The V8 M3's are decent cars, but the lack of tourque is the dealbreaker for me. From 1500RPM when I mashed the gas it was about a 3 second delay before any relevant power came on. It felt like an eternity. I raced one when I had my 135i about 6-7 years ago and left it in the dust off a slow rolling start. It took all the way to 90MPH until the M3 started to catch up. That kind of power delivery is not condusive for daily driving. On a track where you can keep it in the high RPMs all day long, thats a different story. Because of this, i never thought about it again of trading in the ISF for a V8 M car.

Now the newer Inline 6 Turbo M3s have adressed the lack of tourque, but still not the instant tourque of the ISF.

 

Good post!

 

The S55 is an in-line 6 and it makes gobs of torque. The isf isn’t really a torquey V8 compared to most.

 

Good catch on the inline six vs v6, my mistake I will edit my post. Going from my reliable "butt dyno" there still is a slight hesitation from the S55 turbo spool up that is felt in comparison to my ISF. I actually currently own a 2017 M4 with comp package (6speed manual, convertible) and a 2012 ISF. My ISF pulls noticeably harder the first couple thousand RPM. I love both cars, the driving feel is much different in each.

 

Is the drive feel different between both due to the turbo engine vs NA - or other areas?

 

I would say other areas as well. The M4 does a good job masking its turbo lag compared to some other OEM turbo cars I have owned and some I modified (Mazdaspeed6, BMW 135i, Civic SI) but there still is a hint of it if you don't rev up the RPM from the start.

Some other aspects of the drive of the ISF vs. the M4 Comp are completely different. The ISF feels like a smaller car when maneuvering, the turning radius is tighter, steering feel is more sensitive (although this can be configured in the M4 but has an artificial feel). The M4 has a more comfortable ride and feels more like a grand tour car to me as opposed to a track weapon, which I enjoy because I bought a convertible to cruise and carve the roads, not as a track toy. I am impressed with the structural rigidity of the convertible and with the hard top up, feels just like a coupe. Obviously, with the manual trans I have in the M4 it gives the sensation of more driver involvement. When I bought my ISF I thought I would use the paddle shifters on a daily basis and as it turned out I ended up not using them very frequently, only when I had a planned spirited run. In sport mode the ISF does a good job holding the gears and not up shifting. The ISF has a nice sound compared to the M4 which has a raspy exhaust note in the comp package in sport plus mode. The induction noise when the cams come on in the ISF is a great experience for me and something I truly enjoy with the car. My ISF is much more of a usable car for passengers as anybody other than my 5 year old would not be comfortable in the back seat of the M4, especially in convertible trim. From a pure acceleration factor, they are both very quick. The ISF just feels faster off the line and the M4 pulls a little harder in the high RPMs. I think the ISF can change gears faster than I can manually shift, plus I am not destroying my clutch by doing full throtle shifts in the M4. In the ISF I just keep the gas mashed as I blip through the gears.

I highly recommend test driving both cars and see what feels better to you. I understand I am very lucky to have both in my driveway and get to experience the completely different characters of each depending on how I feel. Hopefully this insight helps you.

 

Thank you for the thorough comparison - very helpful actually

 

Just spend the $1700 to get them upgraded and be done with the problem forever. People spend 2-3x that amount on an exhaust alone. It's not that expensive.

 

The DCT matches much better with the S55 from my experience, for some reason, the 6MT in the M3/M4 creates some extra lag, especially noticeable during shifts. It also doesn't help that you drive an F83 which weighs over 4100 pounds, when your car weighs almost as much as a Dodge Grand Caravan it will feel noticeably less responsive and slower. An F80 M3 for comparison comes in between 3400-3600lbs, a SIGNIFICANT amount lighter than a convertible M4.

I've owned a 2012 IS-F, 2 E92 M3s, 1 E90 M3, and an F80 M3. The F80 M3 response for being a turbo car is amazing, it has better response and less lag than a GT-R. I feel no hesitation from almost any RPM. Fact, the engine response was so rapid in the early year F80 it was making the car harder to control because power would come on so hard in the lower revs that BMW had to issue a firmware update that actually induced more lag. They did this to try and contain the beast since it was such a torque monster from down low. My F80 has an E85 tune and it produces over 640 ft-lbs of torque at the wheels. The stock F80/82 is already a really fast car stock, once you put a proper tune on it, the power and response becomes next level.

Here is a good video to watch where Chris Harris talks about the S55 and compares it to the S65 (previous gen M3) in pretty good detail.

 

My buddy has a 2016 M3 and the first thing I noticed was how torquey it was. I bet full torque is much lower in the rpm due to the turbo. We have to wind our engines out.

 

My kid has an N54 335is, 2010, and he's slowly tuned it up. The torque is impressive. Even stock it was impressive.

 

I have an e90 M3 and used to have GS F. If you are concerned about the overall size of GS F, you probably won't be happy with it. It was for this reason I moved on from GS F although I think it's a great car. e90 is the perfect size for daily/sporty driving IMO. I like its hydraulic steering as much as I love its engine. I also happen to think it's one of the best looking sedans out there. IS F is likely more reliable but e90s are not terrible either.

 

Interesting to hear other perceptions of a car. I currently own an f80 m3 and previously owned 2 Isf’s. I find the steering in the m3 quite a more responsive than the isf, the torque isn’t even really comparable now that I’m stage 1 tuned, it’s fully spooled by 2000 rpm and will spin the tires though 3rd on my 6mt. I feel the f80 is a nice progression from the isf, and maybe more so than the gsf as it’s characteristics are more of a small car than a bigger one. Doesn’t have that screaming red line the s56 has but the f80 is a platform that isf owners looking to move on should consider, its a great car.

 

as an ex owner of two E92 M3s, this is a bunch of B.S. There is no such thing as done with the problem forever, that's forum fanboy kool aid. The main bearings are also a wear item on these engines, although it is less frequently talked about because when they grenade, most assume it's the rod bearings and that's the end of it. No one replaces the main bearings on an S65 preventively as it requires tear down of the engine. Look at pictures of torn down engines and see the condition of the main bearings for yourself. Incredibly poor design from a durability standpoint.

So all in all, the S65 is a great motor when it runs, but there is a significant reliability cost to give you that 8400 rpm redline out of a V8 and IMO, you should only get into one of these if you're OK with the idea that the engine could let go at anytime, without warning. For those willing to accept that, it's a very rewarding car with a visceral experience that is hard to match. Also know that it's also fairly gutless at low RPM - very different from the ISF, Last but not least, you'll find it isn't much bigger than the IS-F so you're really going from one small car to another small car. The F80 suggestion is a good one, i strongly recommend you set aside the anti turbo bias and go drive one. you may be pleasantly surprised.

 

I guess countless e9x M3 owners including myself have been extremely lucky to have enjoyed many trouble free miles (some way above 100K). I just took it out for a drive this morning, had a blast like I have everyday for past couple years. Have some S65s failed? Yes. What percentage though? Also, there's no evidence that S55 is more reliable than S65. I would be more worried about having S55 beyond warranty. Not to mention S55 sounds terrible (so much so that BMW decided to pump fake sound through stereo). I think going from NA V8 to any garden-variety turbocharged 6 used in bmw's and audi's nowadays is a downgrade. but that's just my opinion.