Efi

[joyridin']

All this stuff sounds pretty normal. My brother installed a FAST system on a Corvette over the winter and it ran rich until they got a few moles on it.

If you cannot mount the pump low and have the pick-up on the bottom of the tank, I would not go with an external pump. The internal pumps work pretty flawlessly if everything is hooked up correctly and it is submersed in gasoline to keep it cool. I have a 450 lph in my car.

[DWRAT]

Any update yet?

[likenu2]

Morning DWRAT,
Brought the car back to Bob yesterday. He downloaded the information from the onboard computer to his laptop and was sending the information to the FAST engineers. While he was in Memphis at Good Guys, he spoke to the engineers from FAST as well as the engineers from Comp Cams, and that seems to be where the problem is laying, that the cam is a very hot cam. I said to him that I hoped that I didnt make a very very expensive mistake and he assured me that no matter what he will make it right what ever it takes. That is encouraging. I dont know if I will hear from him today or what but I am in no rush to get it back as long as when I do it is right. Will keep you posted when I have more info.
Joe

[Detroit Bill]

Originally Posted by likenu2

Morning DWRAT,
Brought the car back to Bob yesterday. He downloaded the information from the onboard computer to his laptop and was sending the information to the FAST engineers. While he was in Memphis at Good Guys, he spoke to the engineers from FAST as well as the engineers from Comp Cams, and that seems to be where the problem is laying, that the cam is a very hot cam. I said to him that I hoped that I didnt make a very very expensive mistake and he assured me that no matter what he will make it right what ever it takes. That is encouraging. I dont know if I will hear from him today or what but I am in no rush to get it back as long as when I do it is right. Will keep you posted when I have more info.
Joe

What are the cam specs?

[likenu2]

Cam is a hydraulic roller
Lift: .594"/.618"
Duration (@.50"): 242/248
Compression: 10.5:1

[eschaider]

Your cam is not hot. At 242/248 and only around .600" lift you have a nice street cam. My suspicion is your centerline is 114˚. With a 114˚ centerline you only have 17˚ of overlap — that is nothing to speak of.

Fast attempts to provide entry level self learning systems that can manage either fuel only, timing only or fuel and timing. FAST markets these systems essentially as plug and play up to about 650 HP. They also offer a version that is good to 1200 hp but appears to differ primarily in fuel pump volume and injector size necessary to support the higher power.

Self learning systems do well in daily driver type applications where the car is driven like a — daily driver. Performance applications do not do as well with the self learning variety of EFI systems available today. Performance applications almost always benefit from a tunable system that you have control over fuel, mass airflow or engine load and monitor a wide range of operational variables that your tuner would adjust for your particular installation.

While throttle body injectors are a convenient way to swap a carburetor out for EFI you are basically building an EFI system that duplicates a 30 year old model Detroit has long since abandoned, even for daily drivers. The throttle body injection model brings with it all the wet manifold flow and distribution issues the carbureted model it replaced had. Wet manifold systems produce significant cylinder to cylinder distribution and fueling issues that at best have compromise solutions.

FAST offers EFI systems with individual port injection and cylinder level fueling control. Other than price or visual appearance there is no reason to opt for 30 year old injection technology. The newer technology will not only run better, it will give you the ability to literally tune it to the engine size and design you have chosen for your build. Additionally there is no upgrade for this cam or that cam sort of stuff. You will however need to have the system tuned for your engine. You will spend more money than you have for your current system and you will have a much better performing engine.

Alternatively Ford's FRPP guys can offer you tunable modern day EFI systems that are among the most sophisticated management logic systems available today. Disable the TiVCT logic for the variable cam timing and you have an extraordinarily tunable system built for a n/a or supercharged environment. You specify the engine displacement in the tune and the fuel source volume and you are off to the races so to speak.

What you have right now can be made to run properly, it just takes time and effort. It will give you 30 yr old EFI performance but it will maintain a great deal of the original visuals these cars had. The modern day FAST approach or the FRPP approach will require you to go to a port injection model, not all that hard since you already have the bosses on your manifold. You could even keep the throttle body air valve to maintain some of the original car's looks.

BTW whenever you run a return style EFI system it is always to your advantage to keep the fuel pressure regulator out of the engine compartment. When you put it into the engine compartment you heat the fuel before returning to the tank and boil off the light ends. The light ends are the additives the oil companies add to their low octane base fuel stock to produce high octane fuel. In short order it is possible to reduce high octane fuel in your tank to low octane fuel if you allow the pressure regulator to be heated in the engine compartment.

Parting thoughts, although others have already said it, the in tank fuel pumps are by far the best for these types of applications. They are quiet, available in stunning capacities and are cooled for better performance and long life by being submersed in the fuel.


