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      01-20-2021, 01:15 PM   #15
Holset
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Drives: F90 M5 Comp LCI
Join Date: Feb 2012
Location: Sweden

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Nice post Adam--- any street data by chance (on my cell so I might have glossed over it).
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
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