Okay guys, so maybe I have a little too much confidence in my car but I think something is kinda wierd. Today I had a little run against a mid-90s automatic Camaro Z28 with nothing but a crappy exhaust and an 800 pound sub box in the back. He definately nailed me on the launch (I have my winter tires on now, on 14" winter rims), but I guess I kept up pretty even top end. On the way back I fooled around with a basically stock GS (N/A) and he basically kept up with me. I was definately shocked.

My setup: Super16 @ 7psi, E-Manage, DIS-2, 440cc injectors. I have all the necessary mods (I can go into greater detail if you guys need.) I think the car is definately running a bit rich, I have the FMU with the 12:1 disk. The E-Manage is compensating for the larger injectors, and Im also using it to cut MAP voltage off at 4.65v. The car has some issues idling sometimes, I think its just pig rich at lower RPMs. But I worked with the E-Manage enough to work it out as best as I could. Above idle I have the E-Manage set to 0. I havent datalogged any runs yet, Im gonna have to do that soon. Oh yeah, and my car is basically gutted of everything except the door panels and the passenger seat.

In any event, I just generally thought I would do better against the z28. And WTF was that with the GS? I didnt hit fuel cut, I only have a crapass blinkyblink a/f gauge, but it was pegged somewhere near .96 to .98v. It seems like the car builds massive power + torque in the range of 3000-4500rpm, but it definately wanes off quickly after that to redline (boost stays pegged at 7psi.) I have a crank pulley coming soon, and I wanted to turn the boost upto 10 but now Im kinda scared. I mean am I crazy here, or is my car just slower than it should be? Anything you guys can recommend that I can look into? Any help would be great... Thanks!

I know I have a lot of tuning to do.

NeoVB
2005 Subaru Impreza 2.5RS
1997 Mitsubishi Eclipse GS TURBO
1995 Mitsubishi Galant ES DOHC TURBO
1991 Eagle Talon TSI AWD

The Z28 should get you, but the N/A Eclipse should be toast. Are you sure the Eclipse was N/A? Maybe you were in 3rd gear when you could have been in second...

7psi pulls pretty strong like you said between 3 and 4,500rpms but the power still levels off noticeably...

If you raise the boost to 10psi the engine will blow.

______________________________

Ryan
IRyanHester@Hotmail.com

'03 Mazda 6s

I hate the way power levels off/drops after 55XX rmp. Anyway it seems pretty normal for our cars to do this. I'm wondering if mr slick and his megasquirt system does the same.

Kevin
The old:


The new:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Megasquirt powered 420A
Custom turbo system

http://www.ms-custom.com

ive noticed my power drops off after 6500rpm

Originally posted by MrSlick

Originally posted by RxR_Eclipse I hate the way power levels off/drops after 55XX rmp. Anyway it seems pretty normal for our cars to do this. I'm wondering if mr slick and his megasquirt system does the same.

My motor just keeps pulling all the way to my 8k redline... No power drop off.s But then I'm running at 20+psi... Turbo efficiency has a lot do with things too... As well as your exhaust setup. If you can't get the exhaust gases out, then you can choke the motor... And eveyrone should geta wideband. Sounds like he's running pretty rich too.

Kevin
The old:


The new:

I think he should have been right with the Camaro. When I was around 230whp (which is a little higher than 7lbs of boost) I was beating stock mustangs and camaros.

You definetly need to get a wideband to see where your fuel sits.

Hm, I havent considered the exhaust angle. Right now I just have a 2.5" paceshitter, but its being replaced shortly with a 3" setup. I do need to get some tuning in quick, Im gonna call up Turbotrix and see if I can get in there. As for turbo efficiency, I would think that the super16 would be petty good.

Whats the best a/f ratio to run anyways? I was thinking somewhere in the 10.5 - 11.5:1 range, but does that seem too high or to low? I was told that with proper fuel management and timing management I should survive at 10psi. As for timing advance, Ill be able to datalog that shortly with the E-Manage, so where should I keep it around? I think Ive heard 17 degrees is pretty good at WOT. I guess the car just needs some major tuning.

Eh, and I guess my SMIC setup is pretty crappy. I need a FMIC Im gonna have to check the IATs, Ill just have to borrow my friends pocketlogger. I guess Im going to regap the plugs to .035 instead of the .040 that its set to now and see if that makes a difference.

