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ok just wondering. How do the turbo guys deal with the fuel problems. I read alot of posts by the jr guys but i have not read any about people with the revhard or drag kits. is there something very different about the fuel needs of turbo vs. super that you cant learn from the turbo kits. Just Wondering. laters
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94gsr, Drag3 and yellow paint goin on in april
Wow...great article Jim! Even though this is the second time you wrote it...DOH! WEBTV.. http://www.hostboard.com/ubb/wink.gif
Sigh... http://www.hostboard.com/ubb/redface.gif Anybody wanna buy a B&M Commandflo?
http://albums.photopoint.com/j/View?...436&Sequence=0
http://albums.photopoint.com/j/View?...435&Sequence=0
I should've waited a while longer before I bought the thing but since Lundgren and others are having problems adjusting it. I'll wait until Nitro has something else to say. If not, then I may opt to return back to Summit (good thing they have a 30-day no hassle return guarantee). Anybody have it working yet....comments???
[This message has been edited by zip (edited January 15, 2000).]
I've measured more like 50psi with vaccuum which is 7psi higher than stock and 60psi with the vaccuum line disconnected, again 7psi over stock. The point is the same 1:1 rise ratio is maintained but at elevated pressure. The ECU compensates for the higher flow rate when in closed loop operation. Apparently it has enough latitude.
The 5:1 fuel to boost rise ratio stops at around 4.5psi of boost or at around 85psi of fuel. This appears to be enough at 6psi. In this case the rise is a bit too fast until 4.5psi where it levels off. I'd say the mixture moves progressively to the rich side of optimum until 4.5psi of boost is reached, above that the mixture leans out somewhat as boost increases, but not too much. With the 3.8 inch pulley there's 5% more air, but no more fuel. In this case it's leaner, definitely too lean with some cars. Maybe just barely adequate with others. It's on the edge. JR is relying on the limits of the fuel pump the supply as part of the fuel management system.
I agree, larger injectors and a riser with a lower ratio are in order combined with lower idle and boost fuel pressures. If the pressure is kept below 70psi, the GSS317 pump has adequate capacity for the boost levels we're talking about.
Now thats what I'm talking about!
That post was great JRCivic and confirms my theory of the B&M conspiracy.
BTW- Where do I get a guage to mount on the filter??
[This message has been edited by Turismo (edited January 15, 2000).]
okay now this may be a very stupid question for all you goru's.. But since I didn't install the fuel pump and had no idea there was a differnce between a high output one and reg .. How in the world could I tell which one I have by looking at it?? Does that mean I have to rip out my back seat and unscrew that metal disc in the middle to take it out and look?? BTW .. excellent excellent post JRCIVIC.. it is really cool to know we have you expertice on hand. How about ummm "intake 101"?? There is much debate over short tube or aem. Whatcha think?? http://web.camaross.com/bb/eek.gif
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1998 Super Sonic Blue Gs-r
Jrsc w/ fuel pump upgrade
boost & air/fuel guage
Modified CAI
Ground Controls w/ agx's
Neuspeed front strut bar
Power slots
To reiterate what Jim stated, the fuel pump you should have when boosting higher than stock boost is either the GSS317 or the GSS342 (preferred) stamped on the body of the fuel pump.
As for the intake, here's what TOO had to say:
__________________________________________
Air Induction: A properly designed induction tube with air cleaner should
be used. I don't favor tubes that are of small consistent diameters, as the
column of air in the tube is to slow to properly react to a supercharged
engine's needs. Although, a cold air box is needed, the short large diameter
induction tubes are the correct route to go. They are also somewhat less
expensive. Do not, under any circumstances, use one that tapers smaller as
it approaches the throttle body. I don't care what anyone says, throttle
bodies like slow moving air to draw from, and to do them right, the tube
should actually grow larger as it nears the throttle body.
___________________________________________
I hope that helps.
[This message has been edited by zip (edited January 15, 2000).]
For those who aren't sure of what pump they have mounted in their tank... do this test.
BOTTOM OUT THE JR FMU:
Loosen the 1/2" jam nut on the FMU and using a 3/16" hex key, turn the adjustment screw ALL of the way in. This will close the fuel return line and the pump will stop delivering fuel when it reaches its maximum flow rate. The GSS-317 (Low press) stops at about 85psi. The GSS-342 (high press) stops at about 115-120psi.
