I currently have NGK TR55s in the car. I've had them for about 10k miles.

With my heads/cam package in sig, I'm running over 11:1 compression.

Should I switch to a TR6 plug?

If so, what gap should I use?

No nitrous or other engine mods planned.

 

I would stay with the tr55's.

 

Most thing's I've read here say TR55 for N/A and TR6 for nitrous.

But.....
http://www.ngksparkplugs.com/techinf...00&country=US#

Higher Compression Ratios/Forced Induction will elevate spark plug tip and in-cylinder temperatures

Compression can be increased by performing any one of the following modifications:

a) reducing combustion chamber volume (i.e.: domed pistons, smaller chamber heads, mill ing heads, etc.)

b) adding forced induction (Nitrous, Turbocharging or Supercharging)

c) camshaft change
As compression increases, a colder heat range plug, higher fuel octane, and careful attention to igni-tion timing and air/fuel ratios are necessary. Failure to select a colder spark plug can lead to spark plug/engine damage

 

Anyone have thoughts on this?

I can't be the first heads/cam guy to change plugs.

 

Yea, me too, I have often wondered if I needed to go 1 colder w/a h/c setup.

 

I went with TR5's. They are the same as TR55's, but come gapped smaller to begin with. See if a TR55 is gapped at .055, the spark plug electrode shouldn't be moved +/- .010. Some do it anyway but I digress. So if you want lower than .045, the Tr5 works well. I have TR5's gapped at .039, and run 11:1 compression.

BTW, this advice came from patman, so kudos go to him.

However, in reviewing my spark plugs, the white portion is light pink. Not 100% sure what that means. This quote: "Today’s pump gas may use additives that cause a discoloration of the plug core nose; they could be pink, purple, or blue. Do not consider this coloration as an indication of heat range when reading spark plugs." from here: http://www.carcraft.com/techarticles/64378/ makes me not worry too much about the color.

 

Im starting to buy a list of parts for my head swap. This is what I will have, small cam .522 216/220 dur, TEA stage 1 heads at 61cc chamber, with all the bolt ons on a stock cube motor. I was recommended this by ngk by email.

Hello,
> >
> >I would recommend the TR6IX stock no. 3689. This plug comes gapped to
.040. If you plan on opening it, go no more than to .050 and do so
carefully as it is a fine wire design center firing electrode and can be
broken.
> >
> >Jon MacQuarrie
> >Motorsports and Events Coordinator
> >Aftermarket Division
> >NGK Spark Plugs (U.S.A.), Inc.
> >46929 Magellan Drive
> >Wixom, MI 48393
> >(248) 926-6313 Direct Dial
> >(248) 705-1485 Cell
> >(248) 926-6938 Fax

 

I emailed NGk about this very question. They said for 100HP boost go one range colder. It doens't matter if the 100HP is from nitrous or high compression and a big cam. They told me to run TR6s for my head and cam car.

 

Thats good that they told us the same thing!

 

Only get a colder spark if you are planning on getting some N2O in there as well. You should stick with the TR-55's gapped around .50 or so. +/- a few either side.

 

Which is basically what I read on their website.

Kinda interesting, because it seems to be "contrary to popular belief" on this board.

Here, almost everything I've read (search feature) says to stick with the TR55s for heads/cam cars.

So, if it's true that the TR6 would be better, I'd consider that VERY helful info.

Has anyone here been using the TR6 on a heads/cam car and had a problem with them "fouling?"

 

As soon as my motor goes back together, I will be running TR6's in it. It will stay N/A h/c until it is broken in and a rearend is put under the car then it will see some spray. Until then, it will run on the same plug I plan to use for N2O.

 

i run TR6's with only 10.8-1 comp, no problems

 

Great info, thanks.

What gap should I use? .045 ok?

 

I just got off the phone with NGK and for my soon to be installed Dart 205's milled .020 (11.2-1) and F14 cam they recomended there BKR7EIX-11 (6988). How's that sound?

 

I know this thread is old but at least I used the search button.
I after reading several threads I have still to find an answer.

I have a head/Cam/intake/Exhasut car running 11:1 compression. I have both Tr5's and Tr6's.

Which plug should I run and what should I gap it to??

 

See the other thread you started on the same subject.

 

Lol, nearly 5 years.

 

I Know, I used the search button.
lol

 

I ran the TR55 plugs when I had all the bolt ons and a cam with stock heads...when I went to the high compression heads (11.5-1)and a different cam I started using the TR6 plugs...both work great and have the correct color when I pull them.