wrd1972

iTrader: (12)

Looking at the strap on the plug, the transition change is closer to the 1/3 point towards the threaded base. From what I have gathered, this is tad too hot and this was using the TR6 which is one point cooler than the TR5.

Am I wrong here?

kinglt-1

iTrader: (26)

If your not running nitrous a tr55 is what plug should be in the car imo. I though most guys ran tr6's on FI setups or small shots?? I do not see how a tr6 is too hot for your setup... Again I ran a tr55 in my 383 and the plugs looked great, maybe your running to lean?

wrd1972

iTrader: (12)

Just got off the phone with Chris & Ray at nitrous outlet and had a good conversation. He thinks the best plug and gap is TR6 gapped at .035".

He is doubtful that anything different than the above is really needed. He also explained to me to take some new plugs to the dyno and install a couple prior to the run to get the real visual data in order to make a good determination. I can take a few TR55 also to test too.

Thanks for the help guys.

djjab57

iTrader: (17)

I forgot to mention you can call them anytime as they can be very helpful. Very nice guys over there

mdacton

iTrader: (3)

you are very wrong the ground strap discoleration is showing you the timing curve...... has nothing to do with the heat range.

The wrong plug may cost you nothing but it could be as much as 30hp or more.

I tuned a car where we found almost 45rwhp from going one step up on the plug and 1 degree more timing. car picked up almost 3 tenths also, ran better everywhere.

Fine tuning is where you can set yourself apart from the crowd

Wicked94Z

iTrader: (26)

I always ran a 103 at .040 when i was H/C and stock compression, napa always stocked them locally, i think vatozone did as well. mdacton, i think he's making enough power and compression to warrant going 1 step colder on a plug, and in my experience it won't cost him ANY power. I do agree he needs to do more reading on yellow bullet on how to read a plug

mdacton

iTrader: (3)

a cold plug with a cut back strap does not get hot enough to clean it self, I wouldnt run it on the street.

In his car I would just use a 106 autolite. he isnt a racer or anything. so thats what I would do.....


I have dynoed all these plugs....and there is something to be had from finding the correct plug for your combination and too cold is the easiest way to kill power very very fast

SS RRR

iTrader: (2)

Just to add some spark to the fuel to create a fire.

http://forums.bimmerforums.com/forum....php?t=1282968

http://racingsecrets.com/spark_plug_reading.shtml

Wicked94Z

iTrader: (26)

i dont think a 6 heat range plug is cold enough to cause fouling problems in a street driven application running 11:1 compression especially an extended tip plug. hell im running a r5671a-8 on the street, it runs decent when cold, even on e85. i guess we'll agree that his motor will decide what it likes

wrd1972

iTrader: (12)

Excellent information.
Thank you.

It seems from research that its a mixed bag with some saying TR55 and some saying TR6. The only way to know for sure is the dyno. Depending on how things go on tuning day will determine if I can actually run both and see.