92 Dodge Stealth Fuel Injector
Andreas Mbili
The stock 3000GT fuel injectors for the 3000GT VR4 or Dodge Stealth R/T Turbo are rather undersized for the potential of the car and are one of the first things that owners upgrade once they get beyond basic bolt-ons.
In practice once you begin to get over the 300AWHP mark it is a good idea to start looking at larger injectors, but first you will need to choice your tuning method as just installing larger injectors on a stock ECU car will make the car run very rich and provide no benefit as you will still hit fuel cut as the ECU perceives load to be near 100% injector duty cycle. This will typically happen as you exceed 15 PSI of boost near redline.
E85 is a wonderful, pump, high octane and high boost capable fuel. We run it in our shop car. One of the issues with it is it requires approximately 40% more fuel due to its stoichiometric ratio being 9.7:1 instead of 14.7:1. Therefore you should plan your injectors being 35-40% larger than if you were going to run gasoline.
For a 100% stock ecu your only real option is to use an airflow signal modifying device, such as a MAFT or a SAFC. These devices trick the ECU into seeing less load, but since your fuel injectors are flowing more the net effect is you have a tunable AFR and the ECU will not see fuel cut. For a simple example if you are running 720CC injectors you will remove 50% from the airflow signal.
As you can see in the above map the timing is fairly flat above 160 load, which is about when the stock ecu starts getting up over 5-6 PSI of boost. If the ECU perceives less load than this it will add a lot of timing advance. Since you are reducing the airflow signal using a piggyback the ECU thinks the load is less and therefore its important to not run overly large injectors if you are not making a lot of power.
If you intend to run pump gasoline at any time it would be wise to not exceed 720-750cc injectors. 1000cc injectors are more suitable if you intend to make around 600AWHP on E85, but on Gasoline you will need more than one piggyback device as many will not remove more than 50% fueling and you are modifying the airflow signal so much that you are likely to have excessive timing, especially at part throttle.
If you are running somewhat older technology injectors that are low impedance you may still want to stick to 1000CC or less or you may have issues holding a stoic idle on gasoline as their low pulse width response may be non-linear.
Similar to the fuel injectors the stock fuel pump on the 3000GT VR4 and Dodge Stealth Turbo is quite small at about 195 LPH. Just about the time the stock injectors run out the stock fuel pump runs out as well.
The stock wiring also allows for significant voltage drop to the pump, so running a heavy duty power supply from the battery using some 8 gauge wire and a relay triggering the relay on with the stock fuel pump power wire is a great start and needed for any aftermarket fuel pump.
Once you exceed the stock fuel pump ability a popular option in the past was the Walbro 255, but we have found the newer 450 and 525 series Walbro pumps to be a great and quiet alternative. Keep in mind a large hotwired pump may overflow your stock fuel pressure regulator at idle. This can normally be tuned around, but keep in mind we have sometimes seen 60 PSI at idle using one of the large pumps and the stock FPR. A popular mod is to use an after market fuel pressure regulator.
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Refurbished OEM fuel injectors for the Mitsubishi 3000GT and Dodge Stealth. They are ultrasonically cleaned and then flow tested. New filter baskets, o rings, and seals (upper and lower) are included.
Fuel Injector Clinic injector sets are precisely flow matched to within 1%. Each injector within each set is individually numbered and results for each injector are listed on a detailed flow sheet included with the set.
Fuel Injector Clinic injectors are flow tested and rated at 43.5psi (3Bar) at 90F fuel temperature using CF-16B calibration fluid.
Superior short pulse width control and tight manufacturing tolerances make these injectors easy to tune and provide great drivability.
Fuel Injector Clinic injectors are set up to and include all o-rings needed to fit the factory application for the listed vehicle. For aftermarket or other unusual setups please contact us prior to placing your order to make sure you receive injectors that fit properly.
Every injector is covered against failure caused by defects in original manufacture by their 12 month warranty.
This injector set contains low impedance injectors matched to your vehicles factory fuel injector control system which may include an injector resistor pack working in conjunction with your vehicles OEM ECU. These injectors are also suitable for use with an aftermarket ECU made or set up for low impedance injectors driven by a peak and hold signal or by a saturated signal together with a resistor pack.
As I been continuing my build I found that the DSM Mitsubishi 3000GT/Dodge Stealth uses a fuel rail with 11mm injectors with the perfect spacing for the Z31 manifold. This will allow you to upgrade to the more common 11mm style injectors rather than trying to source hard to find bosh barb type injectors.
Once I got the injectors and rails I test fit them in the manifold to see what kind of mounting brackets I needed to hold them down correctly. I started off making measurements and ended up with the design you see below. I made the first set on a band saw and drill press and got the basic shape needed to work. I am currently seeing if there is interest in the Z community for these mounts and if there is I will have them produced on a milling machine for better tolerances.
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