are they 1 or 2 steps colder? also how often are you guys changing yours out at? and what gap have you been using on your LT1! Thnx.

 

One step colder and gapped at .035 if I remember correctly.

 

They are one heat range colder than stock, and I gap mine at .030. I also change my plugs about every 10,000 miles or so. Hope this helps.
Later
Nate

------------------
'94 Trans Am A4
367 tire smokin' ponies at my command

 

Well, FWIW in terms of NGK plugs they are just 1/2 heat range colder than the stock replacement (which is a 55 heat range) as far as I remember. I know many people are using them, but I don't think they are cold enough except for a very small nitrous shot. I have a low CR motor, but I run a SC along with a 150 shot. I am using an "11" plug, which is 6 and 1/2 heat ranges colder than a "55".

Rich Krause

------------------
'95 Z-28 383: Vortech, nitrous, etc.
AIM: rstevenkrause

 

WTF, are you serious thats seems different?!?! can anyone else comment on this? the biggest shot i run is 200shot!

 

Look at NGK's web site www.ngksparkplugs.com.

Their stock replacement recommendation is the TR55VX. The number is the heat range, higher is colder. A TR6 is 0.5 heat ranges colder than a TR55. FWIW on their site is the following: With modified engines (those engines that have increased their compression) more heat is a by-product of the added power that normally comes with increased compression. In short, select one heat range colder for every 75-100 hp you add, or when you significantly raise compression. Also remember to retard the timing a little and to increase fuel enrichment and octane. These tips are critical when adding forced induction (turbos, superchargers or nitrous kits), and failure to address ALL of these areas will virtually guarantee engine damage.

Like I said, a TR6 isn't cold enough for anything other than a very small nitrous shot. But heck, they're your pistons!

Rich Krause

------------------
'95 Z-28 383: Vortech, nitrous, etc.
AIM: rstevenkrause

 

Well what plugs would you recommend for the NX 20920 kit (up to 150 shot)? Prolly won't run the 125 or 150 much if any but wanna have the right components if I do.

 

Well, like I said you need something colder than the TR6, IMHO. OTOH, there are a lot people using the TR6 sucessfully. It's just that I am conservatve when it comes to expensive engine parts! That said, I would use a plug 2 full heat ranges colder than stock and run a bit narrower gap unless you have an aftermarket ignition.

I am most familiar with the NGK plugs and don't have any of the other catalogs here at home. I think their coldest plug for a stock head is the TR6 so I can't help you with a specific plug. If no one else posts some alternatives, I can look it up for you in the next couple of days.

Rich Krause

------------------
'95 Z-28 383: Vortech, nitrous, etc.
AIM: rstevenkrause

 

What heat ranges are the Autolite 103s and 104s? Anybody know? I'm the same way as you, taking all the safety precautions imagineable. From what I just say Derrick Redd say in another post I may go with 104s.

 

I will check but it will take me a couple of days and will post if no one else has.

Rich Krause


------------------
'95 Z-28 383: Vortech, nitrous, etc.
AIM: rstevenkrause

 

Much thanks rich. You can email me at loadre@hotmail.com if you don't feel like posting a reply. Later, Brian.

 

NGK non platinum plugs that will work in LT1
TR4
TR5
TR55 stock heat range
TR6 same heat range as BPR6EFS but v-power

R5724-8 non resistor
R5724-9
R5724-10 coldest range available for stock head.



------------------
snoochie woochies