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#2458928 - 02/28/18 12:51 PM Re: Guess my Dyno numbers [Re: Thumperdart]
BradH Offline
I Live Here

Registered: 01/30/03
Posts: 14236
Loc: Valhalla... eventually
Originally Posted By Thumperdart
Why so lean...........

That's the first thing I noticed, too. scope

Chuck: Is that an out-of-the-box Q-Series 950, by chance?

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#2458966 - 02/28/18 02:13 PM Re: Guess my Dyno numbers [Re: 10sec440]
Chuck@Best_Machine Offline


Registered: 01/21/03
Posts: 961
Loc: Farmington Hills, Mich
Your right, the data says its lean. As nice as it is to be overloaded with data, sometimes you have to do what the engine wants. Plugs looked perfect as well as the exhaust ports. It was a Q950 Stock jetting was way to rich, I would have liked to try a 1050 but didn't have any on hand. This is for a 100% street car 68 Road Runner 4 Speed, it should be a lot of fun

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#2458978 - 02/28/18 02:35 PM Re: Guess my Dyno numbers [Re: Chuck@Best_Machine]
Thumperdart Offline


Registered: 07/12/04
Posts: 18980
Loc: State of confusion
Anytime a hot/bigger motor runs a 4150 type carb they CAN go very rich due to the added velocity that larger cubes create and are more sensitive to tune from my experience. The RIGHT Dommy will smooth that right out.......... beer


Edited by Thumperdart (02/28/18 02:38 PM)
_________________________
72 Dart 470 n/a BB stroker street car `THUMPER`...Check me out on FB Dominic Thumper for videos and lots of carb pics......760-900-3895.....

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#2459002 - 02/28/18 03:22 PM Re: Guess my Dyno numbers [Re: 10sec440]
AndyF Offline
Too Many Posts

Registered: 01/20/03
Posts: 24952
Loc: Oregon
The O2 sensor information on a dyno can often be wrong. A small air leak into the exhaust system will make everything look lean even if the engine is running just fine.

I also learned the hard way that O2 sensor data can be messed up electronically. It is a small digital signal and there are lots of ways to mess up small digital signals.

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#2459029 - 02/28/18 04:30 PM Re: Guess my Dyno numbers [Re: Thumperdart]
Cab_Burge Offline
I Win

Registered: 08/23/03
Posts: 31677
Loc: Bend,OR USA
Originally Posted By Thumperdart
Why so lean...........

The AFR read out says lean, the BSFC says a little fat up high.
Test,test and test some more until it goes slower or looses power, correct work
Maybe it needs a slightly bigger high speed bleeds work
I agree on a bigger CFM carb. to help eliminate the manifold vacuum increasing restricting the air flow into the motor work


Edited by Cab_Burge (02/28/18 04:35 PM)
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Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)

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#2459052 - 02/28/18 05:27 PM Re: Guess my Dyno numbers [Re: Cab_Burge]
BradH Offline
I Live Here

Registered: 01/30/03
Posts: 14236
Loc: Valhalla... eventually
This has been debated / argued before, but you cannot tune a carb by BSFC #s. BSFC doesn't tell anything about the air-fuel ratio. It's simply a measure of efficiency of the amount of fuel used to make the power recorded.

EDIT: LINK to article on BSFC vs Air-Fuel Ratio...


Edited by BradH (02/28/18 06:02 PM)

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#2459067 - 02/28/18 06:06 PM Re: Guess my Dyno numbers [Re: Chuck@Best_Machine]
BradH Offline
I Live Here

Registered: 01/30/03
Posts: 14236
Loc: Valhalla... eventually
Originally Posted By Chuck@Best_Machine
... It was a Q950 Stock jetting was way to rich...

How much did you have to lean it out from the standard tune? I'm a little surprised you said it was too rich from what I recall the out-of-the-box settings are.

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#2459085 - 02/28/18 06:56 PM Re: Guess my Dyno numbers [Re: Cab_Burge]
Chuck@Best_Machine Offline


Registered: 01/21/03
Posts: 961
Loc: Farmington Hills, Mich
Originally Posted By Cab_Burge
Originally Posted By Thumperdart
Why so lean...........

The AFR read out says lean, the BSFC says a little fat up high.
Test,test and test some more until it goes slower or looses power, correct work
Maybe it needs a slightly bigger high speed bleeds work
I agree on a bigger CFM carb. to help eliminate the manifold vacuum increasing restricting the air flow into the motor work


I agree!

Of course the customer will add a air cleaner and full exhaust and that will change things to so no reason to chase a couple HP onthe dyno and like most guys he will do a little tuning once it's in the car. Reliability and driveability are more important.

