[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.

[AmuroRay]

I have a race intercooler, a manual and running FBO - and I don't notice turbo lag at all.

The extra volume is likely not the issue (since the Evo is barely larger than stock) and most people are running 5" cores (VRSF, BMS, MAD) that are all larger (Evo 1 is 4.5") are bar and plate (more internal surface area) and have zero lag.

Sounds like a bad tune (piggyback vs tune) and worse parts (stock intake box, Evo1, etc)

[thejeremyman9]

Thanks for sharing the detailed info. Are you on stock turbo inlet? I do think there are several factors that dramatically change throttle response/"lag" even more than IC. I also agree that automatic vs manual makes a big difference in how the response feels in practice.

I ran the VRSF 5'' for a few years before i went to VRSF race, which is a much larger core with a significantly larger volume. With that swap there was no perceptible change in throttle response or lag, but i am tuned, and have a turbo inlet and airbox mod.

From modding my own car incrementally and testing various intakes, tunes, ICs, etc, combined with what i have heard reported from others, i would say the biggest things that impact throttle response are:

1. Turbo inlet
2. Tune (especially once you change from OEM hardware)
3. Intake setup (even if just filter/airbox mod) - and some intakes can make it worse

[XutvJet]

Stock inlet. My other mods are the FTP CP and M Performance exhaust; not that they add power. I've run the M2 lower airbox on and off for years now. I think the 6MT drives better without it. It certainly sounds good but at the expense of daily driving driveability. Maybe I'll swap it back in and see how it runs now

The Dinantronics piggyback is shockingly good. Never any weird driveability issues, certainly not like those reported for JB4. I bought it used right when flashes were just coming to market. I don't understand how having a piggyback would influence what I'm experiencing.

I want throttle response and running the stock IC certainly provides that for me. As noted, my friend's BM3 Stage 2 435 6mt with the CSF IC has worse tip in lag than my M235 did with Wagner. He even agreed. We're neck and neck from 40mph-120mph even with me running the piggyback and stock IC. My M235 is 110lb lighter though.

Perhaps you two have just grown accustomed to turbo power delivery over the years? I know I did until getting my Cayman and then the M235's power delivery felt really artificial. I hadn't driven a naturally aspirated performance car since 2011; owned a tuned 2012 WRX prior to the M235. All I know is I'm enjoying the way my M235 drives now. It's not a massive difference, but it is noticeable, especially during daily driving and moderate throttle.

[AmuroRay]

Maybe - but between the intake, inlet and diverter valve, all had a positive impact on throttle response.

I'll uninstall my tune and see how my car drives, for now here is my log:
https://datazap.me/u/amuroray/rk-fro...=0-2-4-7-23-40

the car hits boost target in less than a second.

[mike@x-ph.com]

Thank you for sharing OP; there is more to this than just the intercooler. You have one of the smallest intercoolers on the market, the throttle response should not be an issue.

[thejeremyman9]

Originally Posted by XutvJet

Stock inlet. My other mods are the FTP CP and M Performance exhaust; not that they add power. I've run the M2 lower airbox on and off for years now. I think the 6MT drives better without it. It certainly sounds good but at the expense of daily driving driveability. Maybe I'll swap it back in and see how it runs now

The Dinantronics piggyback is shockingly good. Never any weird driveability issues, certainly not like those reported for JB4. I bought it used right when flashes were just coming to market. I don't understand how having a piggyback would influence what I'm experiencing.

I want throttle response and running the stock IC certainly provides that for me. As noted, my friend's BM3 Stage 2 435 6mt with the CSF IC has worse tip in lag than my M235 did with Wagner. He even agreed. We're neck and neck from 40mph-120mph even with me running the piggyback and stock IC. My M235 is 110lb lighter though.

Perhaps you two have just grown accustomed to turbo power delivery over the years? I know I did until getting my Cayman and then the M235's power delivery felt really artificial. I hadn't driven a naturally aspirated performance car since 2011; owned a tuned 2012 WRX prior to the M235. All I know is I'm enjoying the way my M235 drives now. It's not a massive difference, but it is noticeable, especially during daily driving and moderate throttle.

If you are very sensitive to throttle response, i would highly recommend considering getting the MST v2 or CTS turbo inlet. It was the single most important mod for me actually feeling that improved response immediately

I am definitely used to turbo power delivery since i daily drove a Twin Turbo 3000gt for 11 years before i got the 335, but i do also have a sandrail that is NA so i have an independent data point on driving NA

[n55david]

We all ran or are running the race intercoolers with no issues..

Get a legit inlet.. cts or mst v2

[XutvJet]

Originally Posted by mike@x-ph.com

Thank you for sharing OP; there is more to this than just the intercooler. You have one of the smallest intercoolers on the market, the throttle response should not be an issue.

Yes, it is one of the smallest ICs on the market, but I don't how that's a concern to the topic at hand. My M235 is in excellent shape and no boost leaks either. I ran the Wagner IC for three years without issue minus the throttle response matter. No codes or weird datalog data. There definitely is an minor issue in terms of reduced tip-in throttle response and it's not just a factor with the IC I have. The same effect is present in a different 6MT car with the same mods and a flash tune.

