Opel GT Forum banner
1 - 20 of 27 Posts

·
Opeler
Joined
·
1,303 Posts
Discussion Starter · #1 ·
Hey all,

This has been mentioned in a couple of threads of mine, but I wanted to dedicate a new thread for those that may undertake this conversion in the future.

To level set this: I have a 1970 GT, with a 2.2 engine paired to an automatic transmission. The engine was rebuilt (2.2 motor in need of rebuild) and had to overcome improper valve springs (Help! Not running right after rebuild) to get to this point.

I can now go out to the garage, turn the key on, wait a few seconds before cranking the car to have it fire right up. How did I get to this point with this conversion. It took several things.

1) Fuel Pump for EFI. I installed a Holley Sniper Retrofit pump in my fuel tank. I removed the tank, had it professionally cleaned at a shop, used the 3 1/4” hole saw to creat room for the pump. I followed instructions and installed the pump.

431634


2) Fuel Lines. Obviously, the stock line won’t do the trick, plus I needed a return line. The Sniper unit can technically be ran without a return line but with the small fuel needs of our engines and the volume of fuel EFI pumps push, it’s better to run a return line. I did a combo of Gates Barricade rubber lines and Earl’s Easy Form 3/8 tubing, which can be formed without the need for a tube bender. I did use a tube bender for some areas, but the rest I could hand form. I followed the existing fuel line path under the car for ease of installation. The trickiest part of the whole thing was getting the lines in/out of the car to the tank. I ended up using a spot that allows for them be inconspicuous while, which was nearby the existing fuel tank outlet location,
but a spot that allows the lines in/out of the car without inside interference. I used a step bit to create the holes and found the stock replacement throttle grommets to be the perfect solution to use to slide the hard lines through. The lines come through on the other side of the tank mounting bracket piece, whfor connecting the hard lines to rubber lines, I used 6AN fittings that have hose barbs for the rubber lines to attach to. I can link specific parts if need be. This whole process resulted in a totally leak free installation that allows proper flow of fuel to and from the tank. The only leak I had was that I forgot to use thread tape on one of the fittings going in to the fuel pump, which resulted in a leak and ate the paint off of my freshly painted gas tank, which was frustrating in many levels!

431635


431636


431639


3) Intake Manifold: I needed an intake that would accept the Holley Sniper 2300 bolt pattern. I was able to purchase a Cannon intake from a member that was already set up for a Holley carb. The issue that I had to deal with was that it was for a 1.9 head and not a 2.2 head. Therefore I had to use one of RallyBob’s raised port intake flanges. I had the existing mounting flange on the intake machined off and had the new flange welded on. I did some port matching to match and smooth the flange openings to the intake runners using a thin belt sander, which worked like a charm. The Cannon intake is much larger than the stock intake and has a different flow design; many members have sought after this type of design in the past.
431640


431641


4) Sniper Unit: I had to modify the unit itself to get it to fit on the intake manifold. Before doing this I called Holley to make sure it wouldn’t void a warranty issue, the assured me it wouldn’t and said it was very common to make some modifications to it to adapt to many applications. I had to cut off part of the throttle lever, specifically for the kickdown function. I used a simple cutoff wheel on a Dremel for this job. That was the only “major” modification required, beside that I had to enlarge one of the mounting holes because the intake had a stud in place that was slightly slanted. Again, simple modification.

431642


5) Throttle Linkage: This had to be to started from scratch essentially, and this is something that I feel I will need to continue to fine tune to get 100% perfect feel. I am using universal Lokar throttle cable to actuate the throttle for the Sniper. Since my car is an automatic I had a spot for a kickdown cable on my throttle arm. I took the pedal off and pulled the throttle arm out. After looking at it, there was room to add another hole in the throttle arm. I drilled a hole in it and then I used the same belt sander to shape the throttle arm to allow for free movement of the throttle cable clevis. After that was done, I reattached pedal and connected everything up. As I step on the pedal, it raises the throttle arm, which pulls the throttle cable and pulls the throttle arm of the sniper. I made a bracket for the Lokar cable to mount to to hold it in place, then routed the throttle cable around the around the back of the engine and along the passenger side of the engine to another bracket that I bought that the other end of the Lokar cable mounts to. The cable had to be cut to fit, but all in all, it wasn’t too bad. I have an assortment of throttle springs that I need to try out to help with the pedal feel.

