Progress Thread Progress Thread- From6to8's 1994 Cobra Supercharger install

from6to8 · Mar 8, 2026

Noobz347 said:
Ok... That does seem to be as it should be.

I just didn't want you teeing off a quarter inch line to two components at the same time. You're going right to the source which should be totally fine.

Yes it seems from researching even before and everything that it was viable. I did put a clamp on it and so it's it's very tight and secure so if that was a little slight vacuum leak which I doubt, then next time I drive it I will see if that makes a difference. But it's crazy how it still doesn't make any sense why I would see 32 33 fuel pressure initially when I start the car cold and then as I drive it and get back in the yard pull it in the garage I saw 22. I'm going to call the tuner in the morning

Noobz347 · Mar 8, 2026

from6to8 said:
But it's crazy how it still doesn't make any sense why I would see 32 33 fuel pressure initially when I start the car cold and then as I drive it and get back in the yard pull it in the garage I saw 22.

Your idle is higher before the engine gets warm. The engine should be heat-soaked when you set the FPR.

from6to8 · Mar 8, 2026

Noobz347 said:
Your idle is higher before the engine gets warm. The engine should be heat-soaked when you set the FPR.

I don't get what you are saying, I did not actually touch the fuel pressure today as initially I was going to do. When I checked it and saw that it was 32 to 33 upon startup that's when I just took the car for a drive and came back. I didn't mess with adjusting the fuel pressure again because I saw that it was that high initially when I started the car and even as it warmed up about a good 7 to 10 minutes before I took off it was still 32 33. So after driving the car and getting back and it being at 22 that's why I'm curious to know is that normal.

Not sure rather me adjusting the fuel pressure higher than 33 which with the vacuum line on anyway normal is what 35 to 36 and then 38 to 40 with the vacuum line off correct?

Noobz347 · Mar 8, 2026

On a side note and not that there is anything wrong with your FPR:

Try an OEM non-adjustable FPR. This is fix a lot of the guessing games. Once this is done, monitor/observe your fuel pressure behavior over a couple of days.

Also: While idling and with a heat-soaked engine, note your FP. Then turn everything on. Headlights, radio, full fan and A/C. Let me know if your fuel pressure fluctuates and the electrical load increases.

Also: Check your PMs.

from6to8 · Mar 8, 2026

Noobz347 said:
On a side note and not that there is anything wrong with your FPR:

Try an OEM non-adjustable FPR. This is fix a lot of the guessing games. Once this is done, monitor/observe your fuel pressure behavior over a couple of days.

Also: While idling and with a heat-soaked engine, note your FP. Then turn everything on. Headlights, radio, full fan and A/C. Let me know if your fuel pressure fluctuates and the electrical load increases.

Also: Check your PMs.

Pm's?

Noobz347 · Mar 8, 2026

Private Messages

from6to8 · Mar 9, 2026

Noobz347 said:
On a side note and not that there is anything wrong with your FPR:

Try an OEM non-adjustable FPR. This is fix a lot of the guessing games. Once this is done, monitor/observe your fuel pressure behavior over a couple of days.

Also: While idling and with a heat-soaked engine, note your FP. Then turn everything on. Headlights, radio, full fan and A/C. Let me know if your fuel pressure fluctuates and the electrical load increases.

Also: Check your PMs.

I looked back at after I installed the glow shift fuel pressure gauge before the supercharger install I looked at what the fuel pressure was and it was 30 PSI cruising. So this is what I after doing a little more research earlier this is what I came up on and this one post that I found somewhere it might have been the corral but something along the lines of seeing a certain fuel pressure and having a negative vacuum it's something about since you have that negative vacuum you're going to see a lower fuel pressure and a tuner might have it set that way. I'm going to screenshot some things I saw earlier when I asked a question to Google AI but I'm going to verify when I call the tuner tomorrow. Maybe this is really I was supposed to be so in essence seeing 22 when I pulled in the yard in the garage after driving around some today if I was instead of negative 11 on the vacuum if it was around -18 then that's the difference between it being at 30 with a negative 11. So a 22 with a negative 18 vacuum filling in the yard or pulling in the garage and stopping might be correct.

from6to8 · Mar 9, 2026

Noobz347 said:
On a side note and not that there is anything wrong with your FPR:

Try an OEM non-adjustable FPR. This is fix a lot of the guessing games. Once this is done, monitor/observe your fuel pressure behavior over a couple of days.