I think most folks that mod cars are fearful to admit that that are compromises with most aftermarket parts with respect to fitment, driveability, performance, etc. It's hard to admit that there is usually a compromise with most every aftermarket performance part. People, including myself, like to mod cars thus they often buy mods that really aren't necessary to the type of driving they do and buy that mod solely because it's something to modify and make different.

The reduction in initial throttle response shouldn't be a deal breaker for most anyone, but people should know the positives and negatives of aftermarket parts and even some factory-offered performance parts. Lastly, they really should consider how they drive and the conditions they drive in before adding an IC......and many other mods for that matter.

[thejeremyman9]

Couldn't agree more with doing a self-evaluation of your needs before buying a mod and not just buying what the most common or popular mods are.

Do you have datalogs on stock IC with your piggyback?

[AmuroRay]

Originally Posted by thejeremyman9

Couldn't agree more with doing a self-evaluation of your needs before buying a mod and not just buying what the most common or popular mods are.

Do you have datalogs on stock IC with your piggyback?

I'll put money it's the stock intake and paper filter. I know people love to believe that intakes do absolutely nothing, but they had a positive impact on power and throttle response. This was especially true when I upgraded the Inlet and diverter valve.

Only one mod I regret so far, and that's the midpipe. It was welded at an angle that sometimes touches the brace under the car, and causes it to vibrate. I hate it.

[XutvJet]

Originally Posted by thejeremyman9

Couldn't agree more with doing a self-evaluation of your needs before buying a mod and not just buying what the most common or popular mods are.

Do you have datalogs on stock IC with your piggyback?

I ran datalogs with the Torque app as noted in my link providing in my first post. The IC did improve things, but for street driving and reduced throttle response, it does seem necessary as the stock IC can handle everything completely fine unless you're doing 3+ back to back longer pulls or track driving. The stock IC can handle some hard B road driving without the IATs getting crazy. Now if I had mountains/elevation to zip around in, I would have left the IC in as that load would likely push the IATs up a bit more.

[XutvJet]

Originally Posted by AmuroRay

I'll put money it's the stock intake and paper filter. I know people love to believe that intakes do absolutely nothing, but they had a positive impact on power and throttle response. This was especially true when I upgraded the Inlet and diverter valve.

Yep, stock airbox and Mahle paper filter. I have the M2 lower airbox, AFE intake scoop (sits in the grill area), and AEM dry air filter. I've tried every intake combo possible with these parts over the past 6 years. I always think that some combo is going to be the magic one, but I ALWAYS come back to the stock airbox and Mahle paper filter and it's been that way for 1 year now. It drives the best and feels the best in terms of throttle response, especially with a 6MT. I could never feel any improvement in power. I felt noticeable improvements with my HJS Euro 6 DP and then running the piggyback in Stage 1 and can feel a hefty improvement flipping it to Stage 2. With the intake parts? Nothing except some slight throttle hesitation at low to moderate throttle below 4000rpms and a little more diverter and induction sound.

I've datalogged everything and I've seen absolutely no notable data improvements to support that the car is making power, lower IATs, etc. with the intake parts. The variances are like 5% or less at various rpms and as a scientist myself, that is just noise. Now if I saw a consistent improvement of 5-10% across the entire rpm power band, then I'd reconsider. So many people on these forums (including myself) and aftermarket parts manufacturers and vendors so want to believe they can out smart a factory part design on a performance car, especially intake parts. In almost all cases, the factory part is not a restriction even though it may look restrictive.

[thejeremyman9]

Originally Posted by XutvJet

Yep, stock airbox and Mahle paper filter. I have the M2 lower airbox, AFE intake scoop (sits in the grill area), and AEM dry air filter. I've tried every intake combo possible with these parts over the past 6 years. I always think that some combo is going to be the magic one, but I ALWAYS come back to the stock airbox and Mahle paper filter and it's been that way for 1 year now. It drives the best and feels the best in terms of throttle response, especially with a 6MT. I could never feel any improvement in power. I felt noticeable improvements with my HJS Euro 6 DP and then running the piggyback in Stage 1 and can feel a hefty improvement flipping it to Stage 2. With the intake parts? Nothing except some slight throttle hesitation at low to moderate throttle below 4000rpms and a little more diverter and induction sound.

I've datalogged everything and I've seen absolutely no notable data improvements to support that the car is making power, lower IATs, etc. with the intake parts. The variances are like 5% or less at various rpms and as a scientist myself, that is just noise. Now if I saw a consistent improvement of 5-10% across the entire rpm power band, then I'd reconsider. So many people on these forums (including myself) and aftermarket parts manufacturers and vendors so want to believe they can out smart a factory part design on a performance car, especially intake parts. In almost all cases, the factory part is not a restriction even though it may look restrictive.

Agree for stock intake (Especially with M2 lower box as that does make a difference vs the closed box only drawing air from the front - that's why the BMW added it). Consistent with how i felt testing different intakes including Dinan and CTS.

