EAS BMW M4: Basic bolt-ons for one wild ride!


The F82 BMW M4 tuned by EAS is a beast of car that hauls four people stupid-fast.

Obviously, we expected this car to be fast.  Who wouldn't?  What we didn't expect, however, was all that low end torque!  And how much, you ask?  Let’s see those dyno graphs now, please!


Starting with a 414 WHP baseline, EAS has taken this car to a rush-inducing 471 WHP with just the addition of a tune, air filters, cat-less down pipes, and cat-back exhaust.  The peak gain was 85 WHP at a very usable 5000 RPM.  Not bad for a few bolt-ons on 91 octane!

Thanks to the turbos, the torque is where this engine really shines.  The torque went from a peak 411 LB-FT to 495 LB-FT, with a net gain of 85 LB-FT at 4000 RPM.  This gain is especially nice because, like it seems to happen with most factory turbochargers tunes, you usually gain the majority of your torque at too low of an RPM range to really use because factory turbos are frequently small.  In the EAS BMW M4's case, however, the gains between 3000-5500 RPM are massive (that's nearly 100 LB-FT difference at 5000 RPM!), and at a very usable powerband for anything this side of flat-out drag racing. 

Now let's go for a quick ride.  Please excuse the poor video quality.  It may have been done with a phone in one hand and a steering wheel in the other.  Not saying it did, but maybe. Notice that midrange torque, and how much louder the car gets when it peaks its boost.  Surprisingly, even with the cats deleted, this car is so quiet while cruising that you can barely hear any engine sounds if the AC is turned on.  At wide-open-throttle, however, it's a different story.  There's plenty of audible grunt to rubberneck any innocent bystanders. 

Earlier, we showed you the difference between the S55 3.0-liter turbocharged engine and the outgoing S65 4.0-liter V8.  What we didn't show you is the difference between the two cars after a few simple bolt-ons.  Check this out:

This shows the difference between the EAS BMW M4 versus an E92 BMW M3 with bolt-on performance parts.  Both cars have full exhaust upgrades with no cats, intake and software.  The M4 puts out 471 WHP while the V8 did 396 WHP on the same dyno. To be honest, that's still very impressive for the 4.0-liter, given the fact it's producing nearly 100 wheel horsepower with no turbo.  Still, check out the difference in the overall power curve.  Now let's see how that translates into torque below.
And there you have it–495 LB-FT vs 283 LB-FT, a difference of 211 LB-FT of torque.  The two cars produce nowhere near the same experience.

Turbos are just plain “no fair”.  Well, what if we supercharged the E92 V8?  Do recall that in the first page we mentioned EAS sold and installed a boatload of superchargers for the E9X M3.  So, why not? Let's compare those two in dyno form below.

The blue curves represent the power and torque of the EAS BMW M4 while the red lines represent an E92 M3 with a basic ESS supercharger kit.  The supercharged car made 547 WHP, which is 76 WHP more than the EAS BMW M4, but the M4 has a way fatter torque through 6600 RPM, and a net gain of 130 LB-FT of torque at their peaks.

So, which one would I take?  On the one hand, I've got gobs torque with the turbo, while the supercharged car gives me the top-end rush.  For the shorter road course, it seems the new M3 would have the advantage (with enough tire grip), while anything dealing with redline-slamming acceleration through the gears would nudge the supercharged V8 significantly ahead. 

But then I'd also have an older car with the V8, and the new, wider F8X M3/M4s just look so good.  Plus, the newer cars are going to net me the better gas mileage. 

But what about the sound?  Am I going to prefer the song coming from the new turbocharged-six–which does sound pretty good, mind you–over the melodious roar coming from one of the best sounding V8s ever produced? 

I'm usually a “top end” kind of guy and I've always loved the sound of the S65 V8, let alone the rush from the performance of a supercharged one (and I've been fortunate enough to experience a few different setups).  But after today's experience, I'm in love with the EAS M4 and its mildly tuned S55 turbo engine.  It's uber impressive!




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