[XxMerlinxX]

So I've heard a lot about using different plugs when running a nitrous setup. I'm going to run a 75 shot from a Zex wet kit. I figured I'd use 1 step colder copper plugs. Now what about gapping? Should I gap them to stock specs or should I gap them less?

 

[mrtomcat]

stock specs is fine but you need 2 steps colder

 

[sean2sean]

denso ik22

 

[Liqquid]

Originally posted by sean2sean
denso ik22

I like the ngk's and the autolites.

you can keep stock specs on the gap, but .035 is always the recommended with nitrous (per manufacturers). I have used gt-s stock .044 and .035, I haven't had trouble with the stock gap, and it is the best of course when you're not spraying.

 

[XxMerlinxX]

stock specs is fine but you need 2 steps colder

I thought I'd only have to go 2 steps colder if I was running NX's 75 shot and not Zex's since Zex is at the crank and not at the wheels?

 

[mrtomcat]

they actually say even at a 50 shot you're supposed to have that.

I say better safe than sorry.

I use the NGK's btw and like them

I heard mixed results on Autolite's

 

[sean2sean]

colder it is... the safer it is...

 

[Liqquid]

generally the colder the safer... to the point that it fouls them out and won't idle,

I use 1 step colder for street and 50 shot,

2 steps colder at the track, 75 shot....

the 2 step colder hasn't givin me any trouble anyways with idling or performance, but I have actually had some trouble with the 1 step colder and 94 octane when using a 75 shot, as a result of that, I use the 2 step colder and gt 104 mixed with 94 when I run the 75 shot.

also it's a good idea to check the plugs for signs of excessive heat, so running a differant set at the track has its advantages... Gives me an excuse to check them often.

 

[XxMerlinxX]

Liqquid, are you running 75 at the crank or at the wheels?

 

[King Torq]

here is something i posted on spyderchat, regarding the 1zz (so it is applicable to the celica GT):

Spark Plug and heat range info: this may help others, took me a bit to dig it up. As most know, you want to run a copper plug with a colder heat range, so here are some part numbers to consider.

Stock heat range copper replacement from NGK would be:
BKR5es-11 and BKR5e-11 (the S is for standard, without the s is v-split on the tip i believe).

To go one step colder, change the 5 to a 6, and to go two steps colder change the 5 to a 7. Note that a colder plug may hurt eng. perf. a touch, prolly just noticable at idle...

One step colder should be sufficient up to about 45 rear wheel hp increase, while a two step should be used on bigger shots (imo). Or if you mill the head or do a piston swap/whatever to increase compression, then you would want to go colder too.

Note that the gts comes standard with the '6' heat range to help with the higher compression.

The other option is iridium, which is more efficient but runs hotter. if you were to do this you would want to go 2 steps colder b/c they run hotter, but the benifit would be they are less likely to foul out as the coppoer would. ex, stock heat range of BKR5EIX-11 and two steps colder the 5 would be a 7. note these are about 3x the price of copper, personally, i have always preferred running copper and changing them more often... but the jurry is still out on this one.

Oh, and gap is important, as stock gap is around .44, it needs to be decreased so as not to 'blow out' under the extreme added pressure, a gap from around .35 up to .40 should be feasable,.. personally im planning on 38 and take it from there.

 

[Smaay]

MY gap is .030 On the turbo cars it need to be tighter, just for all the same reasons that king torque just described...im using 2 step colder iridium plugs

 

[Liqquid]

Originally posted by XxMerlinxX
Liqquid, are you running 75 at the crank or at the wheels?

it's an nx setup so supposedly to the wheels... however dyno charts from nitrous cars show the initial "hit" of the nitrous is the only time that the shot actually equals what it is suppose to.

regardless, yes it should be to the wheels.

 

[boostjunkie26]

How is your fuel economy when not on the juice?

Do you notice more sooting of the plugs when going two ranges colder?

How often do you guys run the nitrous?

 

[Liqquid]

No buildup on the plugs, nitrous has a way of cleaning them off... making it hard to read. mostly I look for any signs of blue "tinting" to the metal, meaning it was getting too hot.... other than that I can tell if it's too rich by looking at them, but since I only run the 2 steps colder at the track, it doesn't see alot of stop n go or idling.

Fuel economy would be kinda hard to look at for that same reason, don't run them all the time.

I got to the track as much as I can afford to, and as the weather permits.... in MI that means not nearly as often as I'd like lol.

 

[boostjunkie26]

Thanks for the response, Liqquid. I'm just curious how a more "daily driven" nitroused celica would be with those colder plugs.

 

[mrtomcat]

Originally posted by boostjunkie26
Thanks for the response, Liqquid. I'm just curious how a more "daily driven" nitroused celica would be with those colder plugs.

I left them in on a daily basis when I still had the nitrous and the car drove just fine, The idle seemed a little off at times but you got used to it.
When I dynoed my car without spraying it only put out 169 whp with the colder plugs and the fastest n/a run was a 14.8.
Basically it's fine for everyday driving but not too hot for racing n/a

Now I need to have them because of the turbo.
They are holding up pretty well

 

[Liqquid]

Originally posted by mrtomcat
I left them in on a daily basis when I still had the nitrous and the car drove just fine, The idle seemed a little off at times but you got used to it.
When I dynoed my car without spraying it only put out 169 whp with the colder plugs and the fastest n/a run was a 14.8.
Basically it's fine for everyday driving but not too hot for racing n/a

Now I need to have them because of the turbo.
They are holding up pretty well

14.8 eh? me too, N/A. what a coincidance!

My suggestion would be this, 1 step colder for the street and daily driving, with a 50 shot and use the best pump gas you can find.

If you think you'll actually be able to hook up on the street with a 75 shot LOL!!! then do it this way, if you're gonna go out for a cruise one night, put in a 2 step colder plug and some 100 octane.

The race gas won't be cheap, but the smell is addictive so you won't notice after a while lol
the plugs are cheap, coppers cost about 2 bucks a plug.

do things this way and as long as you keep your mafs clean and everything else good, you shouldn't have any trouble... at least I haven't.

by the way the 50 shot is quite a bit on the street to try taking off from a stoplight with... I can't see running any higher than that when I'm out drivin around.

 

[boostjunkie26]

Thanks for the responses guys!