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"