[sbmws]

Im trying to lower my under bonnet temps and help the hot air get out on track days as the car really heat soaks after a few laps

Have read people saying that the Cowl Delete helps hot air out, I searched for a bit but couldnt find any info with actual logged data

Can anyone confirm if this has ever actually been confirmed via logging?


Its cheap enough that I'll probably give it a go anyway but just wondering if it was confirmed

[whyzee125]

Not a good mod IMO. You definitely increase the amount of moisture and dirt that gets into the cabin (blower motor and evaporator area) and change the fundamental design of the shape of the hood/windshield. While I don't fully understand why, BMW designed that to be sealed which makes a low pressure spot at the bottom of the windshield. By losing this seal, you're messing with how it would act in a wind tunnel. Not that you'll feel that in real life, but there is a reason they made it the way it is. Also, without a cowl, you'll get water dripping down onto your engine and your cyl 6 plug and coil will get rusty.

Get a CSF rad, make sure you're running a huge intercooler and run a tune that isn't too hot and you'll be just fine on the track. I looked into going cowl-less and tried it for a bit. Tons of dirt in the blower motor, rust on the blower motor nut, and a rusty plug and coil later I decided to go M3 cowl and haven't looked back.

[sbmws]

currently running a 7inch cooler, E40 St2+ targeting 18psi peak but tapering quickly to 12psi on stock turbos so not really pushing them too hard

I was seeing IAT with DCI go from 30c to 70c after 2-3 laps and the car heatsoaking in 30c ambients

I dont have an undertray so would assume plenty of air is already getting up in there

I dont want to upgrade my IC to 7.5 inch since this will block off even more of the radiator from receiving air


Water wont be a problem as car wont be driven in rain and I can even minimize this further by simply removing cowls at start of track day and put the BMS ones on and then swap back at the end, not sure how much dirt and dust id pick up in a track day but cant imagine it would be a huge amount?

Im assuming you just ran yours all the time?


I'll be considering other things like heat shielding/enclosing the DCIs, ducting for Oil cooler etc but just wondering if this simple change could also help with cooling as every little bit helps with these cars

[335i54n]

u need an undertray, all that little stuff doesnt amount to much and probably cause more issues. hpde an e9x n54 fbo is a hott heavy mess. you need extra water and oil coolers and wmi injection for sure no matter the ic size. you kinda need it all, 1st wmi for iat (along with ic upgrade), then aux cooler or csf radiator upgrade, then oil cooler is usually how the heat builds up besides bbk/race pads also

[sbmws]

Re the undertray the car didn’t come with one and I never bothered to get one but having a quick read of aerodynamics I’ve just realized not having one is probably actually hurting the cooling at speed by encouraging are to come up from underneath and behind the IC and Rad and limiting the the flow of air through them from the front of the car


the cowls im not doing because rather than vent at speed it will pull air in which will again mess up the aero for the rad and IC
Fascinating stuff aerodynamics and airflow I had it all backwards lol

You are no doubt right that I will need to upgrade my Rad, Oil Cooler and add a stand alone Trans cooler to have any real noticeable effects

But i think to start with Im going to create ducting for my stock Oil cooler and tans heat exchanger, will get an under tray and put it on and will in close my DCI so they arent sucking in hot air and see how far that gets me