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ZM2 · 10-20-2019, 01:17 PM

Hey guys, here's an update from another open track day last month:

Max temps
Ambient - 101F
IAT - 152F
Oil - 275F
Coolant - 256F

The only difference with the car was I was mostly running BM3 OTS Stg 2 E30 5.8, vs Stg 2H 5.7. See log links below.

Quick thoughts:

IATs
I'm not worried about watching IATs anymore. The ethanol does a really good job of keeping power levels up when IATs increase. And, this track was more representative of the longer and more open tracks I visit, vs the shorter/tighter tracks that were really driving up IATs in my other posts.

The outcome was a max ambient/IAT delta of 51F, vs 60F on the tighter tracks. Seems reasonable considering a really hot day and pushing the car hard for 30+ min at a time.

Oil/Coolant Temps
These continue to be my bane. The 5.8 map did a better job at not reaching these temps as quickly as the Stg 2H 5.7 map, but I'd still hit temps where the car would begin to pull power (Coolant >241F, Oil >270F).

MAF values with the Stg 2 5.8 map were down a tiny bit vs Stg 2H 5.7. And, 5.8's approach to power trades some boost for timing, so I was seeing peaks of 16.5-psi on Stg 2 5.8 vs 17.9-psi on Stg 2H 5.7.

These factors are what helped the engine not get to power pulling temps as quickly, but I'd still reach coolant temps of >240F after 6-laps and >250F a couple laps later. Also, 5.8 doesn't have as large of a power drop in the upper RPMs as 5.7, so lap times ended up being similar.

Next Steps
I'm not really sure what best to do to address the engine cooling issue on hot days, but here are a few thoughts:

-I don't see meth being effective enough to lower engine temps over long runs. Sure, IATs will be lower, but I'd be using a huge amount of meth to do that, and it would likely only buy me a couple more laps before coolant temps would reach >240F anyways.

-Running pure water vs a water/glycol mix will bring coolant temps down, but water's vapor pressure is lower so I need to figure out our cooling system's operating pressure to make sure it operates high enough so vapor bubbles don't form in low pressure areas around the engine block and create hot spots. Anyone know our cooling system's operating pressure?

-For engine tuning, you can see I was increasing the E mix up to E35, just to see what the car would do. It didn't help with cooling or power (no tune to take advantage of it) and you can see the HPFP straining more as the Emix goes up. So, I could likely upgrade the HPFP and focus on an E35-45 tune that keeps boost down, but increases timing. It wouldn't be a big power increase since I'd keep boost levels down, and I'm guessing it still wouldn't provide many more laps of keeping engine temps down.

-For engine hardware, I'm running the FTP turbo inlet pipe and can change to the new Pure inlet turbo pipe to hopefully gain a little bit more flow. This would be another incremental gain, vs a fix.

Also, I could change from my Dinan turbo to a PS2 and follow the engine tuning thoughts above to go higher on Emix & timing while keeping boost levels lower. This would produce a little more power and likely lower temps, but similar to my thoughts on meth, would the lower IATs really be enough to keep engine temps in check? And, I hate the idea of adding more turbo lag.

-For airflow, changing to an M2C nose and adding fender/hood venting may end up being the most effective approach to keeping engine temps in check. Altho, I haven't seen any data on this, and I'm one of those guys that really likes the M2's looks and do not want to change to an M2C nose or add vents that will impact the car's aesthetics.

So, what do you guys think? I can always take the shotgun approach, but I'm curious which of the fixes above will have the most impact.

Thanks!

