Discussion and questions related to the course Practical Reflash Tuning
I hope this isn’t off topic but
A buddy of mine just blew a head gasket on the dyno at 600 hp at only 17psi on e85 this was a fresh build everything was resurfaced the block is a css with oring and l19 head studs
the engine coolant pressure spiked and it erupted out of the radiator cap and pushed in the over flow
We pulled the head everything looked ok with a straight edge but we had the head resurfaced to be safe cause the gasket failed on the head side the studs were all about the same tq block side of the gasket is perfect I tried to pull the log in the ecu but it was deleted and the map appeared to have been tampered with cause the boost control was turned to 0 and it can’t make 17 psi without it on
We are woundering if it’s possible the tuner had the timing alittle too hot the car also lost 20hp on this pull gasket let go as he was ending the pull from what I could see the timing under full boost at 9500rpm was roughly 21-23degrees that seems high to me but I haven’t done much with e85 and I am still learning forgot to add air fuel was around 11.0 from what tuner told him there’s no pitting on pistons head or plugs aswell
engine is roughly 11-11.5:1 compression aswell which I know also affects max timing
any help would be appreciated I can also upload the map once I get a chance
Hi Austin the ignition does seem fairly high for that amount of compression but there is also may things to factor in like does the map actually reflect the engine timing ( is the base timing correct ) what was the knock doing at that time the far if being tuned in petrol afr is ok but if being measured in e85 afr it is very lean ( my guess is that it is being tuned in petrol afr ) the loss of hp is relivent to the head gasket and the tuner would not have known it was down on power until the end of the run
it looks like only the tuner will really know
Thank you for your input to my knowledge he wasn’t using a knock detector i also don’t understand why he didn’t just use lambda so much easyer. I plan on pulling timing out of the map and doing some road tuning to confirm the gasket will hold before having the car go back to the dyno and spending more money
Car will also not be going back to that tuner
also just curious how acurate will the factory knock sensor be in this application ? I would assume not very?
I don't think the tuner is at fault here. At 600 hp from the 2.4L engine, head gaskets are likely to fail. And when they do it's just as likely to happen right away (like after a fresh rebuilt). No signs of detonation -- just a normal failure of a high-stressed part.
im attaching the file if you guys could check it out and see what you think that would be awsome