Base Fuel Pressure for 1000cc Injectors??

[tsi1991awd]

So I know what the base pressure should be set at on an AFPR for stock injectors....but what should it be set at for 1000cc injectors?

I have 1000cc Delphi's (PTE / FIC) and an AEM AFPR, Walbro 255HP fuel pump. What should I set base pressure to?

 

[donniekak]

Whatever you want. If you want to base your compensation off of stock injectors, 37 psi.

 

[steve]

Exactly! If you decide to run something else use 411cc as the old flow rate when figuring out the correction.

 

[SBR Joe]

Those injectors are typically flow tested at 43.5psi BFP, so to get out of them what theyre rated for, you should run that then tune around it.

 

[steve]

The original 450cc injectors were also rated at 43.5psi, so what.

If he wanted to get the most out them them he should run even higher pressure than that, but as long as the spray pattern is good he can run them at 36 or 43.5 or even 50 psi.

 

[tsi1991awd]

Well I will be tuning with MAF-T and SAFC since I am a broke bi***. I am going to base tune it so I can drive it to the shop and then have it dyno tuned. So I'm not sure if I should up the pressure or keep it stock. Which is why I was asking. I want to get the most out of it.

 

[steve]

Your not runnin 1000cc injectors on gas with a MAFT and SAFC. Maybe E85.

 

[tsi1991awd]

Why can't I run 1000s on pump? I am going to be running E85 in the very near future, but not ATM. Buy once man, buy once.

 

[steve]

Because you can't pull that much air out and expect the car to run.
The most it's recommended to do with a piggyback (which both of them are) is 750's and even that's not great because of the what it changed your load index for the timing maps.

You can't use both the SAFC and the MAFT corrections at the same time to correct for 1000cc injectors.

 

[tsi1991awd]

Why would there be adjustments for the MAF-T up to 1030cc's?

From what I have read, once you tune the MAF-T, you fine tune with the SAFC. Why won't that work out?

 

[SBR Joe]

The original 450cc injectors were also rated at 43.5psi, so what.

If he wanted to get the most out them them he should run even higher pressure than that, but as long as the spray pattern is good he can run them at 36 or 43.5 or even 50 psi.

Completely irrelevant if he doesnt need the full 1000cc's of fuel anyways. At least he will know theyre flowing what theyre rated for, and tune around it accordingly.

 

[SBR Joe]

Your not runnin 1000cc injectors on gas with a MAFT and SAFC. Maybe E85.

Umm...why exactly? He can set the MAFT for the injector size and fine tune with the SAFC. Do i reccomend this with such a large injector on a stock ECU?? No way, its gonna go nuts as it is with pimp gas. Hed have a hell of a time tuning E85 considering how much more fuel is required and in combination with that, having to fight the stock ECU and its horrendous over corrections that hed have to deal with running an injector flowing more than double what it thinks it should have.

 

[SBR Joe]

Why would there be adjustments for the MAF-T up to 1030cc's?

From what I have read, once you tune the MAF-T, you fine tune with the SAFC. Why won't that work out?

Youre absolutely correct, again, its not reccomended running that large of an injector on a stock ECU. This is where BFP adjustments may be made not so much to what they "should" be, but what you need it to be to help correct what the stock ECU is trying to do, because its going to freak the F out trying to correct for that much fuel, so you may want to have it a good bit lower to aid in the tuning, as much as youll be able to at least. Drivability may be not much to be desired, but you can make it work.

When you go to E85, its pretty much guaranteed you will need some sort of piggyback system or stand alone to properly tune and make good power and have good drivability all at the same time.

 

[steve]

Why would there be adjustments for the MAF-T up to 1030cc's?

Just because the MAFT has setting for them doesn't mean they work well enough to use them.

Umm...why exactly? He can set the MAFT for the injector size and fine tune with the SAFC. Do i reccomend this with such a large injector on a stock ECU?? No way, its gonna go nuts, but hed have a pretty much impossible shot E85 tuning with the AFC/MAFT combo beings hes limited to how much he can actually take out, and on top of that, having to fight the stock ECU and its horrendous over corrections that hed have to deal with running an injector flowing more than double what it thinks it should have.

Since Joe points out what I already said, that the stock ECU really doesn't like having that much air pulled out I don't think we need to go into more detail.

However since 1000cc injectors are more like 600cc injectors when running E85 a lot less air has to be pulled out and that's doable.

 

[tsi1991awd]

What if I get a chip and then run the MAF-T and SAFC?

 

[SBR Joe]

Since Joe points out what I already said, that the stock ECU really doesn't like having that much air pulled out I don't think we need to go into more detail.

However since 1000cc injectors are more like 600cc injectors when running E85 a lot less air has to be pulled out and that's doable.

