255, no afpr, but I have emanage. Am I ok?

[MyEclipse5]

I am getting a talon from a guy and it comes with a walbro 255, but no fpr, but he does have emanage.

Before he had an SAFC and it was tuned good, then he got an emanage and ignition/timing harness for $100, so he sold the SAFC and hooked up the emanage, and it doens't have a tune. So he's now selling it to me (well trading).

My question is, will I be able to tune it good? I will invest in a fpr in the future, but right now I'm tight on money, and I'd rather have a wideband so I can tune it better.

Mods:
2.5" exhaust
stock blue tops
255lph
2.25 IC pipping
FMIC
stock boost right now (cause it has no tune)

I'd liek to boost 18psi on 94 octane. I have read up a lot about tunning and it doesn't look that hard, just time consuming. Watch out for knock, and don't run to lean.

Will I be ok for about a month or two without the FPR?

Yes I know this has been beaten to death, but I've read like 100 threads and none of them answer my question about emanage. I realise if you don't have a tuner you need a FPR, but with a tuner is it a different story?

 

[xveganxcowboyx]

No, not really. You could TRY and tune for the over-run if you were to measure the difference, but it would just cause problems. The fuel over run exists independently of any tuning and will throw off anything you try to do (assuming you are over running the FRP). You'll want the AFPR.

Of course many people run without them so you should be fine for a little while. Just wait until you get the regulator to up the boost and try tuning it.

Also, I think the regulator is more important than a wide-band at this point. The Wideband won't do you much good if your fuel delivery is inconsistent.

 

[RockSolidGST]

No , Get an AFRP and save urself the headachs , Do a search and you will see why it is so benifical


And if u spend 50-75$ an hr on a dyno , You can use there wideband.

Try searching on the Classifyed , you can pick up a AFRP for not to much.

Without the AFRP your fuel pressure is going to fluctuate making it very hard to tune.

Do it once , Do it right =)

 

[steve]

I've read like 100 threads and none of them answer my question about emanage.

The emanage makes no difference that's why none of what you read answered your question.

Steve

 

[MyEclipse5]

No , Get an AFRP and save urself the headachs , Do a search and you will see why it is so benifical


And if u spend 50-75$ an hr on a dyno , You can use there wideband.

Try searching on the Classifyed , you can pick up a AFRP for not to much.

Without the AFRP your fuel pressure is going to fluctuate making it very hard to tune.

Do it once , Do it right =)

Do it right, or do it twice!

gotcha, ill get one before my wideband then

 

[DJ23GSX]

I know first hand that tuning is way easier with an afpr. I had issues with my first regulator so i had to run for a few weeks on the stock one and a rewired 255 and it was misserable to tune

 

[nanokpsi]

You'll be just fine. You don't over run the stock FPR at full throttle, just at idle and maybe light cruise. I've dynoed my car multiple times on the stock regulator and its just fine. be optimal,The wiseband is fare more important. It may not be optimal, but if money is tight then just keep the stock regulator.

 

[scottsee]

You'll be just fine. You don't over run the stock FPR at full throttle, just at idle and maybe light cruise. I've dynoed my car multiple times on the stock regulator and its just fine. be optimal,The wiseband is fare more important. It may not be optimal, but if money is tight then just keep the stock regulator.

Who told you that??

Fuel pumps are either on or off.. Depending on voltage, fuel pumps will flow higher or lower GPH rates. It's up to the fuel pressure regulator to 'regulate' the BFP in the fuel rail. Closed loop or Open loop has nothing to do with it. The only reasion it's not as much as an issue with Open loop is becasue you can 'somewhat' tune around it 'with a wideband'..

 

[JayRolla]

Actually Ive heard a lot of people say at WOT not having the AFPR with a 255 doesnt madder. It only overruns at cruise and idle.

 

[scottsee]

It over runs all the time, open loop just wont show the feedback.. Your base fuel pressure does not change because you go wot. You just increase 1 to 1 with boost.

 

[JayRolla]

Ok you are right, but you can still tune WOT with no problems right?

 

[xveganxcowboyx]

My understanding is that at WOT you should be consuming enough fuel to not over-run the stock FPR. If more fuel is entering your engine than it does not have to be diverted abck to the tank. This makes the FRP work as it normally should. At idle and light throttle you are consuming much less fuel which means more has to be diverted. This is when over-run is a problem.

 

[JayRolla]

Thats what I thought.

 

[scottsee]

Ok you are right, but you can still tune WOT with no problems right?

You just need to account for the increse in base fuel pressure and lean out your fuel tables accordingly... No need to be cocky...

