Injector Upgrade, new parts for fuel injection Options

[McMark]

I've been working on upgrading the components of my custom fuel injection setup. One of the upgrades I've had in the works for awhile was adapting the newest Bosch injectors. These have an improved spray pattern, are high-impedance, and are available in a variety of spray volumes. And they're TINY!

But like any of this stuff, you can't just bolt them on. I decided to make some fancy adapters that would look mostly original. This was one of my first projects to help teach myself Fusion360 CAD modeling.



Got a couple 3D prints from some of our members, which illustrated a few issues with my design. A few changes were made and I pulled the trigger on an initial run of 20 pieces (5 engines).

Just received these parts back from anodizing and did a final test fit. Everything looks perfect. So it's time to install this and my upgraded AAR on my 1.7 Turbo and see how these new additions help things.

[McMark]

Will the upgraded AAR be available as a group buy at some point? (IMG:style_emoticons/default/biggrin.gif)

Yup. As soon as I make sure it works. I'm also pondering some possibilities that would allow my AAR to be installed as a standalone part -- making it applicable to D-Jet and L-Jet cars.

Looks good. Are those injectors reasonably priced?

I buy mine from DeatshWerks at $260 for 4. But these injectors are on TONS of new cars. So the pick-n-pull available should be HUGE.

also , are the connectors plug and play or is modification of the stock FI connector from the harness required?

Adapter plugs could be made available pretty easily.

I see this new bracket is not indexed to the tine on the manifold. What keeps the injector bracket from rotating around its bolt and moving from side to side?

Nothing, I suppose. I'm not sure why they would be moving around. These will use the stock fuel rails as well, so that should provide some additional rigidity to guard against that concern. If I do another run I'll look into adding these tabs. I didn't add them initially because I was concerned about machining costs.

Is there any reasonable way to have the electrical connector point the same way as the stock injectors?

Nope. (IMG:style_emoticons/default/sad.gif) It does rotate freely, so you can put them left/right/down or anywhere in between.

Nicely done, for your future runs, please add some big fillets between the "sheet metal" part and the cylindrical part, also at the nipple to larger diameter corner, since these are direct metal moulded parts

I'd love to hear more about what you mean. These are CNC machined from aluminum, but you said "direct metal moulded parts" so I thought maybe you meant DLMS/3D-metal-printing. I understand that adding fillets would add strength, but it doesn't seem relevant to this part (no strength necessary). If you're seeing something I'm not, let me know.

Very nice. My only concern is have you added another potential leak point in the system where the injector mates with the bracket?

Sure. It's an additional potential leak point, but there's not much to be done about this. New injectors are ALL rail mount, so in order to upgrade I had to accept this fact. But it's a potential leak that present in every car that uses a rail-mount injector, which is pretty much every car produced in the last 10+ years. So I'm not doing anything unusual here. Those cars don't have leak problems, so as long as my parts are machined right they shouldn't have a lea problem either.

[JeffBowlsby]

I see this new bracket is not indexed to the tine on the manifold. What keeps the injector bracket from rotating around its bolt and moving from side to side?

Nothing, I suppose. I'm not sure why they would be moving around. These will use the stock fuel rails as well, so that should provide some additional rigidity to guard against that concern. If I do another run I'll look into adding these tabs. I didn't add them initially because I was concerned about machining costs.

It looks like if the bracket rotates, the injector could come loose so its seals could become loose. The bracket will rotate if its nut becomes loose or otherwise fails to prevent rotation. The OEM fuel rails when installed will not prevent this rotation.

Install an injector as in your photo and loosen the nut. Does the injector tilt when the bracket rotates? If so, the gaskets may not seal against the pressurized fuel.

Believe me, your idea is interesting...if it works. The harness connections actually align better when they lay off to the side like yours do. What are those - Delphi or Weatherpak connectors that would be needed? They could be mounted to an existing harness, not sure about an adapter to a D-Jet/L-Jet harness - seems not to be the best solution.

On the injectors, what are their flow ratings and how well do they substitute for stock injectors?

[McMark]

I see this new bracket is not indexed to the tine on the manifold. What keeps the injector bracket from rotating around its bolt and moving from side to side?

Nothing, I suppose. I'm not sure why they would be moving around. These will use the stock fuel rails as well, so that should provide some additional rigidity to guard against that concern. If I do another run I'll look into adding these tabs. I didn't add them initially because I was concerned about machining costs.

It looks like if the bracket rotates, the injector could come loose so its seals could become loose. The bracket will rotate if its nut becomes loose or otherwise fails to prevent rotation. The OEM fuel rails when installed will not prevent this rotation.

Install an injector as in your photo and loosen the nut. Does the injector tilt when the bracket rotates? If so, the gaskets may not seal against the pressurized fuel.

Believe me, your idea is interesting...if it works. The harness connections actually align better when they lay off to the side like yours do. What are those - Delphi or Weatherpak connectors that would be needed? They could be mounted to an existing harness, not sure about an adapter to a D-Jet/L-Jet harness - seems not to be the best solution.

On the injectors, what are their flow ratings and how well do they substitute for stock injectors?

I know what you mean about tilt. I thought about that and I'll be doing some 'forceful' testing of their resistance to leaking. That's paramount. But again, this is how most injectors are installed these days -- and the upper o-ring system is a tight fit. Lots of compression to ensure a tight fit. And Bosch provides machining specifications which were all used in the making of this part. So this isn't a part I completely made up -- it's built to the factory design specs for these injectors.


It's a Delphi connector and if everything works out I plan on offering uncrimped connectors for converting a harness or an adapter plug that will retain the original connectors. Obviously an adapter is less preferable, because of the corrosion issue.

The smallest available from DeatschWerks is 42lb/hr @ 3bar/43psi. Converting those to 2bar/28psi results in 34lb/hr, which is pretty close to stock 2.0 injectors. BUT I'm pulling that stock flow rate from your Injector Substitution thread which doesn't specify the fuel pressure those flow rates are measured at. So if the listings in your thread are already at 3bar, then that changes things. There are other sizes available, including 31 lb/hr @ 3bar. So sizes shouldn't be a problem.