NX direct port jetting HELP
05-28-2009, 09:38 AM
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NX direct port jetting HELP Hey I purchased a NX direct port pihrana nozzle kit for my Fast 90 and it came with some Speed inc high flow rails. I am connecting it to my stock fuel line with a Walbro 255 intank and hot wire. Good price from a member i could not pass up for my future build!
I do not have a fuel pressure gauge currently on the car, I have gauge but no pillar pod yet. PSI should be like 58 PSI right?
I need to buy jets for the direct port kit, I am dyno tuning on Saturday, I want to start small at like a 150 and move up to a 200 just for tuning, 300 for the future. What jets should I run on the nitrous and fuel side. I call NX 3 times and got 3 different answers.
I looked at there site and and only one tech had the same answer for 200 N-26 F-14 jets nothing for 150 hp!
another told me 200hp N-26 F-16 and 150hp N-24 F-12
3rd said 200hp N-26 F-16 and 150hp N-24 F-16
What jet are you guys running and what should I start at to be safe. I know it is over kill system for a 150 and 200, but it is new to me and I want to start small and work up.
Thanks for you help!!! Art
I do not have a fuel pressure gauge currently on the car, I have gauge but no pillar pod yet. PSI should be like 58 PSI right?
I need to buy jets for the direct port kit, I am dyno tuning on Saturday, I want to start small at like a 150 and move up to a 200 just for tuning, 300 for the future. What jets should I run on the nitrous and fuel side. I call NX 3 times and got 3 different answers.
I looked at there site and and only one tech had the same answer for 200 N-26 F-14 jets nothing for 150 hp!
another told me 200hp N-26 F-16 and 150hp N-24 F-12
3rd said 200hp N-26 F-16 and 150hp N-24 F-16
What jet are you guys running and what should I start at to be safe. I know it is over kill system for a 150 and 200, but it is new to me and I want to start small and work up.
Thanks for you help!!! Art
05-28-2009, 09:49 AM
#2
On the 150 use a 14 jet for the fuel.
Keep in mind these are starting points for your tune up. The reason why you got two different answers were breaking the jetting on a directport into 50hp increments gets tricky. They have changed there flow jetting several times so technically either would probably work. I would start with a 14 jet though.
Looking at your mod list I can tell you you the odds are very high you are going to see a drop in fuel pressure causing a lean spike even with the fuel pump and hotwire kit.
When the solenoids open it will require a sudden burst in pressure to fill the distribution blocks and lines. What you have fuel system wise will be taxed very hard and struggle to recover. If I were you I would look into our dedicated fuel system or a dual intank set up relocating the regulater to the fuel rail. Our dedicated is much cheaper...
Dave
Keep in mind these are starting points for your tune up. The reason why you got two different answers were breaking the jetting on a directport into 50hp increments gets tricky. They have changed there flow jetting several times so technically either would probably work. I would start with a 14 jet though.
Looking at your mod list I can tell you you the odds are very high you are going to see a drop in fuel pressure causing a lean spike even with the fuel pump and hotwire kit.
When the solenoids open it will require a sudden burst in pressure to fill the distribution blocks and lines. What you have fuel system wise will be taxed very hard and struggle to recover. If I were you I would look into our dedicated fuel system or a dual intank set up relocating the regulater to the fuel rail. Our dedicated is much cheaper...
Dave
05-28-2009, 09:58 AM
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Thanks Dave,
So N20 - 24 and Fuel -14 for starters
Should I tap into the fuel line right at the connection from stock line to the -8AN line or at the cross over tube point. I do have the farthest point of the rail blocked off, or should I tap into that for the fuel solenoid?
Yeah your dedicated system will be my next purchase, if I get my bonus
And you probably think 200hp it to much for the fuel system?
So N20 - 24 and Fuel -14 for starters
Should I tap into the fuel line right at the connection from stock line to the -8AN line or at the cross over tube point. I do have the farthest point of the rail blocked off, or should I tap into that for the fuel solenoid?
Yeah your dedicated system will be my next purchase, if I get my bonus
And you probably think 200hp it to much for the fuel system?
05-28-2009, 10:04 AM
#4
No problem. I would come out of the caped off end of the fuel rail. Yes I really belive 200 will be a bit much. The 150 may give you trouble. But then again every car is different. Just put a fuel pressure gauge on the car and watch it.
Let me know if you need any advice. I am only a phone call away.
Dave
Let me know if you need any advice. I am only a phone call away.
