[AmuroRay]

According to what I read from MHD, the lower cooling targets from the radiator actually can lower oil temps by 10F as well.

This all comes back to the coolant system is being used to cool the oil.

Sport / Race Cooling Mode
Reduces the coolant temperature for better performance, lower oil temperature and less engine stress.

https://mhdtuning.com/pages/mhd-flasher

Today's update brings many nice things to the MHD F+G Series users:
...

Another nice feature for N55, B58 and N13 cars: We found a way to bring the M switchable coolant feature to non-M cars. With the coolant flash option activated, the coolant target will be 95c in eco / comfort instead of 106c+. If you switch to sport mode (or comfort + transmission in S or M), the coolant target will be 85c with performance or 80c with track option selected. This allows the engine to run cooler and oil temperature will also benefit from that significantly. We also changed many fan settings to further improve how quick the system reacts to the different modes, this also helps to reduce the IAT and under hood temps when staging at a drag strip or slow city driving.

https://www.facebook.com/MHDtuning/p...1282609467056/

[F87source]

Originally Posted by AmuroRay

Street performance is indicative of track performance. If it doesn't work on the street, it's not going to get better on the track. Not to drag anyone over the coals, but I was and continue to be correct on the intercooler sizing and impact, from throttle response to power, to IAT control despite not having "years of on track experience" I know the theory behind these factors, how they work and WHY they work - I can review datalogs see trends and provide input like anyone else.

And as always, I'll do my best to substantiate everything I say with sources. I'm here to help you (and save you money) but ultimately, you're going to do what you're going to do.

This is absolutely not true.

1) On the street when you are doing massive high speed pulls you don't have any traffic ahead of you. This is a huge factor because on track you have traffic, and this means dirty turbulent hot air coming off the back of cars. Dirty turbulent air is not laminar and therefore isn't going to flow through radiators as effectively, it will also not follow contours of ducts the same way laminar air does. This is a huge problem in motor racing and why you always hear teams over the radio tell their drivers to pull into the clean air for better cooling. It is also why cars will deviate from the racing line until the last moment before the corner so they can better cool their car instead of following the cars in front.

2) On track temperatures are so much hotter than ambient air temps because of the high speed running on track. Again this is different than the street.


So no street performance is no where indicative of track performance, there is a reason why track tuning exists - because you simply cannot replicate those conditions on the street or dyno.


If your tune or setup doesn't work on the street it is so garbage you shouldn't even think about the track.



The theory also says the more things you stack infront of radiator that requires cooling the less flow energy going through to the radiator, and the hotter the cooling air becomes making cooling ineffective. There is no way around this fact.

[F87source]

Originally Posted by AmuroRay

I found the silver bullet:



https://f87.bimmerpost.com/forums/sh...ighlight=pikes

Notes:
Tracks the car
Is actually a race car
Has experience
Tested products

Also noted from his setup -
21PSI - and 465whp
No secondary radiator. Zero
Stock radiator?
Intercooler and secondary Oil cooler occupying MORE space and airflow than a taller intercooler would
Despite this Coolant temps in full attack mode were 237F at the highest

There is no silver bullet, btw that setup he ran overheated like crazy and you are missing the more updated versions. Like we said before this has been an issue since the beginning and we studied typseed's setup extensively - there is no way you are seeing things we haven't already seen, digested, processed, and looked at again and again and again. At this point tyspeeds setup is so far from streetable that we didn't even think about it anymore.

1) He added the secondary aux radiator - 2 actually and the larger ones from the S55 and added the e39 m5 aux water pump. Where do you think ZM2 and I got the idea for that? Typspeed was the first, ZM2 was the second, and there is a new option now for running the m235i aux pump with an external controller. I even talked to Enabled to see if we can fully retrofit the m235i aux water pump and have it controlled by the DME like on the m235i.





What do you notice in the lower openings? That's right the aux rad returns.

2) He is (as of the final m2 spec before selling it) running the CSF race spec radiator which is 10 mm thicker than stock and requires an AC delete.

3) He deleted the entire crash bar to run the set up like that + custom internal ducting. Also note, you have more mass flow when you delete the crash bar and cut the bumper opening that wide. Mass flow is everything for cooling. So this is not even remotely applicable to the stock setup, and if you delete the crash bar you lose insurance.

