[tpoddar]

Originally Posted by Moaus

That's what i thought but reality strikes hard.

What octane fuel were you running and what version of the tune (91ACN, 91, 93, E30)? Also, any datalogs you may have collected when using bootmod3

[Moaus]

Originally Posted by sspade

Something no one has asked... what octane tune were you running? Most likely this happened because you were running a high octane tune (93) on garbage fuel. I've seen it before... if you look hard enough you will find examples on this forum of the exact same thing across different engines.

Bootmod3 OTS flash tunes are perfectly safe so long as you "follow the rules" and maintain the vehicle properly. Literally hundreds (more like thousands) of users of these tunes with a very very small issue/failure rate. Again, across different engines. Not specific to four or six cylinder motors.

91(95 in my country) ots tune. Bm3 for only 6 months, i regularly wait for the engine to warm up, never pushed it hard, treatments every 10k. I'm treating my car better than i treat my wife

[Moaus]

Originally Posted by tpoddar

What octane fuel were you running and what version of the tune (91ACN, 91, 93, E30)? Also, any datalogs you may have collected when using bootmod3

2 logs in csv files so i had to zip them.

[tpoddar]

Originally Posted by Moaus

2 logs in csv files so I had to zip them.

These logs are from before the accident happened right? (Hopefully) While these logs are not optimal since you never go WOT, there are many instances of knock highlighting a possible fuel issue. Also, either there's a bug with the logging application or some other issue but the boost pressure isn't correctly logged. Attaching screenshots below -

[tpoddar]

Here's a similar story on a Cooper S B48 (shared components with the 320i). Strange thing is that on the MINI side people are having issues with >450nm torque running stage 2 whereas the bm3 tune on stage 1 is a maximum of 400.
https://www.northamericanmotoring.co...ternals-3.html

[Moaus]

No, these logs are after the problem occurred (drivetrain/shaking idle) so I would be crazy to go WOT.
I think that in this log the dme blocked pressure building.
I do remember about 20.4 psi boost before that.

[tpoddar]

Originally Posted by Moaus

No, these logs are after the problem occurred (drivetrain/shaking idle) so I would be crazy to go WOT.
I think that in this log the dme blocked pressure building.
I do remember about 20.4 psi boost before that.

Any logs you had after installing the tune but before this incident?

[Moaus]

Originally Posted by tpoddar

Any logs you had after installing the tune but before this incident?

unfortunately i do not.

[tpoddar]

Originally Posted by Moaus

unfortunately i do not.

how did you check if the tune was working fine with your car in that case?

[Moaus]

Originally Posted by tpoddar

how did you check if the tune was working fine with your car in that case?

well, i didn't (and didn't in all of my tuned cars i had before).
now i just want to know what could be the cause of that and what should i do next... i had a seat leon stage 2 before, she ran like a cheetah!

[tpoddar]

Originally Posted by Moaus

well, i didn't (and didn't in all of my tuned cars i had before).
now i just want to know what could be the cause of that and what should i do next... i had a seat leon stage 2 before, she ran like a cheetah!

So in the brief experience I have had I can point out two factors and how they might've caused this accident :-
1. The B48B20A engine in the 20i motor is 11:1 CR and to push 18-20 psi of boost you require great quality fuel. I for example run my car on the 91ACN map with 99RON fuel + octane booster. So my logs are extremely clean even if I'm not making the most amount of power. The fuel and tune combination you have used in the cupra may have worked for that car but for certain this particular engine is very picky about fuel quality. Long story short, bad fuel leads to knocks and detonation which is most likely what happened here.

2. The tune may have increased the risk of Low speed pre ignition given the increased torque output in the low-mid range. This may have caused an issue but it's unlikely.

What did your mechanic have to say about this?

[Moaus]

Originally Posted by tpoddar

So in the brief experience I have had I can point out two factors and how they might've caused this accident :-
1. The B48B20A engine in the 20i motor is 11:1 CR and to push 18-20 psi of boost you require great quality fuel. I for example run my car on the 91ACN map with 99RON fuel + octane booster. So my logs are extremely clean even if I'm not making the most amount of power. The fuel and tune combination you have used in the cupra may have worked for that car but for certain this particular engine is very picky about fuel quality. Long story short, bad fuel leads to knocks and detonation which is most likely what happened here.

