500bhp monster

It is a monster in the right hands

 

Must be undriveable on anything other than a perfect dry road/track

 

Its not really, i drove it around Oulton Park in the snow on full power, also did a good few laps at Anglesey on a very wet day, was fun

 

I was running an open diff at 350bhp and it would spin up at 100mph in the wet Really hope the diff drastically reduces it!

 

it does and did, was really surprised how well the diff worked, i never felt the diff in my 265 work like that, but i can feel the diff in my 250 work like his does, once my monster is built we will see how they compare

 

How is it you're limiting the boost? Do the 3rs have another ecu setting built in, or are you running a separate boost controller?

 

Animal any pics

 

I own this car now , the guy before me hadn't had it long , went to the ring , on the journey home it lost compression on No4 cylinder , sold it as it was and I had it delivered to me on it's way back on a recovery lorry , camera down the bore is showing a melted piston , so engine is coming out to see the extent of the damage , hopefully the head it ok , and it's just taken the piston out , and the bore will clean up , or will fix with a rebore.
It's looking well used , and not looked after now , turbo cooler looks like it been frozen and blown up , the intercooler is looking tatty , the airfilter has half missing , turbo feels good , just ordered a new intercooler and turbo cooler , will start ordering engine bits once it's stripped and I know what's wrong

 

I have a fully forged Megane 3 RS 250 equipped with a large Kuro turbocharger (Garrett-style, ball bearing, internal wastegate), wossner std pistons, a tubular exhaust manifold, a 13-row oil cooler (Setrab), 850cc injectors, and a Wagner intercooler, among other upgrades.
I am currently running 26 PSI of boost, producing around 380 WHP. However, on some occasions I experience knock events, which can reach a value of 1 or 2. Then, when I accelerate again, the knock levels drop until they eventually disappear.
Has anyone experienced similar detonation issues on the F4RT engine?

 

I would say that the compression ratio is too high, it may also be the map it's self.
Mine is running Clio cams, forged pistons, catcam rods and a Borg Warner 7163 twin scroll turbo on a tubular manifold and it produces 440hp.
My compression ratio is 8.2 to 1 and i have not had any knock issues.

 

By no means an expert - but I've been trying to get up to speed on Motec ecu's and in particular "fuel film" and how under acceleration this build up of fuel on the inlet manifold varies during acceleration (and deceleration)

If when you say you "accelerate again" is this immediately after the knock event??
i.e. you back off the revs, then hit it again?
Could be detonation is caused by going slightly lean as "accelerating" fuel is robbing fuel film build-up, but after next accelerating event you already have more film available to contribute instantaneously to "acceleration" fuel demand???

So might need the map to give you a slightly richer mix under acceleration?

From AI
"Yes, inadequate fuel film at the inlet manifold can cause engine knock (detonation) instead of just a stumble or bog, especially under load. While a lack of fuel film typically causes a lean condition leading to hesitation, the resulting rise in cylinder temperatures and pressures can trigger, or significantly contribute to, pre-ignition or detonation.
Here is how inadequate fuel film causes knock:

• Lean Mixture and Heat: Inadequate fuel film means less fuel is vaporizing and reaching the cylinders, creating a "lean" air-fuel mixture. Lean mixtures burn hotter and slower, which can cause excessive combustion chamber temperatures.
• Detonation/Knock: These high temperatures and pressures can cause the end-gas (the remaining mixture) to ignite spontaneously before the spark plug flame front reaches it, resulting in the audible sound of knocking or pinging.
• Stumble vs. Knock:
  • Stumble/Bog: Typically happens during sudden acceleration when the engine is cold or the fuel system cannot instantly create a thick enough film, leading to a momentary lack of fuel.
  • Knock: Occurs under sustained load or high load where the mixture is lean, and the increased cylinder heat causes spontaneous detonation, often resulting in engine damage"

 

Hi, thanks for help my RS!! I send you 4 logs images to see when its started and when dissapears.
It was a very bad day for logging—100% humidity, rainy, and 36 degrees of heat.

 

the images are a bit too busy for me to review
post or message original RStuner log files

 

Log uploaded.
Thanks!

 

I'm not 100% sure I still understand your initial question, and looking at your 4 log images you posted I'm even more confused about what you're trying to show/question?