4) Nope he still suffered from over heating, watch his youtube videos.

How did he solve it for pike peak? He got brushless water pumps which flow much more than the stock water pump, he got water injection, and the biggest one of them all water sprayers for the radiator.

5:28 he talks about the cooling setup, 2 aux rads and the water sprayers. Like I said there is no silver bullet. There is only the extreme setups that would be impossible for a street car. The water sprayers are possible but it would make the car have limited time on track which is fine for pike peak but not for 30 min track sessions.

Originally Posted by AmuroRay

It is, and always has been an oil cooler issue, and possible a airflow issue with the M2's bumper like I surmised a few days ago. I would start with a thermostat and look for a bigger/better oil cooler. No need to reinvent the wheel.

This is inaccurate. Even on tyspeed's setup it was always coolant that was unsolvable despite completely isolating the coolant and oil loops - this means coolant is just out of control even without the oil heat exchanger evening up coolant temps. Sure oil temps are high, but we have till 132C before any load is pulled, with coolant it's 117C and we always hit coolant limp modes before oil. I also think oil temps are easily solved, we can start by widening the opening to the oil cooler. The with better ducting, and if needed it's easy to add more oil coolers with the ability to get an lines and run coolers in series. With coolant we are stuck.


I don't want to be a dick, but ZM2 and I have been thinking about how to solve this problem for YEARS, and it has still been a struggle. We have looked at every possible venture and solution that hasn't even been discussed on the forum yet - like custom valving the heat exchanger, and the list goes on. We even thought about going custom thermostat with high flow capabilities (improved racing sells the best one and there is nothing better) and high flow An lines. We though about everything. So with all due respect - there is no way you can possibly think you know everything or think there is silver bullet that can be done just like that. There is only 1 real solution, more radiator surface area aka a full sized s55 radiator. But to do that you need to delete the intercooler and retrofit the s55 air to water cooler.

[AmuroRay]

Yeah, all of that is wrong.

The coolant is being used to cool the oil , and all that has been done is adding a pathetic oil cooler (with a stepped core instead of full frontal surface area to correct it.

He’s tried a different primary radiator, a bigger aux radiator, different coolant, a lower coolant switch and l now an auxiliary pump and you’re still arguing it’s a coolant issue despite the obvious.

Read what both Bootmod and MHD said about the coolant relationship to the oil - the coolant is being used to cool the oil, and the hotter the oil gets (because it can’t shed head like radiator does) the more difficult it is to keep the coolant temps low.

There is a reason I went with multiple examples instead of just one - this has been a well documented issue in the turbo era of BMWs. ZM2’s done literally one upgrade to the oil system with a oil cooler that likely does nothing, from a brand who steals designs (ATM Intercooler) , and often times do zero R&D on their products (instead relying on the end-user to test the products for them)

The Pikes Peak M2 doesn’t even use the regular CSF oil cooler (which by the way has zero actual data aurrounding it. Surely sounds like a “tested” product)
How big is the core? What are actual measurements? Is there any logs or data how it performs?

Instead - it offers the most marginal decrease in oil temps, and has caused to coolant system to pick up the extra slack. Read what the Pikes Peak diver said about the radiator - CSF had asked him to put it back on the car - no doubt as a way to advertise their products, regardless of their worth.

Give yourself an hour and just look up on bimmerpost time attack BMWs with 400/500/600hp - all of them complain about oil cooling and not water cooling. You’re looking at a symptom and both the underlying issue.

[AmuroRay]

https://motoiq.com/breaking-records-...k-bmw-135i/10/

135i - VRSF RACE Intercooler that is supposedly terrible for racing. - also noted, 2 auxiliary oil coolers

https://www.2addicts.com/forums/show....php?t=1864339

Video of a F20 with a dual oil cooler set up with over 400whp and claim of no cooling issues.

Also present on the page - someone who has the CSF eBay cooler with a claimed 3F difference over the stock unit.

Final post on the page is from a owner of a time attack M235i with a thermostat and oil cooler setup (DO88) who claims his cooling issues have been figured out.

https://www.2addicts.com/forums/show....php?t=1739152

Here is his review of the DO88 cooler and upgraded tstat in 105F+ weather

Right now my worst case scenario base line was a time attack race from last season.
It was 40c+, high humidity, and I was using my a/c while staging.
The highest i saw was around 245-48f according to my old logs (ill have to try and dig them up, but thats what I have in my notes that i can find).

