dewcustom

i am wanting to put on direct port fuel injeciton but not sure what type to get i like pats tpi but not sure it will fit under the hood i have a stock hood with a scoop that i add it looks like the old 427 scoop with it i was able to fit a airgap intake a 1" carbspacer and a 4" element w/ the drop base. but the problem is that from the water neck up the hood is stock. so what i have been looking at is the edelbrock rpm pro-flo efi it will fit no problem and it seems like i nice user freindly system but is there a better system for power or driveability.

ok this is what i have
a 1970 vette with a 388 stroker rpm heads witha 3 angle valve job i have 10:1 comp. with forged pistons
there is alot of other stuff but i don't think it matters

also i plain on super chargering it in the future :auto:

zwede

If you plan to supercharge the edelbrock is out. NA only. I would look at the Holley Commander 950, the FAST and the Accell Gen7. The C950 is lower cost (the same as edelbrock). The FAST & Accell Gen7 are more capable and have a nicer interface but cost more.

Ganey

The TPI was designed for a 305.
Better setup rec. for 383+.

MELVIN

I have the Edlebrock Pro Flo 3550 EFI in my 68 on a big block. LUCKILY, Im running a L88 aftermarket hood without the airchamber. I say luckily, as even with a drop base air cleaner, I had to find a 3" high air filter, and still only have about 1" of hood clearence. Understand though, I have a K/N xtreme air lid, which rises toward the hood at a slight slope toward the wing nut, which takes about another inch. Wing nut takes up space as well

With a drop base aircleaner (and to run the pro flo, its a must for clearence), the air cleaner base would hit the IAC (idle air control valve). So to clear it, I had to get a 1" spacer that fit between the top of the throttle body and air cleaner base. There goes a inch of clearence I did have

Since you have a sb (with a hood that Im not quite sure of what you described), clearence may not be an issue

The Pro Flo I picked over other EFI (such as Accel or Holley) for numerous reasons:

1. Pro flo includes a palm sized ECU programmer to fine tune the system. Other brands you must load with a lap top. If you have a lap top, its no big deal I guess, but with this hand held you simply plug into the harness (which will be under the dash, passenger side), and can monitor all fuel/air functions as you drive, to include on-the-spot lean or rich conditions. Also, with this unit, you can save a total of three settings, and engage any one of them with a push of a button. So you can save 3 settings: Example: One that is for economy, one for 1/4 or 1/8 mile racing, or one for high speed running. With the other brands, you have to pull out your lap top, and re enter the parameters you desire

2. The proflo comes with an ECU that is programmed specifically for your engine (when you buy the kit, it has a fax sheet that you fill out with your EXACT cam specifications, mods/size of engine, etc). You then fax it to Edlebrock, and they overnight you the proper chip, that is loaded with base settings

Drivability is outstanding. Fires up immediately, and is smooth as silk throughout the entire rpm band

3. The proflo comes with a distributor conversion kit so you can use either your stock tach drive/points type distributor (which is a must for our tach drive type distributors), or your HEI. Other brands you must use an HEI

4. The unit bolts right up. I had no problems whatsoever with bolting the EFI on.

5. The instructions for installation are straight forward, with lots of pics. tech line is available on the net or phone, pretty prompt responses. Initial start up procedures are easy. Very little tuning is required as it is already set up on the chip for your engine specs (such as initial settings for all rpm bands, WOT, and rich lean conditions). But realize, you must take time to fine tune. It was very easy, as I stated before, you have a indicator that is always visible on the hand held that shows lean/rich conditions

6. Many of the parts are GM mainstream parts (such as the fuel regulator, injectors, etc. So parts are easy to come by. any other replacement parts are available thru Edlebrock

Since we have vacum operated lights, and for some, the wiper door as well, you can hook a vacum line right into the throttle body into a fitting that is already there. Just be sure to ask the tech line where to do it, as you just cant tie into just any vacum line that exists on the EFI (what you do is take the manifold air temp sensor out of the trottle body, easy, it just screws out, install it your air cleaner base, where it functions better anyhow, and place in a fitting at its old location that has a nipple on it to hook up your vacum source). I got my fitting at lowes, in the plumbing section_

Some drawbacks:

1. You cant use your existing fuel lines. They arent big enough, and dont even try. I tried, but bottom line, EFI requires 40-50 psi to function. Use the included fuel lines(s). This is true for all type EFI/TPI injection systems. I was getting serious fuel starvation at WOT due to trying to use the existing diameter fuel lines

2. A return fuel line must be used. Again, it must be of proper diameter. 68-69 vettes have a return line that is too small, and I beleive 70 and - later models do not have one. Regardless, you must install one which means plumbing one into your gas tank. Again, This is true for all type EFI/TPI injection systems

