Injector decision


Active Member
Hey Guys,

I have a stock motor and my injectors are leaky so I am in the market for a new set. Im at the point where I am looking at swapping my 86-87 ecm into it so I thought that I would start acquiring parts to get it swapped over. It will have a 86-87 ecm, Maf t and LS Maf and no cat. I would like to think I will uprgrade the turbo one day so I don't want to buy another set in a couple years so the question is what do 50-60# do to driveability until I maybe one day do the upgrades?

Many will advice to go straight to 80s, especially if you plan to run e85 some day. Here is my take. . . .

The most favorable injector size is the one that operates at or close to the industry std of 80% DC WOT regardless of the fuel and hp target. This can be calculated, but be realistic.

So . . . lets say the 80s are running at 50% DC. That means that all the fuel is injected at 50% of the available intake open time. When we do that, the fuel is "dumped" and fuel drop out becomes a much bigger issue.

When injector size is increased, fuel system will also need to be evaluated. Pump, volume, bypass, etc. need to be evaluated. So . . Goal/ budget/etc all play a role.

Fwiw . . .
A 50lb injector on gas at 3 bar base and 80% DC is capable of 425 crank hp.

Hope this helps and good luck.
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We dont have e85 in Alberta :(. Our refineries are forced to blend up to 10 percent ethanol and that's it. Best fuel we get is 94 octane but 91 is more common.
Fwiw the 80's don't flow 80 unless the base pressure is higher than the typically reported 3 bar. I've noticed some swing in rich/lean at short pulse widths with these when the coils get hot.

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