Not sure if I will have any time attack data for this season, as things are quite messed up due to covid.
I will be doing a roll racing event this weekend and another dyno session the following week (last session a couple weeks ago temps never exceeded the low 220's.

And don’t miss this comment:

Oil is really only there for lubrication, cooling characteristics are a secondary by product of its purpose.
Cooling should be done through the radiator system, which now does not have to [dissipate] any heat from the oil system.

[ZM2]

Alright, let me attempt to catch up to everyone's comments in one post.

I'm going to try to keep this focused on solutions for a tuned, four seasons daily driven OG M2 that does not have a stripped interior and sees street parked sub-freezing winter cold starts on one end and hard track time on large, fast tracks during hot summer days on the other end. Basically, the most difficult combination of scenarios to address possible.

What is clear is there is interplay between coolant and oil temps due to the crossflow coolant/oil heat exchanger. F87source and I have spent a good bit of time thinking of how to bypass this during the summer when it's not needed to warm up the oil quickly on cold winter days. I have not gone this path as there's a lot of custom work that is not guaranteed to not upset the cars electronics somehow.

So, let's exhaust all other options first.

Coolant
We're maxed on capacity, as I do not plan to remove my AC condenser. That means all we can do is be more efficient via increased flow or more thermal exchange.

Flow- We added an E39 coolant pump inline as the M2 only has one coolant pump, while the M235i (and many other N55 motors) have two. While it did not address the inevitable overheating of the coolant, it definitely helped bring temps down quicker when doing cool off laps.

Heat exchange- If we're already using MaxCool, 100% water + wetter vs a 50/50 mix, and we're maxed on coolant system capacity, all we can do is get more air to the coolers. I do not plan to cut up the front bumper or add fender or additional hood vents, so we're really just talking about removing restrictions to airflow to the radiator. Anything that's in front of it (IC, DCT cooler, custom oil coolers, AC condenser, etc.) will absolutely impact the airflow and the temperature of the air hitting the radiator, and thereby the amount of available air-to-liquid heat exchange for the coolant system.

The only item in that chain that can be readily changed is the IC. The smaller the IC, the more clean air that will be available for heat exchange. What's up for debate is just how impactful that is to this overall situation. If I tried this, I'd probably go with a VRSF Comp IC and if it helped with coolant temps, supplement with water injection if IATs are too high on track.


Oil
I'm OK entertaining thermostats and different oil coolers, but let's address these separately.

Plug-in oil coolers
From what I remember, the CSF has more additional oil capacity than the do88. Someone will have to confirm in their specs. Does that mean the CSF performs better or worse? No way to tell without real-world testing. Either way, I'm guessing the difference b/n the two isn't going to fix the coolant and oil temp problems I'm having--there's just no way a marginal gain there is enough for the entire system.

Custom oil coolers
Because of the four seasons daily driven nature of my car, I don't see this being a feasible solution as it would take too long to warm up oil for cold winter starts. Plus, the only place to put an additional oil cooler on the OG M2 is behind the kidneys, impacting airflow on the coolers and radiator behind it, potentially addressing one issue to make another issue worse.

Thermostats
Obviously, these do not increase capacity and primarily work by keeping nominal oil temps lower, providing more headroom before oil temps get higher. That might translate into an extra lap or two but wouldn't fix the larger problem. So, the question that remains is the stock oil thermostat a flow restriction in the oiling system and do any of these thermostats remove that restriction to increase total oiling system flow (and heat exchange), and if so, are they safe to run in the winter for cold starts?

Here's a recent track log when it’s not even that hot out: https://bootmod3.net/log?id=635c1292d10b43dbd4c99ae4

You'll note we hit coolant limp mode before oil, but no doubt both are impacting each other pre/post-limp mode for both.

So, here’s a log of me ramping down to the stock tune: https://bootmod3.net/log?id=62ee7093c090c6b67441bfce

You can see similar temp issues even with lower power. Temps were not an issue at stock power levels previously, and the only mods I did before stock power seemed to become an issue was the Suvneer hood and the Evo3. This added to the evidence of potential airflow issues.

This is a complex problem to solve for, and I don't think we'll figure it out with back and forth in the forum.

So, the question is, what should the prioritized list be based on cost, daily driving reliability, and anticipated impact on track?

