John McGraw or anyone else that ran EFI in their SRIII (or other) cars

[firstgear]

The modern EFI systems I believe all require that a return fuel line be run back to the tank. When you built your SRIII (or other) framed cars (C1),

1. what did you do for a gas tank
2. did you keep it in the stock location
3. where did you attach the return line
4. where did you run it from the front to the rear?
5. what did you do for a fuel pump?

any photos that you can share would be appreciated.....thanks, Herb

 

[John Mcgraw]

Herb,
All EFI cars require a return line to the tank to return unused fuel to the tank. How the particular engine delas with this line widely varies.
For example, Camaros up to 1999 had the regulator on the fuel rail on the engine, so the return had to come all the way from up front. After 2000, and on all Corvette LSX engines, the regulator is in the fuel supply line, and the return only needs to come from the filter/regulator. I mounted my filter/regulator on the rear frame rail right under the tank, so the return line is very short and there is only one line going forward to the engine. I use the stock GM Corvette Filter/regulator, it is pretty hard to beat!

As to the fuel tank and pump, this can vary as well. You can use an external pump and weld a return fitting into the top of the sending unit. This is probably the least desirable setup, since the pickup tends to suck air, and this in turn makes for driveability problems and decreased pump life.
Keep in mind, that these engnes have to have almost 70 PSI of pressure at ALL times, even when at idle. The computer decides how long to fire an injector with the assumption that it has full pressure at all and the car will run like cr*p if the pump sucks air from fuel sloshing around inside the tank.
The better solution, is to have a tank fabricated to utilize an internal pump like the Walbro 255, that is submerged in fuel at all times. These tanks will have a well for the pickup, and will usually have a spiral baffle around the well to keep fuel from moving away from the pickup. They can rework an original tank, but I opt for a new, Stainless tank with all the features mentioned. This setup will give a quiet, longlasting pump and will supply fuel in almost any conditions,and will never rust! These tanks are not cheap, and will tear the heck out of a $1000, but it includes everything including pump, pickup, tank, and spiral well. There are several tank companies building these tanks, but I have always used Rock Valley and have never been displeased wit one of their tanks. I have friends who have external pumps and modified tanks, but to a man, they said that they would go with an internal pump if they had it to do again. The price of the tank sounds high, but just look at what a quality high pressure external pump like an aeromotive costs!


Regards, John McGraw

 

[firstgear]

Herb,
All EFI cars require a return line to the tank to return unused fuel to the tank. How the particular engine delas with this line widely varies.
For example, Camaros up to 1999 had the regulator on the fuel rail on the engine, so the return had to come all the way from up front. After 2000, and on all Corvette LSX engines, the regulator is in the fuel supply line, and the return only needs to come from the filter/regulator. I mounted my filter/regulator on the rear frame rail right under the tank, so the return line is very short and there is only one line going forward to the engine. I use the stock GM Corvette Filter/regulator, it is pretty hard to beat!

As to the fuel tank and pump, this can vary as well. You can use an external pump and weld a return fitting into the top of the sending unit. This is probably the least desirable setup, since the pickup tends to suck air, and this in turn makes for driveability problems and decreased pump life.
Keep in mind, that these engnes have to have almost 70 PSI of pressure at ALL times, even when at idle. The computer decides how long to fire an injector with the assumption that it has full pressure at all and the car will run like cr*p if the pump sucks air from fuel sloshing around inside the tank.
The better solution, is to have a tank fabricated to utilize an internal pump like the Walbro 255, that is submerged in fuel at all times. These tanks will have a well for the pickup, and will usually have a spiral baffle around the well to keep fuel from moving away from the pickup. They can rework an original tank, but I opt for a new, Stainless tank with all the features mentioned. This setup will give a quiet, longlasting pump and will supply fuel in almost any conditions,and will never rust! These tanks are not cheap, and will tear the heck out of a $1000, but it includes everything including pump, pickup, tank, and spiral well. There are several tank companies building these tanks, but I have always used Rock Valley and have never been displeased wit one of their tanks. I have friends who have external pumps and modified tanks, but to a man, they said that they would go with an internal pump if they had it to do again. The price of the tank sounds high, but just look at what a quality high pressure external pump like an aeromotive costs!


Regards, John McGraw

thanks John, not sure what I am going to do, but saw one of these

and I really like the way it looks, it is really $$$$, and the fuel tank above adds some more cost....I need to think about it some more.....like getting comfortable with spending that much money.....but as Sharon says, you can't take it with you..so I need to think about it some more....

Herb

 

[Tyler Townsley]

The 2004 1/2 up corvette use an in tank setup that has no return lines. If you are going to have a tank built it might be a cheaper way to go as these pumps are avail used. Since they have been reliable most wrecker have a pretty large supply on hand. In fact you can get the whole tank with pump installed, that way you can use the mounting on the new tank. Cut it off and epoxy it to the tank.

