NOS and Spark plugs?

Scrapla · 08-12-2003, 06:30 PM

In my 347 Im gonna use the NOS 5115 kit, 150hp whats a good plug to use, how much colder should I go anyone have a part#, how often do I have to change my fuel filter cause I hear thats very important with NOS that you change it frequent, andwith the colder plugs can I just use them all the time or should I only use them when I plan on sprayin and is there any power loss with them?

08-12-2003, 06:59 PM

You should be running spark plugs that are 2 steps colder than stock. I currently run NGK right now, but have ran Autolites in the past. Both have done me right. Sorry can't remember the part#s. As for the fuel filter, I don't change mine much different than I did even before the nitrous. But I had one clog up on me and was making my motor stall under 2,000 rpms. So ever since that episode I change my fuel filter about every 5,000 miles. Given, I don't drive my car a lot either...just on weekends really. What year of Mustang is the kit going in? Have you replaced the stock fuel pump? Is it really big enough for a 150 shot? I run a 155lph in the tank but had to step up to an additional MSD 200gph inline pump also...to compensate for the increase of nitrous going into the motor. You have to make sure your fuel system is pushing enough fuel volume. Do you have an aftermarket ignition? I didn't see it listed in your sig. You should get one when running nitrous. I talked to NOS tech...and with my Crane HI-6 ignition & PS91 coil they said you don't have to close the spark plug gap down to .035. Stock is .054, they said that gapping the plugs at .050 would be fine...especially if you have an aftermarket ignition system to help burn up all that fuel and nitrous the motor is taking in. So there is no need to swap out/in plugs when going to the track. Just gap the colder plugs at .050 and be done with it. I haven't noticed any loss in power from that minute of a difference in gapping.

Scrapla · 08-12-2003, 11:02 PM

I have a 90gt, I have a new stock fuel pump with plans on 24# injectors and an inline fuel pump, I also have the ps91 coil and was gonna get the crane ignition anyway.

08-13-2003, 01:49 PM

Sounds like you'll be fine with the inline pump. You still may want to stick a bigger pump in the tank too....but that's just my opinion. The Hobbs fuel pressure safety switch will shut off the flow of nitrous into the motor if there isn't adequate fuel pressure & volume...so you'll know if the inline pump is pushing enough or not. Which inline pump were you going to go with? How much does it flow? I don't think you don't need the 24lb. injectors though. Were you going to get those because of the nitrous? Unless you have aftermarket, better flowing cylinder heads, bigger cam & better flowing manifold...you don't need 24lb. injectors. From looking at your sig. it looks like you are still running the stock heads, cam & intake, right? If that's the case...the 19lbers will be plenty.

Scrapla · 08-13-2003, 05:41 PM

I was looking at the BBK inline which claims to flow over 50gph and over 310lbs at 70psi for about $239, The 347 will be gettin trick flow ported upper and lower intake and also ported gt 40 heads with 1.6rr's and the cam is a custom grind from the maching shop assembling my motor.

08-13-2003, 07:43 PM

Sweet! Sounds like a good combo you got going. Duh, I must have forgot that in the first post you mentioned the 347.

That pump should be sufficient...but I'd double check though and call up NOS tech., describe the fuel pump to them and that you have the stocker still in the tank and they'll be able to tell you for sure if you are ok. Because the dry nitrous kit boosts the fuel pressure up to 80psi. when the nitrous is going into the motor. Good luck.

08-12-2003, 06:30 PM	#1
Scrapla Registered Member Join Date: Apr 2002 Location: Florida Posts: 532	NOS and Spark plugs? In my 347 Im gonna use the NOS 5115 kit, 150hp whats a good plug to use, how much colder should I go anyone have a part#, how often do I have to change my fuel filter cause I hear thats very important with NOS that you change it frequent, andwith the colder plugs can I just use them all the time or should I only use them when I plan on sprayin and is there any power loss with them? __________________ 90gt 347 and some bolt ons :-) RICE HATERS MEMBER #73

08-12-2003, 11:02 PM	#3
Scrapla Registered Member Join Date: Apr 2002 Location: Florida Posts: 532	I have a 90gt, I have a new stock fuel pump with plans on 24# injectors and an inline fuel pump, I also have the ps91 coil and was gonna get the crane ignition anyway. __________________ 90gt 347 and some bolt ons :-) RICE HATERS MEMBER #73

08-13-2003, 01:49 PM	#4
Simi Stang Guest Posts: n/a	nitrous setup Sounds like you'll be fine with the inline pump. You still may want to stick a bigger pump in the tank too....but that's just my opinion. The Hobbs fuel pressure safety switch will shut off the flow of nitrous into the motor if there isn't adequate fuel pressure & volume...so you'll know if the inline pump is pushing enough or not. Which inline pump were you going to go with? How much does it flow? I don't think you don't need the 24lb. injectors though. Were you going to get those because of the nitrous? Unless you have aftermarket, better flowing cylinder heads, bigger cam & better flowing manifold...you don't need 24lb. injectors. From looking at your sig. it looks like you are still running the stock heads, cam & intake, right? If that's the case...the 19lbers will be plenty.

08-13-2003, 05:41 PM	#5
Scrapla Registered Member Join Date: Apr 2002 Location: Florida Posts: 532	I was looking at the BBK inline which claims to flow over 50gph and over 310lbs at 70psi for about $239, The 347 will be gettin trick flow ported upper and lower intake and also ported gt 40 heads with 1.6rr's and the cam is a custom grind from the maching shop assembling my motor. __________________ 90gt 347 and some bolt ons :-) RICE HATERS MEMBER #73

08-13-2003, 07:43 PM	#6
Simi Stang Guest Posts: n/a	nice Sweet! Sounds like a good combo you got going. Duh, I must have forgot that in the first post you mentioned the 347. That pump should be sufficient...but I'd double check though and call up NOS tech., describe the fuel pump to them and that you have the stocker still in the tank and they'll be able to tell you for sure if you are ok. Because the dry nitrous kit boosts the fuel pressure up to 80psi. when the nitrous is going into the motor. Good luck.

08-12-2003, 06:59 PM	#2
Simi Stang Guest Posts: n/a	You should be running spark plugs that are 2 steps colder than stock. I currently run NGK right now, but have ran Autolites in the past. Both have done me right. Sorry can't remember the part#s. As for the fuel filter, I don't change mine much different than I did even before the nitrous. But I had one clog up on me and was making my motor stall under 2,000 rpms. So ever since that episode I change my fuel filter about every 5,000 miles. Given, I don't drive my car a lot either...just on weekends really. What year of Mustang is the kit going in? Have you replaced the stock fuel pump? Is it really big enough for a 150 shot? I run a 155lph in the tank but had to step up to an additional MSD 200gph inline pump also...to compensate for the increase of nitrous going into the motor. You have to make sure your fuel system is pushing enough fuel volume. Do you have an aftermarket ignition? I didn't see it listed in your sig. You should get one when running nitrous. I talked to NOS tech...and with my Crane HI-6 ignition & PS91 coil they said you don't have to close the spark plug gap down to .035. Stock is .054, they said that gapping the plugs at .050 would be fine...especially if you have an aftermarket ignition system to help burn up all that fuel and nitrous the motor is taking in. So there is no need to swap out/in plugs when going to the track. Just gap the colder plugs at .050 and be done with it. I haven't noticed any loss in power from that minute of a difference in gapping.