Jump to content
HybridZ

questions on boost spike, and pop off valve.


Guest Anonymous

Recommended Posts

Guest Anonymous

I hope someone can help me with their knowledge of boosted Z motors. I have an L28turbo motor in my 240Z. I notice when I take off hard, the boost might go up to say 9psi in 1st, then in second through fifth be at 6psi. Is this because of boost spike? Is it actually set at 6 and goes above it sometimes? I have a manual boost controller, so i dont know whats its set at till i drive it.

Its strange that the boost doesnt seem to be too consistent. I have also modified my pop off valve, but I think that may also be the cause of inconsistent boost levels. Does anyone agree with that? Also does anyone know what size and thread plug I need to plug the pop off hole?

 

What is the cause of boost spike? And how do you minimize it? thanks everyone, badhobt

Link to comment
Share on other sites

Get rid of the POV, most turbo engines don't have one. I used a pipe plug which threads right in (1" or 1 1/4") but it's galvanized steel and looks crude I'm sure you could find brass. A member suggested that there is a manifold plug on the VG30ET that fits...you could check it out. DAW

Link to comment
Share on other sites

That is correct, the VG30 intake manifold has the correct plug for the Lseries manifold. Nissan sells them, so you can go to the wrecker or call and pin down the part number from Nissan.

I first tried a manual boos controller and it lasted about 1 week. I could not control the boost very well and did also get a 2 psi spike or so. I then went from a 100.00 dollar manual part to a blitz 450.00 dollar part. Big difference in curve and maintained highest boost level over the entire rpm range.

You may want to consider a better controller that will let you change settings on the fly.

Link to comment
Share on other sites

Guest Anonymous

I have the type with the spring and ball. So you guys think that the boost controller could cause the inconsistency huh? Damn thats gonna be an expensive switch to an electronic one. thanks guys I appreciate the help. If you have any other pointers Id like to hear them.

 

Also, Im looking to go with the early fuel injected manifold. What is your opinion on that? I heard that the turbo intake actually has larger runners than the stock. Have any of you gone to the older manifold? Thanks again

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...