Qtr mile or ENGINE dyno results

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Rat Patrol

Rat Patrol

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Id like to see some retro fitted qtr mile ETs, MPH and build posts

Or - if you've engine dynoed your motor - the build and HP output.

NO chassis dyno stuff please - it'll corrupt the data and de-rail the exercise :)

I'll start -

112mph @ 3650 lbs - 6.1 Modman with single 800 Thunder.

Anyone else run a mph or dynoed there motor?
 
You should call Mike at EFISource they have a Duster bracket car with a stock 6.1 other than headers and tb running pretty deep in the 11's IIRC.
 
Rat Patrol said:
NO chassis dyno stuff please - it'll corrupt the data and de-rail the exercise :)


Your view is interesting. I chassis dyno'd 3 different cars,including the one I have now. Took the HP the chassis dyno said they had, went to Wallace calculators, plugged in the weight.Car ran E.T.& MPH exactly as it said it would. Then I took the Weight, E.T. MPH, it gave me the same H.P.the dyno gave me, so how is that corrupt?

My Dusters scaled weight is 2850 ( me in it, fueled)

Chassis dyno says:
675 H.P.
Wallace says:
9:41 @ 143
Car ran:
9:40 @ 142 MPH
Click to expand...
 
^^^^^^ Agree with him

I am a die hard drag racer, I don't go for the number's either.I build a new car, and take what it gives me, then fine tune it from there for constancy. I don't care what E.T. or MPH it's going to run, all though I pretty much know what it is going to run when I build it. I want it consistent. So the chassis dyno is a great place to get tunning close, and find any other issues.The track when racing, is not the place to test.
Our track only has Test and tunes on Friday night.That track is not the track you get on Saturday, nor is the temp's you will see.
Yes, MPH tells you more then E.T. MPH means HP, E.T. just means quick!
 
dusterdragracer said:
^^^^^^ Agree with him

I am a die hard drag racer, I don't go for the number's either.I build a new car, and take what it gives me, then fine tune it from there for constancy. I don't care what E.T. or MPH it's going to run, all though I pretty much know what it is going to run when I build it. I want it consistent. So the chassis dyno is a great place to get tunning close, and find any other issues.The track when racing, is not the place to test.
Our track only has Test and tunes on Friday night.That track is not the track you get on Saturday, nor is the temp's you will see.
Yes, MPH tells you more then E.T. MPH means HP, E.T. just means quick!
Click to expand...

Theres two issues here -

1st - does WALLACE quote RW 0r FW HP. ?.Heres a challenge for you - pump in the avge mph and weight of a stock 6.1 LX car of 107 mph @ 4300 lbs and see what HP you get......Im betting it will be the quoted factory Engine hp and nowhere near rwhp. :)

But to be frank - I dont want to argue about calculators - the one I use came in exactly as per my Engine HP using weight/ Mph....so I dont think this debate has a future..... ;)


2nd - By corrupt - I meant that drivetrain losses vary from car to car - so why would I use Rear Wheel HP as a guide on whether my car is down on power?

AS YOU SAY - unless I can get quoted engine dyno HP....Track MPH and weight is my best tool which is why Im asking for examples -

Unfo yours is so damn quick its not a lot of help ! LOL!!
 
Rat Patrol said:
Theres two issues here -

1st - does WALLACE quote RW 0r FW HP. ?.Heres a challenge for you - pump in the avge mph and weight of a stock 6.1 LX car of 107 mph @ 4300 lbs and see what HP you get......Im betting it will be the quoted factory Engine hp and nowhere near rwhp. :)

Most all calculator's use Flywheel horse power (Wallace does).But you forgot one important variable, that is altitude.I have to ignore that for my area, because attitude here is 2200 +. NHRA adjusts our clocks to 10:05 for the 9:90 class. When I use calculators, I ignore our altitude, and calculate it at sea level. Simple, we run 3 teethes slower here the sea level.And about 1-2 MPH slower.

But to be frank - I dont want to argue about calculators - the one I use came in exactly as per my Engine HP using weight/ Mph....so I dont think this debate has a future..... ;)

No argument from me, I just use them for approximates anyway, I sure wouldn't want go bragging to anybody how fast my car might be based on a calculator print out.
The point I was trying to make is, it does work for me, and isn't all that far off.


2nd - By corrupt - I meant that drivetrain losses vary from car to car - so why would I use Rear Wheel HP as a guide on whether my car is down on power?