Technically, but without being able to do proper air flow table adjustments, its probably going to drive like crap even if he gets the WOT tune dialed in. Regardless, whether using pump gas or E85, he should really just get DSM link or something similar to save having the headaches of trying to psych out the stock ECU to make it doable.

 

[SBR Joe]

What if I get a chip and then run the MAF-T and SAFC?

That would work because the chip would have the proper global fuel adjustments for the 1000cc injectors right off the bat, but if youre thinking switching up fuel types, itd be a pain unless you had a dual image map to switch back and forth. Also, that would pretty much eliminate having to use the MAFT for tuning at all, you would just set it for 450cc injectors and make any tweaks needed with the SAFC

 

[steve]

That would work because the chip would have the proper global fuel adjustments for the 1000cc injectors right off the bat, but if youre thinking switching up fuel types, itd be a pain unless you had a dual image map to switch back and forth. Also, that would pretty much eliminate having to use the MAFT for tuning at all, you would just set it for 450cc injectors and make any tweaks needed with the SAFC

Exactly.
Dual map chip, DSMLink, or Speed Density using DSMap.

Technically, but without being able to do proper air flow table adjustments, its probably going to drive like crap even if he gets the WOT tune dialed in.

If your the least able to use an SAFC, dialing in the corrections for E85 across the board isn't really a problem. You won't get the ability to dial in the sort of timing that E85 likes it the basic corrections are no harder than dialing in a set of 650's on pump with an SAFC. So I don't grasp what your trying to say. However, it's not really important.

 

[tsi1991awd]

What about a chip from DSMChips?

I really don't have the cash to put down on the eprom conversion plus cost of V3. If I had a chip, maybe I would stay with pump for a little while and see how it goes....

How would I be tuning with the chip? Would everything just be set in already and I wouldn't even touch the MAF-T at all? I would only make corrections using the SAF-C?

 

[SBR Joe]

What about a chip from DSMChips?

I really don't have the cash to put down on the eprom conversion plus cost of V3. If I had a chip, maybe I would stay with pump for a little while and see how it goes....

How would I be tuning with the chip? Would everything just be set in already and I wouldn't even touch the MAF-T at all? I would only make corrections using the SAF-C?

Youd have to do the EPROM conversion regardless, and you can get V3 lite for like 309 from me, i think the stage 3 chip from DSM chips is somewhere around 175 bucks? I could be wrong. And you wont be tuning the chip at all. You tell him your target AFR's, peak timing, octane youre using, base fuel pressure youre running, etc and hell make a map for you. IF it needs tweaked at all, its very minimal and will be done with the SAFC. The MAFT you wont touch, youll just set it for 450cc injectors and leave the rest at ZERO. Usually his maps are about right on the money everytime ive used them anyways.

Jeff does GREAT work and ive been using his chips in my 14b car for some time now, but my setup is staying as is, same fuel, same mods, etc so i dont have to worry about any sudden adjustments with a different setup. I will however switch to DSM link when i go E85 like in my 2g. Unless you plan to keep your setup the way its going to be when you get the chip made, link may be a better investment simply because you can do on the fly adjustments rather than have to get a whole new map burned to the chip everytime you alter something.

 

[steve]

Talk to Jeff (Keydiver), I'm sure he's done them before.

 

[SBR Joe]

If your the least able to use an SAFC, dialing in the corrections for E85 across the board isn't really a problem. You won't get the ability to dial in the sort of timing that E85 likes it the basic corrections are no harder than dialing in a set of 650's on pump with an SAFC. So I don't grasp what your trying to say. However, it's not really important.

Usually the air flow tables need tweaked in link and such when running E85 just to get the drivability sexed up.

And in regards to the timing, chances are the timing will climb through the roof VIA stock ECU freak attack with the 1000's. Itll try and compensate by dumping gobs of timing in so it could very well work out half way decent now that i think about it....still, for teh sake of all that is proper, id still invest in some sort of piggy back system one way or another just for the sake of ease.

 

[tsi1991awd]

My goal is 380awhp....if the chip from Jeff will do it, then I'll go with that. If I need Link, guess I can try and get V3 Lite...seems like a good deal.

 

[SBR Joe]

My goal is 380awhp....if the chip from Jeff will do it, then I'll go with that. If I need Link, guess I can try and get V3 Lite...seems like a good deal.

Like i said, if you dont plan on switching setups around much then yes, a chip from Jeff will be totally fine and practical. If you want to have a fuel variant, he can make a dual image chip with 2 maps, he did it for me and it worked great (93 octane and 114 octane maps).

 

[tsi1991awd]

Just so I am understanding 100% correctly....the chip will take care of all the timing maps and everything, overriding the supposed "shitty" stock maps and all I have to do is set the MAF-T to 450cc's and leave everything else zero'd out....THEN leave the SAFC zero'd out unless I need to fine tweak something? Up the boost and presto, everything will already be configured automatically???