Just for example, a A/SA Max Wedge on our dyno will make 595 hp and run 10.20 at 3400lbs. So how fast would you think a 3600 lb 4 speed Road Runner would go ?

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#2459091 - 02/28/18 07:06 PM Re: Guess my Dyno numbers [Re: BradH]
Chuck@Best_Machine Offline


Registered: 01/21/03
Posts: 961
Loc: Farmington Hills, Mich
Originally Posted By BradH
Originally Posted By Chuck@Best_Machine
... It was a Q950 Stock jetting was way to rich...

How much did you have to lean it out from the standard tune? I'm a little surprised you said it was too rich from what I recall the out-of-the-box settings are.


I believe it was 4 front and rear

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#2459104 - 02/28/18 07:32 PM Re: Guess my Dyno numbers [Re: Chuck@Best_Machine]
PorkyPig Offline
mopar

Registered: 08/31/06
Posts: 597
Loc: long time lurker, short time p...
Quote:


Just for example, a A/SA Max Wedge on our dyno will make 595 hp and run 10.20 at 3400lbs. So how fast would you think a 3600 lb 4 speed Road Runner would go ?

This should be a new thread all by itself!
popcorn

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#2459108 - 02/28/18 07:42 PM Re: Guess my Dyno numbers [Re: PorkyPig]
Uncle Barry Offline
super stock

Registered: 10/13/07
Posts: 1030
Loc: Big Western Pencilveinya
Originally Posted By PorkyPig
Quote:


Just for example, a A/SA Max Wedge on our dyno will make 595 hp and run 10.20 at 3400lbs. So how fast would you think a 3600 lb 4 speed Road Runner would go ?

This should be a new thread all by itself!
popcorn
iagree I know some 4 speed b bodys that have "650" car show horsepower and probably go bottom 13s or maybe 12s in good air laugh2 boogie
_________________________

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#2459156 - 02/28/18 08:48 PM Re: Guess my Dyno numbers [Re: Chuck@Best_Machine]
tex013 Offline
top fuel

Registered: 03/27/09
Posts: 1839
Loc: Sydney,Australia
Originally Posted By Chuck@Best_Machine
Originally Posted By BradH
Originally Posted By Chuck@Best_Machine
... It was a Q950 Stock jetting was way to rich...

How much did you have to lean it out from the standard tune? I'm a little surprised you said it was too rich from what I recall the out-of-the-box settings are.


I believe it was 4 front and rear


I am not surprised now by this . I had to pull 4 or 5 jets out of the front and maybe 2 rear when I went from 440ci to 505ci. Motor just works the carb harder especially if carburation is a little undersized .

Tex

PS : my 505 with a hair more comp and bit more cam makes 600-620 FWHP . With a 4150 carb , mufflers and exhaust to diff . I am not sure this one will go too much more .


Edited by tex013 (02/28/18 08:53 PM)
_________________________
New best ET 10.259@129.65 .
New best MPH 130.32
Finally fitted a solid cam,
stepped it up a bit more
3690lbs through the mufflers
Power by Tex's Automotive

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#2459298 - 03/01/18 07:46 AM Re: Guess my Dyno numbers [Re: Thumperdart]
DoubleD Online   content
top fuel

Registered: 01/22/03
Posts: 1922
Loc: NE Ohio
Originally Posted By Thumperdart
Why so lean...........


Because lean is Mean................!

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#2459441 - 03/01/18 12:55 PM Re: Guess my Dyno numbers [Re: tex013]
BradH Offline
I Live Here

Registered: 01/30/03
Posts: 14236
Loc: Valhalla... eventually
Originally Posted By tex013
Originally Posted By Chuck@Best_Machine
Originally Posted By BradH
Originally Posted By Chuck@Best_Machine
... It was a Q950 Stock jetting was way to rich...

How much did you have to lean it out from the standard tune? I'm a little surprised you said it was too rich from what I recall the out-of-the-box settings are.


I believe it was 4 front and rear


I am not surprised now by this . I had to pull 4 or 5 jets out of the front and maybe 2 rear when I went from 440ci to 505ci. Motor just works the carb harder especially if carburation is a little undersized .

Makes sense, in that I'd suspect that whomever is in charge of the calibration for those carbs probably isn't told the intended application is 500 cubes making 600++ HP. Yeah, the bigger engine would create more signal than the carb was originally tuned for, whereas a too-big carb would need to be richer to crutch the lack of signal.