[AmuroRay]

Originally Posted by ZM2

Alright, let me attempt to catch up to everyone's comments in one post.

I'm going to try to keep this focused on solutions for a tuned, four seasons daily driven OG M2 that does not have a stripped interior and sees street parked sub-freezing winter cold starts on one end and hard track time on large, fast tracks during hot summer days on the other end. Basically, the most difficult combination of scenarios to address possible.

What is clear is there is interplay between coolant and oil temps due to the crossflow coolant/oil heat exchanger. F87source and I have spent a good bit of time thinking of how to bypass this during the summer when it's not needed to warm up the oil quickly on cold winter days. I have not gone this path as there's a lot of custom work that is not guaranteed to not upset the cars electronics somehow.

So, let's exhaust all other options first.

Coolant
We're maxed on capacity, as I do not plan to remove my AC condenser. That means all we can do is be more efficient via increased flow or more thermal exchange.

Flow- We added an E39 coolant pump inline as the M2 only has one coolant pump, while the M235i (and many other N55 motors) have two. While it did not address the inevitable overheating of the coolant, it definitely helped bring temps down quicker when doing cool off laps.

Heat exchange- If we're already using MaxCool, 100% water + wetter vs a 50/50 mix, and we're maxed on coolant system capacity, all we can do is get more air to the coolers. I do not plan to cut up the front bumper or add fender or additional hood vents, so we're really just talking about removing restrictions to airflow to the radiator. Anything that's in front of it (IC, DCT cooler, custom oil coolers, AC condenser, etc.) will absolutely impact the airflow and the temperature of the air hitting the radiator, and thereby the amount of available air-to-liquid heat exchange for the coolant system.

The only item in that chain that can be readily changed is the IC. The smaller the IC, the more clean air that will be available for heat exchange. What's up for debate is just how impactful that is to this overall situation. If I tried this, I'd probably go with a VRSF Comp IC and if it helped with coolant temps, supplement with water injection if IATs are too high on track.


Oil
I'm OK entertaining thermostats and different oil coolers, but let's address these separately.

Plug-in oil coolers
From what I remember, the CSF has more additional oil capacity than the do88. Someone will have to confirm in their specs. Does that mean the CSF performs better or worse? No way to tell without real-world testing. Either way, I'm guessing the difference b/n the two isn't going to fix the coolant and oil temp problems I'm having--there's just no way a marginal gain there is enough for the entire system.

Custom oil coolers
Because of the four seasons daily driven nature of my car, I don't see this being a feasible solution as it would take too long to warm up oil for cold winter starts. Plus, the only place to put an additional oil cooler on the OG M2 is behind the kidneys, impacting airflow on the coolers and radiator behind it, potentially addressing one issue to make another issue worse.

Thermostats
Obviously, these do not increase capacity and primarily work by keeping nominal oil temps lower, providing more headroom before oil temps get higher. That might translate into an extra lap or two but wouldn't fix the larger problem. So, the question that remains is the stock oil thermostat a flow restriction in the oiling system and do any of these thermostats remove that restriction to increase total oiling system flow (and heat exchange), and if so, are they safe to run in the winter for cold starts?

Here's a recent track log when it’s not even that hot out: https://bootmod3.net/log?id=635c1292d10b43dbd4c99ae4

You'll note we hit coolant limp mode before oil, but no doubt both are impacting each other pre/post-limp mode for both.

So, here’s a log of me ramping down to the stock tune: https://bootmod3.net/log?id=62ee7093c090c6b67441bfce

You can see similar temp issues even with lower power. Temps were not an issue at stock power levels previously, and the only mods I did before stock power seemed to become an issue was the Suvneer hood and the Evo3. This added to the evidence of potential airflow issues.

This is a complex problem to solve for, and I don't think we'll figure it out with back and forth in the forum.

So, the question is, what should the prioritized list be based on cost, daily driving reliability, and anticipated impact on track?

Start with the oil bypass then to the oil cooler - the final part would be the Intercooler. But you’re not gaining any reasonable headroom without first addressing the oil cooling.


You could also call HPA, Bimmerworld and Turner Motorsports (people who campaigned Turbo BMWs) for suggestions.

Supposedly Do88 said their oil cooler was worth a 20F reduction in oil temps alone - and that’s significant - it could be less work for the rest of the cooling system.

