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VTT Double Shotgun Installation
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VTT Double Shotgun Installation
Installation guide for the VTT Double Shotgun dual hpfp fueling kit
Please note, there is not a quick or fast way to do this modification. It is done in a low visibility area, the hardest parts of the job are not only hard to access but they aren’t very visible. You'll have to spend some time trying to figure out how to proceed with some steps because there are several variables ranging from vehicle and chassis manufacturing variances, hardline orientation, personal preferences and individual modifications. The clearances are very tight and there just isn’t much room. Be prepared to take more than one day to do this in case something comes up. Borrowing a lift with a deadline may not be the best idea because this takes time. With this guide, getting it knocked out in half a day might be possible. Hopefully this compilation of tips and additional photos this guide provides can help you cut down the time myself and others spent scratching our heads and struggling. There have been several people who have given tips and input who deserve credit including @longnvu @Shane303 @
@Turby @martymil @Edson and probably others I missed.
There are a couple of optional jobs you can do at the same time as the shotgun install. The new serpentine belt pullies of course, as well as an aluminum power steering pulley and the billet coolant flange that goes into the head. I highly recommend doing all of these things as you’ll be staring them all right in the face and you can’t get any closer to them. The aluminum power steering pulley is entirely optional, but it is a little bit of insurance for the pulley cracking from hitting your subframe, causing the serpentine belt to get sucked into your front main seal. This pulley and a pair of upgraded motor mounts should all but prevent that one scenario from happening. The tensioner and idler pullies are obvious replacement items depending on how many miles they have on them, and the billet mickey mouse shaped coolant flange is another preventative item you should consider since that piece tends to corrode over time and break down.
When you buy the tensioner pulley specifically, make sure you buy a high quality pulley because some of the aftermarket pullies are made of a weaker metal and the T60 will strip out when you try to put the belt on. If you do intend on installing the aluminum power steering pump pulley, I recommend loosening those bolts before you remove the serpentine belt. If you try to do it when the belt is off,the pulley will spin freely when trying to loosen the bolts on it and can make it a bit more annoying.
When doing this installation, I decided to change the way the heater core return lines were ran, so I needed to buy some 3/4" heater hose and straight barb fitting and three clamps. You don't have to do this, but feel free to check out how I did it.
Also my fuel feed line Y hose was too short on one leg, so I needed to extend it a couple inches so that it would fit properly. If you're going to be on the clock, it might be helpful to go buy 6-7 inches of 3/8 fuel hose and some crimp clamps.
To get started with the install, remove the charge pipe, intake manifold, radiator fan, drain the coolant and remove the serpentine belt using the normal procedures making sure to take photos of your belt so you know how to put the new one back on. I also recommend pulling the intercooler as it can free up quite a bit of space and make things a lot easier, and is required for some brands due to clearance reasons.
Heater core coolant return pipe modification
The first thing you have to do is modify the heater core return pipe which leads to the thermostat and coolant expansion tank on one end and plugs into the heater core through the firewall on the other. You can follow the original instructions and parts or you can make your own coolant line, both will be explained.
The kit comes with a bit of 90 degree plumbing which is a combination of 1" and 3/4" hose and adaptors. Coming from the thermostat/expansion tank, the instructions tell you to cut the plastic pipe right before the heat exchanger for those with automatics, after the pipe flares back out. For manual cars, coming from the same direction, after the first mounting bracket the pipe diameter reduces, then flares back out again, this is the same place.
If you have an automatic, you have to cut the hose leading to the heat exchanger after the diameter necks down so that it will fit on the T that is provided. But after some analysis, it may be better to cut after the T for the heat exchanger depending on the space in your particular car and how you want to secure this hose to the car. This retains the factory quick connects and hoses and the T fittings are no longer needed.
Here is the Automatic pipe, the blue line is where the instructions tell you to cut, the red line is approximately where I suggest you cut:
For those who are manual, here is the 6MT heater core pipe, this one is much more straight forward:
You may have to cut in a slightly different spots than those shown above, depending if your hose will fit on the end. Keep in mind the pipe diameters change, so you may end up using some of the adapters that come with the kit to make this work. Now continue to follow the instructions to complete the original coolant pipe modification.
Another other way to go about this if you are manual transmission or have an aftermarket automatic transmission cooler, is to buy a 5 foot length of
Vibrant 20455 heater hose
3/4" straight barb fitting
. Making sure the coolant has already been drained, use some needle nose vice grips or channel locks and pinch the clamp connecting the rubber hose from the thermostat to the plastic heater pipe and slide it toward the plastic side to relieve the pressure from the hose.
