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calculators/examples/ help

Posted By: RustyM

calculators/examples/ help - 02/12/18 10:04 PM

Anyone know of race calculators by weight/engine dyno/converter loss etc to help with building our cars- having realistic expectations and meeting them and/or helps with figuring out whats wrong when we don't meet expectations?

Secondly- can i get real world numbers from folks here running Dusters- weight/engine/hp/et ?
Would like to get to 10.0 with engine we have but not sure thats realistic.

650 hp ( all done at 6 k )
9 inch- 4800 stall /built 727
11.5X29.5 tire
8.75- 4.10 ( I can change gear, just had these here already)
cal-tracs/mono leaf
gerst tubular k/ifs
should sit at 2900-3000 lbs with driver ( =/- a tad ) caged/frames connected /boxed etc.

We mostly run 1/8 mile here.

Thanks guys- just trying to do my due diligence .
Posted By: Al_Alguire

Re: calculators/examples/ help - 02/12/18 10:20 PM

http://www.wallaceracing.com/Calculators.htm
Posted By: CMcAllister

Re: calculators/examples/ help - 02/12/18 10:55 PM

Moroso 89650 power speed calculator or "dream wheel" is a handy item. I have a few laying around here. Mark Williams also does a nice one. wallaceracing/calculators are good if you have the internet handy.

Converter loss is one of those things you sort of figure out once the car's together. Speed-tire size-gear ratios should calculate to a RPM number. If it's off, something is slipping. A few hundred RPM is normal for a torque converter. I've seen some cheapy, poorly speced or broken converters slip a lot more.
Posted By: Biginchmopar

Re: calculators/examples/ help - 02/12/18 11:13 PM

Originally Posted By Al_Alguire


iagree
Posted By: RustyM

Re: calculators/examples/ help - 02/12/18 11:59 PM

thanks guys:

Iv'e been using Wallace quite a bit but, coming out faster than i think the car will be, however, it may be the weight thats just got my head twisted up.
Im used to be B bodies- 330's, Roadrunners/GTX/Chargers etc.

Real world : decent air, decent track prep, good set up- does 650 at flywheel put a 2900-3000 lbs car at just under 10.0 on an 11.5 bias ply 29.5 tire ?

I 4 cornered the car, pretty well the same numbers Andy is looking at with his, weight distribution almost 50/50 each direction and thats with stock k frame in it and a power steering box still on it, steel bumpers on it- 1582 lbs. (Yes to about 80 lbs heavier on drivers front-power steering box/brace is most of that.
with engine/trans/converter and driver Im at 2436 without third member, cage, frame connectors.
With a tiny bit of fiberglass, a little trimming here and there- i think i can make 3000 race ready.

so- please feel free to scold me or school me- what I don't know, I don't know and thats what I want to change.
Posted By: CMcAllister

Re: calculators/examples/ help - 02/13/18 12:45 AM

Moroso dream wheel says... I used 600RWHP since we're running it through a 727. 3000# = 9.75@138. 3200 if you weren't counting the driver goes to 9.90@135. I think with the chassis squared away, it should dip into the 9s.
Posted By: RustyM

Re: calculators/examples/ help - 02/13/18 01:36 AM

I'M not at 600 rwhp though- 650 on engine dyno- a very conservative engine builders dyno but- the motor is what it is.
Posted By: RustyM

Re: calculators/examples/ help - 02/13/18 01:38 AM

ahh- so is the moroso calculator accounting for the drivetrain loss estimate between engine dyno and rear wheel?

if so- those are pretty well the same numbers im getting.

Guess I better add a couple tubes to the cage.
Posted By: Cab_Burge

Re: calculators/examples/ help - 02/13/18 02:50 AM

If you know you won't ever need the cage to run 9.99 or quicker and or faster than 135.00 MPH in the 1/4 then don't add the weight twocents
If your thinking or wanting to run quicker than 9.99 and or faster than 135.00 then do everything now to make the car legal instead of having to do it later, same thing on all the safety gear in the car and for you now also up
Posted By: AndyF

Re: calculators/examples/ help - 02/13/18 02:56 AM

Do you want to run faster than 10.00? If so then you have enough power to do it providing you can get it to the ground. So if you want to run that fast then now is the time to build the chassis so it meets the rules.

On my Duster I've decided to just put a rollbar in it and not to go faster than 10.00. So on my car I'm not going to worry about setting up the front suspension for max weight transfer or trying to pay attention to every last oz of weight. I'm just putting it together to run mid 10's on pump gas and if it is a little faster or slower then I'm not going to worry about it.
Posted By: BSB67

Re: calculators/examples/ help - 02/13/18 03:09 AM

Moroso is net actual flywheel hp, verses an engine dyno as gross corrected hp.

Sometimes due to the specific car set-up, and actual atmospheric conditions, net actual might look like RWHP.
Posted By: CMcAllister

Re: calculators/examples/ help - 02/13/18 03:22 AM

Whole lot of cars out there that will sneak into the nines, but don't. 9.99 and quicker is a new ball game. License, chassis cert, new pants and jacket, gloves, full legal cage, net, etc., etc. Lot of guys don't want to go there just to run in the high 9s. 10.0s is good enough. Add some weight, short shift, throttle stop, de-tune it, whatever.
Posted By: RustyM

Re: calculators/examples/ help - 02/13/18 03:41 AM

Yep- thats what I was shooting for - 10.0's , 9.s are just too much money and, time is an issue.
Trying to make sure goals are realistic, method of achieving goals is accurate, safety issues properly covered.

Sounds like i'm ok so far.

Again- cant say "thank you " enough .
Posted By: CMcAllister

Re: calculators/examples/ help - 02/13/18 05:04 AM

Just write 10.00 on the window and race it. Do whatcha gotta do to slow it down.
Posted By: RustyM

Re: calculators/examples/ help - 02/13/18 05:45 AM

Yep- that works for me.
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