Whats the correct way to adjust the FPSS?
Thread Starter
Joined: Apr 2007
Posts: 9,711
Likes: 999
From: Evansville,IN
Whats the correct way to adjust the FPSS? I know a lot of people don't like these. Some people, including sponsors, say its because most people don't adjust them correctly. I asked HSW what the right way was and they said read the instructions that come with it. I wasn't real happy with that answer, it actually pissed me off. Other than that their tech support has been great.
This is what the instructions say;
Turn the bottle off, disconnect nitrous line, unhook the fuel line the solenoid. Have someone hold the line into a bucket.
Bring the engine RPM within the window switch range.
Activate the system.
Turn the adjustment screw clockwise, which raises the cutout off psi, until the engine starts to pulsate.
Back off 3/4 turn
How does this tell you what PSI the cutoff switch is set at? It doesn't mention anything about a gauge to read fuel pressure or anything.
Am I missing something here? Am I over complicating things?
This is what the instructions say;
Turn the bottle off, disconnect nitrous line, unhook the fuel line the solenoid. Have someone hold the line into a bucket.
Bring the engine RPM within the window switch range.
Activate the system.
Turn the adjustment screw clockwise, which raises the cutout off psi, until the engine starts to pulsate.
Back off 3/4 turn
How does this tell you what PSI the cutoff switch is set at? It doesn't mention anything about a gauge to read fuel pressure or anything.
Am I missing something here? Am I over complicating things?
I know a lot of people don't like these. Some people, including sponsors, say its because most people don't adjust them correctly. I asked HSW what the right way was and they said read the instructions that come with it. I wasn't real happy with that answer, it actually pissed me off. Other than that their tech support has been great.
This is what the instructions say;
Turn the bottle off, disconnect nitrous line, unhook the fuel line the solenoid. Have someone hold the line into a bucket.
Bring the engine RPM within the window switch range.
Activate the system.
Turn the adjustment screw clockwise, which raises the cutout off psi, until the engine starts to pulsate.
Back off 3/4 turn
How does this tell you what PSI the cutoff switch is set at? It doesn't mention anything about a gauge to read fuel pressure or anything.
Am I missing something here? Am I over complicating things?
This is what the instructions say;
Turn the bottle off, disconnect nitrous line, unhook the fuel line the solenoid. Have someone hold the line into a bucket.
Bring the engine RPM within the window switch range.
Activate the system.
Turn the adjustment screw clockwise, which raises the cutout off psi, until the engine starts to pulsate.
Back off 3/4 turn
How does this tell you what PSI the cutoff switch is set at? It doesn't mention anything about a gauge to read fuel pressure or anything.
Am I missing something here? Am I over complicating things?
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You first find the wrench that fits it. Then you lefty loosy it till you see fuel in the hole it used to fill. Find a plug for that hole and install it. Then you drop kick the FPSS twards your most disliked neibor. It is then fully adjusted to factory spec!
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That's funny. Sounds about right though. Dump that thing in the terlet, and give her a flush.
EVERY car I have seen with one of those accursed things on it has problems with the kit coming on and off, or not working at all. I've seen a car with an A2000 pump have problems with the nitrous not working right with one of those things in there.. and the car could have ran with NO problems with an A1000 pump for the power level.
Don't bother with it, if you have a good pump, keep your filter clean in the car and aren't trying to do something stupid like put a 250 shot off the rail, you should have no problems not running one at all.
EVERY car I have seen with one of those accursed things on it has problems with the kit coming on and off, or not working at all. I've seen a car with an A2000 pump have problems with the nitrous not working right with one of those things in there.. and the car could have ran with NO problems with an A1000 pump for the power level.
Don't bother with it, if you have a good pump, keep your filter clean in the car and aren't trying to do something stupid like put a 250 shot off the rail, you should have no problems not running one at all.
Thread Starter
Joined: Apr 2007
Posts: 9,711
Likes: 999
From: Evansville,IN
Good enough for me. I have a racetronix pump and hot wire kit with new screens and filters.
That's all I had in my car with the 402 and had no issues with fuel pressure dropping. I was on a 42 fuel jet, and a set of 42 lb injectors.
One thing I did have, is the battery in the trunk, and the hotwire kit was hooked right to the master kill switch, so it was reappy close to the battery, and I had probably 1/3 of the standard length of wire running from the hotwire kit to the power source.
Not that it should make a big difference. Just don't try to do something nutty like a 250 shot off the stock fuel rails, and you should be fine.
One thing I did have, is the battery in the trunk, and the hotwire kit was hooked right to the master kill switch, so it was reappy close to the battery, and I had probably 1/3 of the standard length of wire running from the hotwire kit to the power source.
Not that it should make a big difference. Just don't try to do something nutty like a 250 shot off the stock fuel rails, and you should be fine.
could you spray a 200 off the rail?
You can spray 400 off the rail, once.
You can ask this question of 10 people and get 10 different opinions. To me, from the car's I have worked on with this type of kit you can go to about200 off the rail, and that's about as much as I would go. The fuel pressure drop to me with much more then that is putting things in a place where consistancy is a concern.
Think of it like this, the amount of fuel that has to supply a 200 shot, along with what the motor needs n/a, is probably like trying to run an forced induction setup, with the same level of power, in this instance, let's say you have a h/c setup that's making 450 to the tires and are spraying 200 hp of nitrous. That's let's say 650 rwhp worth of power.
At this point, the forced induction guys are at a BIG fuel pump, usually an external, they're on a -10 feed line, big regulator and return as well... They get away from the stock rails because they can't keep up with the demand, so to me, it won't keep up with a nitrous setup either.
Once you get to the point that you're putting 200 to a car, you're in fogger country to be safe, standalone fuel system country at a minimum..
Over 200 and the single nozzle/plate setup at the front of the intake isn't distributing as good as it can either, again making a fogger a good idea as well.
Sure people have put 300 to cars in this fashion (thru the intake tract and not into each runner), and will continue to do so... but is it the best way to do it, and will it keep the engine happy for the longest possible time? Probably not.
You can ask this question of 10 people and get 10 different opinions. To me, from the car's I have worked on with this type of kit you can go to about200 off the rail, and that's about as much as I would go. The fuel pressure drop to me with much more then that is putting things in a place where consistancy is a concern.
Think of it like this, the amount of fuel that has to supply a 200 shot, along with what the motor needs n/a, is probably like trying to run an forced induction setup, with the same level of power, in this instance, let's say you have a h/c setup that's making 450 to the tires and are spraying 200 hp of nitrous. That's let's say 650 rwhp worth of power.
At this point, the forced induction guys are at a BIG fuel pump, usually an external, they're on a -10 feed line, big regulator and return as well... They get away from the stock rails because they can't keep up with the demand, so to me, it won't keep up with a nitrous setup either.
Once you get to the point that you're putting 200 to a car, you're in fogger country to be safe, standalone fuel system country at a minimum..
Over 200 and the single nozzle/plate setup at the front of the intake isn't distributing as good as it can either, again making a fogger a good idea as well.
Sure people have put 300 to cars in this fashion (thru the intake tract and not into each runner), and will continue to do so... but is it the best way to do it, and will it keep the engine happy for the longest possible time? Probably not.
I had a fuel pressure gauge on the rail.. I just primed the car, let the fuel pressure bleed down. You can use the volt meter for the continuity test. When it stops beeping/buzzing see what your fuel pressure is and adjust accordingly.. I had mine set at 10psi below the ~59psi stock setting is..