Make sure you have a bucket handy because there is probably some left over coolant still stuck in this pipe. Leave the bucket there, because periodically coolant would randomly come out of the engine, even hours later. Grab a screw driver and gently go around the hose and try and brake whatever mechanical seal may be there, and pull the hose off the pipe. It would help if you pinched the line with a clamp of some kind so you don't have coolant pouring out from both ends.
Now follow this hose you've disconnected back toward the driver side and up to the fire wall. Remove the clip and pull the hose off. You should be able to lift up on this hose once it is free from all the other wires and things, and the plastic portion of the heater pipe should be angled enough to come out of the bottom.
Now hook up your heater hose to the firewall using a new clamp and run the hose straight down to the ground being sure to stay clear of the steering column.
From here there are a couple ways you can route the hose depending on your preference and turbo configuration. I am single turbo and chose to route the hose around the back of the oil pan and up to the front coming out right by the water pump.
You may find that the hose coming from the thermostat is too wide for the 3/4" straight barb, feel free to cut the flared portion of hose so the fit is more snug.
Use some clamps, preferably crimp clamps to secure these lines in a permanent fashion and use zip ties to make sure the hose is secure along the route you chose.
Install Bracket on AC Compressor
Now, we will connect the shotgun bracket onto the AC compressor. This is the belt accessory directly above the power steering and below the alternator, it is the nearest to the frame rail.
There are three bolts that hold this compressor on, two bolts toward the front of the car, directly above one another, and a third bolt toward the rear of the car. The top bolt toward the front is the easiest to access but it’s the last one we need to remove. Directly below this bolt there is another bolt which you cannot see. If you have small hands, you can probably slip a ¼ drive ratchet and a deep 13mm socket and remove the bolt. If not, you’ll need to slid your arm in from the back, feel free to unclip the hoses and push them out of the way.
Now go after the bolt in the back, it should be barely visible and with a litte wiggling it should barely come out. If not, just let it sit loose until you get the third bolt out and then slip it out.
The last bolt is the one on top. The normal instructions tell you to jack up the engine, I did not have to do this but your mileage may vary. I have a 034 drive side mount and a urethane mount from the ADE single turbo kit as that probably makes a difference. You may find that the following method does not work, so if in doubt just follow the original instructions. The bolts did not come out freely, I had to disconnect all three bolts and wiggle the pump around, pulling it toward the front of the car and twisting it until the bolt came out.
Now grab the three new bolts, they are slightly longer than the stock bolts and with out any washers, they should fully thread and secure both the bracket and pump.
Getting these bolts back in is even more difficult because the bracket is there, effectively leaving less space between the entry point and the frame rail. This time, hold the bracket in place and start with the top front bolt, lift the pump up and you should be able to get the bolt to slide in while going in from above the frame rail. Again this depends on your motor mounts and possibly other things, if you had to raise the motor to get the bolts out you may have to make adjustments here as well:
Do not fasten this bolt, push it in so its not resting on the frame rail anymore but let it remain loose in the hole. We need to get the rear bolt in before we secure anything down. This bolt is the most difficult of the three to reinsert in my experience. Once again, you’ll have to shift the pump around until it goes in which is why you don't screw in the first bolt yet.
Once it goes in, you may go ahead and tighten down both the top front bolt and rear bolt. Lastly, the bottom front bolt needs to go in, but because the bracket is here, its basically impossible to reach in from the front so you’ll have to go in from the back door and it should go in with ease.
Install Shotgun Pulley
For the next part, I recommend dropping your FMIC if it isn’t already. You can do this with some intercoolers in place, but the few minutes you spend taking it out increases visibility and access quite a bit and you won't be leaning up against your bumper potentially giving it scuffs or dripping anything on the paint. I also removed the power steering pulley and left it off since I'll be replacing it in the next step.
You can go ahead and try to test fit the shotgun pulley, but if your power steering pump lines are anything like mine, you’ll have a clearance issue. These lines can be different from vehicle to vehicle so you'll have to make adjustments dependent on your situation:
I grabbed a wrench and reclocked the offending line on the power steering pump a little bit and pulled down on the line from underneath by the steering rack and I was able to free up plenty of space.
