I assume from what I've heard and read, that the fancy SplitFire and etc. spark plugs (including AC's version of hi-per plugs) are pretty much a waste of money for my 505 h.p. 454. Thanks for the comments

Tim

You'll hear all different things, I think that split-fires help, just my seat of the pants analysis. I know different engines respond differently. If you really wanted to know for sure, someone with dyno testing experience or a gonzo number of drag passes would have to tell you their results.

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Steve

72 Chevelle SS402/4sp

I feel that, the gain by using these plugs, is acheived thru the extended tip, not the fancy ground strap. For the money, you could get a few sets of extended tip normal plugs, and realize the same gain.

A spark is a spark is a spark - given that everything else remains the same in the ignition system.
Scientifically: given any particular gap and set of conditions, (temp, press,voltage, etc)the spark will occur at the ONE path of least resistance, ONCE, BAM!.
It doesn't matter how many electrodes or types of metal are used, you get one spark at one place each time the plug fires.
The gains that each person feels are the result of new plugs and their own excitement at installing something new.
Hell, every time I put something new on the engine (especially chrome) it FEELS faster.
If you don't believe all this, figure out why Splitfire lost in court and must make reparations to customers.
They are probably not bad plugs, but nothin special either.
Wonder why the magazines don't check em on a dyno ??

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Gotta have a Chevy !In Durham N.C.
Make it look the way you like it, forget what the other guys say!

A spark is a spark, unless you are using an MSD then a sparks is a sparks...FRED

No argument on the actual spark, however the placement of that spark in the combustion chamber can have huge impact on burn speed, and that is how it affects HP.

I've had the best results with autolites. I know, its a ford plug, but I've tried AC, and champions and had fouling problems with both. I have a 355 small block though. If the ACs foul try the autolites.

AC makes the "rapid fire" plug. It has a multifacited core end. The bosch +4 have four electrodes. Platinum plugs have platinum surface. http://www.chevelles.com/forum/smile.gif
IMHO these designs are for "extended" life and do not necessarily improve performance. I have heard, however, that the Autolite plugs have very little resistance and therefore work very well. http://www.chevelles.com/forum/smile.gif I have a set of autolite platinums and they work well. I also like the ac rapidfires. I have a set of bosch +4s to put in my ram air but have not installed them yet. When I do, I will post any differences I notice. http://www.chevelles.com/forum/smile.gif

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Mr. D
72 454 El Camino
68 RS/SS Camaro
73 RS/LT/Z28 Camaro
99 Firebird TA WS-6 A4

[This message has been edited by Mr. D (edited 12-05-99).]

I agree with Steve. Autolites are the best plug I have used. Nothing fancy.