I have and 02 mustang gt and on the dyno n/a I made 260rwhp. When I got it tuned for nitrous the tuner said I lost 20rwhp which put me at 240. He did tell me that he took spark out or made spark adjustment for the new spark plugs but 20rwhp seems steep to me. It was tuned for a 75 shot zex wet kit with one heat range colder plugs (autolite 103). There was no timing taken out cause zex required no retarding at that shot. Has anyone else experienced that much of a loss?

 

20 hp is about right. He probably pulled 3 - 4 degrees of timing and may have even richened it up.

Thsi is why when you run nitrous you need to have multiple tunes....I recomend an SCT switch chip so you can change tune son the fly. No sense in loosing hp when running n/a.

 

Arent you supposed to go 2 ranges colder with NOS? i know its 1 range colder from stock on a N/A, but i think its 2 colder on NOS. Read up on the spark plug sticky, it talks about the plugs with NOS in there.

 

No you use stock heat with out a power adder. I know some will argue you should, but you should run the hottest plug you can without detonation for best N/A performance. Hence why stock heat rang is good for n/a cars. 1 step colder plugs should be used when you have "Nitrous" up to a 125shot. With 150-200shots i would use a 2 step colder plugs and 200-250shots i would use 3 step colder plugs.

 

Oh ok, thanks for the clear up.

 

Spike, I dissagree. You should run the coldest plug possible w/o fouling. That will get you the best performance and fuel economy. The added heat is just for emissions.

 

get a flip switch....

 

Running a colder plug will make for more carbon and less complete burn you want the hottest possible without pre-igniting the fuel.