[XutvJet]

Three years ago I installed a Wagner EVO I Competition intercooler on my 2016 M235 6MT. My full review of this intercooler is here: https://www.2addicts.com/forums/show....php?t=1773277

My car is still running the Dinantronics Stage 2 piggyback and HJS Euro 6 catted downpipe. Both of these parts have performed flawlessly over the past 5 years Yes, I ran the piggyback and downpipe for two years prior to the IC. I got the smaller Wagner EVO I Competition because I don't do any racing/tracking or do back to back high MPH pulls. I wanted something that had good recovery and would drop IATs a bit, especially in hot weather because everything you read on the forums swear that it's critical.

The IC worked as intended and it did drop higher gear and hot weather IATs (see my review). I live in Kansas City where we see cold winters 15-35 degree temps and hot and humid summers with 85-100 degree temps. 70% of the year, temps are in the low 40s to upper 70s. In October 2022, I bought a 2011 Cayman 6MT which I now drive a majority of the time except when it's raining/snowy, below 40, or I need the extra room. As expected, the Cayman has great throttle response due to it's naturally aspirated motor.

This leads me to point of this thread. As noted in my IC review thread, I saw a slight reduction in throttle response in lighter throttle applications. The muted throttle response was most apparent under sub 4000rpm light to moderate tip-in in all gears. Leaving the line in 1st smoothly was slightly more difficult but not something I really noticed until a few months had passed. The car felt stronger in 3rd gear and above, especially in warm/hot weather once under rpms were above 4500rpms. In 1st and 2nd, I noticed no real difference. For the automatic owners, 2nd gear on the 6MT goes to around 72mph and 3rd to around 108mph, yeah, the gearing is LONG in the 6MT.

The reduced throttle response or lag with the IC only lasted about a second (if that) and then the motor responded well. I'm certain this lag is caused by air needing to fill the extra volume of the larger IC and BMW's tuning which is based on running the smaller IC. Again, under heavy throttle, the car performed better and was more consistent power wise, especially once temps were above 80 degrees.

With that said, I've grown accustomed to good throttle response with my Cayman and the lag in the M235 became more of an annoyance as time went on. Also, I've realized over the years, I rarely punch the M235 above 6000rpms in most gears and very rarely wind out 3rd, much less 4th. I don't track the car either. A month ago, as an experiment, I swapped in the stock IC. I was instantly rewarded with better throttle response. Over the past 30 days, we've experienced a wide range of temps including mid 80s down to 20 degrees in the last week. Yes, the stock IC does heat soak worse in warm/hot weather daily driving (as confirmed by my datalogging again), but overall, the car is just better driving without the larger IC in daily driving situations. Now if I tracked the car or drove it harder, I'd definitely keep the better IC installed. When temps are below 60, you're likely not going to see much benefit at all with an upgraded IC unless you're tracking or pushing a ton of power.

I've also driven a friend's 2015 435 6MT with BM3 Stage 2 and an even larger CSF IC. His tip-in throttle is even worse, but he doesn't care as he drives the car way harder than I do mine.

I only post this for those on fence on whether or not an IC is for you. I'd consider where you live, the conditions you drive, how hard you drive, and your mods.

Lastly, I highly doubt automatic owners will notice this lag as their gearing is way shorter, there are tons more gear, plus the torque converter can mask some of this as well.

[atek]

Nice writeup, glad to hear some in-depth real world based thoughts. I have a Zf8 and still on stock IC but have been planning on upgrading in the coming future. I tend to drive on the harder side as well.

[mecheng77]

Great write up, I was thinking because of the massive size there much be a large pressure loss and I’ve kept the stock IC. I’m very glad I did because I love the broad torque band of the N55. Also aftermarket ICs are heavy and the weight is at the extreme end of the car

[XutvJet]

Originally Posted by mecheng77

Great write up, I was thinking because of the massive size there much be a large pressure loss and I’ve kept the stock IC. I’m very glad I did because I love the broad torque band of the N55. Also aftermarket ICs are heavy and the weight is at the extreme end of the car

Yeah, some of these aftermarket ICs can weigh up to 35lbs. The stock IC is around 6.5lbs. The Wagner EVO I Comp is around 16lbs.

I was very impressed with how well the Wagner IC handled road debris. Hardly any fins are damaged after 3 years of use. The stock IC was a disaster with tons of damaged fins. I spent two hours fixing the fins and cleaning out all the debris embedded in it after 4 years of use.

I know people say the stock IC is crap, but in reality, it's pretty decent size IC for its intended application. It even does fine on the 2016-2018 M2 for most owners assuming they're not tracking the car or doing multiple, back to back pulls.

Again though, if you are modded and live in a hot climate and/or do lots of tracking, I'd absolutely upgrade to at least the Wagner EVO I Comp. If you're pushing more power than the typical Stage 2 setup, I'd upgrade as well. Just be prepared for a bit more initial lag. As with most aftermarket parts, there's always some compromise.

I think the best bolt-on mod for these cars is a quality catted DP. My HJS Euro 6 DP has been flawless after 6 years of use. The car drives better in every situation and makes more power everywhere without any tuning necessary. It also sounds better (10% louder, maybe) at every rpm and no drone. One of the very few power mods with no trade-offs unless you don't any additional exhaust volume.

[AmuroRay]

Cross posted this thread I see.
I have a FBO+++, literally every bolt on save a turbo that can be done, and the biggest contributor of turbo lag is not the intercooler, it's the intake.

The stock intake box was so terrible, when I upgraded the inlet (MST V2) and diverter valve (Turbosmart Ds9?) I also had a M2 lower intake with a AFE filter. Throttle response was night and day different than the stock inlet/DV- and there was some added power as well.

I was planning on selling my M2 lower intake box because besides looking pretty, there was no difference between that and the stock intake, right?

WRONG. Not only was total power output down, it was incredibly laggy. Same tune, same parts, same filter, same weather - everything. The stock airbox required me to drive in SPORT to achieve (almost) the same power on tip in that the M2 airbox did in comfort. The car felt more lethargic under 3000RPM as if I was driving in ECO, and then suddenly explosive once boost came on.

Completely undrivable in my opinion, and if I didn't have my MPPK/M2 airbox filter I would assume that's just how things were. I moved back to the M2 airbox, then the CTS (even better) and now the RK Tunes front mount - a Race intercooler and my throttle response is as great as ever.

It doesn't even make sense that the intercooler would cause lag, since it's already pressurized when the car is on - what does make sense is the intake box is creating more pressure drop (which is why there is a noticeable WGDC decrease with an intake vs stock box)