Once you’ve got the room, go ahead and slip the shotgun pulley into place, and stick one of the bolts with the star washer into one of the pulley holes, then lift it up and using your fingers to get the thread started. Go up top and tighten the bolt more but don’t tighten it all the way. Just make sure it's on enough so it won’t fall out while you lift the other side up and put the other bolt in.
You’ll also notice that the lower power steering line that goes into the radiator is in the way. The instructions show it being pushed down like I initially did:
But in a later step, once I had adjusted the other end of these lines on the steering rack to make room for the HPFP to fit onto the back of this pulley, I found that pushing it up was the best like this:
If you can, don't worry about adjusting this hard line until you've figured out what adjustments you need to make to fit the HPFP on the back of this pulley. This way you don't weaken the pipe by moving it more than necessary. You will revisit this when the HPFP is installed, so don't bend this line yet.
Tighten the bolts down a little more until they are almost snug. Then go up top and make sure the pulley is lined up fore and aft with the other pulleys. You don’t want it misaligned otherwise you’ll get belt squeaking and potentially it may jump off the pulley and cause other issues. This is a view from the ground straight up:
Before tightening it down, make sure you also don’t have a lopsided pulley, as it can lift upward and downward on the bracket as well as side to side. Once you’re happy, fully tighten down the bolts, making sure to not let the shotgun pulley move.
Replace serpentine belt and miscellanous items
This is the point where you will do your optional items.
Mickey Mouse Coolant Flange:
Aluminum Power Steering Pulley can be tightened down once the belt is back on:
Don't pull the pin on the tensioner until all the pullies are torqued down:
Once all the optional maintenance items are done, now install the new belt onto the engine, make sure to install it in the same way it was before. Be careful with the tensioner since it can strip easily and they are known to break. Put the belt around all the pullies until all you have left is the top pulley on the tensioner.
Make sure the belt is properly on the crank pulley, it gets stuck and needs pushed down all the way. Make sure all belt ribs line up and keep the belt tight, because you have to max the tensioner out in order for the belt to go on. Be sure not to force the tensioner too far or it will break. Put your breaker bar in with the T60, make sure the torx bit is in snugly and pull slowly in a clockwise direction facing the car and make sure the bit stays square in the hole. Try not to use an extension so your torque angle will be as straight as possible. Once the belt is on, you can slightly depress the tensioner as needed to make sure the belt is seated evenly on all the pulleys.
Install Modified Fuel Rail
EDIT: I may revise this, I found it was easier to install the fuel rail after the intake manifold was installed.
Now its time to pull the fuel rail. Before you do this, make sure the car has been off for a day or two if possible, this will reduce the amount of fuel pressure in the lines and there will be less fuel to clean up when you loosen it up. Also its best if you disconnect the battery if you didn't already, and make sure you do not put the key in the ignition or press any buttons if you have comfort access from now until the whole job is done because theres a chance you'll prime the LPFP on accident and fuel will be everywhere. I actually recommend keeping the key far away from the car, and make sure to pull the battery or at least the LPFP connectors on the hat under the rear seat. Do not let fuel leak into the ignition side of the valve cover. Wear safety glasses to protect from fuel squirting into your eyes.
First, grab some rags or paper towels to help you soak up the fuel that will come out. If done properly you can catch pretty much all of it but it will ooze out of just about every fuel fitting and line you disconnect. You could alternatively pull the ignition coils and the LPFP fuse and turn the car over to evacuate the fuel. But without doing any of that, you can simply put some rags down around the areas you’re working on and if you’re car has been off for a while, it will be a manageable amount of fuel that will spill out.
Start with the HPFP outlet, go ahead and put down some towels and loosen the nut.
Now remove the bolt holding the hpfp outlet line to the block.
And come up top and loosen the top of this hardline, once again covering it up with towels. Now you can remove this pipe:
Next, disconnect the wiring harness from the clips on the fuel rail and disconnect the HPFP pressure sensor plug on the far end of the rail near the firewall:
Now go ahead and remove the bolts holding the fuel rail to the head. If there is plastic hanger covering the bolt, you just pull down and out and the clip will swing up out of the way.
Start removing the nuts for each injector from the fuel rail. Be sure to catch any fuel coming out, pay special attention to cylinder 6, the fuel tends to pool up and drizzle out of there for a while as there is still fuel stored in the rail. Be careful removing the rail, not to spill any fuel on your car.
