SC : Small Pulley and Running Lean

[jaketuff]

Okay, it has been verfied that the 2.75-2.7" is probably the safest setup to have for Boosting the Magnacharger SC.

I had my car dynoed today at Englishtown. The net results were rather difficult to obtain due to a serious LEAN condition running the 2.4" pulley. I have definitely felt a resurgence of boost with the smaller pulley, torque that the car never really has had (duh). But I have always had a mid range punch, this small pulley feeds the low end.

But on the topend the car's fuel ratio to air BOMBS.

I start the run and SAE Hp of about 100 horses, my A/F Ratio is 18:1. Then as the car accelerates and power moves to peak power the car still starves, the ratio moves to 15:1. Ideally 12 would be the target for a good mixture, not to lean or rich. In this dyno run I was documented with 189 peak HP. That could really be 20 hp higher with the right mixture. So romping on the car without upgrading the fuel system is now out of the question for me.

CURING THE LEAN CONDITION
-------I am thinking the GTP Fuel system for the mechanical side. Then I need to find a chip or DHP Program to help enhance my fuel table. The car runs slightly lean in general anyway I believe, for MPG, but with the boost this deficit of fuel to air is increased.

Right now they seem viable. And to get the optimal A/F Ratio with the smaller pulley will mean a kickass ride. The car has awesome torque now and can smoke Kumho at 15-20 MPH! When I run properly I hope to enhance the torque and the topend.

...Any ideas fellas?

JOUT

[aleroboy]

was this reading after the cat on the dyno?
if so don't fret yet.
Do what I'm doing and get a bung put it so they can mount their wide band infront of the cat.

According to Mfuller our stock fuel system will support lots.
also I'm considering this little toy to help dyno tune my car.
http://www.splitsec.com/products/arc2/arc2gmds.PDF

I'm trying to become a dealer (don't like the $550 retail cost)
grandprixstore had these at one time, not sure if they still do.

It's kinda like the MAF translator only it does more.
seen teh maf translator on the dyno todya and it help a highly modded Z28 come down to a safe level.

[aleroboy]

They still have it.
http://www.grandprixstore.com/Merchant2/merchant.mv?Screen=PROD&Store_Code=GPS&Product_Code=602&Category_Code=009

[Watch4MyBu]

Jake you definately could use that. I hope you get all of this stuff worked out because I want to see what that car will pull on a real good run. That 'charger sound wicked in high rpm's . Had a lot of fun today. Good luck with everything and see you guys soon

[MetaGTP1]

I have to get my SC running real soon. My car doesn't run too lean, but we know the upgrades that are needed for maximum action. ;)

[AaronGTR]

It's correct that the stock fuel system will support more HP, but at WOT since your running closed loop (no O2 sensor) the computer can't tell that you're forcing more air in with that smaller pulley. You need to have your fuel maps for WOT recalibrated to account for that and lengthen the injector pulse. Unfortunatly, the only way to do that accurately is to dyno test and tune the program on your car. I think aleroboy is correct as well that you need on O2 reading from before the cat.

We could test my car with the same pulley and make a program but it still wouldn't be 100% perfect for your car. We're not at that point in the program developement yet though. This kinda sucks doesn't it? We have more parts now to make more power but not everything we need to take full advantage of it. The programing is essential, and an intercooler would be nice too. Hold in there guys. I see more power on the horizon for the boost bros.:)

[SpyhunteR]

have you looked at apex S-AFC controller? That might have some little tinkerings you can work w/

[Doug]

I would also see if you can find a bigger fuel pump and a safc would be nice or may be an e-manage if you have a labtop. Also greddy sells a wideband for yourcar and gives the most accurate a/f ratio besides a wideband on the dyno (don't depend on those autometer a/f gage. The are not accurate at all).

[jaketuff]

Originally posted by Doug
I would also see if you can find a bigger fuel pump and a safc would be nice or may be an e-manage if you have a labtop. Also greddy sells a wideband for yourcar and gives the most accurate a/f ratio besides a wideband on the dyno (don't depend on those autometer a/f gage. The are not accurate at all).

