken]

 Ghoste would you happen to have a part number for Big Blocks, transmission and rear suspention?
Like to get a little more up to date information.

                                   Cuda Ken

               

[Ghoste]

The current big block manual is P4876 825 and the chassis manual (which covers trans and suspension) is P5007 160.

[cudaken]

 Ghoste, thanks

                             Cuda Ken