[ZM2]

As for the BMS oil bypass and Mosselman thermostat, as evidenced in many of my logs, once my car is warm my pre-pull/track oil temps are 190F.

The Mossleman stat says it opens at 185F, so I don't see much gain there.

The BMS bypass keeps flow open to the cooler all the time, so likely a more significant impact (and potentially more flow), but doubtful it does anything than provide an extra lap or two. Still, it's cheap and quick install and removal (for winter), so can give it a shot.

We're still not addressing the overall issue, tho. Our two remaining options are CSF to do88 oil cooler and switching the IC:

The only comparable specs I can find b/n the oil cooler manufactures is the CSF requires an additional 1/2qt of oil and the do88 requires an additional 1/4qt of oil, making the internal capacity of the do88 less, but that's not the only factor. I can't find any real-world heads-up data b/n the two, so we're left with speculation. Hard to say if the do88 really is any better than the CSF without actually trying it.

As for the IC, it'd require procuring a VRSF Comp, the pipes to go with it, removing the Evo3 and installing the VRSF. Not a quick and easy job, considering the custom'ish install nature of the Evo3.

For my next outing, I'll have the do88 vs CSF radiator, the new tune, and the BMS bypass all to test for any meaningful impact.

I'm trying to decide if I go ahead to do the oil cooler and/or IC, as well, before my next outing, or gather data that'll likely show we need to do the oil cooler and IC anyways--hah!

[AmuroRay]

Originally Posted by ZM2

As for the BMS oil bypass and Mosselman thermostat, as evidenced in many of my logs, once my car is warm my pre-pull/track oil temps are 190F.

The Mossleman stat says it opens at 185F, so I don't see much gain there.

The car isn't opening the oil flow to the cooler at those temps though. The oil is cold yes, but unless you have a lower switch or bypass valve, the car will continue to allow the oil to heat up to the predetermined setpoint.

On the stock car, this is at least 230F, Mossleman says theirs is 30-60F lower.

So yeah, the gain would be more time spent in the lower temperature ranges instead of the car purposely trying to target a higher temperature, heat soaking and taxing the system more.

The BMS bypass keeps flow open to the cooler all the time, so likely a more significant impact (and potentially more flow), but doubtful it does anything than provide an extra lap or two. Still, it's cheap and quick install and removal (for winter), so can give it a shot.

I'm willing to bet it's more than a lap or two - it's likely doubling the effect of the cooling system because it's not trying to remove heat from 240F oil to keep it in a happy 20F+/- range and instead starting at a lower set point and allowing the system to just function on the effectiveness of the coolers.

We're still not addressing the overall issue, tho. Our two remaining options are CSF to do88 oil cooler and switching the IC:

The only comparable specs I can find b/n the oil cooler manufactures is the CSF requires an additional 1/2qt of oil and the do88 requires an additional 1/4qt of oil, making the internal capacity of the do88 less, but that's not the only factor. I can't find any real-world heads-up data b/n the two, so we're left with speculation. Hard to say if the do88 really is any better than the CSF without actually trying it.

Just eyballing it - the CSF is not a robust looking piece, so I'm inclined to believe the one review I read that said it was worth only 3F in cooling.
For comparison, DO88 does say their oil cooler alone (and no thermostat change) was worth a 24F reduction in temps. Now this is their own data, but on the thread I linked another user confirmed its effectiveness. A user on the M2 side actually has one and reviewed it and could provide more insight.
HunterHofman

As for the IC, it'd require procuring a VRSF Comp, the pipes to go with it, removing the Evo3 and installing the VRSF. Not a quick and easy job, considering the custom'ish install nature of the Evo3.

For my next outing, I'll have the do88 vs CSF radiator, the new tune, and the BMS bypass all to test for any meaningful impact.

I'm trying to decide if I go ahead to do the oil cooler and/or IC, as well, before my next outing, or gather data that'll likely show we need to do the oil cooler and IC anyways--hah!

I would hold off on the intercooler for now, personally. I think the VRSF Race will outcool anything and is still 3-4" shorter than what you have - I get as low as 1F over ambient (usually within 3F on the first few runs) and it's not much taller than other intercooler options. Keep in mind I do have a reflective tape wrapped charge pipe.