Sorry, I should have mentioned the calculation numbers I use and been more clearer on RW vs FW HP.Yes, you are correct,there is no rock steady calculation to convert the numbers from RW to FW HP. But, if you know your dyno, have ran some cars using the real world weight,ET & MPH numbers, you can get a real percentage to work with. For my friend/sponsors dyno (which is a Dyno Jet) it is 28%-30% for my cars (his dyno is stingy).But all my cars have loose 5500 converters, where as my friends stick 451 is closer to only 18- 20 % or less.But it does cross over pretty close, and Wallace calculators are real close. Even when converting 1/8th to 1/4 mile.

AS YOU SAY - unless I can get quoted engine dyno HP....Track MPH and weight is my best tool which is why Im asking for examples -

I agree, but I also wouldn't discount Chassis dyno numbers either.Engine dyno numbers can be manipulated too. Real world is going to be the true answer, all the rest is just, well entertainment and dreaming in my opinion!

Unfo yours is so damn quick its not a lot of help ! LOL!!
Click to expand...

Thanks, but you can take away the E.T. plug in weight and MPH, it still comes out at RW HP times 28% for real world FW HP

Funny, I have friends in Australia, they only talk MPH, they don' care at all about E.T., MPH speaks volumes of HP to them, so you are not alone.

:eye:
 
Seems like we,re on the same oage then -

Yes, well if you're tuning a motor...ET aint a lot of use...too many variables, unless the chassis is well sorted.

BTW - I ran the kerb weight of a 2013 SRT 300 plus driver (4360lbs) and a known MPH of 110mph belonging to a guy I know - I put that thru Wallace...

474 Engine HP - So its pretty close!!
 
Buschi340 said:
does the ratio of the tranny and 3rd member doesn't count for comparisons?
Click to expand...

Doesn't matter if it has a 2.92 or a 3.7 rear ratio..the car will still MPH similar - or near enough - as long as its not red lining across the line...

That is why you use MPH for tuning engine HP.

ET will vary wildly depending on gearing.
 
Rat Patrol said:
1st - does WALLACE quote RW 0r FW HP. ?.Heres a challenge for you - pump in the avge mph and weight of a stock 6.1 LX car of 107 mph @ 4300 lbs and see what HP you get......Im betting it will be the quoted factory Engine hp and nowhere near rwhp. :)
Click to expand...

Wallace uses rear wheel hp. Compare these two, they use the same formula.
http://robrobinette.com/et.htm
http://www.wallaceracing.com/et-hp-mph.php

The Hemi lx cars don't fit the formula.

You can use the formula to compare your power to the ground vs an lx power to the ground, but realize the output 'hp' numbers probably aren't correct. Also, given you have a different tranny, it's not going to be a spot on comparison (lx's have more gears, thus tighter rpm band used, though probably more driveline loss).

2nd - By corrupt - I meant that drivetrain losses vary from car to car - so why would I use Rear Wheel HP as a guide on whether my car is down on power?
Click to expand...

if you're looking at trap speed, then drivetrain loss always matters.
 
IMO, you were headed correct from the start. Looking for 3G Hemi swap guys. I'd go one further- look for 3G Hemi guys with the same tranny as you and a similar engine to you. If you're trying to isolate the impact of your intake and cam, then Mike's car at efi source is a very good comparison, assuming he's running a 727 or 904. Get his trap speed and DA and your trap speed and DA, put in the hp formula and compare. Shoot, look for anyone with a bone stock 6.1 and 727/904 to compare to. Maybe gdemon has trap speeds as well.

Rat- remind me what tranny you are running?
 
Mike already stated that his MS3 tune for a stock Hemi with TB and headers made 475hp on Bartons engine dyno.
 
Rat Patrol said:
Seems like we,re on the same oage then -

Yes, well if you're tuning a motor...ET aint a lot of use...too many variables, unless the chassis is well sorted.

BTW - I ran the kerb weight of a 2013 SRT 300 plus driver (4360lbs) and a known MPH of 110mph belonging to a guy I know - I put that thru Wallace...

474 Engine HP - So its pretty close!!
Click to expand...


I like Wallace, lots of different calculators too.
 
Uhcoog1 said:
Wallace uses rear wheel hp. Compare these two, they use the same formula.




http://robrobinette.com/et.htm
http://www.wallaceracing.com/et-hp-mph.php

The Hemi lx cars don't fit the formula.

You can use the formula to compare your power to the ground vs an lx power to the ground, but realize the output 'hp' numbers probably aren't correct. Also, given you have a different tranny, it's not going to be a spot on comparison (lx's have more gears, thus tighter rpm band used, though probably more driveline loss).



if you're looking at trap speed, then drivetrain loss always matters.
Click to expand...


