RedZR

Gang,

I wanted to change the plugs in my 91 and was told that the AC Delco plug FR2LS is no longer made and has been replaced with a 41-602 spark plug.

I can not find the FR2LS plugs anywhere so I am in a bit of a fix.

Do any of you spark plug experts know if that is indeed the case and know what the differences in those two plugs are?

I tried Rapid Fires once before and did not think they worked as well as the FR2Ls plugs- so I am kinda stuck. I do not want to use the platinum...lots of $$s with questionable benefits.

Any advice is appreciated !!
Dan

Hib Halverson

The 41-602 is one of ACDelco's new, replacement quality, single-platinum plugs. They're ok.

A better choice for the LT5 is the RapidFire #9. I used them for a number of years with good results. Plus the RF9 is a little colder which gives better performance when you're driving hard. The RF9 is basically a platinum verison of the FR1LS which was the original LT5 plug released in the fall of 89.

Nowadays, I've gone one better than the RF9 and use the Denso "Iridium Power" IT-22. Great plug for street and track. For LT5s that see normal street driving use the IT-20. Only downside is the Densos aren't cheap.

FastZR1

Hib,
Are the Iridium plugs really all that? I have heard people talk about the plugs being very good. But then others tell me they are not worth the money.

I value your inputs, so I wondered if you really thought the iridium plugs are everything they are suppose to be. What do they run, 8 bucks a plug or so?
Ed

RedZR

Hib,

The RF 9 will be ok for normal street driving, right?

Dan

kabnvtt

Ya know I swear I just replace the splitfires that were in my ZR1, and I went to the local GMC dealer and the FR2LS are the plugs they sold me, this was about 2 months ago, so if they were discontinued it was fairly recent, If you would like me to check on Monday let me know. To be sure that I have the FR2LS plugs I will pull one out tonight and get back to you.(kabn6@charter.net). :)


[Modified by kabnvtt, 9:08 PM 7/19/2003]

kabnvtt

Just checked a plug and they are FR2LS plugs. :cheers: :cheers:

Hib Halverson

"Are the plugs reall all that?"
Well....I guess it depends on how far you want to go to get the best performance out of your car and whether or not you want the latest spark plug technology in your engine.

If you are on a tight budget, I think the best plug is the RF9 because they can be had for less money than Denso Iridium Power plugs.

If you can afford more money, I think the Denso IT-20 or the IT-22 is the way to go.

What do you get with Iridium? Durability is just a small be better than the single platinum Rapid Fires. Also, as an Iridium plug needs less voltage to fire, in some cases, you're going to see a little better driveability at part throttle.

Will you get 15 more hp through using Iridium plugs?

No way.

Yes.
I ran them on the street for a number of years before I switched to the Densos.


[Modified by Hib Halverson, 12:59 PM 7/20/2003]

RedZR

Hib,

Do the Rapid Fires need to be "over torqued) on the 375 hp cars?
I hope not....

Dan