Granatelli Motorsports coil packs

[Greg Hazlett]

Hmmmm...I have the GMS coil packs-but mine are just the solid state connnectors, is that the same thing you have- and am s/c as well...wonder if I can open the gap.

 

[Five Oh Brian]

Hmmmm...I have the GMS coil packs-but mine are just the solid state connnectors, is that the same thing you have- and am s/c as well...wonder if I can open the gap.

My GMS COP's are the "Hot Street" coils - click here to see at their website. I suggest that you try a few different gaps and see what your car likes best. Seems that more gap is a good thing, up to a point. It's just finding that point that's the trick.

 

[Greg Hazlett]

Got it..not the same thing I have.

 

[Turbolvr321]

I know this is a stupid question, but Ill get it out of the way.

COP upgrade makes the plug burn hotter correct? When you switch to FI, you put "cooler" plugs in (such as HTO). So, why would it be better for FI, if your gonna put cooler plugs but hotter COP?

Im new to the FI game, maybe Im not getting the logic behind it all... Someone shed some light here... School me...

 

[Five Oh Brian]

I know this is a stupid question, but Ill get it out of the way.

COP upgrade makes the plug burn hotter correct? When you switch to FI, you put "cooler" plugs in (such as HTO). So, why would it be better for FI, if your gonna put cooler plugs but hotter COP?

Im new to the FI game, maybe Im not getting the logic behind it all... Someone shed some light here... School me...

A wider spark plug gap (up to a point) allows for better ignition and combustion from what I've gathered. However, with forced induction, the increased cylinder pressure is more likely to blow out the spark making combustion less efficient and causing a slight misfire.

Seems there are two ways to combat this:

1. Gap the spark plugs down lessening the likelihood of spark blow out, but at the risk of losing some power, or
2. Run a higher voltage coil to make the spark more durable so it doesn't blow out at the preferred wider spark plug gap.

I found that I could get away with a wider gap by running higher voltage coils. I run a colder range spark plug (FRPP 3V0's) that's a copper core (much better conductor than platinum, BTW). Doesn't seem to make the car run "hotter" as no timing is being pulled at the track and my results indicate moderate power gains. I wasn't shooting for more power, just a smoother running car (I had slight misfire/blowout with the stock coils), but am very pleased with the results.

Apparently, you can widen the gap too wide and melt the spark plugs and/or destroy pistons. .045" is not wide enough to cause harm from what I can tell, and so far, so good in my car. FWIW, Ford Racing markets the 3V0 spark plugs as appropriate for forced induction and they ship them pre-gapped at .045", so I suspect they feel that gap is safe for the intended & marketed use.

 

[Dreadknought]

Subbed.

 

[Five Oh Brian]

Went to the dyno today for a car club challenge event (a couple other S197forum members were there, too). This is the same dyno were all of my car's tuning was done, so the numbers are comparable. Last year my car made 364 rwhp. Since then I've added an SLP catted X-pipe & GMS coil on plugs. No other changes (spark plugs were gapped at .045 last year and today). Car made 393 rwhp today for a gain of 29 rwhp with the X-pipe and coils.

Would have liked to dyno those two mods seperately, but it just didn't work out that way. However, I did run at our local drag strips after each mod was done, and each showed an improvement in trap speeds and ET's.

 

[aznjpnboi86]

Congrats Brian, I wish I would have gone but I am kinda sick. Makes me want to mod more on my stang....

 

[JeremyH]

Hmmmm...I have the GMS coil packs-but mine are just the solid state connnectors, is that the same thing you have- and am s/c as well...wonder if I can open the gap.

Got it..not the same thing I have.

Greg you have stock cops with solid ss conenctors vice the springs. He has the actually gms cops.

 

[JeremyH]

I know this is a stupid question, but Ill get it out of the way.

COP upgrade makes the plug burn hotter correct? When you switch to FI, you put "cooler" plugs in (such as HTO). So, why would it be better for FI, if your gonna put cooler plugs but hotter COP?

Im new to the FI game, maybe Im not getting the logic behind it all... Someone shed some light here... School me...

Not a stupid questions at all, very good point...

 

[Greg Hazlett]

Greg you have stock cops with solid ss conenctors vice the springs. He has the actually gms cops.

