I have a fast burn GM crate motor with hot cam. GM performance make a FI system that fits vortec heads.

Can I use this with my motor?

What computer do I use? Painless?

I know fuel pump and regulator need to be done

Just making sure it will work before puchasing.

 

I suggest megasquirt. Will fit any system/combination. You just will have to learn programming it.

 

Will it even come close to fitting under your hood? If you don't know ... maybe you should begin another thread that clearly identifies the FI system (such as ramjet for example) and ask if ramjet (kinda tall?) fits your car

 

PM Bullshark, Bob is very knowledgeable on this subject

 

No reason why FI wouldn't work as long as you have an intake that is compatible with the fast burn heads. I seem to remember reading somewhere that the Ramjet 350 intake would work if you have the hood clearance. Also the Holley commander 950 sb intake I think. You need to check this out though. I believe I read this on one of the Sallee discussion board threads....

If it were me, I would use one of the latest after market ECU systems like Accel, Fast XFI or Big Stuff. more $$, but worth it IMHO.

You can go with a GM ECU if you want to really dig into the technology using MEFI Scan & Tune, or EFI live for later model GM stuff.

Bullshark

P.S Here it is I found it

http://www.sallee-chevrolet.com/Disc...3418/3896.html

 

I'm not concerned with hood clearance. If it doesn't fit, we go L88

Do I have have to run new fuel line I know the current line is 3/8 and the return from the carbon canister is 3/8

 

3/8 line both directions back from the fuel pressure regulator should be fine. Make sure it is FI High pressure line. Original steel lines should be fine, just make sure you use AN fittings and any flexible line is Stainless steel braided Earl type high pressure silicone rubber. I am not very familiar with the old carbon canisters and their ability to handle this?

Bullshark

 

Carbon canister line is steel just like fuel from tank. The vapor line does dump into the top of the tank.

 

Your canister line is 1/4 inch. You already have a fuel return line next to the 3/8 pressure line. You should use it instead. I went one step farther and replaced the 1/4 fuel return line with a 5/16 line in stainless but the body needs to come off for this. The factory 1/4 fuel return line is satisfactory.

 

I was told the return line is not large enough. Both line (In & back) need to be 3/8. I was also told the carbon canister return line is 3/8. I guess I better checkthat out myslef.

 

The factory size fuel lines on the newer Corvettes with fuel injection is 3/8 pressure and 5/16 return. A couple of guys on here have been using the factory return 1/4 line with no ill effects. I can confirm that the canister return line is 1/4 as I just went to the garage and measured it as my body is currently off the car. I personally used the GM ecm and just paid a professional outfit to burn a chip. You send them all the specifications and they go from there. PCMFORLESS is highly recommended on the C4 forum here and they are who I used as well.

 

Then I guess I could run a new return line along the frame in 5/16 back to the tank. I will also give PCMFORLESS a call.

Any pics of your work?

 

I used the existing factory 3/8 steel line as my return line and routed new 3/8 feed from a Holley external electronic fuel pump. If your going to go to the trouble of routing a new line, my recommendation is to use 3/8. I personally believe 1/4 is to small and 5/16 is minimum. The reasoning behind all this is to give your fuel pressure regulator the best operating range and response possible. Bernoulli equation for you Fluid dynamics guys Too small a return line can cause pressure fluctuations to the injectors.
Also, IMHO, you don't get an optimal (and sometimes even satisfactory) tune when you have some remote tuner burn you a canned calibration. Not only that, you are held captive for any future mods. That is why for myself, I insist on having control of my destiny. Accel, Fast, Big Stuff among others give you that flexibility. It is becoming a wide open market now that MSD, Edelbrock among others have also jumped in and now offer very capable systems.

Let me know when you home in on your preferred configuration or need any opinions, I will glady offer my 2 cents

Bullshark

P.S. I forgot to mention that the return nipple on the fuel tank needs to be replaced to accommodate a larger return line. It will do no good to run larger (3/8) line only to pinch down to 1/4" at the nipple.