Also: While idling and with a heat-soaked engine, note your FP. Then turn everything on. Headlights, radio, full fan and A/C. Let me know if your fuel pressure fluctuates and the electrical load increases.

Also: Check your PMs.

Another update lol. I got to thinking last night of anything that I might have done since I brought the car back home from the tuner. So when I installed the glowshift Fp and dual wideband, I mocked the wiring in case I needed to make any changes before tying the wires in permanent. I had the +12v wire for both gauges tied together at first and wanted to try them seperate as glowshift said since the dual gauge needs more of a consistent voltage or something of that nature, putting the wires on separate fuses might be needed. I wasn't sure I needed to but I did so anyway so I put the Fp gauge wire on the 10A low oil module, low coolant, cluster warning, chime fuse but I did it old school and just wrapped the wire around the fuse terminal ( the correct side by the way) since it was only temporary. I thought about that last night as I layed down to sleep and was like let me try that before I call the tuner. Well went home this morning from work on a quick break and put that wire back on with the other gauge which has a fuse tap and fired the car up. Back to reading 36 with the vacuum line on and so I felt much better and relieved...........

Now I will drive the car more than likely Friday or Saturday or even Sunday as I'll be off and should get to be my first good day to take her on a nice long drive around an hour one way and just have fun. Gives me a chance to observe things and she how she does and if all goes well I can start buttoning up the wires. Once I can call this a great success and that everything is pretty much settled, I will start a thread for my 95 331 build that's finally more underway. The builder will call get back with me in a few days or so to give me part numbers for pistons and rods.

gkomo · Mar 9, 2026

Hopefully this was all just faulty readings due to the electrical stuff. Do you have a photo of the whole car all this is about? I get confused on which cars you have and are talking about sometimes.

from6to8 · Mar 9, 2026

gkomo said:
Hopefully this was all just faulty readings due to the electrical stuff. Do you have a photo of the whole car all this is about? I get confused on which cars you have and are talking about sometimes.

Yes indeedy man hopefully that's it and yes I will attach a few

gkomo · Mar 9, 2026

Super nice Cobra! What wheels are those? They look like Kansei but I can't tell.

from6to8 · Mar 9, 2026

gkomo said:
Super nice Cobra! What wheels are those? They look like Kansei but I can't tell.

preciate it man and forgestar f14

from6to8 · Mar 14, 2026

Well something's still going on with the fuel pressure. I googled some things earlier and it took me to a thread and I'm just copying and pasting my reply there even though it's an old thread on the corral.

Google brought me to this because I am having something going on with my fuel system after vortec installed and 255 pump. Had an adjustable pressure regulator on the car for over 10-15 years and I put the OEM One on to see if that was it but still no difference fuel pressure now reading after I put the OEM One on it's reading 25 at startup. The crazy thing is like I drove the car today for about a 30 minute trip got on it pretty decently a little bit but not the whole trip. Pulled up in my mom's cul-de-sac and fuel pressure was around 19. Stayed there for a few hours went to the car to start it up in fuel pressure was still showing around 19. Something is off I'm going to probably just put the adjustable pressure regulator back on and adjust the fuel pressure but it's still crazy why it actually started out yesterday when I started driving the car it was at about I want to say 28 so why would it have dropped all the way down to 19 20 and then when I started the car a few hours later it was still at 19?

I want to adjust the pressure at the regulator first just to see what it does even though the car is Dyno tuned so I want to be careful with that. But I want to just adjust the pressure up and see what happens if it holds pretty steady or what

Noobz347 · Mar 14, 2026

What smog and EGR hoses and devices do you have left?

