Spark plug gap argument thread

**snoopra** · December 25th, 2010, 03:41

I'm working nites

...no days off..

.....till mid January. I still sneak on to read the latest

We've been in the news too many times in the past months (We, meaning the Refinery) so my expertise is needed for some repair guidance

**ramin** · August 23rd, 2011, 18:57

Hi Guys, I have been reading the forum for years but this is my first post.

I noticed everybody talked about calling APR but I didn't see any updates. I called them today and they said the tune is based on the OEM plug gap, so their recommendation is to just stay with that same gap of 0.032.

**ttboost** · August 23rd, 2011, 19:01

Originally Posted by ramin

Hi Guys, I have been reading the forum for years but this is my first post.

I noticed everybody talked about calling APR but I didn't see any updates. I called them today and they said the tune is based on the OEM plug gap, so their recommendation is to just stay with that same gap of 0.032.

Then their tune doesn't raise the boost level at all, or VERY little.

**V8weight** · August 23rd, 2011, 20:31

Originally Posted by ramin

Hi Guys, I have been reading the forum for years but this is my first post.

I noticed everybody talked about calling APR but I didn't see any updates. I called them today and they said the tune is based on the OEM plug gap, so their recommendation is to just stay with that same gap of 0.032.

The stock plugs come pre gapped to .028- .029".....

**Brav** · August 23rd, 2011, 20:53

Another request - anyone have info on which uprated "snap on" coils to use?

**ramin** · August 23rd, 2011, 22:02

Originally Posted by V8weight

The stock plugs come pre gapped to .028- .029".....

Just to be clear, APR didn't tell me the size of the gap. I inserted that per my search online. The APR guy just said to stay with stock size.

See, for example, http://rss.rpmware.com/ngk/ngk_spark.../i-134850.aspx

**ramin** · August 23rd, 2011, 22:05

Originally Posted by ttboost

Then their tune doesn't raise the boost level at all, or VERY little.

I am not sure how much APR stage 1 increases the boost level, but I suspect there are other ways to address boost level increase other than changing the spark plug gaps. Couldn't they just change the timing?

**ben916** · August 23rd, 2011, 23:50

Originally Posted by ramin

I am not sure how much APR stage 1 increases the boost level, but I suspect there are other ways to address boost level increase other than changing the spark plug gaps. Couldn't they just change the timing?

off topic:
Welcome!
Got a VIN?

On Topic:
The stock plugs come pre gapped to .028- .029"..... as Stephen says BUT there was prior posting about AFTER tuning, possibly EuroChg tune, the idle was rough, not smooth, etc - a change in the gap to .025 - .026 made all the difference and all the issues went away

**4everRS** · August 24th, 2011, 00:50

APR definitely changes boost levels. I have data logs to prove it. However, I am a bit disappointed in them right now as they told me over the phone to send some data logs addressing a question I had and I haven't heard back 3 weeks running. Anyhow, I run my plugs at .025. If your coilpacks are old, you may be losing voltage and thinking the plug gap is the problem.

Better coilpacks are the revised 1.8t packs. http://www.ecstuning.com/Volkswagen-...1.8T/ES279618/
Get them at genuine for a better price. They are not bolt down and there is a rubber piece you have to trim to fit the 4.2 hole. you can always use hold downs if you want.

**hahnmgh63** · August 24th, 2011, 01:27

Many Turbo engines that have had boost levels increased, can use a slightly smaller plug gap as the increased cylinder pressures (denser charge) makes it more difficult for the electricity to jump the gap. Modifying the ignition system to higher voltages can alleviated this but is not easily done on our cars. A perfectly working RS6 ignition system with fairly new coils and new plugs will probably not notice a difference but the coils loose voltage over time before they throw misfire codes or fault (check the resistance of a new coil against your used coils sometime).
As for the new 1.8t coils that is a debate that has been going on for years and has been discussed here before. I also have a daily driver 225bhp 1.8t Audi tt (which specs the exact part # as our cars)(chipped of course w/ downpipe etc.. to over 265bhp) and most of the modified tt guys believe that sticking with the 'E' revision coils but only one that are Hitachi manufactured. Do a Google search and you will find mountains of forum activity on this, just pay more attention to the later dated forum activitiy as many have learned a lot from past coil revisions.

**kismetcapitan** · August 24th, 2011, 09:06

pulling timing on turbo engines generally kills power, as timing is usually advanced to the point of detonation then backed off a bit. Does make ignition mapping easier with turbo engines than with N/A engines, where the sweetspot for optimum ignition timing feels to me to be half voodoo - must sacrifice live chicken to find the right timing :P

Too big a gap in relation to the boost pressure can blow out the spark, and then you'll misfire on that cylinder. I know I went on about this on another thread, but what about surface gap plugs? After scores of headaches with plugs, heat range, and gapping on my Skyline, I just went with surface gap and never had to think about the ignition system again. It did benefit from new coilpacks as well as an ignition amp however - it takes a lot of juice to arc across that gap on a surface gap, and to cut through whatever crud has built up on the thing.

**DiscoPotato** · August 24th, 2011, 14:55

As far as I know if you apply an aftermarket tune to your car, you have to shorten the gap. Being a B5 S4 owner I know this all too well. Im running a gap of .026 on a custom stage 2+ setup.. Stock for me is .032. Even tuning companies call for the shorter gap once a new tune is applied. This is attributed to the raised boost, and thus cylinder pressure.

Ive read multiple threads on this exact subject on many different forums on many different types of Audis.. They all came to the same conclusion..

Safe & smooth = Smaller gap

If you are experiencing spark plugs backing out i'd check your tourques, etc as well. But with a slightly smaller gap you will see that your car will pull smoother.

**ramin** · August 24th, 2011, 17:05

Thanks Guys! I will shorten the gap per your emails once I do my 55k service. My car seems to be running fine now with whatever gap there is. All previous service was done by the dealer, so I am not sure if they even checked the plug gaps when they replaced them last.

**RSSIK** · August 24th, 2011, 19:49

I agree with Discopotato.. I couldnt have said it better myself.

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