NeoVB
2005 Subaru Impreza 2.5RS
1997 Mitsubishi Eclipse GS TURBO
1995 Mitsubishi Galant ES DOHC TURBO
1991 Eagle Talon TSI AWD

Originally posted by neovb
Hm, I havent considered the exhaust angle. Right now I just have a 2.5" paceshitter, but its being replaced shortly with a 3" setup. I do need to get some tuning in quick, Im gonna call up Turbotrix and see if I can get in there. As for turbo efficiency, I would think that the super16 would be petty good. Whats the best a/f ratio to run anyways? I was thinking somewhere in the 10.5 - 11.5:1 range, but does that seem too high or to low? I was told that with proper fuel management and timing management I should survive at 10psi. As for timing advance, Ill be able to datalog that shortly with the E-Manage, so where should I keep it around? I think Ive heard 17 degrees is pretty good at WOT. I guess the car just needs some major tuning. Eh, and I guess my SMIC setup is pretty crappy. I need a FMIC Im gonna have to check the IATs, Ill just have to borrow my friends pocketlogger. I guess Im going to regap the plugs to .035 instead of the .040 that its set to now and see if that makes a difference.

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Megasquirt powered 420A
Custom turbo system

http://www.ms-custom.com

everyones power will drop off after 6300 or so without aftermarket cams.

______________________________
Matt D.
'06 Evo IX SE
'98 RS-T 13.8 @ 106.1

am i the only one that thinks the emanage is a waste? plus the 16g dies in top end

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Megasquirt powered 420A
Custom turbo system

http://www.ms-custom.com

Shit...11 responses and nobody keys in on the fact that he's running 440's with a 12:1 FMU? Since you have the basic FMU, I assume that you are still running the stock regulator. So, you've got a static pressure of around 50 psi. That will leave you pig rich at idle (71% more fuel available than Hahn recommends for the stage II kit). Even with the E-manage helping, I bet you are rich at idle. Even if we assume that 12:1 disk will only provide an actual ratio of 7:1, you'll still be pig rich at full boost (87% more fuel available than Hahn recommends for the stage II kit). I think you need to buy a S-FMU and take a look at your fuel pressures.

Corbin

'95 ESI-T
Now with more power and fewer leaks



Gimme fuel...Gimme fire...Gimme that which I desire

Hm, the stock FPR was removed. I actually originally ran an SFMU with 315cc injectors, but I sold those. I replaced the SFMU with the FMU and went with the stock injectors. I was under the impression that the FMU replaced the stock regulator.

Very soon Im just gonna go with a 1:1 fpr and use the e-manage purely for fuel control. Yeah, I know the e-manage isnt all that great ... and I still cant seem to get the ignition management to work

NeoVB
2005 Subaru Impreza 2.5RS
1997 Mitsubishi Eclipse GS TURBO
1995 Mitsubishi Galant ES DOHC TURBO
1991 Eagle Talon TSI AWD

The S-FMU can function as a stand-alone fuel pressure regulator (it has a static setting). You would remove the stock regulator for this. But, the standard FMU is just a riser (it has no static setting). The stock regulator is needed to set the base fuel pressure (around 50 psi static). If you remove the stock regulator and just use the standard FMU, you lose the predictable base fuel pressure. Your base fuel pressure will be based off of whatever pressure losses occur in the FMU and return tubing. So, it might be sitting at 20 psi or something. When you boost, the FMU will add onto that pressure. I wouldn't recommend that you continue to run like this.

If you use the E-manage with the 1:1 FPR, would it alter fueling based on throttle position or boost pressure (with an external sensor)? Doesn't the E-manage reduce fueling by reducing the stock MAP output? I'm going somewhere with this...

Corbin

'95 ESI-T
Now with more power and fewer leaks



Gimme fuel...Gimme fire...Gimme that which I desire

Originally posted by neovb
Hm, the stock FPR was removed. I actually originally ran an SFMU with 315cc injectors, but I sold those. I replaced the SFMU with the FMU and went with the stock injectors. I was under the impression that the FMU replaced the stock regulator. Very soon Im just gonna go with a 1:1 fpr and use the e-manage purely for fuel control. Yeah, I know the e-manage isnt all that great ... and I still cant seem to get the ignition management to work

-"Easy Mac"
05 Mazda RX-8 (RR8 #88)
99 Eclipse RS 398whp & 372lb-ft

Oh damn. I did not know that, Im gonna have to order the aeromotive asap. It gets lots of fuel pressure at idle and runs pretty fricken rich all the time, so I thought I was ok.

As for the E-Manage controlling fuel, I can actually have it control the injectors directly. There is no need to modify the MAP table (unless Im leaning the car out) so I wont have to worry about any timing advance.