431643


431644



431638


6) Wiring: The Sniper has a lot of wires, and many aren’t used in our application. If anyone is going to use this, just follow the instructions, they aren’t that difficult. It does necessitate finding spots on the fuse panel that are getting full 12 volts while cranking, this is a sensitive issue for the Sniper...computers! I installed the fuel pump first, using a relay but had I tried to do the Sniper first, it comes with wiring for the fuel pump.

After doing all that stuff over weeks, & months really, and then fixing the fuel leak at the tank it was time to fire it up. It comes with the handheld unit that you need to edit the settings for your motor, that was truly the last step for me. After that, I turned the key and the car fired on the 1st crank! It was a great feeling. The car needs to be ran for a while and driven around to “self learn” and while it is self-learning, it will need to be tuned more precisely by the user or a professional. I am needing to get the exhaust system redone and then I’ll be taking it to a shop to have it professionally tuned.

I’m happy to answer any questions or take comments on this, but I hope this can help others contemplating using this EFI system on their Opel.

Take care!
 

·
Registered
Joined
·
2,109 Posts
Great to hear! You've over come alot of adversity to get to this far my friend. I'm happy you 've persevered
 

·
Just Some Dude in Jersey
Joined
·
15,467 Posts
I would have done it the other way and put the right angle end on the pedal and the clevis at the throttle. That way you don't need to do the grinding of the pedal arm. That's how I did it on my factory FI. Because the clevis end is much shorter than the right angle, you could then have used that conveniently placed bolt hole on the Cannon manifold to mount your cable housing stop bracket.

Funny that your thread popped up today because I just an hour ago figured out the simple cure for the reason that Holley told me I probably couldn't put one of their FI carbs in a side draft configuration. Their FI carbs don't squirt the fuel into the manifold, they squirt the fuel AT the throttle plates, from the air cleaner side. The injectors are on the air cleaner side of the throttle, unlike all other FI systems that I know of. Because of this, the Holley tech told me that at start up the injectors squirt at dead closed throttle plates. If I put the carb on mounted sideways, the fuel squirting against the closed throttles could trickle out of the carb, not much, but some. This condition only occurs at start up and possibly at idle.

The solution? Mount the FI carb at a slight upwards angle, like 15-30 degrees. That would stop the trickle out. I would have to either make an adapter for the carb to fit my Steinmetz angled manifold or have the manifold altered to fit the carb. The idea has only just occured to me, so I haven't decided which method would be better/simpler/cheaper. RallyBob would just alter the manifold, I'm sure.

My plan would be to use the Holley sniper made for Jeeps. Those have a small round surround that seems to be the same size or close to standard cold air intake tubing and adapters, rather than the huge, offset towards the engine, Holley carb style air cleaner adapter that is causing a hood clearance issue on our cars and the need to make some sort of custom "muffin" for the top of the carb to then run to tubing to an air cleaner.

The side draft configured Holley Sniper would eliminate two sharp power robbing right angle bends to the air flow. Like this:

431654
431655
 

·
Member
Joined
·
1,722 Posts
Great write up with helpful info. and photos.
John
 

·
Opeler
Joined
·
659 Posts
Eric, so glad you got all this working! Did you leave the system in the learning mode or did you buy the USB dongle and attempt to custom program the ECU? I haven't gotten that far as mine generally starts right up and drives great. The only nagging problem I occasionally have is the idle either dies when letting off the gas or it won't settle down. The forums talk about these issues with the Sniper but I haven't had time to really investigate.
 

