What are the options for fuel managment. Comparing to a FMU and injectors and etc.

Wellll....thats a pretty broad question...

In my opinion the Voretch SFMU is the best rising rate fuel pressure regulator you can get...always hold rock steadyfuel pressures and you can depend on it.

Run fuel to the engine with a Walbro 255lph Fuel pump (Everyone and their mom uses it...itsa great pump)...

Injector size and actual fuel pressure you choose to run depends on your boost level. For example,I am running 6psi and push 55psi offuel pressure through 315cc injectors.

That is a common setup....

Some others run an '8 injector setup' which is superior.Most with this setup run a 1:1 Aeromotive FMU, someone who runs the setup would be able to explain better...but basically, you have the same pump...but a different FMU and 8 'smaller' injectors that work together to equal and surpass the benefits of 4 large injectors as far as gas mileage and idle smoothness. The 4 stock injectors are used primarily while off boost, then once boosting 4'extra' injectors kick in...settings allcontrolled via an EIC..(Electronic Injector Controller) The car seems to like the stock injectors off boost a tad better. This setup rocks.

So...theres some info...

Agreed, a very broad question. There is really no one right way to do it. Everyone on here sorta has a "what works for them" fuel setup - at least in my observation.

It was my understanding (from a post I put up a long time ago) that you need to run a secondary fuel pump in addition to the Walbro255, such the Accel in-line Hahn uses or something similar. The Walbro isn't enough on it's own to puch fuel -turbo fuel pressure requirements are too high. However, I've been told the combo of the Walbro and an in-line makes the in-line much quietier - which is a nice plus. Please correct me if I'm wrong about this ...

I personaly wouln't recommend a in-line pump in series with a stock fuel pump. I'd highly recommend running just a welbro "in-tank" pump on it's own. For fuel management I'm using a Chill Factory RRFPR. Works great and haven't had any problems with it.

I would also highly recommend NOT using Ford Motorsports injectors. They have bad idle/low RPM spray pattern. They may be cheap but you get what you pay for.

Babyeclipse - are you using JUST the Walbro255 in-tank pump? If so, what size injectors are you using and how much boost are you running? I was under the impression this was difficult to do.

Sorry to raid the thread, but this stays on topic.....

How many of the boosted people use an Apex Super afc or HKS Super afr to help out with fuel tuning. We are boosting the 95 2gnt soon and will have a Vortech fmu, 30 lb injectors, and probably the Walbro 255. Does the Vortech unit do a substantial job in all weather conditions from start-up to operating temps? I have heard people have idle difficulty during warm-up without the afc or afr.

Thanks,
Cody

Originally posted by Jen
Sorry to raid the thread, but this stays on topic..... How many of the boosted people use an Apex Super afc or HKS Super afr to help out with fuel tuning. We are boosting the 95 2gnt soon and will have a Vortech fmu, 30 lb injectors, and probably the Walbro 255. Does the Vortech unit do a substantial job in all weather conditions from start-up to operating temps? I have heard people have idle difficulty during warm-up without the afc or afr. Thanks, Cody

Hey Cody,

There are still quite a few people that have an S-AFC (me being one of them). The people that would have something compareable to the setup you mention would be lightly modded Star kit users. Though I don't have a Star kit (or Hahn for that matter) I am using 42lb/hr, Aeromotive FPR 1:1, Vortech 3:1 FMU, S-AFC, with a Supra TT fuel pump. I use the FPR to drop my idle FP to 30psi so as not to flood the engine at idle. I have large cams which produce little vacuum at idle which causes the ECU to put in more fuel than needed. Even with the lowered idle FP I still have to max out the AFC at -50% at idle. In your case I doubt you'd see anything that drastic.

As far as idle, with my strange setup I have no problems idling. It's obviously not smooth but that's more to do with the cams than the fuel. It has a nice constant lope to it. On very cold mornings it needs a one time blip to the throttle so it doesn't die right after starting up but again it's more to do with the cams than the fuel.

