I have some questions about it.

I have the pertty much the same setup but pieced together.
I have an 'issue' with the fuel pressure still.

I have the Pressure reducer connected to the Nitrous line, then that to the 'vacuum hose tee', and everythign connected up the way on teh diagrams, install info.

I even reduced my timing from 5 degrees to 2 degrees (Car is a pig now w/o the juice ), when I use the nitrous, the fuel pressure increases to 56psi and the car stumbles. Can't figure out what is doing it. No error codes, nothing seems bad.

I tried it at idle, with the nitrous shooting in the open air, not the engine, and when the nitrous hits, the fuel pressure goes to 56psi as usual and the engine stalls. Like it has waaay too mcuh fuel or something...

Also another question is since the nitrous regulator has been connected to the AFPR my fuel pressure has increased from the 38psi (which has been dyno tuned fo rbest HP/TRQ) to 44-45psi (same as when you adjust it with the vacuum disconnected), and I think I am running too rich. Shouldn't the vacuum from the 'vacuum tee' reduce the fuel pressure back to normal levels until the nitrous hits?

Thansk once again for all the help in advance.

 

bueler?

 

what sized shot are you running?

 

50HP

 

Im thinking you may have the vacuum T connected wrong, it installs in a odd way. Common sense dictates it should be installed one way and instead NOS wants it installed for another and with good reason, it has a very unique function.

 

When looking at the tee, the bottom 'leg' is connected to the plenum vacuum port, and one of the arms goes to the afpr, the other to the NOS regulator..

That's the right way.. right?

I also tried removing the bypass jet from the vacuum tee, and this way it seems to put a lot less pressure on the afpr, and a lot more back to the plenum, and the car doesn't stall or stumble as much this way when fuel pressure rises (forgot how high it goes), but now I got a little detonation in 3rd gear, so I'll try swapping a stock '85 vette chip in the ecm as my aftermarket PerfResources one might be putting too much advance at higher gears..

 

if what you are describing is what is seen in this picture of it installed on a ford then yes, also make sure you have these clamped like here in the picture circled in red.

where did you get this kit? used? was the guy that had it before you running a bigger shot? please let me know this could be important...

 

I bought the3 compucar kit new. Comes with 5 jets ranging from .039 to .083 jets.

I am using a .056 bypass jet in the vacuum tee, and a .046 nitrous jet, which should be an 85hp or so shot..

 

how did we go from a 5115 to a compucar?

 

We got there by you recommending to pickup the regulator and vacuum tee from a 5115 kit to use to add pressure to the AFPR.

https://www.thirdgen.org/techbb2/sho...hreadid=190739

 

are you using the jet sizes specified by the 5115?

 

NOS recommended .059 bypass jet with the .046 Nitrous jeting..
The .046 jet I just looked up is for a 95-100HP shot from NOS, so I will try to go down to my smallest jet size, which is a .036. Ths should be a 50HP or so shot..