·
Opeler
Joined
·
1,303 Posts
Discussion Starter · #7 ·
Eric, so glad you got all this working! Did you leave the system in the learning mode or did you buy the USB dongle and attempt to custom program the ECU? I haven't gotten that far as mine generally starts right up and drives great. The only nagging problem I occasionally have is the idle either dies when letting off the gas or it won't settle down. The forums talk about these issues with the Sniper but I haven't had time to really investigate.
I haven’t done much tuning to it to be honest. I’ve driven it around the neighborhood a few times. I think I have an exhaust leak at the header collector and the next weld downstream. At least that’s my thought because when I get in to the throttle the AFR goes very high 22/23 and it makes the engine stumble until it gets itself in the proper AFF range. I really just want to get the exhaust system redone and then get it to the tuner shop after that. There’s a LOT to go through, at least from what I’ve gathered from the Holley Sniper research I’ve done, and I haven’t gone further than some basic tweaking. I know the fuel tables, etc need adjusted, but I’m not ready to dive in to all that right now.

I had a hard time starting it from time to time, and turns out that my starter ended up needing replaced. No issues starting it after that. I will say that it doesn’t seem to want to idle less than 1000rpm though. I’ve tried setting the idle lower, but the idle quality drops substantially. However, for the 1st time since owning my car, when I drop the car from park to in gear, it doesn’t drop the RMP a ton. I have always set the idle about 1000rpm because as soon as I would put the car in gear, it would drop the rpm by ~200-250 rpm...which is normal for auto transmissions in GTs from everything I’ve ever read.
 

·
Opel Key Master
Joined
·
5,288 Posts
I see a few concerns on the throttle cable, one being that you have it connected/mounted to the engine, which moves a lot. This can effect throttle all over the place. The angle at which it goes to the throttle body is a bit much, there might be a 90 degree tube made for a situation like this. My question is have you reinstalled the rear spare tire support and was there clear and issues with the fuel pump? I seem to think it’s pretty close around that area, and even Opel ground out some clearance in the wood for the vent on the tank.
 

·
Opeler
Joined
·
1,303 Posts
Discussion Starter · #9 ·
I see a few concerns on the throttle cable, one being that you have it connected/mounted to the engine, which moves a lot. This can effect throttle all over the place. The angle at which it goes to the throttle body is a bit much, there might be a 90 degree tube made for a situation like this. My question is have you reinstalled the rear spare tire support and was there clear and issues with the fuel pump? I seem to think it’s pretty close around that area, and even Opel ground out some clearance in the wood for the vent on the tank.
I don’t have it mounted to the engine at all, it’s just running alongside it. The place where it is mounted near the sniper unit is a bracket that shares a mounting post on the intake with the Sniper.

I haven’t reinstalled the shelf back there yet. I have a template for what needs to be cut away. The shelf won’t go back in without a relief cut, the pump is above the tank and needs space for the unit and the lines coming in. I’m planning to disconnect the rubber fuel lines at the pump and slide the shelf in place with the cutout for it, then reconnect the fuel lines and button everything else back there.
 

·
Opeler
Joined
·
1,303 Posts
Discussion Starter · #11 ·
What is the bracket coming from the alternator mount? Is this not your throttle bracket?
Yeah, sorry I thought you were talking about the Sniper side of it. That bracket doesn’t concern me that much and I personally don’t think it will affect the throttle much, if at any, since the cable is right from the throttle arms. That mount just holds the sleeve in place. If I’m missing something, let me know but I can’t see how it will affect much.
 

·
Just Some Dude in Jersey
Joined
·
15,467 Posts
Yes, as Keith noted, your cable path and bracket near the pedal are not optimum. You MUST strive to have the cable exit the cable housing and adjuster as perfectly centered as possible. Those adjusters are soft aluminum and that steel cable will carve a slot in it in no time flat. The housing will also get carved. Bicycle manufacturers go to great lengths to assure that cables exit housings and adjusters perfectly centered in order to minimize wear. Wear and slot formation will bind the cable and it could bind and snag the cable causing the throttle to stay open, which is dangerous.

You see where your kick down cable bracket is? You need to make a bigger one with 2 slots and put your throttle cable there, in my opinion. See the last photos of how I did mine. Keith might have a better idea that actually mounts it to the engine.