But I want to show you how overblown I think this frontal measurement stuff is:


This is a "race core" PTF vs the CSF which is the go to for this side of the forums.


This is a VRSF Competition vs Race:


The CSF is actually not much shorter than the race cores - the VRSF comp is actually slightly shorter

[AmuroRay]

I watched HunterHofmans review on the cooler:

https://f87.bimmerpost.com/forums/sh....php?t=1954183

(entertaining as always) and in the comment section, he notes at least a 10F reduction in oil temps. This is JUST on airflow cooling alone - that's pretty good.

[ThreeStripes]

Originally Posted by ZM2

I'm trying to decide if I go ahead to do the oil cooler and/or IC, as well, before my next outing, or gather data that'll likely show we need to do the oil cooler and IC anyways--hah!

I vote for doing the do88 oil cooler along with the other easy oil system mods (and funk motorsports turbo blanket)

[ZM2]

A lot of the temp data regarding the BMS bypass and Mossleman thermostat is not accurate for the M2. The M2 has a completely different cooling program.

If you leave the car in Comfort or MDM modes, both oil & coolant temps level to 220F. If you put the car in Sport/Sport+/DSC off modes, the car will drive coolant down to 165F and oil to 195F when just cruising. Plenty of M2 guys have data showing this, as it was one of the early questions back in 2017.

With MaxCool on those values are usually ~160F coolant & 190F oil for a warmed up engine while cruising. This is backed up by the fact that the MaxCool coolant temp setpoint shown in logs is 70C (158F).

So, IMO the Mosselman thermostat looks pointless for the M2, and the BMS bypass should provide lower oil temps than 190F when the engine is idling/cruising, but I again think the delta won't be that large and won't provide more than a lap or two extra. Regardless, I've ordered it b/c of its low cost and easy of install/removal.

As for the do88 oil cooler, the data chart you provided includes the radiator, aux radiator, and oil cooler all together. As we've noted, coolant & oil temps are interconnected on the M2, so I definitely don't expect a 20F delta b/n it and the CSF oil cooler.

The do88 does look beefier. The CSF is basically a couple extra rows on the front with about a 1/3 height back side row set, while the do88 is a decent bit taller and thicker. Less oil volume than the CSF, but looks like more air cooling opportunity with the do88.

All that said, I'm guessing only 5-10F oil temp difference b/n the CSF and do88 oil coolers on track. Couple that with the BMS bypass and maybe we're looking at a handful more laps before oil temp limp mode on hot days.

As for the IC, based on the fact that the stock map is now giving me issues on hot days after the Suvneer hood and Evo3, I still think we have an IC airflow issue that will need to be addressed.

The oil upgrades are certainly easier at this point, and we all agree the BMS bypass and do88 vs CSF oil cooler should provide benefit, so might as well add those and get data before tackling an IC job, which I still think is in the cards.

[ZM2]

Originally Posted by ThreeStripes

I vote for doing the do88 oil cooler along with the other easy oil system mods (and funk motorsports turbo blanket)

Can the Funk blanket be installed while the turbo is already on the car?

[ThreeStripes]

Originally Posted by ZM2

Can the Funk blanket be installed while the turbo is already on the car?

I believe so. Should be similar experience as the M2C install shown here:

[ZM2]

Originally Posted by ThreeStripes

I believe so. Should be similar experience as the M2C install shown here:

IDK man, I’m thinking my mechanic would laugh me out of the shop if I asked him to install this while the turbo is on the car.

[ThreeStripes]

Significantly harder but doable it seems

[AmuroRay]

Originally Posted by ZM2

A lot of the temp data regarding the BMS bypass and Mossleman thermostat is not accurate for the M2. The M2 has a completely different cooling program.

If you leave the car in Comfort or MDM modes, both oil & coolant temps level to 220F. If you put the car in Sport/Sport+/DSC off modes, the car will drive coolant down to 165F and oil to 195F when just cruising. Plenty of M2 guys have data showing this, as it was one of the early questions back in 2017.

Apparently this change alone is can knock that down (for the non M) from 240F to 200-205F

(Last comment on the bottom)

The M2/M3/M4 all use the same thermostat - you can read the reviews from the on the F80 forum, but they report around 15F reductions (from 220F to 205F)

https://f80.bimmerpost.com/forums/sh...1668360&page=2

https://f80.bimmerpost.com/forums/sh....php?t=1834535

With MaxCool on those values are usually ~160F coolant & 190F oil for a warmed up engine while cruising. This is backed up by the fact that the MaxCool coolant temp setpoint shown in logs is 70C (158F).