I had a link to the iinfo but GM restricted the access.

Tyler

 

[bossvette]

Herb
There is a work around that requires two fuel pumps and a surge tank that is cheaper.

the small red box is the surge tank which is fed by the low pressure pump (1-2 lb) on the right and feeds the Walbro high pressure pump on the left there are returns to the surge tank and main tank also. There is a book by JTR publishing that details the set-up.


That being said I have used Rock Valley for my 76; I sent them a 72 tank which they modified for an in tank pump.

at the time the cost of the conversion was $400


I have not run the first set-up enough yet to know if it works out well I am getting a code 43 and have been from the start so the furthest I have driven is Toledo. The surge tank and the baffles that John talks about are to keep fuel around the pump when the level is low and serve the same function as the fuel bowl in a carb.
Craig sr.

 

[BADBIRDCAGE]

I went with the Rock Valley conversion like bossvette. I sent them a new tank and they installed the walbro pump in the same location as the one in his picture.

I ran a feed line from the pump to a filter mounted on the frame near the rear of the car and continued the feed line up basically parallelling the factory hard line which is now the return line. The original location for the factory feed line off the sender unit is now capped off and can be used for a tank drain if I ever encounter the need.

Rock Valley installs the walbro pump in a kind of fuel can reservoir in the tank to keep from dry sumping the pump and returns the unused fuel back into that reservoir area, but warns that if you get near 1/4 tank you could dry sump the pump with hard driving (like autocross).

Rich

 

[Wilkinshc]

I went with the rock valley tank also, if you check out my homepage, you can see a pic of my tank. It was 1000 after shipping. I used the stock line for return and ran the feed next to the stock line.

 

[firstgear]

I went with the rock valley tank also, if you check out my homepage, you can see a pic of my tank. It was 1000 after shipping. I used the stock line for return and ran the feed next to the stock line.

do you have a link to the homepage? got it...almost seems a shame to put the car back over it, very nice!!!

 

[firstgear]

Craig, thanks for the reference to JTR publishing, does anyone else have some books that they can refer me to on EFI and setting it up along with the fuel set up. I figure if I look at enough photos and read enough I will be able to make a decision on what I am going to do..

 

[bossvette]

Herb
I have several books on EFI swapping and also Street and Performances Video That details TPI rebuild/swaps there is one by Charles D Probst on Corvette Fuel injection and another by Jeff Hartman Amazon should have them also.
Since the TPI has been around for a while and EFI in general has become much more popular there is a lot of literature out there.
Craig sr.

I would love to see that ZL1 run

 

[Loren Smith]

Firstgear - how about a Weber carb setup, and forget about the tank issues:

http://inglese.com/chevroletv8.htm

 

[firstgear]

Firstgear - how about a Weber carb setup, and forget about the tank issues:

http://inglese.com/chevroletv8.htm

looks to me to have too many screws that need turning.......

 

[JohnZ]

looks to me to have too many screws that need turning.......

Yes, but once Webers are set up, they're bulletproof .

 

[groovyjay]

Yes, but once Webers are set up, they're bulletproof .

So are the EFI's...

EFI is the only way to go...

 

[JohnZ]

Here's an EFI system I had a hand in developing for a friend's Grand Sport replica. The Webers (48DCOE's) are dry - they only function as throttle bodies to manage air; the fuel lines are fake. The sequential injectors are hidden in the bottom of each runner, and the TPS is buried back by the distributor. Sneaky, but effective.

 

[firstgear]

Here's an EFI system I had a hand in developing for a friend's Grand Sport replica. The Webers (48DCOE's) are dry - they only function as throttle bodies to manage air; the fuel lines are fake. The sequential injectors are hidden in the bottom of each runner, and the TPS is buried back by the distributor. Sneaky, but effective.

ok....that has WOW factor for it......only thing better would have been to polish the manifold.....

 

[groovyjay]

Here's an EFI system I had a hand in developing for a friend's Grand Sport replica. The Webers (48DCOE's) are dry - they only function as throttle bodies to manage air; the fuel lines are fake. The sequential injectors are hidden in the bottom of each runner, and the TPS is buried back by the distributor. Sneaky, but effective.

That's what I'm talking about!!! Very cool!

 

[Mac]

How efficient was that system, JohnZ? With all that air access, what did you do for a MAF and the other sensors?

-Mac

 

[JohnZ]

How efficient was that system, JohnZ? With all that air access, what did you do for a MAF and the other sensors?

-Mac

Mac, it's a speed-density system - doesn't use a MAF sensor.

 

[Mac]

Very cool!

-Mac