UltraZLS1

iTrader: (13)

I have always thought that one was to use the stock heat range plug on an ls1 if no nitrous or supercharger is being used.

As of late I have been coming across some different information. One of these is a plug reference chart that says if you are running 11.1 compression one should use a colder plug. Also something about every 50 horsepower increase should designate a 1 step colder plug.

So they are saying that I should use a plug 3 steps closer than stock? wtf?

I have got some tr55's ready to go in after the swap...but now I am worried.

thanks for the input

Troy

2000slpss

iTrader: (27)

on my motor i was advised to use a tr6 by my tuner. the specs on my motorr are in the sig. im at 11.0:1 compression roughly

brad8266

iTrader: (23)

Use TR6's if you need a colder plug. They are the most common colder plug used for our motors. They work fine for a lot of power, almost everyone with big nitrous shots use them.

UltraZLS1

iTrader: (13)

Anyone else? what plug is everyone running with 11.1 compression or higher?

sickss228

iTrader: (27)

I'm running the TR-55's

daryl2cb@yahoo.com

iTrader: (2)

I would say the 55's should be fine, but the tr6's would work as well.

slow trap

iTrader: (22)

i have the tr6s with 11.7 cr.

silverTA2002

iTrader: (1)

I have about 11.3:1 compression.

I used TR55s for 6 months. Pulled them out, and they were (visually) a little too hot.

I put in TR6 plugs, and it runs perfectly.

The plug manufacturers will tell you 1 step colder for higher compression or for every 100hp over stock (no matter how you get the power).

If you're unsure, the manufacturers always tell you to err on the side of "colder."

Slightly too cold is better than slightly too hot.

UltraZLS1

iTrader: (13)

alright...I should probably get some tr6's then.

My dcr is 8.6-8.7 as well...which is not good for the hotter plug I am learning as well.

What should the tr6 plugs be gapped to on an n/a car? I did some searching and found most said around .045.

thanks again

orangeapeel

iTrader: (18)

I run the Tr6 and TR55's in my cars.