431674
431675
 

·
Opeler
Joined
·
474 Posts
Thank you for this information. I am in the final stages of building my motor. I have a 2.5 block with a 1.9 head. My engine builder has been working on this for a long time. This is a high torque relatively low rpm motor.
Your information is very helpful. I always like to see projects running!
Thank you again, I will be following this thread closely.
 

·
Opeler
Joined
·
1,303 Posts
Discussion Starter · #17 ·
Hey all,

This has been mentioned in a couple of threads of mine, but I wanted to dedicate a new thread for those that may undertake this conversion in the future.

To level set this: I have a 1970 GT, with a 2.2 engine paired to an automatic transmission. The engine was rebuilt (2.2 motor in need of rebuild) and had to overcome improper valve springs (Help! Not running right after rebuild) to get to this point.

I can now go out to the garage, turn the key on, wait a few seconds before cranking the car to have it fire right up. How did I get to this point with this conversion. It took several things.

1) Fuel Pump for EFI. I installed a Holley Sniper Retrofit pump in my fuel tank. I removed the tank, had it professionally cleaned at a shop, used the 3 1/4” hole saw to creat room for the pump. I followed instructions and installed the pump.

View attachment 431634

2) Fuel Lines. Obviously, the stock line won’t do the trick, plus I needed a return line. The Sniper unit can technically be ran without a return line but with the small fuel needs of our engines and the volume of fuel EFI pumps push, it’s better to run a return line. I did a combo of Gates Barricade rubber lines and Earl’s Easy Form 3/8 tubing, which can be formed without the need for a tube bender. I did use a tube bender for some areas, but the rest I could hand form. I followed the existing fuel line path under the car for ease of installation. The trickiest part of the whole thing was getting the lines in/out of the car to the tank. I ended up using a spot that allows for them be inconspicuous while, which was nearby the existing fuel tank outlet location,
but a spot that allows the lines in/out of the car without inside interference. I used a step bit to create the holes and found the stock replacement throttle grommets to be the perfect solution to use to slide the hard lines through. The lines come through on the other side of the tank mounting bracket piece, whfor connecting the hard lines to rubber lines, I used 6AN fittings that have hose barbs for the rubber lines to attach to. I can link specific parts if need be. This whole process resulted in a totally leak free installation that allows proper flow of fuel to and from the tank. The only leak I had was that I forgot to use thread tape on one of the fittings going in to the fuel pump, which resulted in a leak and ate the paint off of my freshly painted gas tank, which was frustrating in many levels!

View attachment 431635

View attachment 431636

View attachment 431639

3) Intake Manifold: I needed an intake that would accept the Holley Sniper 2300 bolt pattern. I was able to purchase a Cannon intake from a member that was already set up for a Holley carb. The issue that I had to deal with was that it was for a 1.9 head and not a 2.2 head. Therefore I had to use one of RallyBob’s raised port intake flanges. I had the existing mounting flange on the intake machined off and had the new flange welded on. I did some port matching to match and smooth the flange openings to the intake runners using a thin belt sander, which worked like a charm. The Cannon intake is much larger than the stock intake and has a different flow design; many members have sought after this type of design in the past.
View attachment 431640

View attachment 431641

4) Sniper Unit: I had to modify the unit itself to get it to fit on the intake manifold. Before doing this I called Holley to make sure it wouldn’t void a warranty issue, the assured me it wouldn’t and said it was very common to make some modifications to it to adapt to many applications. I had to cut off part of the throttle lever, specifically for the kickdown function. I used a simple cutoff wheel on a Dremel for this job. That was the only “major” modification required, beside that I had to enlarge one of the mounting holes because the intake had a stud in place that was slightly slanted. Again, simple modification.

