[MKE_M3]

I've been hesitant to get Dual Cone (hot air ) intake because my #1 priority is to keep the car running cool. Since I have an upgraded FMIC, should I get dual cones?

Ultimately, I'd like to know if the FMIC makes up for the hotter intake air. Not from a horse power stand point, but from an IAT stand point. Any one have logs of pre/post DCI, both with upgraded FMIC?

I know this is very specific, but I've been following the forums for over 2 years (check the join date ) and havn't seen this specific situation highlighted. I think it may be a little rare having a FMIC and not having an intake.

[Jeff@TopGearSolutions]

With FBO it should help on the top end.

[MKE_M3]

Thanks. I'm not asking about HP, however, just IATs. Also, I do not have DPs yet

[Jeff@TopGearSolutions]

Originally Posted by jdemetry

Thanks. I'm not asking about HP, however, just IATs. Also, I do not have DPs yet

Well the whole reason behind trying to keep IAT at bay are to increase HP.

[MKE_M3]

I assume lower IAT would lead to lower the operating temps. Is that not correct? My track experience (very high speed track, Road America) was that all the power was useless because I got a limp mode for too high of oil temp. That is why I don't really care if I got a rediculous 40HP from the intake if it meant my oil/water temps went even a couple degrees warmer.

If I can see some evidence of a Dual Cone intake not raising IAT with an upgraded FMIC, I think I'll pull the trigger.

Also, if anyone who knows more than me about engines wants to provide input, am I off base that higher IATs lead to higher operating temps??!!?

[domrep]

TBH, your IAT's will probably increase but by negligible amount...definitely nothing limp mode-able.

[mycoupe]

just get an upgraded drop in filter...people seem to have better luck with those than the dual cones from what I've read.

[Stucks]

I have the same debate going on in my head as the original poster. Bought a tune, CP-E fmic, but still on stock downpipes. I have a bms drop in filter currently in the stock airbox/intake. Ordered the bms dual cone intakes 2 days ago for 95 bucks+ shipping. I figured I'd try them out and see what I like better. They arent that expensive.

[MKE_M3]

I also have the drop it. Please do some logs before and after of your IAT. I agree it's not much extra money, but I'd rather not duplicate efforts if someone else has already done the research . Are IAT read pre or post FMIC? I assume its after FMIC, pre intake manifold?!?! Also, what tune are you running?

[C4sF80M3]

Hmmm. Not sure that makes sense. Lowering IAT's will lower the temp of the air going into the cylinder, which means the air is more dense, which means you will make more power at a given boost level. The larger FMIC will act as a giant heat sink, allowing you to run higher boost than stock while maintaining lower IAT's, making the power the engine is producing more consistent and less prone to detonation. However, more power = more heat, but that is heat that is coming out of the engine.

The dual cones will allow more with less restriction. So more air + less restriction + while being efficiently cooled by the FMIC = more power = more heat.

[MKE_M3]

oy vey, now I'm really confused...

[Ilma]

Originally Posted by c4s335i

Hmmm. Not sure that makes sense. Lowering IAT's will lower the temp of the air going into the cylinder, which means the air is more dense, which means you will make more power at a given boost level. The larger FMIC will act as a giant heat sink, allowing you to run higher boost than stock while maintaining lower IAT's, making the power the engine is producing more consistent and less prone to detonation. However, more power = more heat, but that is heat that is coming out of the engine.

The dual cones will allow more with less restriction. So more air + less restriction + while being efficiently cooled by the FMIC = more power = more heat.

Exactly......

Lower intake temps produce more power = good.

More power produces more heat = bad.

It's a balancing act.

I have tried DCI's and stock airbox back and forth several times (with a FMIC) and although psychologically it bothers me to pull in hot air from the engine bay with DCI's, I still prefer them over the stock airbox.

The only measurable difference I have noticed is that IAT's will recover a bit faster with the stock airbox.

But you have to be flowing air through the intercooler for that to happen.

An aftermarket intercooler made a bigger difference in IAT drop than the air filters do.

You can reduce peak IAT's by about 40 degrees with an intercooler.
DCI's may raise your IAT's by 5-9 degrees on average, but they provide much less restriction to airflow......so your turbos work easier and you get more air at higher rpm's.

[Syndicategt]

Wow, this argument has been going on for years. It's been proven the greater quantity of air volume going into the intake with DCI's out weighs the slight temp increase of sucking in hotter air when tuned. Your FMIC should be good enough to lower IAT's, add meth and you are money.

[MKE_M3]

thanks all for your advice. it all makes sense, but some of it conflicts. I suppose there's no way to really tell if the DCI makes your oil/water temp higher, and if it does, it is negligible. I might just have to pull the trigger.

