Jump to content
HybridZ

looking for info on increasing fuel psi


ZR8ED

Recommended Posts

I've been toying with ideas to increase hp, and I apparently am nearing a dead end in regards to injector capacity. Would simply increasing the fuel pressure help me at all? I'm running 12+ psi of boost with stock fuel pressure. (I have an aftermarket pressure reg)

 

I'm not really looking for a specific answer, but if someone could direct me to a website with information, I should be able to sift though it and figure something out.

 

Thanks..

 

My goal is 450hp. Easy to say, hard to acomplish.

Link to comment
Share on other sites

Hopefully the FPR you have is adjustable. Increasing the pressure will increase the injector flow to correct a lean condition or allow a little more boost. Although the increase will not be tremendous, you also want to make sure the pump can handle the increased flow demand. Regardless of what pump you running, you want to "hard-wire" it by running a 10-gauge wire from the alt to the pump through a relay. Run a 10-gauge ground from the pump to the battery, then use the original pump hot lead to trigger the relay. I would be willing to bet you are probably getting 11+V at the pump at full boost with the original hot lead. Not good.

 

In order to know the result from increasing the fuel pressure, you need to know the injector flow rate and the rated pressure. Divide the new pressure by the old pressure. Find the square root of this number and multiply it by the flow rate. E.g., if the injectors you have flow 300cc @ 36# and you increase the FP to 42#, the injs will then flow 324cc. That should allow you to run another 20+hp. Understand though that the increased flow is across the board and so you will have it at idle also. Might not impact idle that much but you should expect it to idle a little richer. This is where a programmable system shines.

 

Remember to adjust the FPR at idle with the vacuum line off and capped (for a normal idle). This simulates 0 MAP so do not be surprised when you see the FP drop when you replace the vacuum line.

Link to comment
Share on other sites

  • 2 weeks later...

Thanks guys for the info.

 

I have all new fuel hardware. 125psi 70 gph++ pump. pressure reg with vacuum etc..

 

I am just trying to squeak out a bit more power.. it seems I one summer..heck not even the summer..I have almost maxed out my motor. I can tweek some more, but I'm on the cusp of needing larger turbo and injectors.

 

funny though I swore all summer that the car ned not be faster than it was...just more driveable...hehehe the stock boost didn't last more than a week or two... I've tried as much as 15psi, but have settled into 13psi..my I/C is still sitting here in a box waiting to be installed...

 

I have been waiting for 4 months on a special oil cooler, as my stock one is right in the path of my I/C.

 

But that is all to change. My oil cooler has arrived this week. Now all I have to do is wait for an opening in the shop and redo the oil cooler setup..starting at the block. THEN I can start installing the I/C. THEN I can start cranking up the boost some more, THEN I will run out of fuel, and need new injectors...THEN I can turn the boost up some more..THEN I will need a new turbo to handle more boost..THEN THEN THEN..aaaahhhhhhhhhhhhhhhhh

 

Where will it end?

 

Boost junkie bonk.gif

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...