I thought my secondary injectors were plugged but their not, should i leave the DSM injectors in or put the stock ones back in?

 

Why in the hell do you have dsm injectors on a rx7?

 

dsm injectors fit in a rx7 but why would you use them? they are smaller than stock 460's.

 

DSM injectors are 450s i know cause my buddy wanted my 460s

 

I predict another 'why did my car blow up?' thread coming soon

Put the stock ones back in.

 

well, if you were putting them on just for testing then thats ok, but now that you know it wasn't a problem with the injectors put the stock ones back in and start looking for other problems.

 

The "460" rating of the stock injectors can be reverse-engineered by averaging out the acceptable upper and lower flow limits of 444 to 472 cc/min to get 458 cc/min. If you also average the acceptable range for the fuel rail pressure of 34.1 to 39.8 psi you get 36.95 psi. Therefore, the average flow of the stock injectors when installed on a stock RX-7 in good condition is 458cc/min @ 36.95 psi.

Most fuel injectors are rated at 3 bar (43.5psi). I am not familiar with the DSM injectors, but if they are rated in this manner, then 450cc/min @ 43.5psi converts to only 415cc/min @ 36.95 psi. Were you to convert all 4 injectors on the engine, you would see about a 10% loss in fuel delivery, which would result in the engine running about 1.5 AFR leaner than intended.

 

I already put the stock injectors back in but i was just wondering what people would say haha. but when they were in my car it actually ran exactly the same as it did with the stock injectors.

 

Probably because 10% doesn't mean ****, lol.

 

haha true

 

how did you get them to run?! rx7's are saturated injectors dsms are peak and hold arent they?

 

At least the 2nd gen ones are.

Our injectors are supposed to be upgrades for them! Not the other way around, lol.

 

I think it was because it was only the secondaries. Also, most people do not know the sound and smell of running lean. Try running a full 10% fuel reduction (12.5 AFR > 13.9 AFR) on turbocharged 13B and you will soon be picking apex seals out of your turbine blades. If you honestly don't care about a 10% difference, then you have no use for a wideband AFR meter, and can simply stick with a cheaper narrowband unit.

 

You want the secondaries to run a tad rich anyway. Mazda designed the engine to run rich at top end to lube the seals better. Less fuel at top end means less oil or premix getting injected into the engine meaning not good...