I need some help picking out a FI kit. I was thinking about this fast kit for about $1600-- http://www.jegs.com/p/FAST/Fast-Raci...16664/10002/-1

or this much, much more expensive holley commander 950 set up http://www.jegs.com/i/Holley/510/550-821/10002/-1

I have a 383, 500 hp and about 53 ft lb torque flywheel. Cam specs are .540 lift on intake and .562 exhaust. Its mated to a t56. I Know the commander kit has been around for a while, and the FAST kit is realitivily new. I read some posts on other boards and from what i read people like them. I know alot about fuel injection on stock cars (Im a mechanic for about 5 years) but dont know that much about performance fuel injection.

 

Food for thought

https://www.thirdgen.org/forums/post...927-post5.html
https://www.thirdgen.org/forums/post...31-post10.html
https://www.thirdgen.org/forums/post...50-post11.html
https://www.thirdgen.org/forums/post...03-post23.html

https://www.thirdgen.org/forums/dfi-...-about-ez.html

 

So am I better off getting that Holley avenger system? Even though it seems much more its probally better off going with that...thats the HSR set up that I see so much about riht?

 

Fast XFI gives more control but the ez efi stuff does work ok. Just need a conventional distributor for vacuum advance or mechanical advance to control the timing.

Holley makes good stuff too I hear. That kit you are looking at includes the stealth ram intake and accessories, which makes it a complete MPFI swap if you want to run that intake.

The Fast kit you are looking at makes it a TBI. May make it more driveable but will hurt power department. I'd look at one of the EZ efi systems or Holley systems with a conventional intake manifold for port injection...which are many-- TPI, Miniram, Stealth ram, single plane efi, etc.

 

Not sure if I understand what you mean here but the fact is the TBI will probably make more peak hp at wot. However the multiport will drive noticeably better.
I do the Accel Thruster series, with just the electronics or as whole kit, lots of features and tuneability, happy to help.

Try to stay away from the Commander 950, real old technology and limited tuneability. Plus I have access to dyno sheets that prove its inefficency.

 

Here we go again...

-- Joe

 

I was looking into the holley stealth avenger series swap....

 

What I meant was make it more driveable than a carb setup but wont make the hp. TBI wont make the hp that a multiport setup would either with the properly designed and configured intake system. I have yet to see it done. Even some of the top engine builders working with EMC engines cant get TBI style systems to work.

 

dynamicefi.com see port version see datalogging see VELearn see WB input option.

 

You'll need to show me where that system takes into account not only ECT and IAT but also MST to correctly calculate the Volumetric Efficiency of any given application.

FAST, Holley and a bunch of others all call their fuel tables VE tables, but they're clearly pulsewidth tables because their ECM's don't have the ability to calculate the true VE. You can call the fuel tables anything you want, but unless it can do that it's a pulsewidth system, period.

 

Cool.

Who cares?

A value of 0-100 in a column is easier for people to grasp than a pulsewidth, or pulsewidth multiplier as you know many things go into the calculation of the final injector pulse width.

-- Joe

 

The manufacturers that don't have that ability are the first ones to tell you that you don't need it. Funny how that is.

 

How much of an advantage is there for a true VE calculation based system vs the so called pulsewidth systems? I know of some very very fast cars running FAST or BS3 based electronics. Even some very fast stock ECM cars. Power can be made obviously but what other advantages are offered? Is the true VE based system only for weather/altitude corrections? Some of the stock systems seem to be doing a decent job of that so not sure what all can be gained. Just curious

 

Running at WOT doesn't take much tuning/control. Any tuner will tell you that's the easy part.
Driveability is something all together different. Yes it will more notably enhance that but also does a better job of compensating for changing weather conditions no matter what. It won't necessarily make more peak power but it typically is makes more power along the way to peak because of better, more accurate control.

 

Uhm. like OEM ?

-- Joe

 

I definately agree, WOT is the easiest part but driveability with alot of the stock stuff isnt too bad even if it is a pulsewidth based system. Once the so called VE tables are in line, as long as there is some decent resolution to the table, I have yet to find a problem with part throttle conditions. Its good enough for me, smooth enough too. Between 80's deg heat and 30's deg winter air, in pure open loop my air fuel ratios havent changed more than .3-.5. Thats no real compensation in the tune. I know on my oem ecm running code $59, there are some weather based systems and closed loop operation options but I havent had the need to really worry about it. I just burn another chip for cold air tunes. Car sees limited run time anyway so I'm content with that. I'm sure alittle compensation could easily cure the .3-.5 air fuel ratio variance, and to be honest, with 80lb injectors, thats not much of a change in VE table given the resolution I'm allowed to adjust it by.

 

OEM stuff, by design, runs in a very narrow window for 90% of it's run time. It's biggest chore is to make sure it runs at 14.7 stoich for most of that time.
However when someone needs better control, what do they do? They either modify what's there or buy an aftermarket system don't they. And that aftermarket system is expected to run everything from a 4cyl Cobalt to a large cammed blown BBC, way out of the league of even some of the best OEM stuff, that's not what they're designed for.

You're comparing apples to oranges.

 

OEM stuff works fine for me, and 99% of the members.

If I was going to have a second choice, I'd go with megasquirt.

Fast, Accel, Holley, etc is all a waste of money. The only benefit to spending thousands of dollars for a different algorithm to command an injector pulse width is getting to brag to your friends how cool it is, and have a pissed off wife in the process.

A stock ECM with a good tune will run a 500hp 383 all day long. No need to waste money.

-- Joe

 

Your opinion, if you want to settle for "good enough" then that's your call. And with all due respect if your wife gets pissed off for you trying to make something better then that's your problem, not ours.