So, IMO the Mosselman thermostat looks pointless for the M2, and the BMS bypass should provide lower oil temps than 190F when the engine is idling/cruising, but I again think the delta won't be that large and won't provide more than a lap or two extra. Regardless, I've ordered it b/c of its low cost and easy of install/removal.

You're back to using the coolant system to cool the oil and not allowing the oil to cool itself. That's why you keep on running into these issues. Let the oil start cooling early instead of heat soaking the coolant and THEN running through the oil coolers (When the coolant is already maxed out)

As for the do88 oil cooler, the data chart you provided includes the radiator, aux radiator, and oil cooler all together. As we've noted, coolant & oil temps are interconnected on the M2, so I definitely don't expect a 20F delta b/n it and the CSF oil cooler.

I also pointed you to HH review on the M2 where he tested JUST the cooler to be a delta of around 10F. Again, I'm not using one source - I'm using multiple.

The do88 does look beefier. The CSF is basically a couple extra rows on the front with about a 1/3 height back side row set, while the do88 is a decent bit taller and thicker. Less oil volume than the CSF, but looks like more air cooling opportunity with the do88.

All that said, I'm guessing only 5-10F oil temp difference b/n the CSF and do88 oil coolers on track. Couple that with the BMS bypass and maybe we're looking at a handful more laps before oil temp limp mode on hot days.

I'd be surprised if you hit limp mode at all. Between the thermostat and oil cooler, you're looking at a 15F -20F lower start point before the oil starts flowing through the cooler, and then an additional active cooling that could be good for 10-15F on it's own.

That's significantly more headroom than 5-10F.

As for the IC, based on the fact that the stock map is now giving me issues on hot days after the Suvneer hood and Evo3, I still think we have an IC airflow issue that will need to be addressed.

The oil upgrades are certainly easier at this point, and we all agree the BMS bypass and do88 vs CSF oil cooler should provide benefit, so might as well add those and get data before tackling an IC job, which I still think is in the cards.

Did you have issues before the hood? Is it possible that heat is not being vented optimally?

Do other users with the Evo3 report higher coolant temperatures? If you switch, my recommendation is the $460 Race intercooler, but I think that should be last considering how much you already invested in the Evo3 and it's installation.

[ZM2]

Why would I let the coolant and oil get hot before getting on track? It goes straight into DSC off mode, so I’m usually hitting the track with 160-170F coolant and 190-195F oil.

The stock M2 oil thermostat opens below 200F in Sport/Sport+/DSC off without the need for a different thermostat. Those guys you linked to proved exactly my point—the Moss sits at 185F. That’s not much lower than the stock cooling program on M cars in Sport mode. I have no idea why guys with M cars get these thermostats—has never made sense.

The BMS bypass is different and should have more of an impact for the track.

I don’t put a lot of weight in the HH review without logs or track time. The do88 unit does look better, it’s easier than an IC swap, and I found a good deal on it ($515), so we’ll give it a shot.

I did the hood and the Evo3 at the same time, so hard to know which is impacting airflow worse. Logic would say the IC, but some testing would be needed.

[AmuroRay]

Originally Posted by ZM2

Why would I let the coolant and oil get hot before getting on track? It goes straight into DSC off mode, so I’m usually hitting the track with 160-170F coolant and 190-195F oil.

The stock M2 oil thermostat opens below 200F in Sport/Sport+/DSC off without the need for a different thermostat. Those guys you linked to proved exactly my point—the Moss sits at 185F. That’s not much lower than the stock cooling program on M cars in Sport mode. I have no idea why guys with M cars get these thermostats—has never made sense.

The BMS bypass is different and should have more of an impact for the track.

I don’t put a lot of weight in the HH review without logs or track time. The do88 unit does look better, it’s easier than an IC swap, and I found a good deal on it ($515), so we’ll give it a shot.

I did the hood and the Evo3 at the same time, so hard to know which is impacting airflow worse. Logic would say the IC, but some testing would be needed.

Who said you do anything? It’s what the car does - the thermostat opens at a predetermined point, and all that happens is this allos it to open sooner. I supplied you with 3 different people who confirmed as much.