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#2459443 - 03/01/18 01:00 PM Re: Guess my Dyno numbers [Re: PorkyPig]
BradH Offline
I Live Here

Registered: 01/30/03
Posts: 14236
Loc: Valhalla... eventually
Originally Posted By PorkyPig
Quote:


Just for example, a A/SA Max Wedge on our dyno will make 595 hp and run 10.20 at 3400lbs. So how fast would you think a 3600 lb 4 speed Road Runner would go ?

This should be a new thread all by itself!
popcorn

You're right. That way I can ask Chuck more questions and not derail this thread, as well as add my own "before" data and "after" predictions based on my latest engine dyno results. wink

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#2459444 - 03/01/18 01:03 PM Re: Guess my Dyno numbers [Re: DoubleD]
Thumperdart Offline


Registered: 07/12/04
Posts: 18980
Loc: State of confusion
Originally Posted By DoubleD
Originally Posted By Thumperdart
Why so lean...........


Because lean is Mean................!


Ya, mean on rings, pistons and bearings............ whistling
_________________________
72 Dart 470 n/a BB stroker street car `THUMPER`...Check me out on FB Dominic Thumper for videos and lots of carb pics......760-900-3895.....

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#2459447 - 03/01/18 01:08 PM Re: Guess my Dyno numbers [Re: Thumperdart]
BradH Offline
I Live Here

Registered: 01/30/03
Posts: 14236
Loc: Valhalla... eventually
Originally Posted By Thumperdart
Originally Posted By DoubleD
Originally Posted By Thumperdart
Why so lean...........


Because lean is Mean................!


Ya, mean on rings, pistons and bearings............ whistling

I was going to say something along the same lines, but ya' treed me.

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#2459518 - 03/01/18 03:36 PM Re: Guess my Dyno numbers [Re: BradH]
tex013 Offline
top fuel

Registered: 03/27/09
Posts: 1839
Loc: Sydney,Australia
.[/quote]
Makes sense, in that I'd suspect that whomever is in charge of the calibration for those carbs probably isn't told the intended application is 500 cubes making 600++ HP. Yeah, the bigger engine would create more signal than the carb was originally tuned for, whereas a too-big carb would need to be richer to crutch the lack of signal. [/quote]

Spot on Brad , the too rich I encountered with the Modman and 440ci . Seen it a few times on the dyno , raw fuel/black smoke but AFR showing lean .

Tex
_________________________
New best ET 10.259@129.65 .
New best MPH 130.32
Finally fitted a solid cam,
stepped it up a bit more
3690lbs through the mufflers
Power by Tex's Automotive

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#2459578 - 03/01/18 05:41 PM Re: Guess my Dyno numbers [Re: tex013]
Thumperdart Offline


Registered: 07/12/04
Posts: 18980
Loc: State of confusion
Originally Posted By tex013
.

Makes sense, in that I'd suspect that whomever is in charge of the calibration for those carbs probably isn't told the intended application is 500 cubes making 600++ HP. Yeah, the bigger engine would create more signal than the carb was originally tuned for, whereas a too-big carb would need to be richer to crutch the lack of signal. [/quote]

Spot on Brad , the too rich I encountered with the Modman and 440ci . Seen it a few times on the dyno , raw fuel/black smoke but AFR showing lean .

Tex [/quote]

NO outta the box carb will be ideal for YOUR application at least not any that I've heard or seen..... beer


Edited by Thumperdart (03/01/18 05:42 PM)
_________________________
72 Dart 470 n/a BB stroker street car `THUMPER`...Check me out on FB Dominic Thumper for videos and lots of carb pics......760-900-3895.....

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#2459798 - 03/02/18 03:37 AM Re: Guess my Dyno numbers [Re: Thumperdart]
tex013 Offline
top fuel

Registered: 03/27/09
Posts: 1839
Loc: Sydney,Australia
Originally Posted By Thumperdart
Originally Posted By tex013
.

Makes sense, in that I'd suspect that whomever is in charge of the calibration for those carbs probably isn't told the intended application is 500 cubes making 600++ HP. Yeah, the bigger engine would create more signal than the carb was originally tuned for, whereas a too-big carb would need to be richer to crutch the lack of signal.


Spot on Brad , the too rich I encountered with the Modman and 440ci . Seen it a few times on the dyno , raw fuel/black smoke but AFR showing lean .

Tex [/quote]

NO outta the box carb will be ideal for YOUR application at least not any that I've heard or seen..... beer [/quote]

You got that Dom
June is off season , so then i will set up intakes to try dominator and modman again

Tex
_________________________
New best ET 10.259@129.65 .
New best MPH 130.32
Finally fitted a solid cam,
stepped it up a bit more
3690lbs through the mufflers
Power by Tex's Automotive

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