ok so i just got my 1jSC back from the dyno today, and the results are troubling.
Set Up- 1jzgte, brand new E-Bay GT-35r, 440cc, new Walbro 255, boost cut defender, SAFC II, zetronics wide band.
Dyno results 282hp, 235tq @12lbs.


the tuner said any thing past 12lb it would just run out of fuel, i koow ther is no way, i know of a few people with basically the same set up running 17lb on 440's no problem


What do yall think could be the problem? the only thing i could think of is maybe the fuel filter is not flowing properly???
when should i start thinking about a after market Fuel Pressure Regulator?


I'm going to double verify the Walbro tomorrow to make sure it is the right one. but i got it From lextreme so i assumed it was the right one.

 

Supra Forms said 12v MOD??? i think that could be the problem.

 

I would give the 12v mod a try. I just did this today and it was really easy, took 30 mins. I cant really mash on it cause I have a slipping clutch issue but I havent sputtered like before at WOT.

 

did you just soder the wires together or did you do the 8gauge from the battery with a relay?

 

If the fuel pump mod doesn't work for you let me know. I have a set of cleaned and flowed 680cc injectors FS on eBay right now. I used for less than 200 miles in my '84' turbo Supra.

eBay: 130589662717

 

Soldered the wires. I was bored at work, eventually I will do it right when I get a relay and some time to mess with it .

 

Something is not right 440cc injectors will support more than 300 whp. What is your air fuel ratio and what type of fuel are you runing. I know a few guys that have done low 400s on 440cc injectors.

 

I use to have a couple of turbo Regals with Walbro FPs. The Buick guys always hot wire them. I'm assuming that is the same thing or similar as the 12V mod being mentioned. It definitely wouldn't hurt to give it a try.

 

That's probably what it is.

Walbro's run great with a solid 14v, but flow less then great at lower voltages and higher pressures over 90psi.

 

12volt fuel mod is not the correct way to ensure consistent voltage to pump.. hardwire to battery however at your power levels this should not be a issue .. i always recc to my customers eliminate the stock oem filter and use a inline filter with a 40 micron steel mesh filter ...i also would use a aftermarket fpr with gauge to moniter fuel pressure on the dyno .. also did you flow test and clean inj prior to install

 

God, will you use like, at least one period? Your post's make my eyes bleed.

So tell me why removing the FP ECU, and hardwiring the 12v wire that comes off the main 12v+REL eliminating the "Variable Voltage control" is NOT the correct way?

That is hardwiring it. What you are suggesting is "Doing it again" for no good reason. Why?

 

read read .. thats all nuff said.. you want 13 volts not 12 .. pumps work best with better voltage period .. line size feeding from oem is less then desirable and does will create unwanted resistance ..they were never designed with elevated and sustained voltage requirements

btw if my posts irritate you reading them , then ignore them and stop being annoying.. this is not grammer school

 

yes i agree the 12v mod seems like the easy way out. Do you have a rite up for doing it properly, hard wiring it to the battery. i know there is a relay involed i just need to know the correct way to wire up the relay

yes i did have the 440's sent off and flow tested and cleaned. came back good as new flowing 440 across the board.

 

12V mod will help, but Lexforlife is right you will get better voltage by running your own line instead of using the oem line. this has been discussed before, its not much more but every little bit helps.
Alot of us just have the 12v mod done with walboros and have no issues at much higher hp levels, so OP try that first.

 

ok

ill do a quick writeup later as im in the middle of a is300 turbo build for a customer right now so if you can hang tight until alittle later and ill tell you what color wire to splice into to tap fuel pump ecu as trigger wire to activate relay being used