3. The wiring harness is easy to hook up, but a little difficult to get thru the firewall. The proflo had just enough slack to get it thru the firewall, and install
the ECU and in line fuse holders

4. Some folks state you must install a baffle in the gas tank, as any air that might enter the fuel line under hard acceleration (when under, say a 1/4 tank or less) will immediately and briefly stall the motor. A carb you can get away with brief fuel starvtion. EFI you cant. I did not install a baffle, but I have yet to run into this problem, even when low on fuel

The proflo comes with fuel pump, all fuel lines, etc

5. Throttle bracket. It doesnt come with a throttle bracket. You must order or get one from Summit (Cant remember the part number, but its a universal type bracket, about $12

6. I already talked about the air cleaner

dewcustom

well zwed you named the three that i was considering the proflo the holley steathram and the accel streetram.
i guess the most important issue is if the last two will fit under my hood, does anyone have measurements of them i need to know the height of the throttle body inrelation to the forn most part of the intake (where it seals to the block under the water neck) that is the only place i have a problem.

zwed how come you can not supercharge the proflo i thought i could use a carb bonnet like you do with a carb.

i know that with any system i will have to set initial peramiters but do any of these self adjust under diffrent conditions like rich or lean at difrent temps under difrent boost levels

is there any advantage in one of the ram style units over the pro flo style

like i said before i have been looking at the proflo for some time it comes as a complet kit and i dont have to take a lap top evey where but i love the look of the accel :crazy:

zwede

It will be very hard to fit the stealthram or super/street ram under a vette hood. Haven't measured on a smallblock, but on my big-block it was impossible even with a L88 hood. If you search the archives at http://www.chevytalk.com under the EFI forum you should find some measurements. I remember this being discussed.

The pro-flo ECU cannot handle boost. The others (Holley 950/FAST/Accell) can. For the edelbrock it's not a problem hardware-wise, but rather the ECU is not setup to handle a 2 or 3 bar MAP sensor, needed to sense boost.

Holley has a kit very similar to the edelbrock with the same style intake for about the same money. Only difference is you need a 7 or 8 pin HEI for computer controlled timing, where the edelbrock can use your existing distributor. This is the kit I went with.

All of these systems will attempt to adjust the mixture to the correct ratio while in closed loop. Your job is to set the fuel map close enough so that the needed adjustment falls within the range the ECU can correct. I recommend you download the Holley tuning manual from their website. The tuning procedure and theory applies to all aftermarket EFI, not just Holley.

The ram-style does seem to make slightly better power, but the difference isn't earth-shattering. With the top-fed style you can set-up functional cowl induction if you have a L88 hood. I have pics of this on my website. I think a top-fed system using cowl-induction will make the same power as a stealthram using hot underhood air (no proof, just my opinion).

As for the laptop, it is only needed when you want to adjust things. Once it is set you don't need the laptop.

zwede

Also: If you go with the accell, make sure you get the Gen7. I hear the Gen6 is not nearly as nice interface-wise. The Laptop program only runs under DOS. Gen7 is much better.

SmokedTires

The Holley will support your 388 just fine, but I don't know if it can run injectors large enough to support your engine if you add a supercharger. Most likely you injectors will be high impedience and as you raise the injector size/ lb to compensate for the supercharger the heat generated in the ECU goes up which may not be possible with the Holley Commander 950. I think Holley says up to 650hp for the Commander 950, so I'd contact them before you lay down the cash if your serious about supercharging ;) .

The FAST & Accel Gen 7 should have no problems :) .

dewcustom

what about getting a used tpi and a new ecu from holley or accel there is one that is close to me that came form an 86 camaro that i can get for 150 but no ecu

PatsLs1vette

what kind of rpm are you looking to getout of it?I can get 5500 out of mine and thats it,ive also ported everything and my heads are helping me.Like corey68 said maybe a superram setup will be better or another fi setup from edelbrock or others.

zwede

The Holley ECU can run 4 low impedence injectors or 8 high impedence. High impedence injectors are available in upto 50 lbs/hr. That's quite a lot of hp. I'm running 42 lbs/hr on the 454 and I have quite a large buffer before running out of injector.

If you do need bigger than 50's, you can get an auxillary injector driver box for the holley ECU that will let you run 8 low-impedence injectors.

The FAST and Accell Gen 7 have the additional injector drivers already built in, but they also cost substantially more than the Holley 950. Your call...

SmokedTires

:iagree: Markus that was mp point exactly. I too have 42lb injectors for my sbc, but if I were to adda supercharger to turbos in the future, then I would need to get an auxillary injector driver box for my Holley ECU.

I just recieved my ECU back from Holley yesterday with their Race Version Upgrade :D !

dewcustom

i don't want to run any higher than 6000 rpm

and i may or may not supercharge it but if i do it wont be for a year or two