Does the spark plug gap need to change as you build more power?
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Does the spark plug gap need to change as you build more power? I'm currently putting down 398 rwhp cam only through an automatic, unlocked loose converter, 12 bolt w/4.10 and on slicks which takes away a lot of power, so I have roughly 518 fwhp. I was wanting to know as the motor makes more power, does the gap change any? I'm running TR-55s, but plan on changing them soon.
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I plan on running the TR-55s again, will it still be the same? Also, does that 50 hp apply to power over stock? If so, I've added roughly 200 fwhp from stock which would put me at .039 gap.
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Well if you close up the gap .004 for every 50 hp you add to stock, then I would need to close it up a total of .016 which would put me at .039 from the stock gap of a TR-55 (.055).
I ran a tr6 at .038 on my 422ci with a 100 nx shot with 600 rwhp. Your rear wheel hp is a little over 100 from stock. Probably close to 150 with the high stall and big gear. I still think at most I would do a .045 on a tr55. If you want to go lower a tr6 come stock gapped at .035 and could be upped to an .042-.043. A stock car puts down at least 300 rwhp and your a little over a 100 rwhp now which is where I am getting my calculation from.
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The hp ratings that GM advertises is motor hp (fwhp). My car was advertised as 320 hp I believe. I'm putting down 398 as of right now and with roughly 22% drivetrain loss, I figured 518 fwhp. So thats about 200 hp above stock. Thats where I got my calculation. I never dynoed my car stock.
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Originally Posted by strokedls1
For every 50 hp the gag should be closed up .004. I would assume you would gap to .045-.048 with your combo on a tr6 plug.
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I would like to confirm as well if this information is correct because I am going to change them very soon and I want to make sure I have the correct gap before installing them. Thanks.
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From: TEXAS
Originally Posted by Dragaholic
The hp ratings that GM advertises is motor hp (fwhp). My car was advertised as 320 hp I believe. I'm putting down 398 as of right now and with roughly 22% drivetrain loss, I figured 518 fwhp. So thats about 200 hp above stock. Thats where I got my calculation. I never dynoed my car stock.
Those stock hp numbers were HIGHLY under rated. My car was dynoed at 308 rwhp while being advertized at 320 fwhp. If you add in any drivetrain loss, that's well above the advertised 320hp.
Originally Posted by Dragaholic
The hp ratings that GM advertises is motor hp (fwhp). My car was advertised as 320 hp I believe.
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From: Nortern Idaho
Originally Posted by cyphur_traq
You've been around too long to believe that horseshit. If you truely believe that GM rated the cars honestly than you need your head checked(again?).
Originally Posted by Rays C5
I know this applies to nos cars but I've never heard of this for n.a. cars. Can you elaborate as to why???
If you are cramming in more air then you have a bit more pressure and want a smaller gap to maintain a strong spark. The idea is still to have the largest gap for the power. The smaller gap is less efficent. There is no exact gap number that you have to hit to make the car run. It will work with a pretty good spread. Gap them out at .045 with the tr55's and you will be fine.
