Fk8 direct port methanol injection.


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Mar 6, 2019
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Myrtle beach South Carolina
2018 type R 2015 c300
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So here’s what would need to be done to a radium port adapter to run direct port methanol.
You can NOT do this to the stock manifold due the fact the ribs must be ground off and can not be done without compromising the structural integrity of the stock manifold. Further more it would require using a nut to fasten it which could come loose and fall into the engine. The other drawback is you manifold can literally explode. This is the only way to make certain you do not risk damaging your engine. Removing the nozzles would then become difficult as well.

The original injector bosses need to be cut down. You can not drill the original holes cause it will break through the gasket seat and the nozzle will be to close to cylinder head and contact it on install.
Here’s a pic of the original hole and you can see how close it is to the back of the plate.

hers a pic after having my fabricator fill the holes.

he did an awesome job. Due to the fact that the original holes are very close to the gasket seat they could not be filled all the way. This will not effect mounting the nozzles or structure in any way.
Here you can see how the heat could have melted the edge if you fill it entirely.

This was just a test fitting to see an idea how deep the injector needs to go. I left room cause you can not use aem nozzles due to the fact way the holes need to be drilled. 90 degree nozzle holders are required. This is because you can not drill the oem angle and if you do not go straight down the port adapter is too thick and the nozzles will not be able to spray correctly into the air path.

You can see the original hole next to the drilled and tapped one here that could not be totally filled with damaging the adapter.

you can see here even a flush cut requires some material cut away to allow a correct spray pattern. This was not easy using a dremel by hand to do this without damaging it in anyway. This is not your standard DIY project.

looks a lot better after painting. The threads must be retapped after painting to prevent damaging of the threads or binding when installing the nozzles. Anti seize works really well in aluminum. It will not make the fitting back out cause the npt fitting is self locking from the taper. You can see how the heat wanted to melt the first hole. Going forward I plan to leave more material like this other hole next to it. This gives more material so heat won’t melt it.

Here’s a pic after painted. I used high temp engine paint. I didn’t see a point of using header paint as it will never reach 600 degrees. Plus VHT is fully cured only after 690 degrees after the first round of heating at 400 degrees.
All in all it was more work than I was hopping but not terrible. You can NOT offset drill the original holes without compromising the gasket seat. It was the first thing I thought of until I received it and realized just how close to seat it was.
I used a band saw and a drill press. I have a fully adjustable speed drill press that’s reversible. This is honestly what is needed to do this right. There’s no way you could drill and tap this by hand and get it spot on.

The new holes are not in the center of the plate from front to back but rather .125 and inch closer to the manifold side. This was to ensure clearance from the head and center the hole from the depth of the gasket seat to the other side if the plate.

I was told that someone was working on an adapter plate for this but it will be hard to overcome a few things. Space is one due to the constraint of how thick the plate is. The hole needs to be vertically drilled to penetrate far enough for correct spray pattern.
It’s only as thick as the plastic on the manifold and would be hard to make thinner.
Another even Flush mounting the nozzle still Requires more removal of material.
mid you recess mount the nozzles you will need to crest enough room so that all types of nozzles can be tightened.
I could have recessed this more but then it would not only be more difficult to tighten but mounting the nozzle holder would be tougher also.

FYI to use the radium plate you must update the diverter solenoid position to 2019+ positions. This relocates the diverter solenoid to the manifold and uses a 2 pipe metal vacuum line. The third one that is blocked off can get in the way of the port injection rail.
So now to the big part cost.
My original aem meth kit with filter and solenoid was just over 500.
4 new nozzles at 3gph or 189cc. 105 from snow performance
Direct port kit with distribution block is about 200 from snow but does comes with their solenoid. Was more money to buy without the solenoid.
Radium port adapter 300.
Fabricator filling in the holes plus
Drilling and tapping holes plus clearancing material.

So about 1200 in cost but stil 1000 dollars cheaper than port upgrade. I know some are thinking the port upgrade is better. Being the tuning process and fuel limits are the same I see no value in going to full port. The port kit isn’t sequential so it’s not really more advantageous over methanol.
Both have the same risk when they fail. Both have the same fueling limits.

If I ran a snow performance stage 4 controller tapping the rpm signal and boost reference it can control methanol just like the split second controller and still comes in cheaper. Would have cost 250 more for the initial kit in the beginning. I may still go this route eventually. Thanks for reading.
Please contact me at [email protected]
I do not check this page that often.
if you are interested in having this done pm me and we can work out the details. Or email me. If you want to talk on the phone pm me I will give you my business number.