Now, don't forget to return the adjustment screw back to your original baseline settings. (60 psi is a good start... it is the factory setting)
The fuel pressure gauge, as zip showed in the picture above, mounts directly on top of the fuel filter. It can be bought from just about anywhere, and it is CHEAP... $35 to 60 depending on where you go. It comes with everything you need to install.
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'93 Civic Si H/B with B18C1, JRSC @ 8psi
Best 1320: 12.88 at 110 mph
The B&M filter mount gauge is $29.95 from Summit, part number BMM-46054...now if I could just find a 610mm belt part number...
That fuel business all makes sense, but this doesn't:
Why during tip in does the A/F meter go lean? Figure when the car was N/A (pre Blower) you could floor your car in any gear with the stock fuel pump and not have to worry about lean conditions. So now with the kit,(with stock pump and injectors) during hard tip in, the gauge goes lean, but at that second you are not yet in boost. Why is this? Shouldn't the fuel management be the same at N/A conditions with or without the blower?
The only other thing that has changed is the intake plenum which may flow more air than the stock intake thus causing a lean condition during hard tip in.
Your comments...
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'96 JR6 GSR Sedan
'93 Honda CBR 900RR
-------------------------
4Sale:New Holley 255 fuel pump kit
#12-906 (Integra/civic)
$200 shipped COD
OK guys, after fighting MrBurns' car, I did a crash course in FUEL !!! Yes zip, this one is for you. Thanks for pestering the s__t outa me to post this.
First of all, we have a few basic given parameters. I will refer only to the 255 lph pump in this post, and I will differentiate the Walbro GSS-317 (Low pressure) and the GSS-342 (high pressure) as "LP" and "HP" respectively.
Now, JR ships the FMU preset from the factory at 60 psi of baseline (vac. off) pressure. This unit adjusts for both vac. AND boost conditions. It raises the fuel pressure in VAC at about 1 psi per in/hg. It raises the fuel pressure in BOOST at 5 psi per pound. Its minimum pressure limit is about 42 psi.
Thus, at idle (800 rpm) the fuel pressure with vac on is about 42-44 psi. If you pull the vac hose off the FMU and put your finger over it, your gauge will read about 60 psi. (I have made an assumption here that your fuel pressure gauge is on your fuel filter... if not, buy one and put it there !!! This is the only place that you will get the numbers that I am referring to here)
Now, for the pulley clarification. The 6 psi (4.0") pulley typically makes between 7 and 8 psi of boost on the typical GSR. The 8 psi pulley (3.8") pulley blows about 9.5 to 10 psi.
The LP pump runs out of pressure at about 85-90 psi.
The HP pump runs out of pressure at about 115 to 120 psi.
To test this in your car, do the following. Loosen the 1/2" jamnut on the FMU and screw the adjustment screw (3/16" hex) ALL the way in. This closes off the return line to the tank, and the pump will push until it can't flow any more. This reading is the max that your pump will flow in any given boost condition in YOUR CAR !!!
Does anyone see a problem yet !?!
Here is the dillema. IF your baseline setting is 60 psi, and you have 7 psi of boost, the FMU wants to keep 95 psi (60 + (5x7)) of fuel pressure in the rail, but the pump can only flow 85 !!! This creates a slow lean condition... as the injectors pull fuel from the rail, the pump will try to keep pushing, but it cannot keep up.
Worse yet, for those of you with the 3.8" pulley, the FMU is ordering about 110 psi, and the pump is done at 85 !!!
The solution is the HP pump. Since it flows 115-120 psi, it CAN AND WILL keep up.
Now, some people want to go with bigger injectors... and this is fine, but you must do the following. (Remember, the bigger the injector gets, the harder it is to control the idle)
for the 3.8" pulley, get 270 to 280 cc injectors. Pull your idle pressure on the FMU to about 52 to 54 psi. If you go with less than this, you will probably get some pinging at throttle tip-in in the midrange. The reason is that you will have NO enrichment from full vac to 0 psi boost.
