Fitted 810cc injectors on Sunday...

n1smo200sx · Post by **n1smo200sx** » Tue Feb 13, 2007 9:21 pm

Replaced my 370cc stock injectors on Sunday with 810cc injectors.with same map on the gotech,the car started up!!!No fuel coming out the exhaust or nothing!!Revs right through the range up to 7K!Will take it to Manny for dyno next week,don't understand what's going on.Any comments.

The Calibrator · Post by **The Calibrator** » Tue Feb 13, 2007 9:55 pm

What is the resistance of those injectors, what gotech and how are they wired up?

If Gotech std and 3 Ohm injectors the inj driver is probabaly dying and cant open them properly.

Most of the cheap engine managements out there cant cope with 4 low impedance injectors on one driver.

if that is the case you will need a resistor box which will increase your injectors dead time which will cause other issues including an inability to control the fuelling at idle.

Why do you need such large injectors?

n1smo200sx · Post by **n1smo200sx** » Tue Feb 13, 2007 10:19 pm

Direct replacement injectors according to Ian.Don't wanna run out of fuel at 1.5bar,that's why. Gotech Pro can drive the injectors just fine.

veecee · Post by **veecee** » Tue Feb 13, 2007 11:20 pm

why do ppl in south africa go moggy with their fuel injectors?

there are formula's to calculate the required amount of fuel at specific power levels with specific fuel pressures and volumes, and a host of other variables depending on how accurate you want to be.

two seconds on google produced these:

http://www.rceng.com/technical.htm

http://www.iroczone.com/calcs/injectorsize.htm

http://z31.com/software/injector.pl

http://www.200sxs13.nismo.org/Injector.html

those are overkill i reckon - check here...

those injectors are enough to support 824 hp - if all the values in my calculations were correct - i was too lazy to convert imperial!!!

i reckon direct fit means that they will physically go into the same holes, but 810cc?

will you be able to idle smoothly???

The Calibrator · Post by **The Calibrator** » Wed Feb 14, 2007 5:28 am

I suggest you stick a multimeter across the 2 pins and actually measure the resistance of the injector.
You are going to kak trying to get injectors that size to idle especially in batch fire but hey what do I know.

Have you measured your fuel pressure? You will very possibly pick up pulsing in the fuel rail from all those injectors whacking open all at the same time.

The Calibrator · Post by **The Calibrator** » Wed Feb 14, 2007 5:31 am

those injectors are enough to support 824 hp - if all the values in my calculations were correct - i was too lazy to convert imperial!!!

i reckon direct fit means that they will physically go into the same holes, but 810cc?

will you be able to idle smoothly???

Umm
I dont think Fuel injection engines run 175psi fuell pressure its more like 40 or 45psi.

14.7psi= 1bar

veecee · Post by **veecee** » Wed Feb 14, 2007 6:11 am

The Calibrator wrote:
Umm
I dont think Fuel injection engines run 175psi fuell pressure its more like 40 or 45psi.

14.7psi= 1bar

lol - see what happens when you try to be half a smartass!!! you just end up being an ass!!!

Hennie Marais · Post by **Hennie Marais** » Wed Feb 14, 2007 1:00 pm

Those injectors will be safe up to 500hp on around a 80% dutycycle. Just have the injectors cc'd to make sure.

If you're running gotech pro then I guess you've got a 60-2 trigger wheel and running wasted spark, which means that the injectors is firing in pairs, so low imp. injectors will be fine. Check the fuelpressure and fuelpump.

The will idle just fine. I had 720's in my bakkie and it was smooth, it's been replaced by 1000cc and it still idles smooth.

The quality of the injector make a big difference, some use this cheap shit bosch type that lasts only for a while and then starts dropping in flowrate. So be carefull of R500 injectors.

n1smo200sx · Post by **n1smo200sx** » Wed Feb 14, 2007 6:04 pm

Thanx Hennie.u the only one that make sense.The car is there by Vlakkies,but he's in Japan at the moment.I replaced the fuel pump with a walbro about 4 months ago from Import Parts.the fuel pressure tested fine 2.8bar at idle.ian says it is the fuel pump,but why is it revving up,with no adjustment on the map??It idles smoother than ANY sx I've seen around town!

The Calibrator · Post by **The Calibrator** » Thu Feb 15, 2007 6:29 am

What were the fuel mixtures before and what are they now?

What is the fuel pressure now?
Its pretty logical either the injectors are not flowing what they are supposed to or they are not opening for the same time period or the fule pressure is lower.
Another possibility is that the car was setup way to lean before and is now richer but not by enough to cause flooding.

I suggest you start measuring things so you can get to the bottom of the problem.

Om te meet is te weet.

Hennie Marais · Post by **Hennie Marais** » Thu Feb 15, 2007 10:22 am

check the pump flowvolume by removing the feedline and filling a 2L bottle. Time it, it should take around 30sec if it's a 255L/H pump. If that's not the problem and the pressure is set correctly, then you have to check the injectorflow.

veecee · Post by **veecee** » Thu Feb 15, 2007 10:54 am

see - the voices of reason have spoken.

widowmaker · Post by **widowmaker** » Thu Feb 15, 2007 12:59 pm

did you mean injectors from a 810cc Smartcar or TATA maybe?

ram tam tam, voetjies innie dam

n1smo200sx · Post by **n1smo200sx** » Thu Feb 15, 2007 4:37 pm

The car was dynoed by Mannie in Joburg,the 370cc were running lean at 0.6 bar on max duty cycle.Well,i will get to the bottom of it when I go back there next week. Anyone know who can benchflow the injectors if the dyno shows it running lean?Near Centurion or Pta.

veecee · Post by **veecee** » Thu Feb 15, 2007 10:53 pm

i'd like to see pics of your car!

i've always wanted to know what the altezza style tail lights actually look on a "real" sx - not a heavily vinylled drifter!!!

and the 18's too.

please show!

and i know of injector people in strijdom park, nowhere near pta - sorry!!!