Ed

[likenu2]

Thank you for all that information Ed, gave me a lot to take in. And the fuel pump is an in the tank model. Thanks again.
Joe

[philminotti]

Ed is spot on with his comments. My cam is 248/252 .633 on a 108 center...warm street cam. I'm running FAST XFI sequential port injection. Self learning was for the birds. It needed a dyno tune by a real pro before it would even think about behaving.

Phil

[DWRAT]

Originally Posted by likenu2

Cam is a hydraulic roller
Lift: .594"/.618"
Duration (@.50"): 242/248
Compression: 10.5:1

Your specs look pretty hot to me, it's the biggest hyd roller Comp offers for your motor.
This cam is very close to your specs and it states "NOT FOR E.F.I." 35-427-8 - Xtreme Energy

Worst case you may need a different cam but I know Bob Reems will take care of you.

[eschaider]

duplicate post

[eschaider]

Originally Posted by philminotti

Ed is spot on with his comments. My cam is 248/252 .633 on a 108 center...warm street cam. I'm running FAST XFI sequential port injection. Self learning was for the birds. It needed a dyno tune by a real pro before it would even think about behaving.

Phil

Having experienced the phenomena first hand with FAST's XFI, Phil you can speak with considerable authority.

Originally Posted by DWRAT

Your specs look pretty hot to me, it's the biggest hyd roller Comp offers for your motor.
This cam is very close to your specs and it states "NOT FOR E.F.I." 35-427-8 - Xtreme Energy

Worst case you may need a different cam but I know Bob Reems will take care of you.

Hot is a relative term DWRAT. As Phil indicated, he thinks of his 248˚/252˚ .633 lift cam as a warm street cam. Terms like mild, aggressive and hot are the modern day incarnations of the old 3/4 race and full race camshaft terminology. God bless his soul, Isky was the most creative of all the cam manufacturers when it came to naming conventions and terminology.

Because of what is available and what people demonstrate an appetite for many cam companies provide warnings like that of CompCams for certain profiles. The reason has less to do with the cam profile and more to do with the most common types of entry level EFI systems being sold/bought.

Today most systems use a speed density fueling model. The less sophisticated, earlier Alpha-N model is sometimes also included in the EFI computer but not always. Alpha-N systems basically relied on throttle position and engine speed to determine engine fuel and spark requirements. Change a carb, intake, or cam and you had to reprogram the EFI system because all its tables relating to throttle position, spark and fuel demand had to be redeveloped on a dyno.

Speed density systems were a step up from the Alpha-N engine management model because they used engine volumetric efficiency tables to map engine load. Still, when you made changes that materially changed the engine's volumetric efficiency you still had to redevelop the engine's Ve maps on the dyno. The FAST XFI, system for example, is an excellent speed density system and I believe they may also offer a MAF based option in their EFI today.

The Mass Air Flow (MAF) system model was a major step forward in engine management controls. With the introduction of the MAF based system you no longer had to guess about Ve because the MAF flat out told you exactly how much Air Mass just went into the engine making it now a self contained system. Programmed (tuned) correctly with some head room for "good air" the MAF base system could actually accommodate changes in engine design such as cams, ported heads and stroker cranks.

If you can lock down engine specs to a manageable range you can build a simpler, not all that programmable EFI system that can, within limits, properly manage fuel and spark for the target engine. Increase the engine Ve with a hotter cam and that simpler EFI can not accommodate the additional air mass and still properly fuel the engine — hence the warning from Comp.

Now contrast that with a fully programmable speed density system and suddenly the camshaft upgrade is possible to accommodate — although a dyno session will be necessary to properly map out the spark and fuel requirements for the new Ve. Now consider a MAF based system and you have a much wider latitude before the trip to the dyno becomes necessary.

The down side of the MAF based system is the need to upgrade the MAF to a larger MAF if the engine's Ve is substantially increased — think of a bigger blower as substantial, that's the bad news. The good news is after the new MAF is installed and the MAF xfer table is loaded into the EFI computer you are, with a few tweaks, back in business.

When Mercedes, BMW and other high end manufacturers go racing they use MAF based systems for a reason — certainty, predictability and performance. As luck would have it so does Ford. Even better Ford systems can be bought directly from FRPP and also through the aftermarket. The aftermarket source for a system that looks so close to a Ford corporate racing ECU is offered by these guys, Pro-M Racing.

If you are interested in learning more about the EFI they offer this is an excellent link to begin at, click here => Pro EFI

If you want to get a better look at the kit click here => Universal Kit

The system is predictably a MAF based system that is extraordinarily flexible.


