Supercharged E90 M3 vs F06 M6GC

Considering either supercharging my e90 M3 or making the jump to an F06. Has anyone driven both a SC’d M3 and an m6gc enough to make a real comparison? I know they’re two totally different cars with different use cases but curious to hear opinions.

I only live about 1.5 miles from work and commute once a week to a second location which is about 120 miles round trip all highway, often with traffic. Maybe 3 or 4 track days a year, if that, but canyon runs as often as life allows. Two kids under 3, which are rarely if ever in the car (we have an suv for a reason).

Let me know what you guys think.

I haven't driven an M6gc but I own a supercharged E90 (ESS VT2-625) and have driven several other high performance cars. I've attached and linked C&D test results for a 2014 M6gc. The 60-130 mph time is 13 - 3.7 = 9.3 seconds. That's on the high end for a stage 2 supercharged E9X M3, comparable to how one would perform in 95 degree weather after sitting in traffic. Quite a few supercharged E9Xs are capable of low 7 second 60-130 mph times, especially in colder weather. If you're in Cali with low humidity, supercharging the E90 is probably going to result in a quicker car on average. But just understand going in that supercharged E9Xs are very sensitive to heat / heat soak. You can literally vary between GT3 and GT4 (981) acceleration depending on ambient temperature and air flow.

One other way to look at it though is that the supercharged M3 will at worst be as quick as the M6gc is stock. Unsure if post-2014 upgrades or mods significantly change that though.

https://www.caranddriver.com/reviews/a15113469/2014-bmw-m6-gran-coupe-test-review/

The M6GC can be modded as well.

I just about snap my neck every time I see a M6GC in the wild, especially in black. They have a great street presence and share the same engine as the M5 (roughly?) so modding is always an option.

Good calls; edited my reply. No clue what happens if you mod the M6. Assumed OP meant SC E9X vs. stock M6.

If you are willing to mod one to be faster, then you are willing to mod the other to be faster. Does he want a smaller and lighter and older car or a larger and heavier and newer car? The E9x would be better on the track and canyons, but the F06 would be better the rest of the time in my opinion. The F06 would still be a lot of fun in canyons. The supercharged E9x might well heat soak on the track and not be as much fun.

Tough decision.

Modding is definitely on the table, though with the M6GC it would likely be upgrade brakes and suspension as much as possible and then simple bolt ons a plus a tune.

Are most who hard track their E9X not FI? I didn’t realize heat soak was that big of an issue with these, but have not ran the full gamut of research I would do before pulling the trigger on modding.

pbonsalb hit the nail on the head... The M6GC would be better during more of its actual daily usage which is why its even an option. Is it enough better that it’s worth it is the question

Longboarder made some good comments about supercharged E9x M3. The most popular and affordable kits use a water to air intercooler with a small coolant capacity that can’t keep up with sustained use such as on a track. People have gotten around that with larger trunk mount tanks. There are also refrigerant kits that use the car AC but I am not sure anyone has tried one on an E9x M3. Evolve, GPower and AA made or still make centrifugal systems with air to air intercoolers that would probably be better but those systems cost more.

The M6GC is a gorgeous car! It's probably the better car for daily use and drag racing (turbos are easier to mod/tune for big power). For track and canyon runs I would probably prefer the smaller lighter M3.

Roll race of my old ess650 vs a tune+exhaust M6 coupe at the 11:28 mark on the vid. Very close race looks like M6 would win. At this event I had the 5 gal water tank so i was prob doing 60-130 somewhere in the 7's.

Longboarder wrote

Roll race of my old ess650 vs a tune+exhaust M6 coupe at the 11:28 mark on the vid. Very close race looks like M6 would win. At this event I had the 5 gal water tank so i was prob doing 60-130 somewhere in the 7's.

That's pretty close! Amazing what you can do to a twin turbo car with a tune and simple bolt ons.

The M6 doesn't ride as well as you'd expect considering how big and heavy and soft it is. But it's not *worse* than the E9x, the longer wheelbase does help.

I'd not buy one without driving it first for that reason. If you're expecting acres of pillowy softness with supercar acceleration, it does the second thing (well, supercars from 2015 anyway, wtf is even happening with these 9-second factory street cars now) but the first thing, to my butt, it does not do. For that you need an Alpina

Richbot wrote

The M6 doesn't ride as well as you'd expect considering how big and heavy and soft it is. But it's not *worse* than the E9x, the longer wheelbase does help.

I'd not buy one without driving it first for that reason. If you're expecting acres of pillowy softness with supercar acceleration, it does the second thing (well, supercars from 2015 anyway, wtf is even happening with these 9-second factory street cars now) but the first thing, to my butt, it does not do. For that you need an Alpina

I havent driven the M6 but my M8 coupe rides very harsh even in comfort settings. The e92 M3 is much more comfortable in comparison. In fact, it is the most comfortable car I have ever owned.

If the M8 a Competition? At least with M5, many say the Competition version rides harshly. I skipped it for that reason. A few say there were changes to the 2021 M5 Competition that improves the ride. I would assume such changes would carry over to the cousins like the M6 and M8.

My 18 M5 is more comfortable and rides better than my former 08 E90 M3, but the E90 was on H&R springs (sport not race) and Bilstein B8.

pbonsalb wrote

Longboarder made some good comments about supercharged E9x M3. The most popular and affordable kits use a water to air intercooler with a small coolant capacity that can't keep up with sustained use such as on a track. People have gotten around that with larger trunk mount tanks. There are also refrigerant kits that use the car AC but I am not sure anyone has tried one on an E9x M3. Evolve, GPower and AA made or still make centrifugal systems with air to air intercoolers that would probably be better but those systems cost more.

I can only speak for the G-Power (GP-Infinitas) system.
It can get VERY warm in the summer where I live here in Northern California, like 109f a couple of weeks ago.
I've had my car to Thunderhill Raceway on a 103f day as well.
The car doesn't suffer noticeable (to me) power loss in either situation, but on track some fluid temps will eventually climb high enough to put the car in limp mode.

( I think the GP-Infinitas kit is priced much lower now, than it was when my kit was purchased in 2009)

You are presumably aware that your GPower car has a very different heat exchanger system than the much more common ESS or VFE supercharged cars. This explains your experience.

pbonsalb wrote

You are presumably aware that your GPower car has a very different heat exchanger system than the much more common ESS or VFE supercharged cars. This explains your experience.

You are correct.

When I first started spending some real time on the forum, trying to learn about these cars, I didn't understand what the "Heat Soak" concerns were all about. Then the more I read, the more I started to understand the differences.

I just wanted to add some personal experience about living with the G-Power system, just in case anyone that stumbles across this thread might be as confused as I initially had been.