My engine doesn't like NGK TR7's
 

I have a 390, etp heads, 83mm turbo, I was getting a slight misfire in light throttle applications, installed a new set of TR7's and wires and still had the misfire. Decided to pull the plugs and take a look at the color, put a set of TR7IX's and the misfire cleared up.

The misfire wasn't bad enough to show up as a afr change in the datalogg but you could hear a random pop in the exhaust.

Anyone else have problems with TR7's/BR7EF?

Seems like everyone is using BR7EFs

BR7EFs here. 383/pt88/e85/900rwhp no issues! what were they gapped to?

BR7EF's were fine on the dyno but on the track and street they misfired for me too. They were clean and the timing strap looked good but for whatever reason they didnt work under boost in "real world" conditions

gap .026

i have the br7ef's at .028 and no issues so far. i wouldnt use the ext. tip plugs besides to throw through junk car windows

Bring gap down to .020

i have mine set at .026 but I have not yet driven the car. posted a thread recently to see where other people were gapping them at.

still had the miss and the idle got rougher when I tried going to .022

I am not sure if your running any n20 or a blower/turbo etc.....but tr6's may be better for your application. I didn't see a sig

What is the AFR at during idle?

Did you drop any of them? Porcelain cracked?

Spark plug wire not tightened on the boot?

How tight are you tightening them?

Shouldn't be doing that at all. Also there is no such thing as a TR7;) BR7EF:)

Never would I run a projected tip plug in a boosted motor even though I didn't know any better a year ago. Do people do it and live through it...yes, is it right? No.

Do u wear glasses? :twak:

Autolite AR3911s should do the trick

14.40-14.6
no not dropped, had the same problem with 2 sets
I'm not sure how tight.

The reason I went with the TR7IX's is I did a search and there is some complaint of the BR7EF plugs on the supercharged cobra & lightning forums and the IX's cleared up the misfire and drivability issues.

I wouldn't normally run extended tip plugs but I upped the octane with 3 gallons of 114 per tank (95 octane) and run 100% meth with conservative afr's and timing.

i ran my tr6 on my built 365 all the way up to 22psi, not saying it was right but the throttle response felt alot better off boost, gaped .026

I'll remember that, thanks for the suggestion.

Very interesting.

I run B9EFS and have no troubles.

naah. just missed the post. im guilty of skimming. This info is relevant to me if hes the Mike i am thinking of.

i just switched to bp7efs from tr6's sofar so good gapped at .028" 813rwhp on stock short block 5.3L 9.9to1 comp on vp c16 fuel.

tr6's run so much better than br7ef's for a street car is crazy

but at some point you gotta have that br7ef.

i might switch back to tr6 and keep it under 20lbs of boost.