The BMS is better if you’re looking for maximum flow and the best absolute cooling, though the car will not heat up as fast. The Mosselman will heat up like OEM, but the switch to route the oil through the cooler will happen sooner regardless of driving mode or circumstance.

[M2guru]

Originally Posted by ZM2

The do88 unit does look better, it’s easier than an IC swap, and I found a good deal on it ($515), so we’ll give it a shot.

Care to share?

[ZM2]

Originally Posted by M2guru

Care to share?

https://autocouturemotoring.com/prod...-cooler-racing

With code ACMVIP15.

Also got my do88 radiator and Antigravity battery from ACM.

EDIT: 3-week lead time bc it’s shipping from Europe.

[AmuroRay]

Originally Posted by ZM2

Current setup and cooling mods:

Power - 470-480whp
BM3 Stg 2++ Multimap with E50
TTE460 turbo
Dorch Stg 1 HPFP
Turbosmart plumb back BOV
HJS 300-cell downpipe
Akrapovic Exhaust
MST v2 inlet
3.5-bar TMAP
Stock airbox & filter

Cooling
do88 radiator
do88 aux radiator
CSF oil cooler
Stock DCT cooler with larger M2 CSR DCT oil pan
Evo3 IC
Suvneer GTS vented hood
BM3 MaxCool setting
E39 in line additional coolant pump (with F87source help)
E50 fuel
Motul 300V oil
100% water + wetter in the summer

As for latest logs & changes, I switched from the CSF to the do88 radiator and am running a new Stg 2++ Multimap tune that Halim gave me.

I don't have a good comparison log of the CSF to do88 radiator switch bc I've been racing cars this year vs HPDE in my M2. What I do have is a session from Summit Point Main (CSF) and NJMP Thunderbolt (do88) in similar ambient to compare against. You'll see in the logs below that it took many more laps in the NJMP/do88 log to get coolant temps to 235F, even tho I was running a 50/50 mix at NJMP vs 100% water + wetter at Summit. However, I think this is junk data, as the tracks are vastly different, including 150+ mph top speed at Summit vs 135+ mph at Thunderbolt, and the braking zones at Summit are much harder.

Secondly, in the track logs I'm running Stg 2+ Multimap v1.0, which pegs boost at 20.8-psi thru the rev range. My setup could hit that no problem, but Halim released v1.1 & 1.2 which changed the tuning strategy so that guys with stock turbos could run the Mutlimap with no issues. It means a little less power for my setup (and why Halim gave me a Stg 2++ Multimap to use), altho, I potentially like the tuning strategy a lot more for the track.

You'll note in my Stg 2+ v1.2 and Stg 2++/Stg 3 Multimap logs that the tune is no longer pegging boost, instead boost is higher a lower rpms and drifts lower in higher rpms (3-4psi lower at redline), keeping the turbo in a higher efficiency zone & lower WGDC in upper rpms. To me, that means I should be generating less heat on track, albeit a little less power, but probably worth the trade off.

So, for the sake of science, before changing the intercooler I guess I should get another hot summer day HPDE log with the do88 radiator w/ 100% water + wetter and the new tune to see how coolant temps look. While I'm sure they'll be better, I'm not overly optimistic as the track logs are at 50F ambient and I'm still hitting 235F coolant temp at NJMP which has 15mph lower top speed than Summit. Who knows tho, maybe the radiator change and 100% water + wetter, plus the new tune, will have a decent combo impact.

Summit Log
Stg 2+ MM v1.0, CSF radiator, 100% water + wetter
https://www.bootmod3.net/log?id=6355...0b43ae5b703a55

NJMP Log
Stg 2+ MM v1.0, do88 radiator, 50/50 mix
https://www.bootmod3.net/log?id=6386...0b43af6b73a3a3

Stg 2+ MM v1.0 log
https://bootmod3.net/log?id=6333161dd10b432642ac8a1b

Stg 2+ MM v1.2 log
https://bootmod3.net/log?id=6471344fc090c66243bfeef0

Stg 2++ (Stg 3) MM log
https://www.bootmod3.net/log?id=647b...90c6aa737bb893

I'm just reviewing this now in some detail -
If your notes are correct, you're saying the first and second log are CSF vs DO88 Radiators? Same map, different tracks, ambient and different coolant mixture?