with the mods i have do i have to change injectors? a local guy says i should but i dont really think i need to go bigger yet. also do the stockers go bad after so many miles?

my mods are as followed:
K&N cai
LT headers w/ory
under/overdrive pulley kit
160* thermostat
cc305 cam
1.6 rr
torque converter and 3.73 gears.

thats basically it, i may be missing a few minor mods.

 

I'd say you're probably fine. If you add heads or a bigger cam then I'd start looking for injectors.

 

I'm sure many will tell you to, BUT I ran my car (with the mods in the sig) for about a year on stock injectors. I changed them and it did not get any faster and does not feel any different. The only major thing that I know of that is an issue with injectors is if they stop up or leak. When you change your spark plugs look at them and see if they look lean. I would think that would tell you if you have a stopped up injector. As far as leaking, if you have a fuel pressure gauge just check your fuel pressure after you kill the car (start the car with the fuel pressure gauge on of course ) and see how long it take for them to bleed down. It should take a while. I'm sure there could be other problems such as spray patterns and such but I don't know how you'd check that. You can tell what size injectors you need by this formula.......... http://www.witchhunter.com/injectorcalc1.php4 Hope this helps.




*EDIT* my stock injectors had 150,000 mile on them when I quit using them.

 

Using a scan tool/software will tell you if you need bigger injectors. If the stock injectors are showing around 80-85% at wot I'd start thinking about new ones. My guess would be 30lbs as a replacment.

 

I just ran datamaster on my 94 with CAI, 4.10's, stall and I was at 95% duty cycle with out a cam or headers. I was getting knock every time the duty cycle reached 93-95%. This was happening at about 4800rpm in drive.

 

DataMaster puts out some screwy numbers for duty cycle. It does the calculation right, but it uses "base pulse width" (BPW) and that seems to produce DC's that are irrationally high.

For a ballpark size on injectors, multiply flywheel HP by 0.07.... that assumes you have a decent tune (0.476 BSFC) and want to keep the DC at 85% or below. Using that guideline, you can push it to about 360 flywheel HP on stock (24.9 #/HR in the program), then start thinking about larger injectors. Not to say you can't make 440HP with the stockers, but you need a very efficient tune, and will be stressing the injectors by driving them to 100% DC. It isn't worth the risk.