So I did some searching around tonight and according to this chart - http://www.megasquirt.info/ (scroll down a tad) - I need roughly 460cc injectors assuming my car will put down 300hp @ 16psi (that's the goal anyways...), does that sound right to you guys? I'm just worried it'll make my idle real bad...

That being said; are there any known issues with the ACCEL injectors that CImotorsports sells? Here's a link to them - http://www.cimotorsports.net/motor-sport-products/accel-fuel-injector-set-eclipsetalon-420a.html . I figured I would just buy those once I locked in on how big I need to go since they come in various sizes for our engines... And if 460cc's is about right for my application then I think I'll just get the 490cc ACCEL's because, like most of us, I do plan on making further upgrades down the road....starting with an aftermarket radiator once all this is installed and running smoothly. So I think 325hp would be a safe number to use for determining my size of fuel injectors to help compensate for slight improvements in the future? Please give me some reassurance here, I don't want to make a $300 mistake! thanks guys

Accell make a nice idle once tuned right. However you can save some money with siemens deka which is who makes the injectors for accell. Try racetronix.com for a matched set of 4. CI wasnt good with timely shipping last i checked or another MOD checked rather.

490 wont be hard to idle; however, they will be a little small. Now without factoring in the turbo size and flow characteristics ect, my car ran 18 psi and the 550's were maxed out. It does depend on your setup but i would go a little larger than 490's.

Terry

Thanks! My biggest reason for choosing the ACCEL's honestly is because I haven't found many options for the 420a :confused: I'll check that site out later when I get off work - sounds promising! Oh ya and the turbo is the Hahn 20g. Appreciate the help...

im using accel 880s with ms and im not having any issues with idle. I would recommend going a little bigger than 490 just in case you wanna up the boost later, so you dont have to buy new injectors again.

can you use evo 550s do they even fit

The Accel injectors are of good design. I had 4 415cc/min injectors with a 16G for quite some time, although making them work properly above ~250 BHP or 15-18 PSI is tricky, you have to crank up the static fuel pressure above 43.5 PSI in order to maintain a good AFR under boost pressure. This allows proper fuel flow at peak boost, however it forces the idle a little on the rich side. In this situation, to maintain a good idle quality the pulsewidth sent to the fuel injectors is very short, on the order of 2.0ms or less, which means chances are the injector isn't opening properly which will make you fail emissions (if that matters) Anyways... Think of it this way - the stock injectors on the 1990-1999 4G63 were 450 CC/min with a rated output just about 210? BHP... If you are looking to make 300 BHP I wouldn't go any smaller than 550 cc/min. Putting aside the flow rate, does the fuel injector fit in the fuel rail properly? Is the impedance of the fuel injector 2-3 ohms or 10-12 ohms? Does the ECU have the capability of supporting low impedance injectors?

Thanks for the help! I have no clue how the impedances work with fuel injectors but I will be running MsNs so I know that won't be a problem... Are larger injectors not very likely to fit the stock fuel rail? I was under the impression all injectors were physically the same size and would fit my fuel rail...maybe I need to buy a new one?

Failing emissions is a big concern as I am due this summer - I think in July... I can always tweak MsNS in a brief amount of time (once I learn how) to adjust the fuel settings to pass emissions as long as that is the sole reason I might fail, correct?

just grab a new fuel rail.

Originally posted by navyguns
just grab a new fuel rail.

Why? You dont know what your talking about.

Physically a larger injector will fit the stock rail. If you need to, you can change the orings smaller/larger if you needed too.

This guy here just doesnt know what he is talking about.

There are lots of injectors that have the right size O-rings to physically fit the stock manifold, fuel rail, and electrical connector that are not blatantly sold for the 420A. You should pay attention to whether the injectors are saturated or peak/hold. The MSnS can control either, but there are reasons to choose one or the other. You might want to call up the guys at RC Engineering www.rceng.com. They could help you pick an injector and recommend a distributor to buy from (their direct pricing is high).

Corbin

'95 ESI-T
Now with more power and fewer leaks



Gimme fuel...Gimme fire...Gimme that which I desire