2. The tune may have increased the risk of Low speed pre ignition given the increased torque output in the low-mid range. This may have caused an issue but it's unlikely.

What did your mechanic have to say about this?

he did ask me what kind of oil i put (castrol edge 5w40 is perfectly fine) and
he also mentioned it is not a one-day event but over a period of time.

[tpoddar]

Originally Posted by Moaus

he did ask me what kind of oil i put (castrol edge 5w40 is perfectly fine) and
he also mentioned it is not a one-day event but over a period of time.

So the LSPI theory can be ruled out. If you tune the car again after it's repaired do check the fuel quality and proceed.

[Moaus]

my mechanic can't seem to find the right piston in my country, can someone advice from where can i order one ?

[tpoddar]

Originally Posted by Moaus

my mechanic can't seem to find the right piston in my country, can someone advice from where can i order one ?

You can go to the vacmotorsports website and order a set of forged pistons for your engine. You can also choose to lower the compression ratio if you'd like to make it safer for the future.

[Moaus]

Originally Posted by tpoddar

You can go to the vacmotorsports website and order a set of forged pistons for your engine. You can also choose to lower the compression ratio if you'd like to make it safer for the future.

thank you for your fast reply - i'll look into it.

[Moaus]

Originally Posted by tpoddar

You can go to the vacmotorsports website and order a set of forged pistons for your engine. You can also choose to lower the compression ratio if you'd like to make it safer for the future.

i'm a bit confused about the bore size/compression ratio.

if i'm not mistaken stock is 82mm/11:1.

should i stick with the same size ?

options for bore size: 82mm, 82.5mm.
options for compression ratio: 11:1, 10.5:1, 10:1.

what about coating ? (skirt/dome) do i really need it? (seems like overkill).
i don't want to change anything else apart from having bm3 again on the safe side without having more issues engine wise.

[SRHosein]

Originally Posted by Moaus

i'm a bit confused about the bore size/compression ratio.

if i'm not mistaken stock is 82mm/11:1.

should i stick with the same size ?

options for bore size: 82mm, 82.5mm.
options for compression ratio: 11:1, 10.5:1, 10:1.

what about coating ? (skirt/dome) do i really need it? (seems like overkill).
i don't want to change anything else apart from having bm3 again on the safe side without having more issues engine wise.

Sorry to hear about your car. I have BMW 330e B48 (360+whp) which is basically 20i engine. I have been running it hard, track use, stage 2 BM3 tuned and now custom tune. I beta tested with BM3 and have it for over 1 years. No issues thus far and this is my daily car. I maintain the car myself and use shell helix 5W40 ultra A3/B4 Spec (40 because of my temperatures). I also know numerous users pushing 22psi on custom maps with no issues. 1 user did 25 psi on aftermarket turbo and pistons lasted two months. BM3 maps are very conservative but specifically designed for good quality fuel and properly maintained car. If tuning, its more power boost ect to your car so maintenance should be on point.

1. Piston Size - I would say try CP stock bore and ratio, if deviating, your stock map may not run properly and you may need to custom tune for it. I also planning to upgrade and was looking at CP Mahle and Supertech. Supertech has best price but I was leaning towards CP. For Mahle I could not find stock piston ratio. Who ever you are doing the work with make sure they good, I have seen users getting blowby issues after replacing forged pistons and plenty oil in intake.

2. Coating - Big Boost turbo made 900+whp without any coating. However, the skirt coating maybe a good idea if your cylinder walls are worn.

[Moaus]

any more shops to order from ? vac told me it can take up to 4 weeks ! i need it as soon as possible.

[tpoddar]

Any updates on your car? Moaus

[Moaus]

Originally Posted by tpoddar

Any updates on your car? Moaus

Well, just yesterday got the cp pistons with complimentary extra cost by customs

Hopefully it'll be installed by Thursday and I'll have a couple of logs stock / bm3.
I will make sure to update.

[tpoddar]

Originally Posted by Moaus

Well, just yesterday got the cp pistons with complimentary extra cost by customs

Hopefully it'll be installed by Thursday and I'll have a couple of logs stock / bm3.
I will make sure to update.

Yes keep the thread updated. Do post logs on bm3, that'll help find out if fuel was the only issue that caused the accident or there was something else.