Volkswagen Passat Forum banner

Just installed Denso Iridium

2170 Views 23 Replies 15 Participants Last post by  kevindow
I just installed my new Denso Iridium spark plugs, $13 a piece and the car rides so much better, it feels like a new car and it is just sssoooo smooth, and accelerates better, I have a 1999 B5 tip. I recomend this to all B5 drivers. when I took out my old plugs they were Bosh super and it drove good but this is soo much better, I bought the Bosh super like 3 months ago and it was a great upgrade but his Denso are the best.
So those Bosh are going to the trash now!!
1 - 20 of 24 Posts
Thanks for the info. I might have to check them out!
Hey what's up man! Where did you buy them at? How hard was it to replace them, and do they come pre-gapped? For $13 a piece they better! I saw you are selling your stock rims and turbo, did you upgrade? If so, I want to see pics. We should roll up to Treffen together if you are going.

Later bro, keep in touch.

-Paul
Treffen?? when? and where is that at?? I bought the plugs @ autozone, and they dont come pregaped but they sell the gapping tool. I'll send you pics when I get a hold my inlaws dig. cam. maybe this weekend :thumbup:
sparkplugs.com has them as well
WHITE1.8T-B5 said:
Treffen?? when? and where is that at?? I bought the plugs @ autozone, and they dont come pregaped but they sell the gapping tool. I'll send you pics when I get a hold my inlaws dig. cam. maybe this weekend :thumbup:
The Midwest's Premiere
Watercooled VW & Audi Event 
 
August 21 & 22

Oakton Community College 

Des Plaines, IL

check it out here:
http://www.chicagovw.org/ click on the "TREFFEN" button for more details. We can roll up for both days, or just one. I'll try and get at least 2 more people that might be down.
See less See more
I just ordered the Denso IK22's today from AutoZone (one heat range colder which Neuspeed recommends after being chipped). I'll leave a post and let everyone know how they work out.

Get this, they have a little dyno graph at the start of the catalog (Denso that is) that shows the HP curve for a Mustang before/after and they claim a 23 HP increase just by switching to Denso spark plugs... :???:

My question is, obviously being one heat range colder, these plugs have a smaller gap (.8mm vs 1.1mm on the IK20's). Is this a problem or do I need to regap to some other value (which would then change the heat range I'm assuming)

Thanks,
-Chris
My take on spark plugs is that they are like the pit-stops in an endurance race i.e. You can't win the race by having good pit-stops, but you sure can lose it with bad ones. The stock plugs are good ones. If $50 in spark plugs gave even five more horses, don't you think the VAG engineers would be all over that shit?

If you are really crazy you can do what they call "indexing" of your plugs whereby washers of differing thicknesses are utilized in order to face the plugs a certain direction in the cylinders. I guess this is only effective if you have access to a dyno and lots of free time. I read one article where someone was able to get something like one HP by doing this on a 4-cyl 150HP motorcycle engine!

From NGK's US web site:
http://www.ngksparkplugs.com/techinfo/spark_plugs/faq/faqpower.asp?nav=31200&country=US

Q: How much of a performance improvement can I expect from changing plugs?

A:
A common misconception is that changing spark plugs will result in a large power increase. In most cases, removing even seriously worn out spark plugs will only result in very modest power gains, typically about 1-2% of total engine output. This could be even less for computer-controlled vehicles, primarily because most newer vehicles have more powerful ignition systems and the vehicle's computer can make adjustments so that vehicle operation seems smoother and more seamless.

Many people think that simply supplying more spark to the firing tip can and will combust more fuel. What they don't understand is that most newer cars' engines are so efficient that they are already burning all of the available fuel. Simply adding more spark voltage can't burn more fuel because there is no more fuel to burn.

When a stock or near-stock engine is given a fresh set of spark plugs, peak efficiency is restored. The power gains that come from this restored state of tune are usually minimal. Any company that tells you that their spark plug will provide significant gains in power in a stock or near-stock engine is making blanket statements that may not be supportable.
TheJezter said:
My question is, obviously being one heat range colder, these plugs have a smaller gap (.8mm vs 1.1mm on the IK20's). Is this a problem or do I need to regap to some other value (which would then change the heat range I'm assuming)

Thanks,
-Chris
Heat range is built into the plug (how much heat the plug can remove from the cylinder). How much you should gap your plugs is a function of how much electricity your car's ignition system can generate. More gap increases the resistance and reqires more electricity, but generates a bigger spark. Gap it too small and you are not taking advantage of what could be more reliable ignition. Gap it too much and you will not ignite the fuel/air mixture every time which can lead to lower horsepower, rough running (although the ECU may compensate somehow), etc.

You will want to stick with the stock gap that VW puts on the OEM plugs (whatever that is).

Theres some more info of this sort on NGK's (and surely other plug manufacturers') website(s).
WHITE1.8T-B5 said:
I just installed my new Denso Iridium spark plugs, $13 a piece and the car rides so much better, it feels like a new car and it is just sssoooo smooth, and accelerates better, I have a 1999 B5 tip. I recomend this to all B5 drivers. when I took out my old plugs they were Bosh super and it drove good but this is soo much better, I bought the Bosh super like 3 months ago and it was a great upgrade but his Denso are the best.
So those Bosh are going to the trash now!!
I agree with you Totally... I never thought these plugs could make such a HUGE and noticeable difference in performance. I highly recoommend them especially for a B5 running 15-17psi Boost.

I spoke to DENSO directly to find out the best heat range for my application.

Enjoy 'em... perfect choice.

Sam...
There has been much debate over on the Vortex about gapping the Densos. Apparently the gap on the IK20s is .040 or so and if you regap them it's easy to break the ground electrode. Personally I would rather stick with the stock gap of .032 (I think!) since it stresses the coilpacks a lot more to use a bigger gap.
my coil packs 1 and 3 have been popping out (About 1/4 inch)causing some driveability problems on every drive i take. I thought maybe its bad plugs or a bad gap on my old regular Denso plugs so maybe i'll try these. What gap are u running WHITE 1.8T and and u chipped (which chip)???
not chipped and I regapped the 44mm. to 32mm. and they run :thumbup:
Well i just got my Denso Iridium IK20's in the mail today from sparkplugs.com and i'm gonna try em with just the pregapped .44 or whatever it is. They say not to gap em and Denso thinks our specific car should have that gap for that plug so i'm gonna stick with that and i'll let ya know how it goes.
I've got the IK20's running in my B5 now with the stock gap of .32 and they told me NOT to regap. Car has been running fine for 2 weeks now. I don't think I notice any performance increase but wondering if I am getting better gas mileage. I need to run a few more tanks to see. My old OEM plugs were 30K miles old and due for replacement so just replacing may be the increase I see.

-Chris
you guys are crazy :crazy:

Iridium is more durable than platinum, platinum is more durable than copper.

thats it.
Any performance "increase" that is noticed after a spark plug change is usually a result of the old plugs being less than perfect rather than the new plugs being super duper....
I second that
JB said:
you guys are crazy :crazy:

Iridium is more durable than platinum, platinum is more durable than copper.

thats it.
Cali boy's got a point ;)

Look at the guys running RS4 kits in their S4s, practically all of them run bosch supers (copper plugs). Plats & Iridiums are crap for performance, better for longevity.

That good ole $1.62 denso prolly gives better performance than your $13 plugs.

Dave
crew217 said:
That good ole $1.62 denso prolly gives better performance than your $13 plugs.
Heck, at $1.62/ea I'd buy a set every 5K miles.

Anyone have *actual* experience with cheapo Denso copper plugs in a Passat??
1 - 20 of 24 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top