Logs
Stg 2 E30 5.8 earlier in the day:
http://www.bootmod3.net/log?id=5d7a500eae729b06e29120da

Stg 2 E30 5.8 in the afternoon:
http://www.bootmod3.net/log?id=5d7a93fcc090c677bd36877e

Stg 2H E30 5.7 in the afternoon:
http://www.bootmod3.net/log?id=5d7a6ef3c090c677bd3686df

10-20-2019, 01:17 PM	#89
ZM2 Brigadier General 2811 Rep 3,695 Posts Drives: 2017 LBB M2 Join Date: Mar 2017 Location: Baltimore iTrader: (1)	Hey guys, here's an update from another open track day last month: Max temps Ambient - 101F IAT - 152F Oil - 275F Coolant - 256F The only difference with the car was I was mostly running BM3 OTS Stg 2 E30 5.8, vs Stg 2H 5.7. See log links below. Quick thoughts: IATs I'm not worried about watching IATs anymore. The ethanol does a really good job of keeping power levels up when IATs increase. And, this track was more representative of the longer and more open tracks I visit, vs the shorter/tighter tracks that were really driving up IATs in my other posts. The outcome was a max ambient/IAT delta of 51F, vs 60F on the tighter tracks. Seems reasonable considering a really hot day and pushing the car hard for 30+ min at a time. Oil/Coolant Temps These continue to be my bane. The 5.8 map did a better job at not reaching these temps as quickly as the Stg 2H 5.7 map, but I'd still hit temps where the car would begin to pull power (Coolant >241F, Oil >270F). MAF values with the Stg 2 5.8 map were down a tiny bit vs Stg 2H 5.7. And, 5.8's approach to power trades some boost for timing, so I was seeing peaks of 16.5-psi on Stg 2 5.8 vs 17.9-psi on Stg 2H 5.7. These factors are what helped the engine not get to power pulling temps as quickly, but I'd still reach coolant temps of >240F after 6-laps and >250F a couple laps later. Also, 5.8 doesn't have as large of a power drop in the upper RPMs as 5.7, so lap times ended up being similar. Next Steps I'm not really sure what best to do to address the engine cooling issue on hot days, but here are a few thoughts: -I don't see meth being effective enough to lower engine temps over long runs. Sure, IATs will be lower, but I'd be using a huge amount of meth to do that, and it would likely only buy me a couple more laps before coolant temps would reach >240F anyways. -Running pure water vs a water/glycol mix will bring coolant temps down, but water's vapor pressure is lower so I need to figure out our cooling system's operating pressure to make sure it operates high enough so vapor bubbles don't form in low pressure areas around the engine block and create hot spots. Anyone know our cooling system's operating pressure? -For engine tuning, you can see I was increasing the E mix up to E35, just to see what the car would do. It didn't help with cooling or power (no tune to take advantage of it) and you can see the HPFP straining more as the Emix goes up. So, I could likely upgrade the HPFP and focus on an E35-45 tune that keeps boost down, but increases timing. It wouldn't be a big power increase since I'd keep boost levels down, and I'm guessing it still wouldn't provide many more laps of keeping engine temps down. -For engine hardware, I'm running the FTP turbo inlet pipe and can change to the new Pure inlet turbo pipe to hopefully gain a little bit more flow. This would be another incremental gain, vs a fix. Also, I could change from my Dinan turbo to a PS2 and follow the engine tuning thoughts above to go higher on Emix & timing while keeping boost levels lower. This would produce a little more power and likely lower temps, but similar to my thoughts on meth, would the lower IATs really be enough to keep engine temps in check? And, I hate the idea of adding more turbo lag. -For airflow, changing to an M2C nose and adding fender/hood venting may end up being the most effective approach to keeping engine temps in check. Altho, I haven't seen any data on this, and I'm one of those guys that really likes the M2's looks and do not want to change to an M2C nose or add vents that will impact the car's aesthetics. So, what do you guys think? I can always take the shotgun approach, but I'm curious which of the fixes above will have the most impact. Thanks! Logs Stg 2 E30 5.8 earlier in the day: http://www.bootmod3.net/log?id=5d7a500eae729b06e29120da Stg 2 E30 5.8 in the afternoon: http://www.bootmod3.net/log?id=5d7a93fcc090c677bd36877e Stg 2H E30 5.7 in the afternoon: http://www.bootmod3.net/log?id=5d7a6ef3c090c677bd3686df Last edited by ZM2; 10-20-2019 at 03:17 PM..
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