R8 coil packs for the 118TSI

[necrogt4]

I went for the R8 coils to solve misfiring issues under full load with an APR stage 2 tune.

I'm curious, what is motivating you guys to look at different coils? Are you running a different tune?

[The_Hawk]

From everything I read some misfiring is normal or at least very common on the CAVD design (moreso when it's cold), something to do with the spark getting blown out on injection of fuel. There are other theories about what causes it but most seem to agree that the stronger spark of the R8 coil helps, even on a stock motor.

I've personally noticed no difference with those misses on a stock or stage 1 tune and in my experience it's been about 100 misses per 1,000km on each cylinder on average. It would be interesting to see a larger sample of the cumlative misfire count from more 118TSI owners (which you can look up with VCDS or PolarFIS or many others).

[necrogt4]

For anyone that's interested I was chasing down high fuel consumption issues and thought it might be my NGK R8 coil packs so I swapped back to my factory coil packs with a surprising result... They actually perform better than the NGK coils.

I am running NGK BKR7EIX plugs which I installed at the same time as the coils (didn't try them with the old coils, and even so I still would have installed the R8 coils at the time).

A bit of history. I had an APR stage 2 tune installed and started having misfiring issues at WOT ~6k rpm in 3rd gear. So I took my car back to my mechanic and we tried a number of things, including brand new VW coil packs. These performed worse and I had misfires under normal driving. We then installed OEM plugs (made by Beru and standard gapped at 1mm, which I'm pretty sure is wrong). These ran extreamly well for about 100km and then became very sluggish. I had to re-gap them to get any sort of power. So I bit the bullet and ordered the R8 coils, adapter and plugs.

The part number for standard coils on my Polo Gti 1.4 is 036 905 715G but there are a number of "OEM" manufacturers, one of which is "Beru" and these are the "new" coils that I tried with my mechanic and did not run well. The factory original coils bear the same part number but are marked "Eldor" and are made in Turkey. They run better than the R8 coils and the standard Beru ones.

So if you've got the Eldor coils (or can find a used set on eBay), just try a set of NGK plugs with them and see for yourself.

[Mk R]

Hey thanks man! That's great info. I'm running that stage 2 map with the Bosch OEM equivalent and BKR7EIX. No complaints. I'm keen to see the difference with BKR8EIX. According to the Greeks, the idle is rougher but the high end is much better (less misfires) with a tune.

[necrogt4]

Hey thanks man! That's great info. I'm running that stage 2 map with the Bosch OEM equivalent and BKR7EIX. No complaints. I'm keen to see the difference with BKR8EIX. According to the Greeks, the idle is rougher but the high end is much better (less misfires) with a tune.

No worries! I'm still getting high fuel consumption on the BKR8EIX so I'm going to try some other plug options. How's fuel economy under normal driving conditions for yours?

[Mk R]

No worries! I'm still getting high fuel consumption on the BKR8EIX so I'm going to try some other plug options. How's fuel economy under normal driving conditions for yours?

Do you mean BKR8EIX or BKR7EIX?

- Short trips around the hood (<5km) (enthusiastic driving) I get 12-14.

- Longer trips with good traffic flow (also giving it some curry between 3-5,000RPM) I get 9-10

- Relaxed highway long distance I get 6-7 depending on average gradient.

Once you take the heavy boost acceleration out of the picture it gives you the fuel consumption of the NA 1.4 engine.

[necrogt4]

My bad, I meant BKR7EIX.

Before I'd get 7-9lt for semi spirited driving around town. And down to 6-7 for highway driving. This was with the stage 2 tune.

It's 10-14 around town now. Actually less when I drive it with a bit of gusto (12ish). Highway is unchanged.

[Mk R]

My bad, I meant BKR7EIX.

Before I'd get 7-9lt for semi spirited driving around town. And down to 6-7 for highway driving. This was with the stage 2 tune.

It's 10-14 around town now. Actually less when I drive it with a bit of gusto (12ish). Highway is unchanged.

Yeah, stage 2 really dumps fuel into the cylinders at high revs. That's a common experience with stage 2 maps across VAG cars too.

I'm surprised you managed 7-9 around town. That actually seems more erroneous than 10-12. Could also be that our turbos are cooked now. Pull your intake pipe in and see if you've got much lateral play in the turbo shaft. I've got 2-3mm now and that's on a relatively new turbo that had about 1mm play 4 months ago.

Venom Turbos do cheap hybrids for our engine and Mellet do a cheap (eBay) but good quality CHRAs to refresh the stock turbo.

[necrogt4]

That's some serious turbo play

I'm guessing the fuel economy savings come from running a Polo vs a Golf? DSG too.

[Mk R]

Man, that's nothing. My old turbo was 4-5mm+ play after 130,000km. Most new ones seem to have about 1mm in-out and 0.5-1mm lateral play. The current turbo was used when i installed it. Still goes hard.

The Mellet CHRA is about $300 shipped so not a huge deal but it's a front off job even with the turbo right there.