Nevertheless I've look at parameters just before and after 28m53s400ms (gear change, and your second log image). Knock values before and after the gear change are different for a few reasons including different boost, ignition advance, rpm, load and film thickness (note that before your "boot to the floor", throttle was only 15% so not much steady state film thickness, and after the run and gear change I think the film thickness would be substantially more, so able to favourably impact on knock level)

 

Ok, So I should stay calm, since it's something normal and not considered as engine kocking or pinging?

 

No I didn't say that - not at all.
My comment would be that I'm impressed with the engine build in that it's still hanging together, considering the knock intensity - not so much the magnitude, but the area under the curve
i.e. "The area under the curve from an engine block sensor is often used as a direct indicator of knock intensity"

Compare the area under the knock curve for your engine vs mine (was pretty much stock when I had Fastchip tune; now running Motec and Flex (E85)).

Also one would expect for the cylinder having the knock event that the ignition timing would be reduced, however looking at your log it is always increasing!?
You can clearly see this in the Fastchip tune - retarding ignition in case of a high knock event.
The interesting thing will be how much advance (quick response) or boost (long term) you need to take out and impact on performance to bring knock "area" back to a reasonable level, or if the better solution would be to increase compression ratio as suggested by Ian in an earlier post.

I would definitely dial it down until you get it sorted. Also consider Motec ECU with ability to run ethanol mix, which will pretty much stop you being knock limited, and save melting your pistons.

 

Ok, I understand, the noise from my engine extends for longer periods when I step on it. Do you think that noise could be due to too much ignition advance or because the fuel quality is very poor? I’m not using ethanol, but several people have already told me to use it. I’m sending you a log with less advance. Many thanks for your help. You made me notice something I had no idea about.

The Fuel is V-Power 98RON with 2x 250ml Bardahl Octane Plus

 

All the above plus other things - compression ratio, boost level etc
Sorry mate you need to get expert advise, not from an "amateur" like me. Suggest a dyno run where you can use a stand-alone knock sensor and headphones to get a better feel of knock levels and adjust the map accordingly

The reason being that knock levels at WOT seem to have reduced a little (is this enough however??), but it doesn't seem that the ignition advance is being reduced to control knock episodes??

Also, I noticed you are having knock events on partial throttle and no boost which is not good - eg 17m43s700ms

I'll leave it with you. I'm off for Easter holidays. Good luck

 

Have a good Easter holidays!

 

I will look at those logs but around 3500 - 4000 a lot of engine noise is to be expected due to increased cyl. pressure.
right now I don`t have time but will compare with mine. are you from Argentina?

you need to confirm that noise is real knock with by proper third party audio monitor gear like Tuner Nerd or better Plex.
this was the tuner`s job not yours.

(in the other hand , @ Zoto

I have the M130 up and running with turbo shaft speed and emap data, etc.
as I run seq ignition (external Bosch ignition module) now I have individual coil trims , etc.
the integration works perfectly , still in testing /, started just some days ago.
waiting for the level 2 logging activation for the further setup.
I also put in IDS 1050 - XDS injectors that are working like a dream.)

 

This is about "knk slow timing cor."?
.

 

In order to take into account the long target of knock control (from fuel RON105 to RON 91), it is necessary to store the knock offset correction function of the fuel quality (slow correction loop). The stored value is limited to a maximum (= 7,875°CRK). At each engine stop or stall the value of the slow correction loop is memorised. At each new start or reset, the stored value is compared to a maximum in order to avoid the learning of mistaken value. Thus, at each new start, when entering the critical area, the memorised and corrected value should be directly applied in order to avoid knock appearance and protect the engine. Nevertheless, this particular functionality is dependant from the application choice thanks to the calibration constant C_KNK_COR_SAVE_SLOW (if one writes C_KNK_COR_SAVE_SLOW = 0°CRK, this functionality has no influence on the strategy).

 

Wow, I have know idea of that!
I bought an octane analyzer to check the fuel in Argentine. I dont now if its 98 RON or worse.
I tried to elevate the ocatenes with bardahl but only with 2 bottles in 50 liters. I will try with 3. Its supposed to be 1 bottle for 40 fuel litters

 

Could it be a bad
Knock sensor, incorrectly installed position with bad torque? Could someone send me the correct position and torque? I"ll try to buy a new one and reinstall it correctly. I found only the torque, 20nm +-5. Thanks in advance.