[Lozza47]

Hi all,
I just recently flashed to Stage 2 (93oct) with BM3.

My only mods are a downpipe & full exhaust.

I logged some back to back WOT pulls, and IATs were sitting around 85-91 F. Ambient temp was 54.5 F.

Car never went over 91 F unless sitting at idle for a while.

All other parameters looked pretty standard.

The question is, based on this brief information, do I need an upgraded FMIC?

Another question was, there is an OTS map for stage 2 (91oct). It pulls timing back a couple degrees and boost target very slightly. Would this map be the better one to run (still using 93oct though) while waiting for an FMIC upgrade?

[The_otherM235i]

Post a log, maybe we can have a better look. do you *need an inter-cooler?

no.

should you get one for better preformace and safety.... yeah lol.

[cooolone2]

Intercooler will provide more stable temperature ranges and less heat soak issues than without.

Should you?

Well, outdoor ambient temps being in the mid 50's is hardly a good temp to gauge the answer to that question... Where are you located and what's the max temp range you can expect there during summer?

[Lozza47]

Originally Posted by cooolone2

Intercooler will provide more stable temperature ranges and less heat soak issues than without.

Should you?

Well, outdoor ambient temps being in the mid 50's is hardly a good temp to gauge the answer to that question... Where are you located and what's the max temp range you can expect there during summer?

The max temp I would see in summer is probably 100 F.

[mike@x-ph.com]

You should not run stage 2 maps without an intercooler.

[XutvJet]

I'm currently running a Dinan Stage 2 piggyback and catted downpipe. This power level is close to what the conservative Stage 2 flash tunes are making and probably around 30whp/20wtq more than what a stock N55 M2 is making which uses the same intercooler as the M235.

I've only been running the Dinan Stage 2 piggyback in "Stage 2" mode for the last 3 months, thus the maximum ambient temperature I've driven the car in is ~70 degrees. I have the Torque App so can I log IATs.

In sub 50 degree weather and during normal city and highway driving with a few brief 2nd and 3rd gear blasts, IATs tend to be 15 to 20 degrees above ambient. When ambient temps get closer to 70 degrees, I'll see IATs at 20 to 30 degrees over ambient. Interestingly, the IATs do drop a bit during my normal brief 2nd and 3rd gear pulls. This is completely consistent with what I saw prior to adding the Dinan Stage 2 piggyback. When temps get into the 80s, I fully expect to see 30-40+ higher IATs over ambient.

Some do need to realize that an aftermarket intercooler will do little to lower IATs during normal, minimal boost driving. They could actually INCREASE IATs slightly because they are comprised of a lot more metal, thus more of a thermal heat sink. Why you ask? Because during normal driving, especially stop and go and sub 45mph driving, there is a very little air blowing across and going through the IC and intake tract to offset all the radiant heat from the engine bay and radiator, thus the IC and piping tends to heat the slow moving air inside these systems.

During hard driving like 3rd gear+ pulls and racing, the correct size aftermarket intercooler is very beneficial. We do know that the N55 M2s suffer from heat soak and power reduction when raced in 80+ degree conditions. If I were racing my M235, I'd have an aftermarket IC. For street driving, I'm still evaluating that need to see if my IATs are any more elevated during the summer temps and humidity than they were prior to the Dinan Stage 2 piggyback.

[Lozza47]

Originally Posted by XutvJet

I'm currently running a Dinan Stage 2 piggyback and catted downpipe. This power level is close to what the conservative Stage 2 flash tunes are making and probably around 30whp/20wtq more than what a stock N55 M2 is making which uses the same intercooler as the M235.

I've only been running the Dinan Stage 2 piggyback in "Stage 2" mode for the last 3 months, thus the maximum ambient temperature I've driven the car in is ~70 degrees. I have the Torque App so can I log IATs.

In sub 50 degree weather and during normal city and highway driving with a few brief 2nd and 3rd gear blasts, IATs tend to be 15 to 20 degrees above ambient. When ambient temps get closer to 70 degrees, I'll see IATs at 20 to 30 degrees over ambient. Interestingly, the IATs do drop a bit during my normal brief 2nd and 3rd gear pulls. This is completely consistent with what I saw prior to adding the Dinan Stage 2 piggyback. When temps get into the 80s, I fully expect to see 30-40+ higher IATs over ambient.

Some do need to realize that an aftermarket intercooler will do little to lower IATs during normal, minimal boost driving. They could actually INCREASE IATs slightly because they are comprised of a lot more metal, thus more of a thermal heat sink. Why you ask? Because during normal driving, especially stop and go and sub 45mph driving, there is a very little air blowing across and going through the IC and intake tract to offset all the radiant heat from the engine bay and radiator, thus the IC and piping tends to heat the slow moving air inside these systems.

During hard driving like 3rd gear+ pulls and racing, the correct size aftermarket intercooler is very beneficial. We do know that the N55 M2s suffer from heat soak and power reduction when raced in 80+ degree conditions. If I were racing my M235, I'd have an aftermarket IC. For street driving, I'm still evaluating that need to see if my IATs are any more elevated during the summer temps and humidity than they were prior to the Dinan Stage 2 piggyback.

This is very interesting thanks for the response. I don't track my car, or do many back to back pulls. Only an occasional WOT on the freeway on my way home from work.

So far, like you, I'm within the 20 degree c margin. I'm very curious to run a proper log in summer with more spirited driving though.
It is 100% true that a bigger intercooler will net some gains and some piece of mind, but for my style of driving and considering the price of a decent brand fmic, I'll wait until I know I need one.

[stlb5]

Originally Posted by Lozza47

This is very interesting thanks for the response. I don't track my car, or do many back to back pulls. Only an occasional WOT on the freeway on my way home from work.

So far, like you, I'm within the 20 degree c margin. I'm very curious to run a proper log in summer with more spirited driving though.
It is 100% true that a bigger intercooler will net some gains and some piece of mind, but for my style of driving and considering the price of a decent brand fmic, I'll wait until I know I need one.

I have an aftermarket IC and my IAT's average 10 degrees F over ambient in normal driving. When I come to a stop, they certainly rise, but quickly go back down once I'm moving again. Here's some data for you:

Stock IC

Aftermarket IC

You can see the IAT's don't rise nearly as much. One final thought, especially since it sounds like you're trying to talk yourself our of buying an IC, intercoolers don't gain you any power, it keeps you from losing as much power.