 

[My91TalonTSi]

Have some people ran the stock FPR with a 255 and not had a problem? Yes. But if it was my build, I would try to do it right the first time and get the AFPR.

 

[nanokpsi]

It over runs all the time, open loop just wont show the feedback.. Your base fuel pressure does not change because you go wot. You just increase 1 to 1 with boost.

You're wrong here scott. It only over runs the stock regulator because the fuel demand is so low at idle and light cruise. The stock regulator can't physically allow enough fuel to be carried away from the rail. At wot with any decent sized injectors, the pump is flowing LESS due to high pressures and the injectors are flowing MORE fuel into the cylinders. Thes two things combine to fall under the stock FPR fuel limitations thus allowing fuel pressure to be constant.

To try to suggest someone to buy a AFPR before an in car wideband is beyond compreshension.

 

[nanokpsi]

Who told you that??

Fuel pumps are either on or off.. Depending on voltage, fuel pumps will flow higher or lower GPH rates. It's up to the fuel pressure regulator to 'regulate' the BFP in the fuel rail. Closed loop or Open loop has nothing to do with it. The only reasion it's not as much as an issue with Open loop is becasue you can 'somewhat' tune around it 'with a wideband'..

Maybe you should be asking who informed you

 

[HighPSI TSi Guy]

Have some people ran the stock FPR with a 255 and not had a problem? Yes. But if it was my build, I would try to do it right the first time and get the AFPR.

there is no right or wrong. there is only a difference in how.

total fuel volume delivered is a product of fuel pressure vs injector duty cycle. It is a direct relationship and the volume is determined by load maps in the ECU. A change in one can be compensated for by changing the other. If you passed 6th grade math it shouldn't be hard to understand. think of it like balancing a scale. a non-linear fuel pressure curve is only a problem if you're too ignorant to tune around it. If your E-damage setup has the MAP sensor you're good to go, that makes compensation for non-linear fuel pressure very easy.

though, in my experience, it really is never off by more than a few PSI and even then once you're out of vacuum you're into the linear areas of fuel pressure flow and it doesn't matter anymore, and the close loop feedback of the ECU will take care of the leaning out.

I get 30mpg highway/18 city in my daily beater with a stock FPR, 720cc injectors, and a 255 high pressure, and custom EPROM chip.

 

[scottsee]

I don't agree, If I'm 'proven' wrong I'll apologize.. But I don't believe I am..

 

[scottsee]

From what I've been reading, looks like I completly wrong. Damn, I suck at life...

I'm very sorry Nanokpsi, Jayrolla, xveganxcowboyx,

 

[xveganxcowboyx]

It's all good. Chalk it up to a lesson learned. That's what this is all about.

 

[nanokpsi]

No problem Scott. I'm sure plenty of people will take away good information from the discussion. The more accurate info that is out here for the community, the better

 

[JayRolla]

Yea im wrong quite a bit when I think I know it all.

 

[steve]

a non-linear fuel pressure curve is only a problem if you're too ignorant to tune around it. If your E-damage setup has the MAP sensor you're good to go, that makes compensation for non-linear fuel pressure very easy.

I really would like to hear your plan for tuning around regulator overrun. Please include consideration of the part throttle engine dynamics and discuss how the fuel trim time constants in closed loop compound the problem. Maybe a little discussion on how the tuning might interact with coasting injector cut and load variations cause by random external forces like terrain and wind loading would make it interesting.

Or you could just install a fuel pressure regulator that doesn't overrun and ignore these nasty little details.

I guess you could also just run a sloppy fat tune to avoid running lean when the regulator decides to track. Which of these is the "too ignorant to tune around it" case?

Steve

 

[nanokpsi]

I really would like to hear your plan for tuning around regulator overrun. Please include consideration of the part throttle engine dynamics and discuss how the fuel trim time constants in closed loop compound the problem. Maybe a little discussion on how the tuning might interact with coasting injector cut and load variations cause by random external forces like terrain and wind loading would make it interesting.

Or you could just install a fuel pressure regulator that doesn't overrun and ignore these nasty little details.

I guess you could also just run a sloppy fat tune to avoid running lean when the regulator decides to track. Which of these is the "too ignorant to tune around it" case?

Steve

I run a rewired 255 with a stock regulator and tune via dsmlink. According to my logged wideband I am around 14.5-14.7 at idle and I am running the "default" global for my injectors. Doesn't seem like much of a need to tune around it, let alone anything requiring an explanation

Would you rather have less than perfect fuel trims, or a leaky AFPR (aeromotive comes to mind)?

There are few times I would discourage a fuel system mod, and I'm not trying to come off that harsh. Its just that there should be other mods on the list before dropping a couple bills for an AFPR, especially an in car wideband.