Anyway for the stuff you put up there in your list, if you keep the stock non-adjustable FPR you'll definitely need an AFC of some sort. If you get an adjustable FPR you can probably avoid using an AFC but I like having someting for fine tuning anyway.

If you got anymore questions let me know.

Originally posted by Avenger

Hey Cody, There are still quite a few people that have an S-AFC (me being one of them). The people that would have something compareable to the setup you mention would be lightly modded Star kit users. Though I don't have a Star kit (or Hahn for that matter) I am using 42lb/hr, Aeromotive FPR 1:1, Vortech 3:1 FMU, S-AFC, with a Supra TT fuel pump. I use the FPR to drop my idle FP to 30psi so as not to flood the engine at idle. I have large cams which produce little vacuum at idle which causes the ECU to put in more fuel than needed. Even with the lowered idle FP I still have to max out the AFC at -50% at idle. In your case I doubt you'd see anything that drastic. As far as idle, with my strange setup I have no problems idling. It's obviously not smooth but that's more to do with the cams than the fuel. It has a nice constant lope to it. On very cold mornings it needs a one time blip to the throttle so it doesn't die right after starting up but again it's more to do with the cams than the fuel. Anyway for the stuff you put up there in your list, if you keep the stock non-adjustable FPR you'll definitely need an AFC of some sort. If you get an adjustable FPR you can probably avoid using an AFC but I like having someting for fine tuning anyway. If you got anymore questions let me know.


Thanks for the info. :) I forgot to mention it, but we are gonna have an afpr too. I think we'll try it first without the safc. I would like to get "turbo grind" cams after a while as well, then maybe go with the safc at that time.

Cody

Originally posted by techboy
Babyeclipse - are you using JUST the Walbro255 in-tank pump? If so, what size injectors are you using and how much boost are you running? I was under the impression this was difficult to do.

im running just a walbro intank pump and im using accel 40#'ers.(415cc/hr?) no problems.

Originally posted by babybeclipse
I personaly wouln't recommend a in-line pump in series with a stock fuel pump. I'd highly recommend running just a welbro "in-tank" pump on it's own. For fuel management I'm using a Chill Factory RRFPR. Works great and haven't had any problems with it. I would also highly recommend NOT using Ford Motorsports injectors. They have bad idle/low RPM spray pattern. They may be cheap but you get what you pay for.

thats the weird thing, normally I agree with that statement. Then again on more then one occasion ive seen pepople who have problems idleing idle just fine on 42's at LOW pressures...weird.

Originally posted by Chamuko

Originally posted by babybeclipse I personaly wouln't recommend a in-line pump in series with a stock fuel pump. I'd highly recommend running just a welbro "in-tank" pump on it's own. For fuel management I'm using a Chill Factory RRFPR. Works great and haven't had any problems with it. I would also highly recommend NOT using Ford Motorsports injectors. They have bad idle/low RPM spray pattern. They may be cheap but you get what you pay for.

thats the weird thing, normally I agree with that statement. Then again on more then one occasion ive seen pepople who have problems idleing idle just fine on 42's at LOW pressures...weird.

It is very possible that those injectors have a very picky minimum pulse width requirement that is violated when trimming back pulse width by modifying the MAP signal with an AFC. Every injector has a minimum pulse width and fuel pressure requirement for it to work properly ... it's just damn hard to find that information.

my ford 400cc injectors idle nicely at 15 psi. i cant complain one bit.

So, if I am understanding this corretly, the problem with running just a Walbro in-tank is not that it doesn't work, but that fine tuning at idle becomes difficult b/c you are using larger injectors?

Originally posted by techboy
So, if I am understanding this corretly, the problem with running just a Walbro in-tank is not that it doesn't work, but that fine tuning at idle becomes difficult b/c you are using larger injectors?