Go ahead and transfer all the red caps from the new rail to the old one and move over any hardware from the old rail such as the pressure sensor on the end and any plastic clips. The center clip will not fit because the new hpfp line goes there.
Now its time to put the new fuel rail back on the car by reversing the process. Make sure you torque down the hardlines to spec which should be around 23nm and put the harness back on the clips.
The next step is putting in the hpfp. The work required for this will vary from car to car because the power steering lines can be bent or clocked in various ways. My car has an M3 Steering rack for example, so not only have I messed with these lines before, but they may be clocked, oriented or designed completely different in your case.
Earlier, we had to clock the power steering line coming off the power steering pump to make room for the shotgun pulley. This time, I needed to clock and bend the hardline on the steering rack itself because it was covering up the back of the pulley where the HPFP mounts as you can see here:
This was actually the hardest part of the install for me up to this point in terms of physical effort. What I ended up doing is clocking the lower line on the rack by turning it all the way down and then bending the line down and toward the front of the car. In this photo, you can see the hardline is now actually below the pulley:
I'm not saying this was the best way, but for the given space it was the first thing I tried. It would probably be better if you bent it toward the engine so the hose comes out in a better position, but there is just not very many places to grab onto and this line is pretty stout.
As I have explained already, on the other end of this line which goes into the radiator, I had bent this lower line downward so the line passed under the pulley. But with the steering rack hardline bent under the pulley, there was too much extra hose going to the radiator:
Moving this hose around meant the hose would be kinked under the shotgun pulley or bunched up behind the radiator. So instead of bending the hardline coming out of the radiator downward, I decided to rebend this line back upward and routed the line up and over the top of the power steering pump instead:
Be patient and figure out which way you want to start bending the steering rack side of the hardline before you actually start bending the radiator side and you should be fine. This line is incredibly hard to bend on the steering rack side, but it will if you work at it.
Before you proceed to install the lower HPFP, you need to do a little prep for the next step while the pump is out, which makes things easier at the expense of having extra hose to maneuver. Grab a ferrule fitting which looks like this:
Stick it on the HPFP inlet while its still out and screw on the 45* Y hose fitting onto the HPFP inlet. Don't tighten it down completely because this is a compression fitting, but make sure the ferrule won't flip around.
Next, grab a pick and pull out the screen inside of the pump. It may seem like there isn't one, but if you look carefully it will be there unless someone has already removed it.
Now, grab the three hpfp bolts with washers and get ready to install the pump.
Look at the orientation of the slots on the back of the shotgun pulley and spin the pump until it is oriented the same way. Without using excessive force, very gently slide the pump into place. You may have to twist it in order for the grooves to line up. Push it all the way in and secure with the new HPFP bolts and tighten to spec using an alternating pattern.
LPFP Fuel Lines
Next, we will install the low pressure fuel lines.
Fuel will likely come out for everything you disconnect from here on so keep the rags or towels handy.
To begin, before we forget lets take out the filter from the stock HPFP which we will now call the 'Upper HPFP'. To disconnect the HPFP feed line, you’ll need an E socket to remove the clip and then a wrench to remove the metal portion of the feed pipe.
Once the pipe is off, get your pick out and remove the filter from the pump and leave the feed pipe disconnected.
If it seems like there is no filter, keep picking at it unless you know for sure it was removed. You can't see them sometimes, but they are in there.
Now take the other long leg of this Y hose, it should have a quick connect fitting on the end. Run the hose down toward the floorboards where the brake and oem fuel lines head to the back of the car. You should see a metal guard plate that protects these lines from the ground debris, stick the line down that direction and we’ll finish connecting that leg in a moment.
If you trace the fuel feed line coming from the tank, just before the LPFP sensor, there is a soft portion of the feed line which connects to the metal feed pipe (you left disconnected earlier) with a push lock. Remove this push lock, then free this soft feed hose from the circular guide clip its in.
Now connect the third and shortest Y hose leg to the metal feed pipe with the quick connect(not the one you sent down by the brake lines) screw the metal feed pipe into the HPFP inlet and tighten to spec. Snap this leg of the Y hose into the circular guide clip. I found that this part of the Y hose was not long enough and had to put a longer hose on it. The hose I replaced it with turned out to be a bit too long but it worked:
Now get under the car where that metal shield is at from earlier and you should be able to see some 10mm nuts holding this sled looking shield onto the car. Remove all these nuts. One of them is on the top of this pan where you can't see, and you can access it with an extension and a socket.