If Wallace uses RW HP, then it is way off (which it hasn't been for me using FW HP), it says my car runs 10:01 @ 135 MPH, It runs 9:40 @ 142 MPH

If you use robrobinette It says it runs 9:72,by plugging in FW HP, if you plug in RW HP, it then says 10:01

Just sayin' I am using real world E.T. & MPH numbers including a RW HP chassis dyno number.

17% is way too conservative, it is in the mid 20's some where, depending on mainly converter loss.But again, there is no real formula.

This info has worked on 3 different cars for me, with different combo's
 
Looks like you are right - the wallace uses flywheel hp. It appears to use the Patrick Hale formula that also was used for the old Moroso speed slide. It's the same formula all the other internet hp to 1/4 calculators use, just a lot of them give the same output as the wallace when using rwhp, not fwhp.

I couldn't find anything definitive about if patrick hale built the formula for engine hp - but I'm sure that's the case.


Emil - what does Mike's duster trap? And what's the weight of the car with driver?
 
Uhcoog1 said:
Looks like you are right - the wallace uses flywheel hp. It appears to use the Patrick Hale formula that also was used for the old Moroso speed slide. It's the same formula all the other internet hp to 1/4 calculators use, just a lot of them give the same output as the wallace when using rwhp, not fwhp.

I couldn't find anything definitive about if patrick hale built the formula for engine hp - but I'm sure that's the case.


Emil - what does Mike's duster trap? And what's the weight of the car with driver?
Click to expand...


Got you,Cool, you had me worried, I thought I had at least a 1000 FW HP to be running the E.T. & MPH I run....LOL

I think the 17% figure, is most likely for stick cars.Auto's are in the low to mid 20's and I would think loose converter auto cars like mine are in the 28-30%...But I am not saying this is a formula by any means.
 
@Rat Patrol....Now that I hacked your page, back to your original question!LOL
I ran 11:98 @ 112 MPH @ sea Level (through mufflers), in my 71 Duster 3400 lbs wet with a 400 HP "engine" dyno'd 340 SB
J heads massaged, don't remember the cam, but it was flat tapet.I want to say 290, but don't remeber.
It was a back half ladder bar car with 14/32's 8 3/4 with 4:56 gears.Grinder brake in a 727, it ran about 2/10's quicker with the 904.
 

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Uhcoog1 said:
Looks like you are right - the wallace uses flywheel hp. It appears to use the Patrick Hale formula that also was used for the old Moroso speed slide. It's the same formula all the other internet hp to 1/4 calculators use, just a lot of them give the same output as the wallace when using rwhp, not fwhp.

I couldn't find anything definitive about if patrick hale built the formula for engine hp - but I'm sure that's the case.


Emil - what does Mike's duster trap? And what's the weight of the car with driver?
Click to expand...

I thought we were gonna disagree - but glad you see it differently.

Fwiw I agree that driveline will effect MPH....but not so that it'll show 50hp variation.

You're also right about Moroso and Hale.

Where most people come unstuck with these calculators is they use the "ET" variable to calculate their Hp - As discussed....ET is so variable, when Huntingdon, Hale and Fox developed their formulas, the ET factorial was by far the least consistent

So plotting for a formula, the hardest factor to average out was ET.

Hence, when tuning for power - we use mph and weight......NOT ET and weight.

Hope Im not telling you something you already know...but for others benefit......

If you want to read about WHY these calculators work on Engine HP - this link is a great read.....especially the first few paragraphs.

Dont let the Math put you off....the most important stuff is right at the start.

http://www.stealth316.com/2-calc-hp-et-mph.htm
 
dusterdragracer said:
Got you,Cool, you had me worried, I thought I had at least a 1000 FW HP to be running the E.T. & MPH I run....LOL

I think the 17% figure, is most likely for stick cars.Auto's are in the low to mid 20's and I would think loose converter auto cars like mine are in the 28-30%...But I am not saying this is a formula by any means.
Click to expand...

I use 20% on mine with a 3800 converter, 727 manualised trans and a 8&3/4

I have found that Moroso and my track times/mph agrees almost exactly with my Chassis HP + 20% losses ( / .80)
 
You'll notice it talks about " HP st the crank" as one of the co-efficients.

When you think about it - it stands to reason - how could a formula possibly take drivetrain losees into account? They are different for evety car - and theres no provision to vary them in the formula or on the slide rule.


The sad thing is that even people at Moroso think its rear wheel - but then they dont understand how it all came about.....those guys died years ago.....
 
Bone stock 6.1 other than the 92mm TB and a set of TTI headers. The tune was worked on by him, pretty extensively btw, using the MS3 kit he sells. Him and Barton even took the time with individual cylinder egt tuning and injector trim to get what they did. That is the base tune in his EFI kits he sells.
 
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