https://www.pulstarplug.com/howtobuy...engine=1422548

if nobody has tried these what are people replacing theirs with, I've always had bosch plat. 4+ in my cars.

just wondering the best mods for a car are the ones that get you better gas milage and power ie: intake, exhaust, spark plugs, lighter weight vehicle etc.. which are the mods i want

 

WOW!! 300 bucks for sparkplugs for that price they better make my XFire spread wings and fly.

 

Hello,

The car somes stock with Denso Irridiums. NGK also puts out their Irridium IX that is comparable to the Denso's. Both plugs work well. Stick to Irridium. We have the NGK in our car now and they work great. All 12 only cost us $84.00.

Anthony
TVT Design

 

With a dual plug ignition system, how much more would different plugs really help?

 

Depends, but they can actually hurt if you don't know what's going on in your engine... You are correct about the dual plug system, it was designed to completely burn all vapors to limit exhaust emissions and meet CARB/EPA standards. That's the only reason... The down side to this design is that the ECU is programmed to tell the coil pack to fire #1 & #2 a millisecond apart for a complete burn depending on the signals from the 02 sensors, instead of a simultaneous firing. This helps maintain the "perfect" 14.7:1 +/- AFR for the CARB/EPA standards, not maximum HP...

What fascinates me about all this hyperbole about performance is that nobody has yet to discuss specific modifications to the engine management system / fuel management system to achieve and maintain the optimum AFR to develop maximum HP from the OEM set-up... That can range from 11:1 to 12.5:1 for forced induction +/- depending on the engine, and 12.5:1 to 13.5:1 for naturally aspirated engines +/-. The OEM system will always attempt to maintain 14.7:1 even with "off the shelf" ECU re-tune programs...

Whatever you do with your spark plugs, do not install hotter plugs in the OEM "stock" engine, because you don't need it, and it will send your cylinder temps thru the roof "so to speak"...

What you need is to adjust the AFR to the optimum level for your modifications and prevent the programming in the Bosch ME 2.8 / 2.8.1 ECU/PCM/FMU from readjusting it...

 

"What you need is to adjust the AFR to the optimum level for your modifications and prevent the programming in the Bosch ME 2.8 / 2.8.1 ECU/PCM/FMU from readjusting it..."

Er, like maybe slightly bigger (24 lbs./Hr.) injectors ???

Slim

 

The only mod you could is install "colder" plugs. But are really not needed on mildly modified or stock engines.

 

go to mbworld.com, there you will find the correct plugs to use and probably cheaper than the dealer. M-B silkscreens thier logo on a cheap $5 plug from bosch and charges you $20 each lol

 

Stay away from platinum plugs too. There are many reports of poor idling & rough running with those platinum "thin wire" electrode plugs in M-B engines.

 

PK16PR11, denso
BKR5EIX-11, NGK (more affordable)

 

Bigger injectors by themselves will not alter the AFR (much)... The ECU will just trim back the the pulse to maintain 14.7:1... Unless you can force more air to match the added fuel, the engine will just alter it's operation...

Here's the point that really needs to be understood... The engine management system is programmed to maintain a stociometric (sp) state... No matter what you change or alter outside of the electronics and ECU programming... This is normally 14.7:1 AFR, which is about 2.7 parts more air than the perfect percentage that creates maximum HP...

You will get minor gains from larger air flow and larger fuel flow, but nothing like it would be if you can get the AFR down to 12.0:1 +/-

 

Just think a minute. wouldn't all of the car manufactuers jump on anything including any spark plug design that would net them more HP and gas mileage over their competitors. Just another ploy to get your money. When I managed a Shell service station, we found that your best and safest option was to put in what you take out, that is, brand and heat range. I'll swear that if I were to not change the plugs at all on a customers car, 50 percent of people would swear their car's running much better. If you are racing your car you may want to run a colder heat range but other than that stick with you stock plugs and enjoy the fact that you should be able to go nearly 100,000 miles without doing a thing.

I was employed 25 years by Champion Spark Plug Company, tool & die, design, engineering department. I was on the team that developed the irridium 100,000 mile plug for Champion.

 

Thanks Chuck... It's always good to have a professional opinion... I switched to much colder plugs quite a while ago because of the design of the engine...

 

Thanks, I didn't feel like explaining it.

 

i havent looked yet so we have 12 spark plug's huh

 

Yes indeed.

 

I’ve been lurking on your forum for too long…great site, btw.

If it’s okay with you, thought this a good thread to jump in and share a DIY:
http://forums.mbworld.org/forums/showthread.php?t=216940

It has since had an ODPS fitted, so IK22s have been installed.

 

I had a buddy split his plugs up in the engine, One colder/one stock One colder/ one stock.... but he did not have 2 plugs per cylinder. His car ran and sounded amazing. It was a Toyota and he did it accidently. He went to buy a stage colder plug and only had money for a few so he kept a few stock and changed a few.

Has anyone tried plugs a step colder in the N/A car? I think that there is potential for more complete fuel burn in our cars having 2 plugs per cylinder. Having one cold, one stock, would give fuel 2 environments for combustion. ( This could work or it could be a disaster).

Any insight on the NA configuration and plug temp would be appreciated.

 

As I understand it, the 2 plugs are fired sequentially, and alternate :
A/B, then B/A, then A/B etc.
This would make it very difficult to predict the results with 2 different range plugs in the same cylinder ...

 

The temperature rating of the plug doesn't affect the temerature of the combustion chamber as a whole, just the temperature of the plug tip. It is a balancing act, you want the plug hot enough to burn deposits off the tip, but not so hot as to cause knocking or pre-ignition. If you've made changes that significantly increase the combustion chamber temperature, such as increased boost or leaner AFR, you'll want to run a "colder" spark plug. The colder plug will transfer more heat from the plug tip to the cylinder head, and thus maintain the correct tip temperature whereas the OEM plug may get run too hot.