Turbo question
 

So I have a hx40 in my 1991 w250 it's non ic but has the banks ic kit and stock injectors fuel pin and 32gov spring and afc tuned and pumped tweaked, I can only build 20 psi with the hx40, this isn't normal is it? My buddy ran the same turbo in his 93 d250 5 speed with 100hp pods now I don't know if this is true but I read that pods were 4x14 and stock non ic injectors are 4x12, I guess what I'm asking is do i need more fuel to light this 40?? Help? Thanks in advance

~Duck

Anyone have any advice??

Most likely yes, the hx40 is known to be a slow spooler. A 351cw has the same comp wheel as a super 40 and smaller housing for faster spool if your looking for something better.

I forgot to add when my buddy ran this turbo in his 93 d250 5 speed with pods he would make a bunch of boost, he said he would pat the throttle and his boost gague would jump like a tach, now the only difference I see is his 4x14 compared to my 4x12 I guess .02 in the injectors makes a big difference then huh? Thank you for your reply

He gave me this hx40 and now he's gonna run a hx60 on his firsty

What are you running for exhaust?

4" turbo back to 6" stack

I ran that same set up and if i remember i made right at 40psi you may want to check for a boost leak also check that the fuel pin that rides on the fuel cone is not stuck also fuel pressure

Pump tune will make a huge difference too. What pump tweaks do you have? Fuel pressure?

The power screw has been turned i have a Denny fuel pin 3200 gov spring and the afc turned a bit, I was thinking I have to have a leak somewhere, I need to put a fuel pressure gague in, thanks you all your guys advice

I have no boost leaks, I've checked my afc diaphram, took out the pos Denny t pin cuz I didnt noticed it would get stuck put in my stock grounded pin, ran it and it felt like it pulled harder but I only peaked at 15 psi boost, my egts at wot where only 9-10 I have to just be plum outta fuel? Any ideas?

Could I just have a up boost gague?

I installed a brand new Super HX40 a week and a half ago. Has a 16 WG housing. It's on a 1990 W250. Minus fuel screw, intake, exhaust, and an intercooler kit, it's fueled stock. With the h1c I made 30 psi boost at 1400 + pyro. I say plus as I would let off as I do not want my pistons seeing those temps. I know it was higher but I don't know how high. Then I swapped to a HX35 with h1c snail and got 33 psi peak boost at 1300 pyro peak. I also ran that setup for a few years.

Now the 40 went on and I started making 21 psi peak. After some discussions with a relative, he reminded me that I am now wastegated.

I disconnected the WG line and went for a test drive. 35 psi.

My point of all this is, is we are a similar setup.

My questions for you are:

1- is yours wastegated? If so has the actuator been removed from the turbo between your using it and your buddy? Sounds like it is blowing off early like mine is.

2- is yours a 40 or super 40?

3- what size snail do you have?

4- what was your boost prior to change?



I don't believe you are running out of fuel. At my HX35 level (two weeks ago), that setup runs at min 4 psi fuel psi at wot. I am putting down 278/720 at wheels on dyno with that set up at 33 psi.

These trucks are just like lighting a cutting torch. With just a little fuel and air your torch barely blows. Add fuel and your torch smokes add air to clean up the smoke but your torch gets hotter. The more fuel the more air you need. Boost comes with more cyl pressure which comes with more fuel, you can lose boost with leaks or being down on fuel. Its a game between fuel/air just as a torch, you add too much air you blow the flame out, too much fuel you smoke alot. Stock injectors are somewhat smaller than pods im relatively sure. Like said above check your wastegate, recheck for air leaks, you may not find the leak at idle. Just remember fuel and air make power to a point of melt down. The DennyT pin shouldnt be a problem it should be a power maker, maybe some more tuning on the AFC. Good luck with your truck.

You need a fuel pressure gauge to know if the IP is not getting enough fuel. I could suck mine down to 0psi with stock intercooled injectors and stock lift pump.