NeoVB
2005 Subaru Impreza 2.5RS
1997 Mitsubishi Eclipse GS TURBO
1995 Mitsubishi Galant ES DOHC TURBO
1991 Eagle Talon TSI AWD

It leans it out by altering the MAP signal, but can richen either by altering the MAP signal or the injector pulsewidth. The E-Manage can either be used to tune by Throttle Position or Boost, but you would have to have a boost sensor (you can buy one or you can make one with a GM 2bar)

NeoVB
2005 Subaru Impreza 2.5RS
1997 Mitsubishi Eclipse GS TURBO
1995 Mitsubishi Galant ES DOHC TURBO
1991 Eagle Talon TSI AWD

-"Easy Mac"
05 Mazda RX-8 (RR8 #88)
99 Eclipse RS 398whp & 372lb-ft

Crap. So what youre saying is that I should basically abandon the idea of using the E-Manage to tune completely, go back to the SFMU to set idle/static pressures, and just use the E-Manage to fine tune? I dont exactly want to spend another 300+$ right now, so can I just reinstall the stock FPR, get a smaller disk for the FMU, and retune for now? My motor isnt built and probably wont be for a while, so I dont exactly need massive amounts of fuel yet.

I really wanted to get the ignition management working, but no go so far. I had a DIS setup so I guess that can work for now. The E-Manage is still acting wierd sometimes. 90% of the time it will start up OK, but every now and again when I try to check the throttle voltages/percentages, the car will not idle or just stall. I think at 0% my throttle voltage is about .64 and at WOT its about 3.88. Ive checked, checked, and rechecked all my connections too.

I guess a good old standalone would make things a LOT easier. Now that I really think about it, all my troubles began with the E-Manage. I got it for free, so thats why I decided to give it a whirl.

Ironically, the car ran like shit until the new injectors went in. I guess its deathly rich but it runs 10000x better than it did before. Wierd.

NeoVB
2005 Subaru Impreza 2.5RS
1997 Mitsubishi Eclipse GS TURBO
1995 Mitsubishi Galant ES DOHC TURBO
1991 Eagle Talon TSI AWD

I'll just add to what Thura said. On the subject of using the 1:1 FPR plus E-manage:

If the main fuel map references throttle position, I don't think this will yeild the best driveability. On a N/A car, fuel needs are pretty proportional to throttle position. On a turbo car, fuel needs don't necessarily follow throttle position. Think about slamming the gas down at a stop light. One second, you are at 0 psi boost at WOT. A few seconds later, you are at 15 psi boost at WOT. The fuel needs will be very different between those two points. So, I think its good to use the external MAP.

I assume that the stock ECU runs the injectors at a very high duty cycle at WOT and peak RPM. So, you wouldn't want try to increase that duty cycle at peak power (there is no room to do this). You'd want to set it up to provide enough fuel at the stock duty cycle (or less) at peak power. So, that means you will be using the stock MAP sensor to lean things out at less than peak power (the 1:1 FPR will keep your available fuel constant from idle to full boost). The stock MAP output will vary linearly from full vacuum at idle up to 0 psi boost (like 1.X to 4.X volts). From 0 psi boost up to your max boost, the stock MAP output will remain constant (4.X volts). So, its output over the total range that you care about is not linear. You'll have to keep this in mind when setting up your fuel map. I figure that you'd be better off ditching the E-manage. Stock injectors, FMU, and stock FPR would do fine for low boost (assuming that you have a decent fuel pump). I'd probably just switch back to a simpler system until you rebuild.

Corbin

'95 ESI-T
Now with more power and fewer leaks



Gimme fuel...Gimme fire...Gimme that which I desire

2005 Legacy GT Ltd, Garnet Red Pearl
speak softly and spool a big turbo

-"Easy Mac"
05 Mazda RX-8 (RR8 #88)
99 Eclipse RS 398whp & 372lb-ft

2005 Legacy GT Ltd, Garnet Red Pearl
speak softly and spool a big turbo

The key word is "available". Like Thura mentioned, the fuel flow through an injector depends on the differential pressure across the injector in addition to injector duty cycle. The differential pressure is the fuel pressure minus the intake manifold pressure. At idle you might be pulling -8 psig in the intake manifold and have a fuel pressure of 42 psig. Differential pressure is 50 psig. At +15 psig (boost) in the intake manifold, you would have a fuel pressure of 65 psig (with a 1:1 FPR). Again, the differential pressure is 50 psig. So, the available fuel flow will be the same at idle as it is a 15 psi boost. When I say available, I mean that is what the injector could supply if you held it open for a 100% duty cycle. Of course, the actual duty cycle will be very different for idle versus full boost. We don't know what the duty cycle is, so we have to discuss available fuel.

If you need some help getting to sleep, read everything on this page:
http://www.geocities.com/vttalon/tech.html That would knock most people out like Hibernol.

Corbin

'95 ESI-T
Now with more power and fewer leaks



Gimme fuel...Gimme fire...Gimme that which I desire