Yeah the Autometer just serves to give you Acid Vision, all the colors and the rapid movement are hard to follow and obviously not the best tool for tuning.

Aleroboy - That sounds like a good idea getting that bung placed in the pipe before the cat. The cat probably leans the flow with the chemical reaction going on in there. But my cat is small and the measurement taken in the tailpipe can't be too far off right?
I am going to investigate the options for tuning.

AaronGTR - The DHP program can help immensely. Even if we run rich it certainly is better. I hope that something is on the horizon from DHP soon.

Spy - Apex would be cool to have aboard, I'll take a look at the S-AFC.

Maybe if I find something reasonable all of us Boost Brothers on the East Coast can share the cost and dial eachother's rides in with computer/software needed. SPAZ, Kman, Amraam, everyone else let me know what yo think. Because if we get the proper ratios we can just use the pulley for more power, the pulley is extremely effective for that!!!!!;)

Pat

[MetaGTP1]

Originally posted by jaketuff


Yeah the Autometer just serves to give you Acid Vision, all the colors and the rapid movement are hard to follow and obviously not the best tool for tuning.

Aleroboy - That sounds like a good idea getting that bung placed in the pipe before the cat. The cat probably leans the flow with the chemical reaction going on in there. But my cat is small and the measurement taken in the tailpipe can't be too far off right?
I am going to investigate the options for tuning.

AaronGTR - The DHP program can help immensely. Even if we run rich it certainly is better. I hope that something is on the horizon from DHP soon.

Spy - Apex would be cool to have aboard, I'll take a look at the S-AFC.

Maybe if I find something reasonable all of us Boost Brothers on the East Coast can share the cost and dial eachother's rides in with computer/software needed. SPAZ, Kman, Amraam, everyone else let me know what yo think. Because if we get the proper ratios we can just use the pulley for more power, the pulley is extremely effective for that!!!!!;)

Pat Hey Pat, are you leaving the pulley on? I know your car is fuel-starved on the top end. Maybe that S-AFC, could get your car the fuel it needs on the top end. I'm going to try my full ASE chip again, since I have the smaller pulley. With the added fuel and spark advance, it may work this time.;)

[jaketuff]

It appears that the GTP guys have found some ways to adjust the A/F Ratio... Check the info in this post...

http://www.clubgp.com/forum/topic.asp?whichpage=2&Forum_Title=ClubGP+%2D+General&Topic_Title=New+product%21%21++Mini%2DAFC&CAT_ID=1&FORUM_ID=1&TOPIC_ID=6408484

I will have to investigate if this is compatibile with our cars. It is under $100 apparently.

JOUT

[jaketuff]

Okay, what I have learned....

The PCM reads the airflow of the MAF and that essentially tells the PCM what corresponding level of fuel to spray. Stock injectors are rated at 19lbs, GTP injectors are rated at 26lbs.


An example ... JET Fuel Curve Modication
The only way that the fuel tables can be modified via the JET is to force the PCM into thinking the car is running more airflow. So the PCM can be told to spray more fuel at a giving level of throttle.

The JET reads the MAF sensor, and then adds voltage to the reading that forces the PCM to enhance fuel. So in summary the throttle is enhanced, say at 75% the car can be told to run 100% WOT fuel spray. Now what JET actually did is unknown.

PCM needs to be re-programmed for most effective enrichment...
But the ability to change the level of maximum spray is limited by the stock PCM, so the JET can only spray 100% at any given time.
Now with a hard reprogram the PCM can be set to 110% (for example) of original fuel flow. That way you can enrich the A/F ratio.

Correct me if I am wrong.

