Higher flow injectors for 3.2 Motronic

[Lyle O]

I am looking to upgrade the injectors on my ’87 Carrera to a higher flow (to better match my engine modifications; I am getting a little lean at WOT). The stock injectors in our 3.2 Motronic system (Bosch EV1, 0-280-150-158) are 26 lb./hr @ 3 bar, low impedance (2.3 ohm), and are NLA anyhow, as are others for the 964, etc.).
I have found these Holley EV1 style injectors, low impedance, at 36 lb./hr @3 bar. They look like a good drop-in upgrade, at least in terms of flow specs, etc. What I am not sure about is whether they will physically fit on the manifold/rail. The electrical connection looks compatible.
Has anyone tried these, and what has been your experience? Alternatively, can anyone recommend a higher flow injector from stock, (in the 35-45 lb./hr range), with low impedance, that is for sure a drop in replacement? I have to think there are good replacements out there that are easy drops-ins. TIA.

Lyle.

https://www.lsxceleration.com/holley-36-lb-hr-ev1-low-impedance-fuel-injector-522-361/

[RarlyL8]

Contact Sal Carceller, Sal.Carceller@cox.net, he has developed a couple of performance injector systems specifically for the 911 Carrera. I've used them and the results are significant.

.

[996AE]

How do you know lean at WOT?

[brighton911]

I'm thinking your lean condition is ECU program related rather than injector sizing. My 3.4 10:1 CR with 964 cams is running Ford MS 24 lb injectors via Megsquirt and they are no where near maxed out at WOT up to 6500 rpm.

[Lyle O]

Thanks for the good input, all.
The complication for me is that I have a low boost turbo (Protomotive Stage 1), 10% enlarged throttle body, cams, etc. It is at WOT, under boost, that I am seeing lean numbers (should be 10-12, I have 12-14.5). Max boost is 5 psi. We are going to look at several things on this, including the tune on the EPROM (Todd Knighton’s), but more fuel is needed and I’m pretty sure the injectors/fuel delivery could be a factor nonetheless. But we will go step by step.

[996AE]

Custom Steve Wong chip?

[Lyle O]

It’s actually custom programmed by Todd Knighton of Protomotive.

[RarlyL8]

Are you using a raising rate fuel pressure regulator?
Generally that will take care of fueling for a mild turbocharged 3.2L Motronic engine.
If there is a problem with your injectors give Sal a call, his injectors are a nice upgrade even for a stock engine.

[Lyle O]

Hi. Brian; yes, it (FPR) is a special RR type that Todd provided. We are verifying the correct pressure increases (as soon as I hook up a fuel pressure sensor and plot the pressures against RPM and boost). I am just thinking ahead in case the fuel flow is still light after the chip, etc. are maxed out. The other possible solution item is a higher flow fuel pump (thinking Bosch Motorsports “044”). But I am probably getting ahead of myself. I will send Sal a note about the injectors, though. I’ve read about his systems and they sound great. I just know he upgrades everything (in the DME) to be compatible with the new high impedance injectors, and I was thinking more about a drop-in solution.

[Rodsrsr]

I would check fuel delivery. Verify pump is producing enough pressure and volume, fuel filter is not clogged and the injectors are clean. I'm not really a fan of the Protomotive system but it is fairly cookie cutter and seems to work well right out of the box.

The rising rate fuel pressure regulators like a BEGI allow for 2 adjustments unlike Todds which I believe is set. I'm also not a fan of running the factory AFM under boost as they don't seem to last too long.

I'm running stock injectors with a BEGI and a draw through MAF with a split second controller. Its analog but the system works flawlessly and allows for adjustments on the fly if needed. That said, I dont think you need to necessarily change the current set-up but address the fuel delivery issue your experiencing. You shouldn't need anything other than a properly working stock fuel pump btw anything else is overkill for .5 bar.