I have heard about a B&M Command Flo variation that was talked about on the board... it DOES NOT work. Here is why: Fuel pressure is controlled by allowing more or less fuel OUT of the rail and into the fuel return line. Thus, lower rail pressures mean a larger opening in the valve to the return. If the minimum pressure of the FMU is 42 psi, the B&M cannot be adjusted to LESS than this... even though the opening in the B&M is larger, the fuel is being held up just 12 inches away by the opening of the JR FMU. You may get a very small change because of the distance, but it is almost undetectable.
This ratio will help you make adjustments on your own cars in your various climates: when you double fuel pressure, you increase fuel flow by 40%. You can work this out the other way if you have bigger injectors. OE size is 235 cc. If you get 270's, that is 15% more fuel at any given pressure... and thus you could reduce fuel pressure safely by 35%. Unfortunately, the JR FMU does not give us this much adjustment down. I am looking into the Vortech FMU, which adjusts from 25psi up to 150 psi and the ratios are also changeable. The JR is fixed at 5/1 in boost, 1/1 in vac. The Vortech can do from 1/1 up to 5/1 in boost or vac !!! Once I have tested one, I will report back.
Fuel 101 is over. If you have questions, E-mail me or post here. If you need a HP pump, E-mail me and I will get one out to you. I have 24 of them in stock.
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'93 Civic Si H/B with B18C1, JRSC @ 8psi
Best 1320: 12.88 at 110 mph
I think it's more like the factory ECU is programmed to supply fuel enrichment on tip in. The stock program senses how far and how fast one is pressing the accelerator (along with other operating conditions) and supplies the necessary enrichment for N/A airflow. When boost comes on suddenly, the enrichment isn't quick enough. The airflow increases much faster than the ECU expects. Running higher pressure throughout the N/A range gives the system a head start. Closed loop operation compensates at idle and cruise, but when you hit the throttle, the programmed amount of enrichment is augmented by the higher N/A fuel pressure.
[This message has been edited by rjaffey (edited January 15, 2000).]
JR Civic,
That is one of the best run downs I've seen on fuel pressure. Everyone appreciates researched knowledge, it helps everyone out - and for every five people replying, there are probably fifty reading and using what you've said to make their kits work better.
The JR regulator produces a 1:1 ratio with lb/in to inHg (are you sure it?s not 1:1 lb/in to lb/in)? That would mean fuel pressure is about 5 lb/in higher at 20 inHg than factory ? about 7% rich. It is just a strange way to deal with throttle enrichment at throttle tip in, because it will have its highest effect at the highest vacuum, not at 0 vacuum - where throttle tip appears. If this is indeed producing an over rich condition at high vacuum and idle ? yes the ECU can easily take this out with closed loop.
I agree with rjaffey regarding the sudden rush of air from the SC ? it seems to be related to the opening of the bypass valve itself. This does not occur on turbo cars that I have seen. I would also add another factor that can produce leaning at ?throttle tip in or boost tip in?? the factory ECU (being NA) stays in closed loop until nearly WOT, and since boost can be produced out of WOT, this is causing a 14.7:1 boost run at anything under 90% throttle.
When you back out the adjustment screw you can lower the baseline fuel pressure (no vacuum, no boost). If you drop it much there will be a moment of hesitation on tip in. On my car that was about 55psi, on another one running 8psi it was a little higher. Once the transition had passed the cars took off, but there was a moment of hesitation during the rapid transition from a steady state to a load state.
The motor is effectively seeing boost the moment the bypass closes even before there's positive pressure in the manifold. This condition demands higher fuel delivery even while there's still some vaccuum. So running the elevated N/A pressure is a means to handle the effect of boost between the point where the bypass closes and the point where the JR regulator starts its 5:1 rise in response to *positive* pressure.
As to the parasitic drag, if what's posted on Eaton's site is remotely accurate the HP requirement at 5500 blower RPM (that's about 4000 engine RPM with 4" blower pulley and around 6psi of boost pressure) is between 6 and 7 HP. It peaks at perhaps 17 or 18 HP at redline and I just see that as additional load, like there's an extra few hundred pounds in the car. If the fuel pressure's too low, the hesitation is there even when changing from steady to load state while the car's in gear (cruise to accelerate). How is this different from the drag created by the blower?
