Quote:
Originally Posted by Freestylerfalcon
Hi friends.
I've been on the brink of going FBO and bm3 stage 2 for the longest time and have decided to finally pull the trigger.
Car is 2014 f30 335i. All stock except a CST intake and bm3 stage 1.
Im going to get charge pipe, catted DP (active autowerke or wagner) and an intercooler.
My question is what size intercooler should i be looking at? My car is a daily that does alot of highway kms. I dont drive like a maniac 90% of the time.
Mike from x-ph recommends a 6" cooler such as the CSF and says lag wont be an issue. (Thanks for answering all my incessant questions mike!)
But ive also read detailed intercooler reviews that talk about increased turbo lag and sluggish throttle response with a massive intercooler. Considering im not always pushing the car to the limits i was thinking a smaller 5.5" cooler like the Active Autowerke one would be better suited?
Any feedback would be appreciated thanks!
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I have a '15 335ix running BootMod3 Stage2 N55 EWG 93 Octane. I have an acute hatred for turbo lag from past experiences. I worked with Mike at X-PH to figure out the best solution with the least amount of turbo lag.
The stock intercooler is actually very efficient. It's an expensive lightweight tube & fin design that has very little turbo lag because it has quick flow across the cooler which prevents the intake pressure drop that causes turbo lag.
The stock intercooler was sized by BMW for the engine's stock horsepower output. So the stock intercooler doesn't have the capacity to handle the cooling requirements when the engine horsepower increases. That causes heat soak which is when the engine's failsafe systems cut power to prevent damage when intake air temperature is too high.
So a higher capacity intercooler is required when engine power is increased.
95% of aftermarket intercoolers are not tube and fin designs like the stock BMW intercooler. They are big heavy bar & plate designs which are cheaper to manufacture. This makes sense because most guys who were modifying their engines were racing. For racing you just need a big cheap intercooler to cool a lot of air. You don't care about turbo lag because the engine is being run lap after lap at high revs on a track.
Turbo lag is most noticeable in daily driving from a standing start when a light turns green, or when you go to accelerate to pass someone or when you hit a nice curve or on-ramp and want to accelerate into it.
A racing designed bar & plate intercooler is more likely to increase turbo lag under these daily driving situations because the air flow is slower across the bar & plate intercooler. This causes more intake air pressure drop which causes turbo lag.
So the perfect intercooler upgrade for a higher horsepower daily driver would be the same tube & fin design as the BMW stock intercooler, only larger with a higher capacity to cool more air.
Wagner Tuning from Germany makes two tube & fin design intercoolers in what they call their Competition series: the large Competition EVO1 and the larger Competition EVO2.
(NOT the Wagner Performance Series EVO1 and Performance EVO2 which are cheaper, heavier and slower bar & plate designs.)
Bigger doesn't necessarily mean better. I was going to buy the Competition EVO2 because it's only $50 more. Mike actually talked me out of it. I was planning to tune my car in the 400hp-425hp range with BM3 Stage2 93 octane. The Competition EVO1 was perfectly sized for that range.
Had I installed the Competition EVO2 then I may have introduced more turbo lag in daily driving. Had I told Mike that I intended to upgrade my turbo and weekend track my car, then he would have recommended the Wagner Competition EVO2 which would have been the correct capacity intercooler for that higher horsepower application.
I've been running the Wagner Competition EVO1 for 18 months and it's been incredible. I didn't notice that I had had some heat soak after multiple runs until it was suddenly gone. I can make run after run at full power. In daily driving there is no added turbo lag. That sweet torque curve is always available every time that I step on the gas.
Now the Wagner Competition EVO1 is $250 list price more than the FMIC that you are considering. But they are not apples to apples comparisons. The Wagner Competition EVO1 is a technology upgrade over the others.
Check out the graphs Mike has on his X-PH website showing the intake pressure drops that cause turbo lag and how great the Wagner Competition is.
Hope this helps!