Re: Guess my Dyno numbers
[Re: Chuck@Best_Machine]
#2458978
02/28/18 05:35 PM
02/28/18 05:35 PM
|
Joined: Jul 2004
Posts: 19,318 State of confusion
Thumperdart
I Live Here
|
I Live Here
Joined: Jul 2004
Posts: 19,318
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..........
Last edited by Thumperdart; 02/28/18 05:38 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.....
|
|
|
Re: Guess my Dyno numbers
[Re: Thumperdart]
#2459029
02/28/18 07:30 PM
02/28/18 07:30 PM
|
Joined: Aug 2003
Posts: 43,284 Bend,OR USA
Cab_Burge
I Win
|
I Win
Joined: Aug 2003
Posts: 43,284
Bend,OR USA
|
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 Maybe it needs a slightly bigger high speed bleeds I agree on a bigger CFM carb. to help eliminate the manifold vacuum increasing restricting the air flow into the motor
Last edited by Cab_Burge; 02/28/18 07:35 PM.
Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)
|
|
|
Re: Guess my Dyno numbers
[Re: Cab_Burge]
#2459052
02/28/18 08:27 PM
02/28/18 08:27 PM
|
Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
Taking time off to work on my car
|
Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... 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...
Last edited by BradH; 02/28/18 09:02 PM.
|
|
|
Re: Guess my Dyno numbers
[Re: Chuck@Best_Machine]
#2459067
02/28/18 09:06 PM
02/28/18 09:06 PM
|
Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
Taking time off to work on my car
|
Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
|
... 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.
|
|
|
Re: Guess my Dyno numbers
[Re: Cab_Burge]
#2459085
02/28/18 09:56 PM
02/28/18 09:56 PM
|
Joined: Jan 2003
Posts: 970 Farmington Hills, Mich
Chuck@Best_Machine
super stock
|
super stock
Joined: Jan 2003
Posts: 970
Farmington Hills, Mich
|
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 Maybe it needs a slightly bigger high speed bleeds I agree on a bigger CFM carb. to help eliminate the manifold vacuum increasing restricting the air flow into the motor 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 ?
|
|
|
Re: Guess my Dyno numbers
[Re: BradH]
#2459091
02/28/18 10:06 PM
02/28/18 10:06 PM
|
Joined: Jan 2003
Posts: 970 Farmington Hills, Mich
Chuck@Best_Machine
super stock
|
super stock
Joined: Jan 2003
Posts: 970
Farmington Hills, Mich
|
... 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
|
|
|
Re: Guess my Dyno numbers
[Re: Chuck@Best_Machine]
#2459156
02/28/18 11:48 PM
02/28/18 11:48 PM
|
Joined: Mar 2009
Posts: 2,470 Sydney,Australia
tex013
top fuel
|
top fuel
Joined: Mar 2009
Posts: 2,470
Sydney,Australia
|
... 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 .
Last edited by tex013; 02/28/18 11:53 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 New World block 3780lbs 10.278@130.80 . Wowser 10.253@130.24 footbraking from 1500rpm Power by Tex's Automotive
|
|
|
Re: Guess my Dyno numbers
[Re: tex013]
#2459441
03/01/18 03:55 PM
03/01/18 03:55 PM
|
Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
Taking time off to work on my car
|
Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
|
... 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.
|
|
|
Re: Guess my Dyno numbers
[Re: DoubleD]
#2459444
03/01/18 04:03 PM
03/01/18 04:03 PM
|
Joined: Jul 2004
Posts: 19,318 State of confusion
Thumperdart
I Live Here
|
I Live Here
Joined: Jul 2004
Posts: 19,318
State of confusion
|
Because lean is Mean................! Ya, mean on rings, pistons and bearings............
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.....
|
|
|
Re: Guess my Dyno numbers
[Re: Thumperdart]
#2459447
03/01/18 04:08 PM
03/01/18 04:08 PM
|
Joined: Jan 2003
Posts: 15,439 Val-haul-ass... eventually
BradH
Taking time off to work on my car
|
Taking time off to work on my car
Joined: Jan 2003
Posts: 15,439
Val-haul-ass... eventually
|
Because lean is Mean................! Ya, mean on rings, pistons and bearings............ I was going to say something along the same lines, but ya' treed me.
|
|
|
Re: Guess my Dyno numbers
[Re: BradH]
#2459518
03/01/18 06:36 PM
03/01/18 06:36 PM
|
Joined: Mar 2009
Posts: 2,470 Sydney,Australia
tex013
top fuel
|
top fuel
Joined: Mar 2009
Posts: 2,470
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 New World block 3780lbs 10.278@130.80 . Wowser 10.253@130.24 footbraking from 1500rpm Power by Tex's Automotive
|
|
|
Re: Guess my Dyno numbers
[Re: tex013]
#2459578
03/01/18 08:41 PM
03/01/18 08:41 PM
|
Joined: Jul 2004
Posts: 19,318 State of confusion
Thumperdart
I Live Here
|
I Live Here
Joined: Jul 2004
Posts: 19,318
State of confusion
|
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.....
Last edited by Thumperdart; 03/01/18 08:42 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.....
|
|
|
Re: Guess my Dyno numbers
[Re: Thumperdart]
#2459798
03/02/18 06:37 AM
03/02/18 06:37 AM
|
Joined: Mar 2009
Posts: 2,470 Sydney,Australia
tex013
top fuel
|
top fuel
Joined: Mar 2009
Posts: 2,470
Sydney,Australia
|
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..... [/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 New World block 3780lbs 10.278@130.80 . Wowser 10.253@130.24 footbraking from 1500rpm Power by Tex's Automotive
|
|
|
|
|