I saw that when he posted the link, thanks!

 

[Greg Hazlett]

Not a stupid questions at all, very good point...

+1 on the good point....why would you do this?

 

[Five Oh Brian]

Finally scanned my dyno sheet from yesterday.....

 

[Five Oh Brian]

Congrats Brian, I wish I would have gone but I am kinda sick. Makes me want to mod more on my stang....

Hi, Jason, you still make more power than me, so I think you should come out to the drag strip before you do any more mods. Time for you to buy a helmet, fire jacket, driveshaft loops, and drag radials....

There were some really big #'s put down on the dyno yesterday. Marc S's Procharged 08 GT laid down 568 rwhp. Bruce H's Whippled 07 GT/CS laid down 540 rwhp. Of the 20 cars that showed up, there were 6 that made more power than me.

 

[Marc s]

Hi, Jason, you still make more power than me, so I think you should come out to the drag strip before you do any more mods. Time for you to buy a helmet, fire jacket, driveshaft loops, and drag radials....

There were some really big #'s put down on the dyno yesterday. Marc S's Procharged 08 GT laid down 568 rwhp. Bruce H's Whippled 07 GT/CS laid down 540 rwhp. Of the 20 cars that showed up, there were 6 that made more power than me.

569 whp

 

[Five Oh Brian]

569 whp

And Bruce was 538, not 540, IIRC. My bad. I'm pretty sure mine was 393.

So, Marc, guess it's time for you to install that automatic in your GT now that your manual has given up the ghost. Blessing in disguise?

 

[Marc s]

Ya maybe, I'm leaning towards installing my Jerico now. The car is going into the dealer this Thursday for a tranny TSB. The dealer said they will repair the trans under warranty while it's out. When I get the car home the engine, trans, and rear end are coming out. Going to start the forged build with ported heads, 127650 cams, C&L manifold and around 20lbs of boost. I am sure I will go Jerico and the CJ 9" rear. As you know, winters are long. This build will give me something to do.

 

[Five Oh Brian]

Ya maybe, I'm leaning towards installing my Jerico now. The car is going into the dealer this Thursday for a tranny TSB. The dealer said they will repair the trans under warranty while it's out. When I get the car home the engine, trans, and rear end are coming out. Going to start the forged build with ported heads, 127650 cams, C&L manifold and around 20lbs of boost. I am sure I will go Jerico and the CJ 9" rear. As you know, winters are long. This build will give me something to do.

You can always drive one of the GT500's as your "daily driver" in the meantime. I'd love to see one of them with snow tires!

 

[Marc s]

Well my 07 GT500 is in my daughters hands as of this morning. Her SRT4 was rear-ended and totaled this morning on her way to work. She was not hurt but the car is a right-off. All is well, she wanted to sell it anyway. Whatever the insurance gives her I get for the down payment on the GT500. I am helping her get a loan for the balance instead of her making payments to me. She went from crying and upset because of the wreck to all grins when she left in the GT500. Surprisingly, the insurance for her is only $96.00 a month. Which is only $12.00 more than the SRT4.

 

[Five Oh Brian]

Well my 07 GT500 is in my daughters hands as of this morning. Her SRT4 was rear-ended and totaled this morning on her way to work. She was not hurt but the car is a right-off. All is well, she wanted to sell it anyway. Whatever the insurance gives her I get for the down payment on the GT500. I am helping her get a loan for the balance instead of her making payments to me. She went from crying and upset because of the wreck to all grins when she left in the GT500. Surprisingly, the insurance for her is only $96.00 a month. Which is only $12.00 more than the SRT4.

Sorry to hear she was in an accident, but it does sound like it's gonna work out well in the long run. Guess you don't have to be the "bank of dad" for the GT500 like you were saying the other day. Kudos on the cheap insurance. I have two teenage daughters with good student discounts and clean driving records, so we enjoy cheap rates, too.

So, gonna put some snow tires on the GT500 for your daughter? Make 'em studded snow tires and she can drag race in the dead of winter. You've got easy access to Bremerton, so she could have the whole track to herself! She might even post better 60' times in the snow than your '08 GT did all season on dry pavement

J/K...