Uwe @ XDI
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XDI-2000cc injectors
A competitor has published pictures of injector tips and corresponding spray videos that show a bad competitor injector.
People have been assuming that "the competitor injector" is ours and that the idle issues come from the "bad spray pattern".
We don't know what injector they found and called "competitor injector", but it's for sure not ours. Please check out the pictures below.
Top row: images from our competitor
Bottom row: XDI-2000cc tip and spray holes
Our XDI spray pattern is very different, and even the tip shape and surface finish are different. The "competitor injector" has a machined surface, ours is sintered material. The "competitor injector” looks like the “Keihin” Injector from the Honda Si 1.5T.
Keihin 1.5L injector and spray holes, we at XDI don't use those
Now Regarding the Actual Spray Pattern Design
For the spray pattern geeks: counter bores reduce the L/D ratio (length over diameter), which leads to wider and shorter sprays (less chamber penetration).
That is not necessarily "better vaporization" or a “better spray”. It's great for emissions and fuel-air mixture with low air speed (low boost) and a ring of spray holes. When you add two spray holes in the center with small L/D, you add short, wide spray plumes in the center. There is no extra air in the center of all these spray holes. The sprays collide instead of mixing with air.
We studied a "dual center spray hole" design years ago. It poses the risk of a blown-off tip at high temperatures and fuel pressures, since it reduces the wall thickness between the spray holes in the injector tip below the required minimum, especially with deep counter bores.
At XDI we designed the outside holes with counter bores (small L/D) to fill the outside area of the combustion chamber without touching the cylinder walls.
We added a small-diameter single center hole with a bigger L/D and higher penetration, to reach the bottom-side corner of the combustion chamber.
That's where a lot of air ends up at higher boost, i.e. higher air speed. That extra air can create a local lean spot if you don't bring any fuel there.
So Why the Rough Idle if the spray pattern is good?
Our injector is BIG. It flows 80% more than the stock injector! What Honda does from the factory is run higher pressure on a small injector to provide the right amount needed, but with maximized vaporization. This is emissions optimized.
With an 80% larger injector, you would get 80% more flow even at idle, which is way too much. At regular stock pressure levels the ECU has to reduce the pulse width to the injector to reduce the required fuel volume for the target air fuel ratio (lambda). Our injector, and almost every DI injector out there, is highly non-linear below 0.5 ms. The Injector to injector deviation in a set goes up as well at those very short pulses.
All our XDI-2000cc injectors are matched at three different operating points to around 1% spread or less within a set for best cylinder deviation.
0.8ms / 20bar to represent idle
10.0ms / 100bar to represent static flow
6.0ms / 200bar to represent wide open throttle operation
EACH SET COMES WITH A DEDICATED DATASHEET WITH THESE FLOWDATA. With these data you can tune each cylinder to within 1%.
We recommend in our datasheet to never run less than 0.8 ms. To keep the pulse above 0.8msec you sometimes need to take the desired pressure down.
In every single log that we got back from customers with rough running issues, the commanded and actual DI pressure was at or above 2900psi, against our tuning recommendation. Our 2000cc injector has to fire so short that it barely opens at all, as a consequence it runs rough.
This is what the tuners and drivers have seen and complained about.
It took some time to find all the tables in the Honda ECU and get access.
There is a software function called CVO (controlled valve operation), that erratically sends the desired pressure up to 2900 psi at idle. This function has been causing the problem in most cases. The erratic nature made it so hard to find and verify.
CVO has to be turned off !
The Bottom Line
We were first to market with our 2000cc injectors, years before everybody else. It just took some time to find and test all settings.
Whatever our competitor has tested are not XDI parts. XDI-2000cc injectors run like stock if the latest settings are used. On Hondata, COBB and Motec.
Latest calibration guide is available here on our website:
https://xtreme-di.com/wp-content/uploads/2026/07/XDI-2000cc-Inj-Guide-Hondata-and-Cobb-7-15-2026.pdf
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