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Originally Posted by Holset
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Originally Posted by Longboarder
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Originally Posted by Holset
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Originally Posted by Longboarder
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Originally Posted by Vic55
Nice post Adam--- any street data by chance (on my cell so I might have glossed over it).
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What's up my friend.
No nothing other than a couple brake boost launches to make sure it still hooked up from a dig as I hear that becomes a problem once tuned particularly with those of us blessed with PZeros haha. So far so good. I think the boost reduction under 4,000rpm is helping.
The real story is how much it picks up over 60 and I need to test but damn the weather and surf have been so good here hard to get a block of time to cross the border into Mexico to do full 1/4 mile and 60-130 tests.
E30 is amazing with this car. Probably because IATs are always high from the air to water system that uses the engine coolant to "cool" the intake charge. Seriously wtf BMW. There's a Chevron in Laguna Niguel (crown valley and niguel road) with e85 pump makes things so easy so us nearby! |
Nice write up and congrats! 
Since you say the dme was locked what build date is your car?
Also you are the first guy that i heard complaining about the cooling system in these cars as they are considered to have sufficient cooling.
You wrote that charge air cooling is cooled by the engine coolant which is not true they are two separate cooling systems.
Check out the attachments these are for the F90 M5 but should be the same for the M8  |
Thanks! It's a 10/19 build date.
Good info on the cooling system. Can you see whether the liquid in the system uses water separate from the coolant? Edit: nvm I see that it is a separate system. What is puzzling to me about this system is that whatever liquid is used to "cool" the intake charge, just keeps circulating within the very hot engine bay.
Anyway regardless the logged IATs were all around 50c on the start which is not good at all but perhaps because we picked a hot day and without good airflow, the liquid in the cooling system heats up. The dyno room certainly doesn't replicate the conditions on the street but perfectly replicated what it is like to start a half mile airstrip run or a 1/4 mile drag run where you are sitting at idle creeping forward as you wait your turn to race.
I used an air to water system on a previous car and it robbed a lot of power. As soon as the liquid measured 115F, the car would start to pull timing. By 150F it had dropped over 100hp on the dyno. I had to get a larger capacity system that routed the liquid out of the hot engine bay and into a new tank mounted in the trunk to cure the issues. |
Okay i am not sure but i think it was around 6/20 when Bmw implented a new Dme lock that hasn't been cracked yet.
About your iat 50c/122f is not that high seems normal sitting at a dyno.
It pretty much impossible to have the charge air lower than ambient air maybe if you put ice in the charge coolant and sprayed the radiator with water/alcohol?  :
You can read up on the whole tech document here https://f90.bimmerpost.com/forums/at...8;d=1530151323 |
One thing that I did note about IAT's on the dyno - I was in the passenger seat for each dyno pull with bFlash on the laptop logging each pull watching the data.
The start IAT like I mentioned was around 50c to begin each run, however I would note that at the end of the pull the IATs would always be lower. For example if start IATs were 50, by 5,000 rpm WOT the would drop down to 47c and then maybe creep up to 48c by 7,000 rpm. Clearly airflow can't replicate a real WOT run on the street so I wonder what IATs would have been had I been on the street vs the dyno room.
Given that LCE Performance was noticing the very high start IATs, my guess is that in the real world and for their dyno testing perhaps in much cooler weather, they see much lower IATs and to their surprise my stock pull at 1.35 bar was the highest they'd seen because it was also the highest IATs they'd seen and my guess is that the stock ECU needed 1.35 bar to make 600 hp with high IATs.
Anyway perhaps the system is more efficient than I thought. The only real way to tell is to do a sustained WOT pull like a half mile in warm temps and compare to data from my other cars with different intercooling setups.