[boom]

Originally Posted by Syndicategt

Wow, this argument has been going on for years. It's been proven the greater quantity of air volume going into the intake with DCI's out weighs the slight temp increase of sucking in hotter air when tuned. Your FMIC should be good enough to lower IAT's, add meth and you are money.

Ummm, I actually showed that DCI was worse than stock airbox at boost pressures lower than 15psi. These were not just glory dyno runs but logged 1/4 runs at Maryland Internation Raceway with timeslips.

http://www.e90post.com/forums/showthread.php?t=491005

My car went slower and the IAT delta from run to run was higher when using the DCI vs stock airbox (page 3 of that thread).

I was a doubter and ran DCI on my old 335i all of the time. After this log session, I'm stock airbox and faster. Perhaps as you increase boost over 15psi the DCI is advantageous. Until then the stock box is better.

[Zasquatch]

Just do the Mr. 5 intake... it's the best of both worlds.

[C4sF80M3]

My main concern was getting the intake out of the engine compartment because of lack of cool air there, which is why choose the UR intake. The stock airbox is too restrictive, but in my case dual cones seemed overkill. So CAI over DCI in my case.
http://www.ultimate-racing.com/Produ...5i_S_CAI.shtml

Originally Posted by boom

Ummm, I actually showed that DCI was worse than stock airbox at boost pressures lower than 15psi. These were not just glory dyno runs but logged 1/4 runs at Maryland Internation Raceway with timeslips.

http://www.e90post.com/forums/showthread.php?t=491005

My car went slower and the IAT delta from run to run was higher when using the DCI vs stock airbox (page 3 of that thread).

I was a doubter and ran DCI on my old 335i all of the time. After this log session, I'm stock airbox and faster. Perhaps as you increase boost over 15psi the DCI is advantageous. Until then the stock box is better.

[Boosted John]

a guy i know had a similar concern as you with he's 335. he wanted to lower the temp under the hood. so he had a couple of holes cut out at a body shop and then put some vent covers on it. he said he noticed a substantial difference in the temp. iirc it was 20-30 degrees lower after that mod..

[MKE_M3]

Originally Posted by Boosted John

a guy i know had a similar concern as you with he's 335. he wanted to lower the temp under the hood. so he had a couple of holes cut out at a body shop and then put some vent covers on it. he said he noticed a substantial difference in the temp. iirc it was 20-30 degrees lower after that mod..

That's intriguing. Do you have pics? Does it look like Harold's car?

http://www.hpashop.com/

[Syndicategt]

Originally Posted by boom

Ummm, I actually showed that DCI was worse than stock airbox at boost pressures lower than 15psi. These were not just glory dyno runs but logged 1/4 runs at Maryland Internation Raceway with timeslips.

http://www.e90post.com/forums/showthread.php?t=491005

My car went slower and the IAT delta from run to run was higher when using the DCI vs stock airbox (page 3 of that thread).

I was a doubter and ran DCI on my old 335i all of the time. After this log session, I'm stock airbox and faster. Perhaps as you increase boost over 15psi the DCI is advantageous. Until then the stock box is better.

1. You are correct about the glory dyno's. In real world racing I do use a drop in with stock airbox for track use. DCI's are hands down better for short drives + drag.

2. You are not using meth are you? This alone will be enough to keep the IAT's down enough to compensate the hot air in the DCI's. Also, your temps were not that much different.

3. I run 16-17 psi consistantly (will be at 20 once the RBs get in). Stock airbox will just become too restrictive at these levels of boost.

That being said, I use DCI's 75% of the time. In the summer or on track days I go back to stock + drop-in.

[boom]

Originally Posted by Syndicategt

1. You are correct about the glory dyno's. In real world racing I do use a drop in with stock airbox for track use. DCI's are hands down better for short drives drag.

2. You are not using meth are you? This alone will be enough to keep the IAT's down enough to compensate the hot air in the DCI's. Also, your temps were not that much different.

3. I run 16-17 psi consistantly (will be at 20 once the RBs get in). Stock airbox will just become too restrictive at these levels of boost.

That being said, I use DCI's 75% of the time. In the summer or on track days I go back to stock drop-in.

I don't run meth yet. My kit is sitting there looking at me but really don't feel the need yet. I agree that above 15 psi you'll benefit from the dci. At what point the dci become more effective is yet to be determined however. It's a pretty easy swap to log the differences though. I don't agree that dci is better at the strip.

[MKE_M3]

Well, since I'm under 15psi, I guess I'll just stick with the stock box for now. I just spent almost 6k on my car in the last few months, so maybe I'll just wait until I start getting bored with my car again.

By then, maybe it will be upgraded turbo time