I can't comment on a turbo setup other than to say that I don't believe the transition is anywhere remotely as abrupt as the onset of boost with the roots blower. With the blower the boost is virtually instantaneous in direct response to the throttle. Changing the throttle position results in more rapid, greater changes in airflow than the stock ECU is programmed to expect N/A, even when some vaccuum is present.
My air fuel gauge hunts back and forth when the ECU is operating in closed loop mode. What I believe I'm seeing is the effect of the feedback and response between the ECU and the O2 sensor. The ECU ups the fuel until it tips on the rich side, then drops the fuel until it's lean, then back, and so on... All the while hovering around stoich where the O2 sensor is fairly accurate. Once I'm on the throttle, the gauge reads pretty consistantly in the 12.5:1 range. I'd say it's within +/- .5 in that area of the O2 sensor's operating range and accounting for the granularity of the A/F display itself.
When I suddenly mash the throttle, transitioning from cruise to accelerate, the display immediately jumps to the 12.5:1 range without going lean and there's no hesitation. As I drop the baseline fuel pressure the A/F display starts to indicate a very momentary lean condition and if I keep dropping the pressure the momentary lean reading and hesitation becomes more pronounced.
Apparently, I have some wheels turning here... many of you have made some suggestions as to what can be causing the temporary "Lean" conditions present at throttle tip-in. I believe that all of you are right, although I have no concrete data to support these theories... now, I disagree as to the extent of these effects. The ECU is designed for a NORMALLY ASPIRATED engine, and thus is not capable of making the fast, drastic fuel changes necessary to compensate completely for a blower. The biggest problem is parasitic drag, or "LOAD" on the motor. Turbocharged engines do not have tip-in problems for this reason. The supercharger, even when NOT in boost, creates drag on the motor. It requires about 25 hp just to spin it at about 4000 rpm... that is like having three (3) Air Conditioning compressors running at once. The ECU cannot account for this load requirement, and thus does not deliver enough fuel enrichment until you get to 1psi boost (four with the older enrichment switch) and then the fuel catches up.
As for the Air/Fuel gauge, although they are helpful in giving you a general picture of where you are with your fuel delivery, they are inherently inaccurate and cannot deliver proper information quickly. This is why you see the lights bouncing all over the place. Being lean for a split second at throttle tip-in is not particularly dangerous... you aren't lean for any longer of a period than say the "lean time" while cruising when the ECU bounces from lean to rich to lean to rich !!! Don't sweat this. Here is where you worry: Watch you A/F gauge as you accelerate at WOT in fourth or fifth gear from 6500 rpm to redline... how far down does the ratio drop... and this took place over MANY seconds... and THAT can be damaging.
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'93 Civic Si H/B with B18C1, JRSC @ 8psi
Best 1320: 12.88 at 110 mph
If the problem is that even with the new JR boost switch that fuel enrichment doesn't start until 1 psi. Is there any vacume triggered solenoid made by any manufacturer that's calibrated to the same vacume the JR bypass begins to operate at. If so it could be used to send the enrichment signal like the relay but at the proper time before 1 psi?
I don't know how true this is, but I heard that at tip in the ECU retards the timing just for a split second during that period where the engine runs lean. Not sure though.
I have installed a Hypertech Shogun in MrBurns' car, and during my tuning of said car, I saw NO evidence that the ECU momentarily retarded the timing at throttle tip-in. In addition, if there was some retard thrown in, the detonation/pinging would NOT occur.
Detonation is occuring in the midrange on JRSC cars because of load... nothing more, nothing less !!! Remember that all operating systems on any given car, given the same input, DO the same thing. This being the case, if the ECU was the problem, then it would be the problem at 2000 rpm... at 6500 rpm... etc. The reason that this problem only exists between 3000 and 5000 rpm is simple: the load or parasitic drag that the blower generates is too high in relation to the amount of HP created... and thus, there is not enough fuel enrichment to compensate for this extra load.
Cure = more fuel+less timing+larger injectors.
Timing will be my next post... stay tuned.
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'93 Civic Si H/B with B18C1, JRSC @ 8psi
Best 1320: 12.88 at 110 mph
> rjaffey: My air fuel gauge hunts back and forth when the ECU is operating in closed loop mode. What I believe I'm seeing is the effect of the feedback and response between the ECU and the O2 sensor. The ECU ups the fuel until it tips on the rich side, then drops the fuel until it's lean, then back, and so on... All the while hovering around stoich where the O2 sensor is fairly accurate.
