So I have these brand-new Mazda injectors model numbers 195500-1370 and I only have two of them. Should I put them in the primary or secondary rail? These suckers have never seen fuel and I am sure they will be an improvement. The injectors are the 550cc T2 injectors. Anyone have advice? If you think I should put them in the secondary rail, how hard is it to remove and install? I have an 87 NA with RB header, RB presilencer, Apexi exhaust, and free flow intake. As far as fuel, I have nothing xcept some 93octane in the tank (no T2 fuel pump).
Thanks,
-DL

 

First off. get rid of the 93 octane and run 87. Trust me. There are countless threads about this and I don't plan on turning this one into another. You'll get more power, and no drawbacks.

Also- You don't need those injectors- ESPECIALLY on the primary rail!!
Some people claim thay get more power by putting them on the seconday rail, but I believe that those cars were running a little lean beforehand, and benifitted from running richer. YOU WILL RUN RICHER!
It could actually hurt power, and lead to high RPM stumbles. ou would need to bump your timing up a lot too.
Unless you have a TON of mods, and maybe a ported engine- you won't be taxing the stock injectors (fuel pump is another story though- I know first hand) Alos- you would need to tone them down with an S-AFC... so if you have to tone the injectors down a lot, what's the point of putting them in??!?

Well, no harm in trying on the seconday rail I guess though... but READ THE FOLLOWING-

I am not sure if those are low or high impedance injectors.
Halfway through 87 they switched from low to high. If you put the wrong impedance injectors on, you will blow your ECU injector drives.
Check the build date of your car- and the color of the injectors on your car. I'm sure someone can post what injector #'s are what inpedance. I am just too lazy to get up and look it up right now.
So.. tired.....

 

Wow, that is great information. Thanks BamBam7! Yea, I noticed the 550's in your sig. Guess I wont be needing these :-(
Anyone need a set of new low-imp. 550's?
Anyone else have an opinion? Please post too...
-DL

 

look for a resister pack by your air filter it is a rectangle box with 4 wires going in if you have it you have low imp. You will want a fuel controler to tune in the new injectors. bigger injectors are a nice upgrade put if you go over rich it will hurt power. better rich than lean though.

 

Actually the plugs were switched in 88. High impedance injectors also have red tops.

 

The factory 460cc injectors will supply enough fuel for atleast 230HP at 80% duty cycle. If you are having a problem with running lean or just want an improvement you probably need to have your injectors professionally cleaned. Consider it part of a major tuneup.