Tuning by checking plugs
 

I've heard of this method a few times but no one ever wants to elaborate on how its done. I realize it takes alot of skill and experience but I'm interested in what your looking for and just general info about how its done.

Anyone here ever do this?

This could be intresting. I have always wondered how they tuned race cars before they had computers.

you need to read them for each enviroment.

If you want to make sure you aren't lean in boost: go out and boost to redline, then shut off the engine, coast to the side of the road and then pull them. Otherwise driving back to the garage and carbon can build back up over and disgue the results.

Do the same if you ping: cut the engine just as you are pinging and take a look at them....

Exactly. Tuning by plugs is OK for na vehicles with carbs. I wouldn't tune a forced induction, fuel injected motor that way.

no not at all. it's no fun.

I've been told by some of the fastest guys around here thats the ONLY way to tune a car properly.

A guy with a build talon, running 10's with 18'' street tires and rims full interior and IIRC around a 136mph trap, fastest street car in Alberta mind you. Said thats how he tunes everything (owns his own performance shop ofcoarse). Same with another performance shop owner...

So I'm thinking theres alittle more to it than it just being an old way of doing it..

Also what are you looking for?


edit: 138mph

No no no not "idiots guide to whats going on in my engine" everyone knows the idiot way to read plugs, I'm talking about professional tuning aspects.

I would tune with an AFR gauge on each cylinder and EGT gauge. Just cause they are fast doesn't mean they are right. I've had SPEC miata guys call me stupid for talking about putting a 1.8 rear on a 1.6.

That's ignorant.

I can use a hammer and chisel to write in a stone. Or I could pick up a pencil and scribble on a piece of paper.

Didn't mean to offend buddy. Not sure what else you're looking for, besides voodoo magic.

I'm not sure what the state of the plugs will tell you that AFR/EGT won't. The plug MIGHT tell you if you are rich or lean, but not HOW rich or HOW lean. Way too much room for interpretation and error.

I wonder if this is the same guy that was telling people that during autocross if you are doing it right your tires shouldn't squeel! It's either him or his business partner.

Dean, if you want to know the secret why not ask the guy who told you this?

Sorry man, I thought I was clear when I said tuning but this type of it is prolly new to most, not that I'm saying it isn't to me either.

Jay the guys that have said are; Ron from revolution, Rob (fastest daytona), Martin from AFI, Blaine from Subracing, and Duane (h22 turbo ek)...

So I don't think their credability is an issue, I know Rob is an asshole but he is good at what he does so I think I'd take his word for it atleast..

I was just curious if anyone here had every heard of it/experienced/knows how to do it...

so people do things the old fashion way and are good at it. But to swear by reading plugs vs. something like logging actual fuel mixtures is silly.

Sounds silly I know thats why I'm inquiring about it. Remember these guys are making more power and running much faster than us guys, so theres gotta b something to it...Just don't exactly know what...

they arent driving miatas.

There's a reason 99.9% of the tuners out there don't do it that way.

You know this for sure? Then why do all the top tuners around here do this?

Well now I'm embarrassed to live in the same City.

I can't comment whether or not this is true, but if it is we are in sorry shape. And this might be why people have flown in tuners from the US. Me I'll tune my own car.

I'm not sure what you are after Dean. You are arguing that it's a valid method of tuning, but you are only basing this on what the "top tuners" in the city have told you. If you beleive them why are you asking here?

Give ole Corky Bell a call and ask him what he thinks. He's well respected and certainly old school.