 

If you run the intank fuelpump setup/sender off a 1982 Corvette the nipple is already 5/16 inch. Many guys on the C4 forum are running a 5/16 inch return line without any ill effects and some of them are at the 500hp mark. After you have a pro burn you a tune you can datalog it running then send them the file and they will tweek it for nothing. Many guys have reported that their tune was within 10hp of a dyno tune. That speaks for itself in my opinion. For any future upgrades it's as simple as them modding the tune then emailing it to you. Then simply burn it to a chip and install. The only down side to this is you must buy some hardware to burn your own chip. The main reason I found for not going aftermarket is the situation where your ECM craps out on you while on a road trip. Try getting a Big Stuff or Fast ECM while stuck in some small town somewhere. Most of them do use the factory sensors though but try getting support 10 years from now when you need a new ECM. My underhood GM ECM cost me $25 at the salvage yard. They are widely available from many early 90's mid size cars. I have six of them now. They were used in Gran Pix, Cutlass Supreme and Lumina models as well as the 90/91 Corvettes. The only problem is the fact you can't use the memcal from them. You must find a V8 memcal from a Vette or Camaro/firebird.

 

I ended up running a new line from the engine to the tank....only to find that the return fitting on the tank was 1/4". So far, I just attached a short rubber line from the new 3/8" to the 1/4". How can you tell if it's a restriction? Put a fuel pressure gauge on your system and see what it reads at idle. When the engine is idling, that is when most of the fuel is being recirculated. Turn the pressure down on your fuel pressure regulator and see if the pressure on the gauge goes down. If it doesn't, your return line is creating more pressure than the regulator.

What I have found to me more important is where the pickup is located. With any less than a half tank of fuel, my pump will starve during hard acceleration. It's a PITA, because you effectively cut the tank capacity in half. I plan to put a sump in soon to solve this problem. When I do, I will add a bigger return fitting so my rubber hose fits better.

Ken

 

Peace Ken, Your car your choice. I personally believe that on the very remote chance a ECM goes south, your stuck towing it to a shop or home anyway. Being a hard headed EE, I know I would opt for DIY fix since I don't believe I could find a trusted source in the middle of "tim-buck-two" anywhere near an acceptable price let alone a capable one. Remember, I have modified the calibration and it is no longer standard. The older ECM's are long in the tooth and not acceptable for my applications (like RamJet 502). We will have to agree to disagree on tune by mail. That is the Engineer in me, just to many variables, and with my trusted laptop I can diagnose and datalog to my hearts content (no chip burning for me, that's old tech)
Again, 5/16 is probably going to be ok for smaller engines, but those BB gas guzzlers are a different animal. Again, if you have to run a new line may as well use 3/8". Internal fuel pumps that can handle the demand have their advantages. My applications were with older 69-72 vintage vettes.

Bullshark

 

Hi Ken, I believe the problem will be the ability of the fuel regulator during fuel demand transients. Steady state is a lesser concern. Bernoulli says P1V1=P2V2 at a restriction. That means pressure is fluctuating rapidly to accommodate flow demand. Fuel regulators can be sluggish. I would recommend modifying that 1/4" nipple. I second the sump need.

Bullshark

oh. Buy the way Ken, I still have your stim board, turns out Gene's megasquirt does have some kind of I/O problem I haven't got around to troubleshooting yet. Let me know if you need it back soon.

 

My hats off to anyone like yourself Bob, who can master tuning their own setup. These newer aftermarket setups are far superior to the older GM units I am referring to. They use wideband oxygen sensors and sequential firing sequences. If you don't mind investing the time it takes to learn about tuning your own setup it's a great option to consider.

 

What I would really like to do is get an electric fuel pressure sender and wire it into the Megasquirt. That would let me log the fuel pressure versus the manifold pressure. Just looking at the fuel pressure gage on the fuel rail, it responds immediately to the throttle with little to no bouncing. Of course, I can only see that at idle and very low load (revving the engine). In the short term, I think I am going to mount a gauge by the windshield where a passenger can look at it.

I had a strange feeling there was something wrong with the MS. The problems didn't make sense. I don't need the stim right now, so go ahead and hold onto it.

Ken

 

My experience with the Megasquirt is that lots of people can get their engine to run. The devil is in the details. Some of the things that seem easy are not. A key example is light load cruising. My engine does not like my current combination of spark and fuel and the result is some surging. The key to tuning anything is knowing what the engine is doing. If you don't have a wideband, or if you don't know what lean backfiring sounds/feels like; etc, you can't tune. I have learned so much more tuning my engine than if I bought someone else's computer. It has been fun, and I wouldn't do it any other way. Not everyone thinks it's fun though, to be sitting on the side of the road making changes on a laptop.

Ken