But the inlet is really what makes the difference, not the "intake" (upstream of the inlet).

[XutvJet]

Originally Posted by thejeremyman9

But the inlet is really what makes the difference, not the "intake" (upstream of the inlet).

I'll look into this. The research I did on this a few years back seemed to show that the turbo inlet advantages were hit and miss.

[AmuroRay]

Originally Posted by thejeremyman9

Agree for stock intake (Especially with M2 lower box as that does make a difference vs the closed box only drawing air from the front - that's why the BMW added it). Consistent with how i felt testing different intakes including Dinan and CTS.

But the inlet is really what makes the difference, not the "intake" (upstream of the inlet).

My CTS was as perfect as the MPPK/M2 lower - but a tad louder but more torque on tip in. The stock airbox with the paper filter is terrible - zero exaggeration.

[thejeremyman9]

Originally Posted by XutvJet

I'll look into this. The research I did on this a few years back seemed to show that the turbo inlet advantages were hit and miss.

A couple years ago Ozy tested 3-4 different inlets on his car with no changes to intake or anything else and we took a close look at the data and his impressions. The MST v2 was a clear winner. After his testing, i bought the mst v2 and did more comparisons. After i had the MST v2 installed, i tested different intakes separately.

https://f30.bimmerpost.com/forums/sh...1656337&page=7

My post starts on page 8 here: https://f30.bimmerpost.com/forums/sh...1656337&page=8

There was indeed a huge debate about inlet upgrade on stock turbo - hence the length of that thread. It wasnt until we started doing more comparative testing that it really gained traction.

Intake testing was separate: https://f30.bimmerpost.com/forums/sh....php?t=1765289

[thejeremyman9]

Originally Posted by AmuroRay

My CTS was as perfect as the MPPK/M2 lower - but a tad louder but more torque on tip in. The stock airbox with the paper filter is terrible - zero exaggeration.

Nothing against CTS intake performance wise, it was just way too loud for me and i dislike that suction sound for this car

[AmuroRay]

I uninstalled my tune and went with the MHD Stage 0. This is actually weaker than the Standard MPPK tune the M235is came with as it runs about 8psi vs 10psi or so for the MPPK.

I must be spoiled, because the standard 300hp/non MPPK tune is gutless. I didn't notice any lag or sudden explosiveness, and overall it feels smooth enough.
I'll upload a log here in a bit, but I actually think "LAG" that people are experiencing is a result of restrictions on the intake side and not on the intercooler.

[AmuroRay]

https://datazap.me/u/amuroray/stage-...og=0&data=4-23

Stage 0 logs, Race intercooler.
Any lag?

Edit: Per the log - 331hp (285whp) at 6000RPM.
https://www.omnicalculator.com/conve...-to-horsepower

This feels so slow to me lol.

[AmuroRay]

Final update:

I was driving around on the MHD Stage 0 tune for about a week. Since my car is for pleasure, it's just taken out for fun and maybe some errands.

I was wrong about the power - it's actually peppy, and it builds well and pulls fine enough, the limits are just lower than what I was originally used to. That being said, the tune is great for what it is. The car drives and sounds great - no clutch jutter when pulling from a light, the engine/turbo still make some sporty sounds despite running half the boost.

But again, I need to reiterate this so EVERYONE is clear on this. There is no turbo lag. I've felt turbo lag once on this car and it was prior to doing my Race intercooler.

My experience with Lag:
When I originally swapped out the turbo inlet and diverter valve with the MST V2 and Turbosmart Plumb back units, I ran on the stock F22/F30 intake box (AFE dry filter) and the lag was terrible. I've repeated this phrase multiple times on this forum:

"I had to drive with the car in Sport/Sport+ to achieve the same throttle response/acceleration with this combination that I could with [an aftermarket intake] in Comfort"

It felt like the car was driving in Eco Plus mode all the time, and the powerband felt weak, and then suddenly "explosive" around 3000RPM and overall power was down. Keep in mind, this isn't just one drive cycle - it's about a week of driving and I was running a Stage 2 tune.

When I swapped (back) to a intake (M2 airbox with the additional opening/ AFE Dry filter) the lag disappeared. Tip in throttle response was strong, and the car felt like it was making 50lbft+ of torque more than before. This effect was stronger (slight increase in torque, slightly sharper throttle response) with the CTS intake.


My experience with a RACE intercooler:
I had the VRSF Race intercooler installed this summer - my car was already BPU/FBO with a stage 2 tune. There was no change to throttle response (though a slight increase in WGDC over my previous intercooler.) And now more recently, when I tested VRSF Race intercooler and RK Tunes long tube front mount intake - on a stock tune with 8psi, you'd expect turbo lag because of the added volume and longer intake tract length, right?

Nope. Great tip in throttle response and plenty of torque. You could drive the car and would almost not be able to tell that it as modded. More than likely when people have "Lag" it's probably the intake and inlet limiting absolute flow and creating more pressure drop (which is why there is a noticeable WGDC decrease with an intake vs stock box)