Yes, in fact the very definition of a "closed loop system": Input, processing, output, feedback
See http://me.mit.edu/lectures/rlocus/2.5-rationale.html for a diagram
> rjaffey: When I suddenly mash the throttle, transitioning from cruise to accelerate...
> rjaffey: I think it's more like the factory ECU is programmed to supply fuel enrichment on tip in....
"Tip in" is a term I've heard a lot of recently. I feel the term doesn't fully explain the problem. There are several things going on which are easily confused by using a single term.
1. Throttle has a transition speed, and acceleration. (this is 'acceleration pump' fueling as described below')
2. bypass valve is closing. (this is a specific fueling issue to the SC kit)
3. Fueling is trying to catch up in hardware (rising rate regulator - all kits but FMAX)
4. ECU may still be in closed loop (see my previous post above - problem with 'slow tip in')
Adding to confusion, And the term 'tip in' seems to be used for many dynamic situations:
1. Mash the throttle from cruise to accel (open loop boosting)
If you have detonations in open loop then it is a fault of the timing and fuel curves. These issues will not likely easily be solved with a mechanical solution, especially at boost pressures over 6psi, where the associated fuel rail pressure will be high enough to blow factory injectors, or be pushed past any actual fueling return at any pressure.
2. Slow throttle transition from cruise to accel (closed loop boosting)
The condition of a cruising, slow throttle transition is where the JR/Moss SC seem to really show its bad side. Take a look at a J&S knock installed in such a car, and my previous notes on the ECU being in closed loop until nearly at WOT, and you will see the difference. I don't care what kind of piggy back or regulator you are using here. There is no way to do this correctly without reprogramming the ECU's closed loop - or going with an aftermarket 3D EFI.
3. SC specific problems including the bypass
JR/Moss's location of the MAP sensor itself may be contributing to the problem. It may be seeing a quick blast of erroneous data to the MAP sensor, either hi or low voltage due to air pressure and turbulence changes as the closing of the bypass occurs. Locating the MAP to the boosted side of the SC seems to help the problem.
Another trick we can do with the SECU (which for those that don't know is a factory ECU with boost recognition and 3D real-time adjustability - but this technique can translate to most 3D EFIs) is to increase fueling in the 1" to 0" vacuum zone - this helps fatten up fueling in an effort to 'predict' boost.
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From my post to Endyn BBS...
Regarding: ?stock program's less than desirable transient response when used with the supercharger.? ... There are two issues. The first is that if you are using a typical rising rate regulator, you should note that it doesn?t perform any likeness of a ?rising rate?, it works like an on/off switch and the so called rate is only specifying the on time ramp. Anyone with an FMU and a dash mounted fuel pressure gauge call tell you that. The issue is that the fuel pressure is only increasing at 1:1 until about 2-3 lbs. This gives a lean situation right as boost crosses 0BAR. A typical and common problem from FI kit owners I have heard over and over, especially once their TA Sensor trick has been ?learned out ? by the ECU. Obviously the SECU can apply more fuel pulse width anywhere in this ?danger zone?. The second issue is the ECU?s accelerator pump feature. ...familiar with carbs...? The ECU watches the TPS delta speed, and if fast enough quickly sends a fuel pulse blast to all cylinders. Again something to be tweaked for ?transient response?.
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> JRCivic: "The ECU is designed for a NORMALLY ASPIRATED engine, and thus is not capable of making the fast, drastic fuel changes necessary to compensate completely for a blower."
The factory ECU is very fast, and certainly CAN compensate completely. The issue is defining what the problem is exactly and then configuring it to do so (reprogramming).
> JRCivic: The biggest problem is parasitic drag, or "LOAD" on the motor.
Magnuson recently invited ZDYNE over for a tour of their facilities in Ventura, CA. For those that don't know, they distribute, assemble, and repair the Eatons for JR/Moss, and many factory 'Detroit' vehicles. We discussed the drag issue, and according to Technical Director Chris Weisberg, the typical drag of the chargers while the bypass is open is less than 1hp. I do not think the "parasitic drag" of the SC contributes to 'tip in' issues - as far as non-boost running.
