There is nothing wrong with running the 97T in the B5. I started out running those plugs in both my Werks engines till I got the Werks #6 plugs. Which is also a medium plug like the 97T but in my opinion the #6 plug has a better tuning window, tunes easier, and great runtime.

Not intending to correct you, but a 97T is a very hot plug with a very thin element...it is nowhere near being a true medium plug like a Werk's #6...personally I think a 97T is very close to a P3 in temp range.....

the werks 5 is hotter than the od 97t. i tuned on a couple of of b5 motors with the od plug and i wasnt happy with the performance. we put a hotter plug in like the os p3,werks 5 and the motor was much more gooder.lol the same with the guys running os engines with the od plug, just a flat performance. i know how to tune and i know the engine designers know way more than i about what plug to run in their motor.

Right I was comparing the #6 plug to the 97T not the #5 plug. I've just had better luck with the 97T's and #6 plugs. Not saying thats THE only plug to run. Just my personal experience..

i know you know your stuff but thats not correct. maybe we are talking about too diff plugs. if you just put the two plugs in the ig you would see the diff right away. the 97t plug IS NOT THE SAME or even close. the werks/os motor will run with these plugs but not at their best.

yep, you run with mr clark out there?

97T is a ultra hot plug design.....I don't like them very much myself, as they have no durability in a higher compression engine.....

in stock trim, stock head shims a B5 and B6 make more HP on a cooler plug like a Werk's then they do on a hot plug like a 97T,OS P3 ..Ihave dynoed several different plugs in the engine.

Thanks good info. I didn't know that about the 97T I just went by it saying that it was a medium plug. That explains why I like the #6 plug better.

maybe you should call amain and tell them they have it wrong also. they list the od 97t as a med turbo plug and the os p3 as a ultra hot plug and the package they come in say the same, and when i light em up i can see the diff. AND they show up the track( this is a much better dyno). like i said one of us has our plugs cross threaded,lol

Neal, thanks for the info. That explains why the 97t tunes so easy and similar to the p3.

Thanks, Rex

Are you saying that O'Donnell is mislabeling the 97T plug?

http://www.odonnellracing.com/glowplugs/

Every manufacturer has their own scale of heat ranges. No common scale is used for all companies. A 97t may be close to a P3, but the 77t is way hotter than anything OS makes. Can't compare the description from company to company.

+1 and all the coils are different so its almost impossible for one manufacturer to get the same heat output from their plugs as another plug. The thinner the coil the hotter it will get and the faster it will fail

the larger the plug body is the more heat it stores..... more steel = more heat........ the thinner the coil, typically the hotter the plug........ the larger the bore the coil sits in, the hotter the plug.......... every manufacturer has a different way to rate these plugs......just like HP on engines...... by its construction a 97T is still a very hot plug..massive plug body, thin coil, wide open bore with element very exposed........... compare to a Werk's #6 (what I consider a medium plug) small plug body, heavy gauge coil, somewhat shielded coil in the bore.......... Another telltale for me is durability.... a medium plug should be safe to use in a higher compression engine, a 97T wont make more then a few tanks when you raise compression...a Werk's 6 or Picco 6 can last for well over a gallon and not break a sweat...To me a 97T is designed as hot plug to be used in lower compression engines ie. stock shimming....

keep it simple run werks plugs :) I ran o.s then switched to Werks and have had great luck with them. I did not have issue tuning on a o.s plug btw, just prefeer the werks plugs just makes sense to run the plug made for the engine :)