I'm starting to think, that there's something [opening up] when the car gets warm and goes into closed loop. Whatever that thing is, is taking a portion of your vacuum.

How does your idle sound and feel at cold start vs. when it's fully warm?

It may be time to install a vacuum gauge in the car to help pinpoint when this change is occurring.

from6to8 · Mar 14, 2026

Noobz347 said:
What smog and EGR hoses and devices do you have left?

I'm starting to think, that there's something [opening up] when the car gets warm and goes into closed loop. Whatever that thing is, is taking a portion of your vacuum.

How does your idle sound and feel at cold start vs. when it's fully warm?

It may be time to install a vacuum gauge in the car to help pinpoint when this change is occurring.

No smog or EGR on the car.

I can diagnose the difference in the idle tomorrow but off the top of my head I believe they sound about the same but I would like to make sure for certain.

I actually have a dual wide band vacuum boost gauge. I researched what the vacuum should be on the gauge and it seems a negative vacuum is perfectly normal on the gauge and so just sitting there idling the vacuum is around I want to say negative 11 or 12

from6to8 · Mar 14, 2026

Noobz347 said:
What smog and EGR hoses and devices do you have left?

I'm starting to think, that there's something [opening up] when the car gets warm and goes into closed loop. Whatever that thing is, is taking a portion of your vacuum.

How does your idle sound and feel at cold start vs. when it's fully warm?

It may be time to install a vacuum gauge in the car to help pinpoint when this change is occurring.

Just in case you forgot as far as how the vacuums go the bypass valve from the supercharger discharge is going to the back of the upper intake and research says that should be fine.

from6to8 · Mar 14, 2026

Also what's weird is when I reported the other day that after swapping the wire from that fuse that I just had tied around the fuse and pushed in there after I tied it back in with the other gauge on the fuse tap, soon as I did that and I started the car the fuel pressure was 36 with the vacuum line on so I just shut the car off went back to work. So basically today was the first day messing with the car or even starting it since then and when I started it today I think it was at 30 so it's weird how it was at 36 that day just by swapping that wire and cold start, and today a cold start and it was at 30

gkomo · Mar 14, 2026

Is -11 or -12 decent? I feel like at idle my gauge shows -15 to -17 vacuum with my Novi. Could be totally unrelated those numbers just popped out at me.

Noobz347 · Mar 14, 2026

So... Start recording your vacuum when FP is normal and when it's not. Note the temp on the gauge too.

Also: See if you can rig up some way to reference your voltage at the fuel pump. Maybe at the FP relay under the pass seat?

Whatever that wire is you were talking about ,around the fuse... Fix that to eliminate it as a possibility.

from6to8 · Mar 14, 2026

gkomo said:
Is -11 or -12 decent? I feel like at idle my gauge shows -15 to -17 vacuum with my Novi. Could be totally unrelated those numbers just popped out at me.

mine shows -18 sometimes. I forgot if it 's at a cold start or once i start driving or what

Progress Thread Progress Thread- From6to8's 1994 Cobra Supercharger install

There's suction so I used that end O_O

Stangnet Facilities Maint Tech... Er... Janitor

There's suction so I used that end O_O

Stangnet Facilities Maint Tech... Er... Janitor

There's suction so I used that end O_O

Stangnet Facilities Maint Tech... Er... Janitor

There's suction so I used that end O_O

Attachments

There's suction so I used that end O_O

now i can hopefully expect to receive the shaft

There's suction so I used that end O_O

Attachments

now i can hopefully expect to receive the shaft

There's suction so I used that end O_O

There's suction so I used that end O_O

Stangnet Facilities Maint Tech... Er... Janitor

There's suction so I used that end O_O

There's suction so I used that end O_O

There's suction so I used that end O_O

now i can hopefully expect to receive the shaft

Stangnet Facilities Maint Tech... Er... Janitor

There's suction so I used that end O_O

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