Ed

[philminotti]

Not to get too off-topic, but it should be mentioned that displacement can really impact the "hotness" of a cam. Just as a big cam can decrease the effective compression ratio, a big engine can "tame" a lumpy cam. I think the OP was a small block...so a hot cam in a 347 may be a grocery getter in a 496. But my self learning comments stand. In self learning, my ECU chased VE numbers to hell and back, even when I minimized allowable %correction at any given time. I do think the quality of low rpm low load vacuum signal is very important to these systems and I do know my vacuum isn't the cleanest or strongest in the world, again because of my cam. However, careful dyno tuning can and does work wonders.

[eschaider]

I think Joe (the OP) is a 427 small block Phil.


Ed

[likenu2]

Ed is right, the motor is a small block 427/535 Ford racing crate engine. Bob ahs pretty much said that the self learning is out of the question. He has had it since Monday going over all the parameters with his lap top and along with the FAST engineers. My concern is if it can not get dialed in right, what will have to be done to go back to the Holly Carb that was on it. That will be the last resort. I do not want to make a very expensive mistake and/or have to "live" with something that I an not happy at all with.
Joe

[likenu2]

Ed is right, the motor is a small block 427/535 Ford racing crate engine. Bob ahs pretty much said that the self learning is out of the question. He has had it since Monday going over all the parameters with his lap top and along with the FAST engineers. My concern is if it can not get dialed in right, what will have to be done to go back to the Holly Carb that was on it. That will be the last resort. I do not want to make a very expensive mistake and/or have to "live" with something that I an not happy at all with.
Joe

[eschaider]

Joe, you could keep the throttle body air valve to maintain a semblance of a period correct appearance, sell off the pieces of the system you are not going to use and replace it with the Pro-M EFI. That Universal Hot Rod kit is nothing short of awesome. With a sealed can to replace the air cleaner and an air pipe to a MAF you would be done other than the trip to the tuner.

A second alternative would be to use one of Ford's own OEM or an aftermarket copy EFI manifold and plenum for your style heads. Alternatively, if you wanted to be really creative you could fabricate a simple runner per port with a plenum and forward facing throttle body reminiscent of something like this:

The individual runners would crisscross each other under the plenum, entering the plenum on the opposite side. With an injector per port this would be an exceptional system.

The thought of the fabrication process is much more daunting than the actual event. The manifold runners turn out to be off the shelf tubing and the plenum can be fabled from an ovaled tube (off the shelf again) that the runners get welded into. Weld in injector bosses are off the shelf items. Use a thick intake flange for the heads and you are pretty much done. You need to have a two bolt mounting pad for an idle air control motor which you can hide on the underside of the plenum and a vacuum nipple for vacuum accessories (power brakes?) and you are basically done.

The finished manifold and EFI would have stunningly good street manners and real world performance. If you want bling polish the aluminum or if you want a more conservative look do a wrinkle finish powder coat.

Best part is you could do this while you drive around on your carbureted engine, building the system at your leisure spreading the effort and expense over time and making it a fun project instead of a painful job.


Ed

[likenu2]

Update: Bob had put the O2 sensor in the collector just outside the fender, FAST engineers said that it was too far away and was sending false readings to the computer and the throttle body. His plan today is to move the O2 sensor to a single tube of the header closer to the engine itself.

Ed, I appreciate all of the information. But I rather prefer the look of a carburetor over the "modern" look. But I am taking all of your information and holding on to it as a back up just in case. Thanks for all of your help. You are obviously very knowledgeable in fuel injection, way more then I am. Thanks again.
Joe

[olddog]

Originally Posted by likenu2

Update: Bob had put the O2 sensor in the collector just outside the fender, FAST engineers said that it was too far away and was sending false readings to the computer and the throttle body. His plan today is to move the O2 sensor to a single tube of the header closer to the engine itself.
Joe

The old O2 sensor is too far away from the engine excuse, is just that, old. Back in the days when no one had access to tune a factory OEM ECU it was true that it would cause problems. That can be corrected in the tune of a Ford ECU today, especially now that the O2 are heated. I am very skeptical that this is going to fix anything.

Also I am very skeptical that these so called self tuning systems ever come close to the same performance level as tuning it right.

[ffr 1137]

...also the O2 sensors are just there to try to maintain stoichiometric at
idle and low speed to keep the EPA happy. Any reputable EFI dealer should inform you that if and when the ECU sees O2 faults it will disregard them (or should) and default to carb mode. I've had O2 faults due to sensors out there too far for 15yrs. Once in a while I have to blip the throttle when coming to a stop. Also mine are 3 wire non heated...lay your leg against the sidepipe there and tell me it's not hot enough

Mike

[joyridin']

Not sure what type of headers/sidepipes you have, but is it possible to sandwich a plate between the header and sidepipe and mount the O2 sensor in that location? It would need about a 1" wide spacer.