Has anyone added a tertiary injector? Where do you mount it? How did u control it?

also

Is there any particular reason that people's primary injectors are considerably smaller than the secondarys? It seems for what i have read that when people are running big injectors they only run them on the secondarys. If people were replacing all 4 injectors wouldnt it make sense to have 4 of the biggest injectors possible?

 

Yep.

Where ever you can fit it. Some have ran them on top of the UIM, the old school HKS front omunt kit came with an elbow that had injector bungs on it. The Pineapple Exsessive FD lower intake manifold has two extra spots right at the bottom of the manifold. Of course, anywhere you mount them you'll also need to plumb fuel to (duh) by way of a rail or an individual feed system. But that must be taken into consideration while thinking of placement.

Many ways. If your EMS has the capability to handle 6 injectors you can simply run it on with your EMS. IF you're still using a stock ECU you can use a seperate Additional injector Controller like the HKS AIC.

People meaning most people running high HP? Well most of them are using a full standalone which allows you to move your transtition point, your duty cycle etc, so they can control them. Having giant primaries (like 1680's) HAS been done by people, but you can only tune the injection so low on a big injector before it just starts spitting. Meaning, you're going to run pig rich at idle.

See the rich idle comment above.

Not unless you like loading the engine with fuel while you're at a stop light. The injector sizing is for driveability mostly. And because smooth transitions can be had with large size differences when using a good EMS.

 

Extra injectors is a crude way to get extra fuel, because they can't be controlled nearly as well as the main ones. All extra injector controllers are pretty basic devices that were popular before fuel controllers and standalones became much more affordable. They can't bring the extra fuel in without sudden step in AFR and the adjustments are very simple, usually two trim-pots for when and how much.

The cost of bigger secondary injecectors and a fuel controller will be cheaper than buying extra injectors and a controller and then actually mounting and plumbing them, and the results will be much better.

The reason the secondart injectors are upgraded before the primaries is that smaller injectors work better than big ones at small pulsewidths, i.e. idle and low load. Most normal driving is done on just the primaries. You don't need (or want) four of the biggest injectors possible, you only need them to be safely big enough for the power your engine is making.

 

im asking this because im thinking ethanol and ill need more injector for that than if i ran gasoline