View attachment 431642

5) Throttle Linkage: This had to be to started from scratch essentially, and this is something that I feel I will need to continue to fine tune to get 100% perfect feel. I am using universal Lokar throttle cable to actuate the throttle for the Sniper. Since my car is an automatic I had a spot for a kickdown cable on my throttle arm. I took the pedal off and pulled the throttle arm out. After looking at it, there was room to add another hole in the throttle arm. I drilled a hole in it and then I used the same belt sander to shape the throttle arm to allow for free movement of the throttle cable clevis. After that was done, I reattached pedal and connected everything up. As I step on the pedal, it raises the throttle arm, which pulls the throttle cable and pulls the throttle arm of the sniper. I made a bracket for the Lokar cable to mount to to hold it in place, then routed the throttle cable around the around the back of the engine and along the passenger side of the engine to another bracket that I bought that the other end of the Lokar cable mounts to. The cable had to be cut to fit, but all in all, it wasn’t too bad. I have an assortment of throttle springs that I need to try out to help with the pedal feel.

View attachment 431643

View attachment 431644


View attachment 431638

6) Wiring: The Sniper has a lot of wires, and many aren’t used in our application. If anyone is going to use this, just follow the instructions, they aren’t that difficult. It does necessitate finding spots on the fuse panel that are getting full 12 volts while cranking, this is a sensitive issue for the Sniper...computers! I installed the fuel pump first, using a relay but had I tried to do the Sniper first, it comes with wiring for the fuel pump.

After doing all that stuff over weeks, & months really, and then fixing the fuel leak at the tank it was time to fire it up. It comes with the handheld unit that you need to edit the settings for your motor, that was truly the last step for me. After that, I turned the key and the car fired on the 1st crank! It was a great feeling. The car needs to be ran for a while and driven around to “self learn” and while it is self-learning, it will need to be tuned more precisely by the user or a professional. I am needing to get the exhaust system redone and then I’ll be taking it to a shop to have it professionally tuned.

I’m happy to answer any questions or take comments on this, but I hope this can help others contemplating using this EFI system on their Opel.

Take care!
I failed to mention a couple of items in my initial write up....

1) O2 sensor. I used the included clamp on kit for this until I get a permanent bung welded in to my new exhaust system. To install this I used a step bit to drill the appropriate size hole in the right spot downstream of the collector. Then I just used the gaskets, fitting and clamps to install it on TJ exhaust pipe.

431683


2) Coolant temp sensor installed in to my thermostat housing and I disconnected the stock gauge wire and sensor and used the Holley provided one.

The o2 sensor and coolant temp sensor (CTS) absolutely have to be hooked up for this system to work right. I should have mentioned them in my initial post about this.

Take care

Eric
 

·
Opeler
Joined
·
659 Posts
I too had to cut a relief opening in the spare tire shelf to clear the in tank pump cover and hoses. I used the system from Tanks Inc. and only needed to cut a relief about 5 x 7 inches. The additional clearance needed was only about the thickness of the plywood so a new oversized piece of plywood over the relief solved the problem and all is good!
 

·
Registered
Joined
·
37 Posts
Hi Eric,

This thread has been really helpful in pushing me toward the 2300 setup.

Curious what you did for the air filter, it looks like things will be fairly tight under the hood.

It will be a few weeks until I get the engine back in and can take measurements, so for now I'm wondering if there is enough clearance for something like the Holley carb hat. Holley EFI 120-232 Holley EFI Carb Hat

Cheers,
Nick
 

·
Opeler
Joined
·
1,303 Posts
Discussion Starter · #20 · (Edited)
Hi Eric,

This thread has been really helpful in pushing me toward the 2300 setup.

Curious what you did for the air filter, it looks like things will be fairly tight under the hood.

It will be a few weeks until I get the engine back in and can take measurements, so for now I'm wondering if there is enough clearance for something like the Holley carb hat. Holley EFI 120-232 Holley EFI Carb Hat

Cheers,
Nick
Hey Nick,

I ended up using an older style K&N “hat” that sits on top of the Sniper and screws on…I didn’t use the base that came with it because I doesn’t sit over the carb. So I just used the top of it with a gasket. It’s very similar to the Weber Snorkel adapter that a lot of guys use for the 32/36 or 38/38. It’s a standard 5 1/8” size, which is very common. I didn’t have any clearance issues with this.
437512

437513


If you have any other questions, let me know.

Eric
 
1 - 20 of 27 Posts
Top