My take on the BBSC

[BryanZublin]

Gas mileage at cruising (light load) should be the same for the various flavors of SC fuel management. This is because at light load the ECU will be in closed loop mode and the average fuel ratio will be at stochiometric. This assumes that the O2 sensor and ECU are still working properly with the SC installed - if not, you will know very quickly as the check engine light will illuminate with an error code of bad O2 sensor.

Bryan Zublin

 

[Factor X Motorsports]

Just sharing some info to save some of you a few bucks... Running race gas or octane boosters do not yield rwhp increases on boostless/nitrousless vehicles that are not mapped for that specific type of fuel. However, if you are running high boost or nitrous it will reduce chances of detonation.

Speed Safely,

Factor X Motorsports

 

[4AU4LIFE]

Thanks Factor X for chiming in with that bit of helpful info. Considering the topic of this thread and the split of your company and Mr. Basch it is very kind of you to put in your valuable information. I for one appreciate you doing that.
Very classy.

------------------
ALL NSX
92 RED/BLACK 5-SPEED

 

[Black&Tan97Tnewportbeach]

If your car has bigger than stock injectors the 'misfires' (little pops) might be the extra fuel igniting in the exhaust manifold. Mine does it, I have a turbo not a bbsc, but at idle there's no boost, just extra fuel on both systems probably.

 

[4AU4LIFE]

Thank's for the info 'BlackandTan'. I feel better about it now.

------------------
ALL NSX
92 RED/BLACK 5-SPEED

 

[sjs]

Originally posted by 92NSX:
Thank's for the info 'BlackandTan'. I feel better about it now.

Not too fast. If it runs rich enough at idle to do that then you may be wearing the rings more than normal. BlackandTan, are you thinking it is too rich at idle in general, or something else like dripping occasionally?

 

[NSXTech]

Originally posted by 92NSX:
Thanks Factor X for chiming in with that bit of helpful info. Considering the topic of this thread and the split of your company and Mr. Basch it is very kind of you to put in your valuable information. I for one appreciate you doing that.
Very classy.

92NSX, All- The "split: as you refer to, was in our decision in which fuel system devices to use. It could not affect the fact that Ken (FX Principal)is definately a class act- it is what took me to FX in the first place.
As to octane, it is not very usefull unless you tune for it, as Ken pointed out. With the new BBSC fuel system, you could have a program change on your laptop to change for track use / race gas use. You can change the fuel / timing maps for that day, then restor for good old fashioned pump gas afterward. You would have to drain all the gas however before and after, as octane ratings do not average out. (IOW, half tank 90 octane and half tank 100 octane DOES NOT equal a tank of 95. One of my SC install customers is a petrochemical engineer for Mobile, and she explained this to me.)
As to milage, when the final, best fuel map is drawn, in the coming weeks, fuel economy will not change because of the SC, but rather, as a few have mentioned, its how you now use the car that changes. IOW, if you never engaged boost (Bor-ring), your fuel economy will be the same. But then why did we install it? <BIG GRIN>

A complete update on the current status of all BBSC issues will be posted in the next few days. I will be home tomorrow, Monday, and will take the time to write a sumarry of where we are at with all the new parts, upgrades etc. My sincerest gratitude to all those who have kept us hopping this last year.

Cheers,
MB

 

[4AU4LIFE]

Hey MB, this the 'MY92NSX' here. The first final production unit was installed on my car in Orlando. Have you gotten a chance yet to take care of my injector cover?

------------------
ALL NSX
92 RED/BLACK 5-SPEED

 

[NSXY]

NSXTech:

You wrote "As to milage, when the final, best fuel map is drawn, in the coming weeks, fuel economy will not change because of the SC, but rather, as a few have mentioned, its how you now use the car that changes. IOW, if you never engaged boost (Bor-ring), your fuel economy will be the same."

To me, a novice, this is counter-intuitive. If you have installed larger fuel injectors than the OEM injectors, the sheer VOLUME of fuel delivered per second will be greater than w/ stock, at any given RPM, even without activating boost. The only way the fuel consumption could truly remain the same as stock would be to decrease the RATE at which the new greater fuel volume is being delivered. Is this how your fuel management system will work? Please comment...



------------------
NSXY
95 NSX-T, 5 sp, Red/Tan, Tubi exhaust, Dali street anti-sway bars, Dunlop SP9000s

 

[ScienceofSpeed]

the fuel tables are expressed as voltage to the injectors. The higher the voltage, the greater the solenoid opens the orifice to deliver the fuel. Higher rate injectors don't necessarily mean more fuel at a given RPM and load than lower rate injectors, as the fuel tables likely contain lower voltages at idle/no load. They do however offer a greater potential fuel delivery capacity when required. This all based on my rudimentary education of these components.

