I run this currently
S1 Cam from Indy solid flat tappet
260/266 - .558/.555 1.5 Rocker and 108 degree lobe separation.

What would be a good change out to a street strip friendly EFI cam for my 415 Small Block.

I run a 5k stall if that matters

I am looking for something that is not so Choppy.

What I have now is OK but not to friendly on the vacuum side for the efi.

I am not sure what direction to go I don't want to loose to much performance but a nice smooth idle would be awesome

EFI doesnt like narrow LSA cams... as in 108... will they
work.. yes.. I have a 105 LSA cam in mine installed at 105
but that gives a good amount of overlap... a wide LSA drops
the overlap to give a smoother idle

I can design you a cam.
Cubic inches, what heads, compression ratio, induction details, if racecar what ET, cars weight, transmission, what EFI system.

The right efi/ tuner can make any cam run evenly. Any efi system with a blending capability of map/tps will idle at very even cadence. No real need to swap cams if you are happy with it.

have to go with open loop idle since map signal will be erratic. Ive been playing with that myself lately on my Gen III and have learned a lot.

When the idle map values go inverse, start substituting tps voltage. The reason you need to go open loop at idle in some situations, is that the exhaust gas is inconsistent in oxygen content. Lambda sensor is "seeing" overlap(high O2), and than blasts of low O2 from combustion. There are a lot of ways to overcome these issues with the right system configuration.

EFI don't care what cam you have, only a bad tuner blames the cam.
I run solid rollers, 280 at .050, and .750 lift

Even according to the techs at the different EFI companys they
all said that the wider LSA is better... that way you dont need
the electronics to try to cover up.. but the narrow cams will
work... on my Holley.. it changes loops at 160* so that is a while
even with a stat(I have 4 1/8" holes in the stat to move water at
all times due to the elec pump)

EFI essentially eliminates the need/effectiveness of fifth cycle scavenging during the overlap, since the fuel is pressurized (rather than drawn) the injector can deliver the fuel (as well or better )later in the induction opening cycle, that also gives you more room for Air (read:Oxygen) to get in the hole and still get the fuel in before the slug turns around at BDC and the compression cycle starts.

Bottom line is when you spread the lobe centers and (generally) delay the ICL the torque curve broadens and particularly part throttle drivability increases compared to a carb. But at WOT it's tough to significantly top a well-tuned Holley when using a conventional single carb/EFI TB intake induction system. You basically tune the cam timing to enhance part throttle drivability. Direct Port injection is usually a different animal though. Those have the advantage of the runner building AIR velocity and don't have to worry about suspending emulsified fuel with it most of the way.

P-Body is correct, wider LSA is better, but if your EFI system can do it, you can dial in a radical cam by sequentially not starting the idle injection pulse until intake reversion is over, and by programming the idle area in Alpha-N (TPS as was stated above). But in order to do any of this I'd need to know what EFI system it is. If it's a no-laptop hands-off system then you have to have a more friendly cam with a wider LSA.

I am running a Comp XS282S with a self tuned and built Megasquirt system (MS3X) and it idles and drives great!

PID Tuned closed loop idle as well. I have the ICV Valve set for 1000 RPM target, and it does a good job of keeping it there no matter the load.

FASTMo your probly right. I am new with EFI and forgive anyone that is trying to learn anything new. I am asking the question because I don't know, and from the look of your response you don't either so next time don't comment on what you don't know. and if you do know you are a [censored] teacher.

thank you everyone else and please keep the advise coming.

You bet-cha !

I have an IAC motor and so far have had to keep it closed and off to have consistent idle with my MS3'd Gen III Hemi. I don't even know what the PID is and the Algorithm for IAC is either always moving or always on and neither makes sense to me. I have good clean idle once it warms up but have not figured out a good warm up mode/cold start setup and I know I will need the IAC for that.

While you may have taken it the wrong way, FastmOP was exactly right. With a well tuned EFI, the cam is of no consequence. And some also claim you have to Alpha-N to make cars with radical cams idle..........I don't. I run everything in Speed Density and have never had a problem. Also getting the injector end angle numbers correct is important on a sequential system. You don't want the injector spraying on the backside of a closed intake valve

Monte

The idea of going wide on LSA to get a decent running motor with EFI just doesn't sound right to me. When did the laws of physics change and ram tuning go away with EFI? From what I have learned, overlap and LSA are dependent on how well a motor breathes at overlap. Better breathing, wider LSA. Poor breathing, narrow LSA. The air doesn't care where the fuel comes from, or how. Examples- Gen3 Hemi, VERY good overlap flow, ,wide LSA. Any four valve per cylinder motor, excellent overlap flow, wide LSA. 440 with stock heads, not so good. Narrow LSA. Smallblock stroker, poor overlap flow, narrow LSA. One last comment- I don't hear of racers changing LSA when going from carbs to constant flow injection, so that rules out any ideas about vacuum signal.
EDIT: Mike, your comment about the EFI engineers saying you won't need electronics to cover up a narrow LSA, it sounds to me like their systems aren't flexible enough to adapt to the right LSA for a radical motor??
So my question for the OPs situation is, what is the best, mnost flexable EFI system that will work for the best cam for what he wants? That way he won't have to crutch anything to get a sweet running package. My interest here is similar, I have a dragpak cam with a narrow 110LSA, and plan on EFI with Apache heads on a Gen 3.

You'll have to forgive my somewhat dated suggestions. I've been screwing around with this stuff since the dark ages, on a wide range of systems. The tps substitution (at idle)is the method I prefer, because I'm familiar with it, and it works well for me.
I believe it was Motorola(?) that came up with engine position map sampling that allowed early efi on Harley Davidson engines to use 100% speed density on a very poor map signal engine to run evenly and consistently. These systems were programed to use a narrow window of map signal in a determined engine position(where the map signal was consistent and strong)and ignore the rest of the map output.
I admit that my exposure to more modern efi systems is limited. Is the holley system capable of adjustable map sampling?

This is thread is a great example of why you should buy the system that the tuner you will be using recommends. Everybody here has their reasons based on past experience.

My last post guys...

Monte: I believe you like Holley EFI, and I tuned FAST for 10 years. Well, I just became a Holley EFI certified dealer and spent an entire week at Holley (3 diplomas :^)) I have wanted to run alpha-N at idle for years but FAST can't automatically switch back to Speed Density - but Holley CAN! It's the Holley-preferred tuning technique for radically cammed motors that want to be driven on the street. I will explain the technical reasons in a paper that will soon be posted on my Technical Info page.

I have tuned many race engines including several blown alcohol and turbo motors and I have always used only Speed Density. No issues. But I wasn't concerned about the low end drivability. Start - stage - WOT. Controlling the injection end angle is a critical part of the equation which tuners will use if their system can do it (both Holley and FAST can).

Gregs: The laws of physics are the same, but EFI can use the capabilities a little bit better. On my dyno I tuned race motors with carburetors and produced good power. After those engines were converted to a smart EFI system I made about the same max power but I was able to tame the idle a bit using the above techniques with no cam change. In a race motor you design the cam for the engine/head combo and then tune as required.

Trendz: Yes

A wide LSA cam is a way for an EFI system that cannot do these things to run better on the street simply because idle is better. Its not much more complicated than that.

Rich, I follow what you are saying, and that is what I figured. I think there would be a small loss of upper mid range and top end power, because the LSA is wider than ideal, shortening needed overlap duration.

Right on!