Once this shield is out of the way, you will see the other end of this soft hose you just disconnected above, it will have another push lock.
Remove the push lock and this OEM fuel hose may now be removed and set aside, it is no longer needed. Now grab the quick connect on the long leg of the Y hose you pushed down here previously and connect it in this spot.
Go back up top and fasten the Y hose line away from the steering column. Tighten down the 45* fitting on the lower HPFP inlet, making sure to clear the steering column.
HPFP Fuel Lines
Now we will connect the high pressure hoses. Grab the other Ferrule fitting, and stick it on the top HPFP outlet.
Grab the high pressure check valve and screw it on the HPFP outlet, leave loose. I don't know if all the check valves are clocked this way or not, but I made it work. I also had to bend this starter cable bracket a little bit in order to get the check valve in the right position.
Grab the long high pressure hose and loosely connect it to the end of the fuel rail in the stock location. And run it down to the lower HPFP and loosely connect it to the outlet.
Now grab the HPFP AIC adapter harness, connect it to the upper HPFP. If you also have the AIC harness, connect it to this adapter harness and run the wires up to the ECU box. I did not have this harness so I left it dangling here until I could connect a controller to it later.
Now take the HPFP extension harness and plug it into the lower HPFP and the factory HPFP plug coming out of the wire distribution box. The factory plug is connected to this pump since it will be the default pump. When the upper pump is not enabled by the controller, this acts like a single barrel shotgun kit. The plug on one end of this extension harness was not made specifically for this application so it is a pressure fit. Push the connector in, and make sure you push until it snaps into place. If it hasn’t clicked, then it probably isn’t installed right. Once connected, zip tie the extension harness out of the way.
This is not seated properly:
This IS seated properly:
Now grab the intake manifold and put it onto the studs. Make sure the long high pressure hose is sitting correctly and does not block the intake manifold.
Once it is situated, install the nut onto the stud between runners 3 and 4 and tighten. Also tighten the long high pressure hose to the end of the fuel rail and lower HPFP outlet. Double check there are no clearance issues and the manifold is seated flush. You may want to install one more nut on the top side of the manifold flange to make sure its seated correctly.
At this point I designed a custom hard line to replace the hydraulic hose which is the short high pressure hose that connects the check valve to the center fuel rail inlet. The provided hydraulic hose is a very tight fit and in my personal opinion can swell and put unwanted pressure on the OEM fuel rail. Also with the EOS intake manifold which has a fuel rail on bottom, the hose pushed up against it and did not fit well.
I will produce and sell a few sets of the hardline for those who may be interested. It will look slightly different because my car has a phenolic spacer and it will be designed for the stock manifold in mind. Installing the hardline is straight forward, slide it down between the manifold runner and tighten it down. For those who will be installing the included hydraulic line, continue below.
Next, look below the manifold, and you should be able to see the outlet of the high pressure check valve sticking up. You need to stick the straight end of the short high pressure hose between runners 3 and 4, then screw the 90* fitting onto the center fuel rail fitting loosely. Going under the manifold, you should be able to bend the hose enough to get it to fasten onto the check valve outlet. You may have to play around with the order this is done to get it to hook up. Once the threads are started, go ahead and tighten down the short high pressure hose on the fuel rail as well as the check valve outlet, and then tighten the other end of the check valve to the HPFP outlet.
Finish installing the manifold, and reassemble the car. Double check for any wires, hoses or anything that may be positioned where it shouldn't be. Make sure everything is connected and fastened down the way it should be paying special attention to all the fuel lines and fittings. Do a scan for all your tools and parts that you may have set down while working which should now be moved away. Fill with new coolant, follow the bleeding procedure and then cycle the ignition 5-6 times without starting the car to prime the fuel system. It is suggested to reset all adaptations except the learned variants with an INPA cable. This will allow the DME to start fresh with the new pump system, and create proper pressure ratios. If you do not have access to INPA, you may experience high HPFP on initial startup. This is normal as the DME will need to learn down as the new pump provides more fuel. Once the fuel system is properly primed, start the car for a few seconds and check for any leaks and make sure the serpentine belt hasn't ran off track. Once satisfied, put the rest of the car back together, not forgetting to reinstall the sled shield on the bottom of the car by the fuel lines.
Until other control options emerge, follow the original instructions.
Document Additional Files
Double Barrel install guide_highlight.pdf
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Forced Induction Forums - SpoolStreet
VTT Double Shotgun Installation