550cc injectors

[DSMZEX]

I bought new 550cc injectors to replace my 450cc.. I noticed that the 550's don't have the black plastic tips on the bottom like the 450's... are those tips necessary? or are they only on certian kinds, or certain size injectors... I guess in a nut shell...what are those black tips...?

In addition are 550cc High or low impedence? I think 450cc are low...Do I need some kind of electrical system modification (resistor) to compensate if there is a difference.

reason: Doing a major upgrade...Super16G turbo...550's injectors, 2G mas, 255lph fuel pump... I just want to do it right...

 

[L2RTSiAWD]

They should be the same impedance.

Not following you on the black tips.

 

[djpast]

They should be the same impedance.

Not following you on the black tips.

hes talking about the pintle caps... i am not seeing any kind of fuel control like an s-afc... its totally needed...

 

[x camaro owner]

the impedance of your injectors will vary depending on how the manufacturer designed them. it is a pretty critically thing and being a 3rd year electrical engeering major with all honors at a big ten school i was surprised to see this bulletin. i don't recall what the resistance of the stock injectors but i am sure you can find it some where, but i do recall it is super low. thats why there is a resistor pack on your firewall to limit current because the injectors will sink more current than the ecu can supply. this is bad thats why that resistor pack is there. if you add injectors with a higher impedance in combination with the resistor pack there won't be enough current to hit full load with the injectors like you did before. if they are the same impedance or very close to it you are fine, by close in mean a couple of ohms not 100ohms. if the injectors do have a high reistance just remove the resistor pack. that wiring should be somewhere on the internet probably vfaq. i have never looked at it cuz i am not messing with the stuff cuz i don't have a big enough pocket book to do it correctly, one tip i have for you is grounding man its all about grounding i am not saying go buy that hyper ground kit cuz its a ripp off. get some nice monster 4 gauage wire or and some connectors to put on the ends use solder. put one to fire wall and one to the block. for even lower resistance run 2 wires side by side because the your total resistance is half of what the low reistance of the 4 gauge wire already is.

 

[flinguist]

So should the 550's have pintle caps or not?

 

[92awddsm]

My 550's dont have pintle caps. I would also recommend some sort of fuel control like an afc or equivilent. With the 2 g mas and 550's, you will have to tune very little but you will still have to tune. If you bought 550's for a dsm, they should drop in without having to worry about impedence.