They measure 2.5, 2.6, and 2.6.
These are high impedance. The concern would be using true low-impedance injectors with a factory 951 DME. In that case, the injectors have less electrical resistance and draw more current. The extra current can over-tax and overheat the injector driver transistors and cause issues. So, as a band-aid, people add ballast resistors to low-impedance injectors to protect the driver. When using a high-impedance injector, that's not an issue and, in fact, it puts less stress on the DME (less current, less heat). In the old days, high-impedance injectors were sluggish and hard to control in this scenario, but modern EV14 Bosch injectors fixed all that. Even with much less current, they are crisp and linear from idle to redline -- game changing really. The one compatibility issue I didn't mention is deadtime, which is higher on these compared to stock. If that is noticeable on a stock chip, I imagine you could mask it by adding fuel via the FQS. Or, if you follow our chip tuning guide, it's literally two bytes to change in the EPROM.walfreyydo wrote: Thu Aug 27, 2026 10:11 amThese appear to be high impedance, but I think our cars require low impedance (at least up until 1990 I think). I didnt think high impedance were compatible with the DME injector drivers. I think thats the crux of the issue with injectors is finding compatible low impedance since most modern injectors are high impedance.Tom wrote: Thu Aug 27, 2026 9:06 am Someone should try these on the stock tune/chips. I have the 650cc version and would say they are a very good injector (linear and easy to control, down to very short pulses). This 380cc version, if true to spec, flows within 1% of the factory injector and is a drop in fit.
five-o-injectors.jpg
Suprisingly my 1989 S2 has low impedance injectors with a resistor pack to up them to high impedance and I think the next year S2 moved completely to high impedance (unverified).
Yes I believe low and high impedance injectors can have very different dead times so as you mention you'd have to compensate somehow. I also thought OEM injectors are EV1 low impedance so how would that not be compatible with the factory 951 DME that was designed for low impedance? I assume running EV14 require swapping the injector harness/plugs from EV1 to EV14?Tom wrote: Thu Aug 27, 2026 1:42 pm
These are high impedance. The concern would be using true low-impedance injectors with a factory 951 DME. In that case, the injectors have less electrical resistance and draw more current. The extra current can over-tax and overheat the injector driver transistors and cause issues. So, as a band-aid, people add ballast resistors to low-impedance injectors to protect the driver. When using a high-impedance injector, that's not an issue and, in fact, it puts less stress on the DME (less current, less heat). In the old days, high-impedance injectors were sluggish and hard to control in this scenario, but modern EV14 Bosch injectors fixed all that. Even with much less current, they are crisp and linear from idle to redline -- game changing really. The one compatibility issue I didn't mention is deadtime, which is higher on these compared to stock. If that is noticeable on a stock chip, I imagine you could mask it by adding fuel via the FQS. Or, if you follow our chip tuning guide, it's literally two bytes to change in the EPROM.
OEM are 4.6 Ohmswalfreyydo wrote: Fri Aug 28, 2026 8:43 amYes I believe low and high impedance injectors can have very different dead times so as you mention you'd have to compensate somehow. I also thought OEM injectors are EV1 low impedance so how would that not be compatible with the factory 951 DME that was designed for low impedance? I assume running EV14 require swapping the injector harness/plugs from EV1 to EV14?Tom wrote: Thu Aug 27, 2026 1:42 pm
These are high impedance. The concern would be using true low-impedance injectors with a factory 951 DME. In that case, the injectors have less electrical resistance and draw more current. The extra current can over-tax and overheat the injector driver transistors and cause issues. So, as a band-aid, people add ballast resistors to low-impedance injectors to protect the driver. When using a high-impedance injector, that's not an issue and, in fact, it puts less stress on the DME (less current, less heat). In the old days, high-impedance injectors were sluggish and hard to control in this scenario, but modern EV14 Bosch injectors fixed all that. Even with much less current, they are crisp and linear from idle to redline -- game changing really. The one compatibility issue I didn't mention is deadtime, which is higher on these compared to stock. If that is noticeable on a stock chip, I imagine you could mask it by adding fuel via the FQS. Or, if you follow our chip tuning guide, it's literally two bytes to change in the EPROM.
the ones I linked have compatible JPT connectors -- no pigtail adapters needed -- and have more resistance than the stock injectors, so are safe for the DME. Dead times are indeed slightly longer, though hard to say if it would be enough to notice.walfreyydo wrote: Fri Aug 28, 2026 8:43 amYes I believe low and high impedance injectors can have very different dead times so as you mention you'd have to compensate somehow. I also thought OEM injectors are EV1 low impedance so how would that not be compatible with the factory 951 DME that was designed for low impedance? I assume running EV14 require swapping the injector harness/plugs from EV1 to EV14?Tom wrote: Thu Aug 27, 2026 1:42 pm
These are high impedance. The concern would be using true low-impedance injectors with a factory 951 DME. In that case, the injectors have less electrical resistance and draw more current. The extra current can over-tax and overheat the injector driver transistors and cause issues. So, as a band-aid, people add ballast resistors to low-impedance injectors to protect the driver. When using a high-impedance injector, that's not an issue and, in fact, it puts less stress on the DME (less current, less heat). In the old days, high-impedance injectors were sluggish and hard to control in this scenario, but modern EV14 Bosch injectors fixed all that. Even with much less current, they are crisp and linear from idle to redline -- game changing really. The one compatibility issue I didn't mention is deadtime, which is higher on these compared to stock. If that is noticeable on a stock chip, I imagine you could mask it by adding fuel via the FQS. Or, if you follow our chip tuning guide, it's literally two bytes to change in the EPROM.