JOUT

[AaronGTR]

I think thats right Pat. Also, you can re-program the ECM to work with larger injectors. Dave has done this with several GP's. That way we know we wouldn't be maxing out our stock injectors, and we'd have room for more power latter. Of course by then we'll have to start worrying about the tranny.:rolleyes:

[jaketuff]

Aaron,

Could you talk to DHP and see if they could help me out? I listened a lot to Dave and see that he has done a lot for the GP/GTP guys.;)

I believe that the injectors are key, and the corresponding program for WOT and normal driving would be very helpful for us Boost Brothers. We are all basically on the lean side, and much modding from here will lead to a leaner state, w/o fuel system upgrades.

What do you think Aaron, could he start with a recommendation for an injector for us 3.4L boys???

Pat

[Watch4MyBu]

hey jaketuff look at www.rcengineering.com . They do a ton of injector work and can work with the factory ones to make them flow better and more fuel

[jaketuff]

Originally posted by joefish2002
hey jaketuff look at www.rcengineering.com . They do a ton of injector work and can work with the factory ones to make them flow better and more fuel

Joe, thanks very much man, I am trying hard with what time I have to get the fuel system tuned!!! Every link helps. :D

Pat

[Watch4MyBu]

no problem man..your success is success for us all

[jaketuff]

I will have to check in with RC Engineering when their site is back up. I have seen their injectors in action at E-town!;)

Latest News in Fuel System Upgrade

I was reading thru Turbo ("Altezza Fever") over the weekend and found something new that can help me/us with upgrading the fuel system. Okay here is the MSD Fuel Pump Voltage Booster...
http://www.msdignition.com/np2002/images/pn2350.jpg

Okay, it will tell the fuel pump to deliver more fuel, via an increase in the signal to the pump (voltage). The more powerful signal will make the pump pump more fuel to the injectors. So the injectors end up spraying more fuel per pulse. It will work without manipulating the fuel tables, because it actually enhances the overall table flow without telling the PCM anything. It bypasses the PCM and goes right to the pump. This is key, because the MSD FPVB will still flow more fuel even at WOT's open loop.

So all thru the fuel curve the ratio of air to fuel will be decreased with extra fuel flow.

Here is what MSD Says...

"Adding a turbo or supercharger to your engine is a great way to improve the power of your car. But you have to remember that when more air is being pushed into the engine, the need for additional fuel raises proportionally. Meeting these new fuel demands could mean larger injectors or ECU programming, both which can be pricey. This new Fuel Pump Booster is the economical (and easy) answer for your engine’s new fuel demands.

The Booster will supply the electric fuel pump with increased voltage in relation to the manifold boost pressure. As boost pressure increases in the manifold, the MSD Booster will increase the voltage to the electric fuel pump. The amount of voltage is adjustable with a potentiometer from a range of an additional 1.5 volts to a maximum output of 22 volts over a range of 5 – 30 psi."

((Fuel Pump Booster PN 2350))

What does everyone else think? Wayne, I know you mentioned this, and we thought it would not work in the end? But from the review above, it seems feasible right - and MSD makes excellent quality - so I think it is worth it?

JOUT

[jaketuff]

Aright, maybe some of you realize my misjudgement above. The Fuel Pressure Regulator will limit any increase in output from the fuel pump. I could augment the FPR, making it flow more fuel pressure. But 60psi is already very high. Magnacharger boosted the pressure b/c it was the easiest way to add more fuel. They have basically maxed out this approach.

*Injectors to flow more, or the ARC1/2 device.... may be the answer. (I am trying to avoid modifying the PCM. But that would be the most efficient thing for the car.)

BTW - APEXi Super AFC will not be very easy to use, the time and potential damage that could be done going thru its learning curve is not worth it. Sure it looks awesome, but the PCU recalibration would cost you about the same. And with the recal you know that your setup would certainly be properly tuned when all is said and done. ;)

JOUT

[aleroboy]

Well somthing that might help a little is the air temp mod.
it's cheap and worth a shot.
Did it to mine when I was in AZ. just to be a little safer till I get different injectors, custom maf, ARC 2, or computer work.
Also need to get back to the dyno and get before cat readings. Since after the cat our readings are about the same this info will also help you out. This way we also know how lean we really are.