-- Chris

Originally posted by NSXY:
To me, a novice, this is counter-intuitive. If you have installed larger fuel injectors than the OEM injectors, the sheer VOLUME of fuel delivered per second will be greater than w/ stock, at any given RPM, even without activating boost. The only way the fuel consumption could truly remain the same as stock would be to decrease the RATE at which the new greater fuel volume is being delivered. Is this how your fuel management system will work? Please comment...

------------------

[email protected]
http://www.ScienceofSpeed.com

 

[Roadrunner]

My fuel milage has been just a little worse since my BBSC. I guess I'm not staying on boost enough!

Actually my milage was just over 20 mpg on the Orlando Basch weekend run. I ran close to 25 mpg on my hiway run of about 300 miles after the hard run. Vince ran me thru every stop toll both he could find in Orlando that evening. He had an e-pass and could roll thru, I had to stop and play catch-up engaging the SC numerous times on the 0-100 accels out of the gate. I only hit 130 once on the interstate home when I ran out 3 and 4 on boost. Still got almost 25 mpg. Not bad!! Hope that answers some fuel questions.

 

[BryanZublin]

Originally posted by ScienceofSpeed:
the fuel tables are expressed as voltage to the injectors. The higher the voltage, the greater the solenoid opens the orifice to deliver the fuel. (snip)

Chris,
I think you meant to say that the fuel tables are expressed as voltage to the MAP signal input to the ECU (higher voltage = higher injector duty cycle = higher flow). The Split Second box does not adjust the injector duty cycle directly. It does it indirectly by supplying the NSX ECU with a new MAP voltage, based on the actual manifold vacuum/pressure measured by the MAP sensor in the Split Second box. The stock NSX MAP sensor is not used.

The previous comments are based on my assumptions of how the Split Second box operates based on the electrical connections it makes to the stock ECU.

Bryan Zublin

------------------
Zublin Engineering http://www.zublin.com

[This message has been edited by BryanZublin (edited 08 July 2002).]

 

[NSXY]

Originally posted by BryanZublin:

Originally posted by ScienceofSpeed:
the fuel tables are expressed as voltage to the injectors. The higher the voltage, the greater the solenoid opens the orifice to deliver the fuel. (snip)

Chris,
I think you meant to say that the fuel tables are expressed as voltage to the MAP signal input to the ECU (higher voltage = higher injector duty cycle = higher flow). The Split Second box does not adjust the injector duty cycle directly. It does it indirectly by supplying the NSX ECU with a new MAP voltage, based on the actual manifold vacuum/pressure measured by the MAP sensor in the Split Second box. The stock NSX MAP sensor is not used.

The previous comments are based on my assumptions of how the Split Second box operates based on the electrical connections it makes to the stock ECU.

Bryan Zublin

BryanZublin:

Wow, you certainly know what you're talking about, but many of us don't, including me. Does the gas milage remain the same w/ larger injectors, or not (and why)?

Respectfully,



------------------
NSXY
95 NSX-T, 5 sp, Red/Tan, Tubi exhaust, Dali street anti-sway bars, Dunlop SP9000s

 

[ScienceofSpeed]

Bryan --

Thanks for the clarification.

-- Chris

 

[Sketch]

Larger injectors alone will not increase fuel consumption, or power. The ECM tries to maintain a constant air to fuel ratio. So unless you increase the air coming into the engine (such as with a supercharger or NOS), the ECM won't inject any more fuel than it would with stock size injectors.

 

[BryanZublin]

Originally posted by Sketch:
Larger injectors alone will not increase fuel consumption, or power. The ECM tries to maintain a constant air to fuel ratio. So unless you increase the air coming into the engine (such as with a supercharger or NOS), the ECM won't inject any more fuel than it would with stock size injectors.

You got it. A properly designed system should remain in "closed loop" mode at light loads where we drive 99% of the time - unless you are on the track, in which case fuel economy is not an issue. A stock NSX vs. a modified NSX both operating in closed loop mode should have nearly identical fuel economy. In the case of an aftermarket supercharger, the drag of the SC when not generating boost will have a small negative impact on fuel economy.

Bryan Zublin

 

[MAJOR STONER]

Curious, anyone know how much a BBSC system weighs?

 

[Zuerst]

Originally posted by MAJOR STONER:
Curious, anyone know how much a BBSC system weighs?

It weights less then you...

 

[emvanderpol]

I was told that the total system comes in at 40 lbs.

 

[MAJOR STONER]

40 lbs. seems very light, I hope that is the case. For some reason I was under the impression that supercharger systems weighed a lot more. Looking at the unit, it seems to be the lightest compared to the CTSC and GMSC.

 

[4AU4LIFE]

does anybody know how much HP the charger takes away from the stock motor to run. I heard the other day a dragster using 400 hp just to run the blower alone !! WOW

------------------
ALL NSX
92 RED/BLACK 5-SPEED