> JRCivic: It requires about 25 hp just to spin it at about 4000 rpm...
Note, any additional "load" on the engine due to the SC drag, could be compensated by figuring in by the ECU, as you hinted with the AC comment, it already compensates for the load of the A/C and alternator(ELD).
> JRCivic: As for the Air/Fuel gauge, although they are helpful in giving you a general picture of where you are with your fuel delivery, they are inherently inaccurate and cannot deliver proper information quickly. This is why you see the lights bouncing all over the place.
The factory heated O2 sensor although very temperature dependent anywhere but stoich (see http://www.zdyne.com/images/O2curve.jpg) , is very fast. It has a very steep voltage response on either side of stoich, a bit like trying to keep a marble on a mountain sharp as a pencil. Its response is quite fast, it only takes a few milliseconds for a stable reading (unlike a gas analyzer that could take up to 30seconds). The lights move quickly because the sensor is fast, this is especially noticed with ECU's reaction is fast in closed loop. We have a wide band Bosch LSU sensor, its response is under 5milliseconds - so we can do a 'dynojet' type dyno run and get accurate AFRs.
WOW!
This board is rocking!
It's taken forever to get the people "in the know" to speak up...now we can start to learn the "whys" and start working on the "hows"!
JeffM, how damn long are we going to have to wait for a "plug and play" ECU for our blowers? I'd like to lose all the fuel pressure(easier on the pump) and use bigger injectors and a properly programed ECU.
[This message has been edited by Zeus (edited January 17, 2000).]
Hey Jeff,
Glad to see you here!
Thanks for the input.
If a programable ECU would solve the problem has anyone tried any of these?? I've been ckecking every avenue for a couple of weeks now and the only real options I see are the "Zydyne" which is not available for the Teg yet as far a sI can tell, and the "EFI Systems PMS" which plugs right in to the factory harness (nice). In case anyone else is thinking about this unit it seemed it's drawback was the limited RPM set points the base model has (only 4) but it's numerous load tables would still make it better than most non-load sensing units. I also have found that with this unit and the new "Windows" software they have that it is programable at any load in 500 RPM increments and has the ability to re-write the "CLosed Loop" function completely. This is the only unit I've seen with this much capability. With an experienced tuner working it it seems one could dial the ECU in perfectly. Any thoughts from those with the experience??
OK race fans... here is the skinny on the ZDyne ECU upgrade. I spoke to JeffM today, and we spent alot of time discussing their new system. It will be an ECU "exchange" program, meaning that you will send in your existing ECU for a retro-fit.
The system is unique in that its design will eliminate the JR FMU entirely. Rather, some amazingly large injectors will be required... to give you a perspective on just how big - ZDynes 88-91 Crx with a non-VTEC 1.6 SOHC with a JRSC at 6psi (NO other mods) uses 450cc injectors !!!
The unit has a serial port so that it can be connected to a laptop and variables can be changed for tuning purposes.
The system sounds promising and I have offered to help JeffM with "Working out the tuning issues" once a prototype is complete... which brings us to the bad news: The release of this product will not be released to the public until the summer !!!
So until then, all that we FI guys can do is wait... and continue to use the "Mechanical" fixes that we know to help FOOL a normally aspirated ECU program.
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'93 Civic Si H/B with B18C1, JRSC @ 8psi
Best 1320: 12.88 at 110 mph
sounds similar to a DFI sent up to me.
Matt
Just a question- What if you wanted to go back stock after the Zydyne alteration?
Tourismo: I've thought about the eventual sale of my GSR (I'm even keeping "double books" on the maintenance records).
At this point, my GSR was stock until something like 36K miles. The JRSC went on at 45K miles. I only put about 7K miles on my car a year, so I hope to sell it in 2 or 3 years with 59-66K miles on it with the whole performance package included.
I used to wonder about how hard it would be to return the car to stock, but ever since the install, I can summon up a 3D model of the engine in my head at will. :-)
It would be a nice customer service of ZDyne to provide stock ECU's in exchange for modded ones. It wouldn't be much skin off their backs to do that.
Later,
Greg Holden
turismo,
I would pull one from your local junk yard if you want to go back to stock. But why would you wanna do that http://web.camaross.com/bb/biggrin.gif . Unless of coarse you are selling the car.