The pump has nothing to do with fine tuning idle. You can run a Walboro intank pump by itself, just fine, using LARGER than stock injectors, or even stock injectors, running lower boost. The reason why you dont want to run a walboro with stock injectors past 7/8 psi, is because you need very, very high fuel pressures through the stock injectors, to supply enough fuel. The fuel flow output of the walboro drastically drops off past around 80-90 psi pressure. The walboro is capable of delivering almost 12 gallons of fuel per minute, at around 45-50 psi, and that is a shit load of fuel..as fuel pressure increases, fuel flow decreases, but its not as important, when running larger fuel injectors, since you have greater flow out of the injector, and you run very low fuel pressure at idle and under boost, compared to stock injectors. I ran around 12 psi on 315's, and fuel pressure was over 100 psi, so a walboro by itself in this case, would prob not be adequite. If you use something like 400's or 440's, then a walboro by itself will be just fine, assuming you dont run over 90 psi of fuel pressure or so..

I use the 8 injector setup, and i love it. After using this setup, compared to a rising rate fuel pressure regulator setup, its sooo much better, and fine tunable. Now, this doesnt mean a rising rate FPR doenst work, or work well, but it has it LIMITS, esp when running large injectors. And you can't really fine tune that setup very well, or effectivly to tune for max power, ect..The nice thing about the 8 injector setup, is you can add/subtract fuel at a certain RPM, at a certain boost pressure, if the need arrises, and it usually will, as our motors have a notorious lean spot in the power band. Its up to you what you want to do fuel setup wise, both ways work, and both are affordable, but much better tuning accuracy with an 8 injector setup, and you can run just a walboro fuel pump(until you max out 12 gallons of fuel per minute). Hopefully this helps you some.. Oh, and I have run the stock intank fuel pump, with the Accel inline pump for over 2 years now, and have NEVER had any problems, even with fuel pressures over 125 psi..

Ok, well that makes sense.

That's kinda where I'm at. I am running a stock in-tank with the in-line Accel. I have 315's up front and I have success with that setup, at least in my mind. Other than the noise associated with the in-line I've been happy with it. I had plans to make fuel modifications this summer, maybe even go with the 8 injector setup (I know Metal Jim is an expert at that), but I wanted to get the car back together and running after my rebuild before I started adding other variables into the overall picture. Problem is, I'm still waiting on my retrofit diff, until that comes - I got nothing to do but stare at my rebuilt engine on it's stand and talk about clutches with you.

I'm running stock fuel system(injectors, regulator, etc) with 4 extra injectors-330cc dodge injectors. Have the extra injectors fuel rail in serie with the stock system and HKS AIC to control the extra injectors under boost.

Originally posted by techboy
Ok, well that makes sense. That's kinda where I'm at. I am running a stock in-tank with the in-line Accel. I have 315's up front and I have success with that setup, at least in my mind. Other than the noise associated with the in-line I've been happy with it. I had plans to make fuel modifications this summer, maybe even go with the 8 injector setup (I know Metal Jim is an expert at that), but I wanted to get the car back together and running after my rebuild before I started adding other variables into the overall picture. Problem is, I'm still waiting on my retrofit diff, until that comes - I got nothing to do but stare at my rebuilt engine on it's stand and talk about clutches with you.

I'm kind of in the same boat as you.... I am runnign the stock fuel pump and the inline one that comes with the Hahn kit. I HATE THE NOISE so I want to change my setup. Would the following be fine???

- For now, put in my 30lb. injectors and replace the stock and Hahn provided IN-LINE pumps with JUST a Walbro IN-TANK. Will the pump be able to handle this at 8-9 psi? It should right?

- When I rebuild and bump the boost to 12-15 psi get larger injectors and still stay with JUST THE Walbro IN-TANK.

I just want to ditch the noisy ass inline so this is what im thinking of doing. Thanks.




"Who needs a 4G63? I'd rather walk the competition than my crank..."

- Bill Hahn.... 420a GOD :bowdown