Dave
05-28-2009, 11:59 AM
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Dave is who my NX direct port came from. I am using a Granatelli 250lph in-tank pump and an accumulator on the fuel side. I have run a 250rwhp shot on my car many times with no issues at all except it broke my 12 bolt once and my tranny. Here is the jet sizes I use.
20N 12F = 125rwhp
24N 14F = 175rwhp
26N 14F = 200rwhp
28N 16F = 240rwhp
29N 16F = 258rwhp
30N 16F = 275rwhp
31N 17F = 300rwhp
Just like Dave said, every car is different. I never took mine above the 258rwhp shot. I wasn't too worried about hurting the motor because I have a new engine that is waiting to go in. Good luck with it.
20N 12F = 125rwhp
24N 14F = 175rwhp
26N 14F = 200rwhp
28N 16F = 240rwhp
29N 16F = 258rwhp
30N 16F = 275rwhp
31N 17F = 300rwhp
Just like Dave said, every car is different. I never took mine above the 258rwhp shot. I wasn't too worried about hurting the motor because I have a new engine that is waiting to go in. Good luck with it.
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05-28-2009, 03:05 PM
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Hey I purchased a NX direct port pihrana nozzle kit for my Fast 90 and it came with some Speed inc high flow rails. I am connecting it to my stock fuel line with a Walbro 255 intank and hot wire. Good price from a member i could not pass up for my future build!
I do not have a fuel pressure gauge currently on the car, I have gauge but no pillar pod yet. PSI should be like 58 PSI right?
I need to buy jets for the direct port kit, I am dyno tuning on Saturday, I want to start small at like a 150 and move up to a 200 just for tuning, 300 for the future. What jets should I run on the nitrous and fuel side. I call NX 3 times and got 3 different answers.
I looked at there site and and only one tech had the same answer for 200 N-26 F-14 jets nothing for 150 hp!
another told me 200hp N-26 F-16 and 150hp N-24 F-12
3rd said 200hp N-26 F-16 and 150hp N-24 F-16
What jet are you guys running and what should I start at to be safe. I know it is over kill system for a 150 and 200, but it is new to me and I want to start small and work up.
Thanks for you help!!! Art
I do not have a fuel pressure gauge currently on the car, I have gauge but no pillar pod yet. PSI should be like 58 PSI right?
I need to buy jets for the direct port kit, I am dyno tuning on Saturday, I want to start small at like a 150 and move up to a 200 just for tuning, 300 for the future. What jets should I run on the nitrous and fuel side. I call NX 3 times and got 3 different answers.
I looked at there site and and only one tech had the same answer for 200 N-26 F-14 jets nothing for 150 hp!
another told me 200hp N-26 F-16 and 150hp N-24 F-12
3rd said 200hp N-26 F-16 and 150hp N-24 F-16
What jet are you guys running and what should I start at to be safe. I know it is over kill system for a 150 and 200, but it is new to me and I want to start small and work up.
Thanks for you help!!! Art
05-28-2009, 04:51 PM
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Dave is who my NX direct port came from. I am using a Granatelli 250lph in-tank pump and an accumulator on the fuel side. I have run a 250rwhp shot on my car many times with no issues at all except it broke my 12 bolt once and my tranny. Here is the jet sizes I use.
20N 12F = 125rwhp
24N 14F = 175rwhp
26N 14F = 200rwhp
28N 16F = 240rwhp
29N 16F = 258rwhp
30N 16F = 275rwhp
31N 17F = 300rwhp
Just like Dave said, every car is different. I never took mine above the 258rwhp shot. I wasn't too worried about hurting the motor because I have a new engine that is waiting to go in. Good luck with it.
20N 12F = 125rwhp
24N 14F = 175rwhp
26N 14F = 200rwhp
28N 16F = 240rwhp
29N 16F = 258rwhp
30N 16F = 275rwhp
31N 17F = 300rwhp
Just like Dave said, every car is different. I never took mine above the 258rwhp shot. I wasn't too worried about hurting the motor because I have a new engine that is waiting to go in. Good luck with it.
05-30-2009, 10:35 AM
#15
I'm sure you are already aware of this, but make absolutely sure you have good filters on the fuel side. The orifice in the jet for a high pressure fuel system on a 150 shot directport is tiny. One tiny piece of trash in the fuel jet and you have problems. Just something to think about. If you go with a standalone later you can switch to a low pressure fuel system, and use bigger fuel jets. You are doing right talking to Dave. He knows his stuff, and will lead you the right direction. I bought all the stuff to build my custom directport from Dave.
