SpeedDensityZ

iTrader: (5)

Well, I am rounding up all the parts to finish out my Ai 200cc build. I need to buy some larger injectors than what I had. Last time at the dyno I made 378rwhp with my old setup and I maxed out my 30lb. Injectors and had to move the fuel pressure up to 55psi to get the air fuel down to 12.8-13.0. Hopefully with the new heads I can achieve about 50-60 more whp. What size injectors do you prefer for a often driven car and weekend warrior. I am thinking about running 37-42 pounders. What do you think?

infinitebird

iTrader: (11)

I would go with 42s.

speed_demon24

iTrader: (6)

How did you max out 30 lb injectors at 378rwhp? My highest pull was 438rwhp and my 32's are keeping up fine.

gatorhead

iTrader: (4)

He was using it on a 383, and with his past setup he had a duty cycle rating of near 94% and that was with the SVO'S so my suggestion would be to go with the 46 lbs. It has to be tuned anyways and if you plan on Juicing it, and I know you are then you won't be upset.

Demon I can understand how you are scratchin your head over that but you have to keep in mind that maybe his parts aren't as efficient as yours. Many variables play a role in that as you well know.

gatorhead

iTrader: (4)

Here ya go Justin!

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

TravisA

iTrader: (4)

Are you still running the stock pump?

SpeedDensityZ

iTrader: (5)

No, I am running a 255 in the tank and an Aeromotive fuel pressure regulator. I dunno why they were maxed out. I have seen alot of high hp numbers with these injectors. I just wanted to know what size injectors people were using with around 430-450whp.

96capricemgr

iTrader: (1)

I know a guy with a 480rwhp car through an unlocked automatic that is using 30lbs SVOs, they go over 100% DC but still keep it fueled and he does not have the pressure jacked.

Do you have a hotwire kit on the fuel pump?

95ZRagtop6M

I went from 30lb SVO (90+ DC, 18.5ms in hot weather) to 42lb Lucas. I did so to prepare it for a 100hp dry shot. Interestingly, the Lucas' seem to make the car run smoother and a bit cleaner at low rpms.

SS MPSTR

iTrader: (1)

If you're going to buy injectors, get the Lucas 42# units - plenty of room left in them. Do yourself a favor and get them matched.

Houdini

iTrader: (2)

When I did my H/C, I left the stock injectors in and made 389 rwhp. Two years later I installed KooK's 1-7/8" headers, 3" dual cut-outs before the cats, a Street Twin clutch with the heavy steel flywheel (prior clutch setup had light weight aluminum) and 42lb Racetronix injectors.

After the tune I made 401 rwhp and the idle is now better than it ever was. I would suggest the 42's to anyone, zero idle issues and plenty of room to grow.

gatorhead

iTrader: (4)

Using the worksheet from the site above I entered 525hp at the crank, which would give you the ballpark that you are looking for. That came out to be 41.25. If you spray that will be at the limits so that is why I suggested the 46 lbs. Now keep in mind some brands flow higher than advertised, you need to find out the advertised flow rate and at what fuel presure they are advertised to run that at. Then choose accordingly.

KY95Z28

iTrader: (6)

I used racetronix 37lb injectors for my 355/AI 200cc build. I made 429 and was only using like 60% of my injectors. I am still using the stock pump.

SpeedDensityZ

iTrader: (5)

What I bought was a Granantelli fuel pump kit. From what I can remember it came with all the stuff to install it and a harness I unplugged from the car and plugged right in to the new pump. Kinda like a plug and play gig.

SpeedDensityZ

iTrader: (5)

I have been looking at the Racetronix fuel injectors. These are the ones I am considering going with. It should give me all the injector I need plus room to grow(hopefully). I do use a 150 NX wet kit and I use it often.

Info ---> http://www.racetronix.com/621031FM.html

96capricemgr

iTrader: (1)

Pretty much all the intank 255lph pumps are Walbro. Had you bought from Racwetronix you would have gotten a slightly better kit and basically the same pump witghout giving such a bad company money.
I am betting the harness you are refering too was a 6" little fine wire thing that goes in the tank. I am refering too a relay harness that gets power from the alternator and runs a larger gauge wire(maybe 10) to the back of the car to get proper voltage to the pump.

SpeedDensityZ

iTrader: (5)

Am I having a problem with the pump though. The car at WOT is pegged at 55psi. and it never drops. It seems like the pump is keeping up just fine.