Kia Forte Turbo Forum banner

1 - 7 of 7 Posts

·
Registered
Joined
·
1,697 Posts
Discussion Starter · #1 ·
so... I have been trying to find what is causing random predetonation. Higher octane would solve it, but not always. Sometimes I would run into no boost scenario. Again, very random cases.

As a part of preparation for tune, I got HKS 50003-M45XL spark plugs. I decided to put them in earlier to see how things would change.

Before doing that I tried with different octane ratings, including 93 for several tanks without any big improvements.

A few days ago I installed HKS (from stock plug) and drove the car for a day. ECM was reset, of course.
I did not feel any difference whatsoever. It pulled same. It acted same. Boost same - peaks at 18 psi.

Then, when I was close to empty, basically blinking last line, I poured 93 from local Shell.
The day I poured it nothing was really happening. Same things. Same boost, same power. At least it felt like that.
However, today in the morning. I am driving to work, like everyday. All seemed normal, car would be same. Nothing felt "different", until a moment when I needed to "jump change lane". There was a car in front slowly making a right turn and quick reaction - punch gas, drop to 2nd, change lane to left.
The car pulled like crazy. Way stronger than I expected, way stronger than normally.

At some other moment I tried this again and I found that it was pulling really harder.
However, I did not see boost spiking same level. Now it barely hits 15 psi, it is rather 12-14 psi at max. Yet power is same.

No, it does not leak, as vacuum readings are same. All is tight.


Then I did two 0-60 pulls. Actually they were 0-100 km/h.
While before I the two runs I had were 7.1 and 6.7 s, now I got 6.8 and 6.5. Also translated to shorter distance the speed was reached by about 10 m in each of the two pairs.
Both runs/pairs are done on the same road. Each one way. Today's runs were limited by low grip - a bit colder (+3 C, vs +12 C the other day).

Yet again - the boost was limited.
Was the power/torque limiter in place that caused less boost to be needed to produce same power?
A bit confusing.

Anyway, I can say that now I can feel the power, but it seems it needed better spark plugs and higher octane to do that itself.
 

·
Registered
Joined
·
514 Posts
i wouldnt be surprised with those spark plugs i'm sure they spark/conduct better than stock.
if we already need better grounds then this can only help even more. i myself cant afford them atm but don't need them yet.
keep us informed on how it operates and if it still keeps power.
 
  • Like
Reactions: drc69

·
Registered
Joined
·
399 Posts
Agree on the $$$. To close to Xmas to spend any real $$$ on the car now.
But let us know what you think on the plugs.
Thx
 

·
Registered
Joined
·
1,697 Posts
Discussion Starter · #4 ·
Guys, maybe they are not the cheapest, but I found them on Amazon, 101.44 shipped for all 4.
So is it much? I guess it is.

IMPO, this is far better investment than intake. At leas it feels like it.
 

·
Premium Member
Joined
·
359 Posts
How many miles were on your stock plugs?

Also were you saying before that you ran 93 with the stock plugs to find no difference in performance over 89 or 87?
 

·
Registered
Joined
·
1,697 Posts
Discussion Starter · #6 ·
How many miles were on your stock plugs?
10941 miles
They looked OK, although I would say in a few places could look like a tad of overheating. Or I might be overreacting.

Also were you saying before that you ran 93 with the stock plugs to find no difference in performance over 89 or 87?
Correct.
In some cases it ran smoother than in others. I also tried ethanol free petrol, but no improvements either.
In 87 I could get the pings quite often, in 89 on very rare occasions, 93 not at all (all stock plugs), but across the board - the best overall performance was in 87 despite the problems. When it ran good, it would pull the best in 87. Boost would be 18 psi on quite long moment at lower rpm. At high (about 5000) it would drop to 15 or so.

Now, with 93 in and HKS 45's - boost as I said will not go above 15, but the performance is better. I am not sure though how is fuel use. I push it too much for testing to see any normal driving numbers.


Next week I am hoping to get tune... I hope I will be able to release funds for it. Would be great to push the mats out... things would be easier.
 

·
Registered
Joined
·
1,697 Posts
Discussion Starter · #7 ·
So for the last several days power was quite constant with boost not hitting 18 psi. The max it would log was 15 and only on some occasions. Most of the time it would hold 12-13 (just like I said above) and pull same strong.

As for fuel consumption - a tad lower. But we are talking about civil driving... not too slow, but normal traffic flow acceleration, in ECO, without WOT, a few 70% throttle. For comparison, based on onboard computer for the trips I used to see 26-27, I got 27-28, maybe 29 on occasion.
So nothing I would really say noticeable.
 
1 - 7 of 7 Posts
Top