BRADP

k well after i get my interface and window switch wired up i took it for a little test drive on the street and ended up melting 3 plugs. i figure that i dont have big enough injectors so until i can get bigger ones i will just set it up for a 75 to 100 shot. how much timing will i need to pull for each and i think i can figure out the rest of the stuff on it. thanks for any help.

jetlag

iTrader: (32)

What others mods are done to your car? Do you have a tune? You should be good on a stock tune with a 100 shot...

Mike@HSW

iTrader: (6)

You are without a doubt running out of injector, certain cars need an injector upgrade at a 50 dry shot. I would do a leak down test on those cylinders to make sure you didnt do any significant damage. I have to imagine you were running severly lean and there is a good chance you did something. The next time you spray the car it should be on the dyno where you can confirm your A/F ratio and check the injector duty cycle. Its more then possible that they will still be maxed out on the 100 shot or even the 75

black01_WS6

iTrader: (13)

well most people that have the interface are adding as much timing N/A as possible then letting the interface make the changes. I have 3 degrees pulled just to be on the safe side for now.

BRADP

how much timing do you think i should pull with the interface pulling it on a 75 shot. and what size injectors should i get so i could juice out a 150 shot

black01_WS6

iTrader: (13)

I have 42 pounders and they work great and will handle the 150 shot all day.


Do you know what your timing is at right now? I would pull 3 degrees and theow it on the dyno and you can always add it back in if needed. With the problems that you are having I wouldn't spray it till you could get on the dyno, and possible a leakdown test.

BRADP

i had the interface pulling 6 or 8 degrees on the 125 shot. when i sprayed it it didnt backfire or anything but it felt pretty lazy. im gunna go to a dyno next weekend and see if i can get the 75 shot to hit pretty good till i get the injectors. but you think three degrees for the 75 should be good

Mike@HSW

iTrader: (6)

what vehicle is this on? give us some more info.

BRADP

its on 95 trans am (lt1 i no it sucks) intake, exhaust, 4.10's, 2800 stall, ngk tr6's juice comes on at 3000 and shuts off at 5200, stock n/a tune, hsw interface, dry nozzle after the maf. bottle pressure at 950

Mike@HSW

iTrader: (6)

if you dont mind, fill out a tech ticket so we can make sure you are on the right track.

http://www.harrisspeedworks.com/support/

as i said before though, it sounds like your simply running out of injector and i wouldnt run the car again till its on the dyno.

BRADP

k i filled out a ticket. thank you guys for the help

black01_WS6

iTrader: (13)

since you have a lt1 look for the red top injectors- a bit cheaper than the 42's and will work in your application.

BRADP

where do you get the red top injectors. im not too worried about the price of injectors i just want my car to run right. if you could just give me a couple places that have the injectors that would work for what i want it to do that would be awsome

Matt@HSW

iTrader: (14)

Yeah, I don't think those stock 24 Lb fuel injectors are going to support a 125 shot. Get the A/F checked with a wideband and start off with a 25 shot, those small fuel injectors are going to limit you. If the tune is stock you don't need to pull any timing, unless you want to be on the safe side. 6-8 degrees pulled off the factory tune with the 125 shot is on the high side, on a 125 I would pull 4 at the most on the factory timing map.

Matt

BRADP

can anybody tell me where i could get some bigger injectors. do any of the forum sponsors have the injectors im looking for

transam69230

iTrader: (49)

are you running wet or dry kit? I thought if you are running a dry kit the nozzle is suppose to be before the maf, so the maf can add fuel.

BRADP

its a dry kit but i have the hsw interface so it adds the fuel so i can have the nozzle before the maf

black01_WS6

iTrader: (13)

almost any of the sponsors on here sell injectors. Racetronics sells them and also have a badass fuel pump upgrade.

just call around and see who has the best price, also you can try the classifieds as a lot of people that go FI end up needing bigger injectors and are looking to get rid of some 42 #'s for around 300.

Also I don't know what the fuel pressure is on the lt1 but you can also look at pontiac GTP injectors- they are cream colored and when used on a ls1 fuel system they almost end up flowing like 40#. They are also easy to tune, and cheap.

BRADP

thanks for all the help and i will be getting some 42's here soon and a tune.

02SOMWS6

iTrader: (6)

did you do a leakdown test? I'm very surprised you didn't burn a valve after melting 3 spark plugs. Guess you got lucky this time