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1998 Super Sonic Blue Gs-r
Jrsc w/ fuel pump upgrade
boost & air/fuel guage
Modified CAI
Ground Controls w/ agx's
Neuspeed front strut bar
Power slots
Well i'm not planning on going back stock, and I'm not all that crazy. But say my engine throws a rod through the cylinder before my warranty's up (not likely but..). I know my dealer will never see my car before then with the JRSC hooked up. And though it would be an EXTREME pain in the ass, I would go through the trouble of taking it off to get a new engine without question- Hence the possible need for stock ECU parameters (and Injectors).
Dealers screw you=You screw dealers (hehe).
zip,
how much you want for the b&m ? Can you email me at [email protected]
thanks,
Greg
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94 Civic FROG
435HP/289 lb-ft. torque.
11 Second Club.
Holden and Turismo,
Since the SECU is an adjustable factory ECU, you can always load up the stock program and run the 240s, factory NA program etc...
Sweet! Thanks Jeff, Guess I'll be waiting for it's release.
I just got on the board so I kinda saw this thread pretty late. Anyway, I have some observations regarding the JRSC on my B16A engine.
My A/F ratio goes extremely lean and sometimes causes the engine to knock. This happens only with a manifold vacuum of 6"-0" Hg. The moment I have a little boost, the A/F meter jumps up to the proper ratio.
At first, I thought the JR Fuel Press Reg doesn't do anything below 0 vac. So, I thought fuel press would be about 45 psi (factory regulator) at 0 vac. Then as boost comes on, the JR FPR takes control and bring it up to 60 psi. So, to get rid of the lean mixture, I was going to install a B&M Commandflo Fuel Modifier to give 55psi at 0 vac. to smooth the transition from factory to JR FPR. Any comments on that thougt?
BTW does the B&M unit fit on the factory FPR after installing the JR adapter that turns the factory FPR 45 degrees?
Second, if the JR FPR does function during vaccum, then my theory is wrong. There is no jump from 45 psi to 60 psi in fuel press. What is causing the lean situation? The fuel enrichment circuit hasn't kicked in?
Thanks for any help.
Welcome aboard.
The JR FPR has a baseline that sets the minimum fuel pressure. It's supposed to be around 50psi. This is to give the fuel system a head start when you get on the boost.
Maybe your's is set too low. It is adjustable. I beleive Lundgren's Site has instructions as to how to adjust this.
http://www.redisoft.com/integra/
BTW, I had told you on our email list that the B&M wouldn't work with the JR FPR. I didn't realize you were trying to raise the baseline pressure. Some guys here have tried to use it to get a lower baseline pressure for better idle. It won't do that.
Greg Holden
96 GSR, JRSC...
I just wanted to bring back this article up because some members may be interested in this post that may not have had the chance to see it in the past.
just curious.. in my turbo set up (using Cartech regulator, 370cc injectors) when I first hit the gas it hesitates for a sec and then takes off. someone mentioned that the base pressure (no vac) may be too low, I have it set to 45 psi... it is worth trying to raise it, but my main question is that the car never did this with the stock injectors at the same base fuel pressure, I wouldn't think the big ones would need more base pressure... any suggestions?
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94 GSR drag gen 3 turbo
Benson's built bottom end
The reason it hesistates is because the engine is getting too much fuel. When you get larger injectors you must lower vacuum fuel pressures and adjust rise rate in boost.
thanks for the input Zip... unfortunately I cannot lower the pressure any more, stock pressures is as low as it will go
Either make the "Rafe" mod to your fuel return line or eliminate the OE regulator all together... it is the flow restriction. Then you can adjust the static fuel pressures to where you need them.
I have 320's in my car and my static pressure is 36 psi.
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'93 Civic Si H/B with B18C1, JRSC @ 8psi
Best 1320: 12.68 at 110 mph
I spoke to the guys at Cartech about doing that, because I have a fuel rail waitinng to go in, but they told me that removing the stock regulator would cause a dead spot in the transitionn from vac to boost... any thoughts on this?
hmmm.. mine sputters and misses on the highway with the stock regulator on http://www.hostboard.com/ubb/frown.gif
I havent been able to figure out what caused that yet