I've been curious about this since the G70 compares to the M340i and everyone says if you want the performance BMW is where it's at. I've never been in a sports level BMW (just some older 330i and SUVs that never impressed me).
It's made me wonder how close a G70 with eibach springs and sway bars is compared to an M340i. If you're comparing a G70 with suspension
mods to their M2, I'd imagine the eibach kit by itself would be close if not better than the M340i.
It's just seemed silly to me to go with an M340i for horsepower and handling for $12k more money than a fully loaded G70 3.3t. I can get a full eibach kit for $850 and if I really wanted the horsepower the LAP3 ECU stage one is basically 450hp on their lowest tune, which is crazy, and I'd still be almost $10k cheaper than the BMW that comes with less features overall.
Stock, the Sport Prestige 3.3T
is closer to the M340i. The M2/3/4
are at another level. Yes, I'm only comparing on chassis dynamics with available G70
mods.
Eibach sport springs and anti-roll bars (mine are Whiteline) were exactly what we started with. IMO, for purely street applications, that is the ideal setup. Ride quality is just about exactly the same as stock suspension, and the slightly stiffer springs rates (~10-12%), along with the lowered CG really helped to reduced the wallowing on turn-in and squatting on power-on corner exit. When you start pushing the limits, the stock shocks become the Achille's heel. Those of you with electronic suspension can at least firm up the damping rate, but even then, the adjustments are overall and not front-rear independently adjustable, needed for fine-tuning cornering attitude. If Koni/KYB/Bilstein made
aftermarket adjustable shocks, that would solve this issue. But... apparently most
Stinger/G70 owners are lowering just for looks, so nobody care to buy shocks, so the majors haven't bothered. That is a shame. Independent damping adjustment is one of the best tool for chassis tuning for optimum vehicle dynamics.
The saving grace is that coilovers
are available. That is what we migrated to. With ours, the front camber plates allow for up to about 3degs of negative camber. If this were a track car, I would dial in max allowable (especially for 18" tires), but ours are everyday drivers, so we settle for between 1.5 and 2.0deg, so we don't chew up our street tires.
Wheels and tires, or course, make the most difference. Ironically, that is also the easiest thing to upgrade. So too are brakes. With good brake pads, the stock Brembos work just fine, albeit for the lighter weight trims of the G70 line, around 3600 lbs (or below, with
mods). G70 V6 AWD pushing 3900-lbs, and especially 4000-lbs
Stingers, really need larger rotors and 6-pot front, IMO.
As far as HP/TQ go, even the 2.0T with our 6MT is plenty enough for the HPDE we are after. We don't drag, and we don't do roll-on grudge matches with the Stangs and Scats. We get our kicks carving corners and doing slice and dice at the track. With the 8AT, the 2.5T hits the sweep spot for me. But I can certain appreciate the appeal of the stout 3.3T. That's where I think BMW has the upper hand. Some of the S58s are pushing 560HP
stock, and they are know for underrating their engine output.
I might not care, but there are plenty that do.
. I did see a newer G90 today though.
