E70 Lowering Options - HELP..

[bcredliner]

I don't know what inconsequential is to you. To me anything that reduces 0-60 time, negatively impacts handling and ride is not inconsequential.

As long as the total height of the rim and tire is greater, low ratio gears or otherwise, acceleration time from 0-60 is always reduced. An exception could be if there was one less shift before 60. Of course, the degree of impact depends on how much greater total height is increased.

You are correct that weight of rims is a factor. There might be taller rims/tires that are lighter weight and don't increase total height than what OP has, but, in comparison to other methods of filling the wheel wells it would be an expensive route to go.

[ucsbwsr]

Originally Posted by bcredliner

I don't know what inconsequential is to you. To me anything that reduces 0-60 time, negatively impacts handling and ride is not inconsequential.

As long as the total height of the rim and tire is greater, low ratio gears or otherwise, acceleration time from 0-60 is always reduced. An exception could be if there was one less shift before 60. Of course, the degree of impact depends on how much greater total height is increased.

You are correct that weight of rims is a factor. There might be taller rims/tires that are lighter weight and don't increase total height than what OP has, but, in comparison to other methods of filling the wheel wells it would be an expensive route to go.

Couple things... You mention the ride quality should be the same with if the spring rates are the same, that is not the case unfortunately since the springs and struts have to operate in harmony. Lowering springs with OEM rates are going to be paired with struts which operating at a lower ride height which it wasn't intended for.

I agree with you on increasing performance when possible, the first mod I did the day I brought home my X5D was replace the heavy OEM 19" wheels on RFTs to 21" Style 612M on Michelin PSS and saved about 12lbs a corner. However the short gearing and thin 325/30 rear tire leave something to be desired so once these PSSs are toast I will run some Continental 5Ps with higher aspect ratios, front will go up some size from 35 to 40 and the rears will jump up 2 sizes from 30 to 325/40. Heavier tire, slower acceleration? Yup. Is the lower rpm at highway speeds and added comfort from the taller tires worth it? Absolutely. If 0-60 times were so important that all mods tailored to acceleration then I would simply not buy a 5,000lb SAV lol. Thankfully I have a 550whp E61 which does a nice job satiating that craving.

The added bonus of the taller tires is less fender gap. We will see once I install the new tires but I might be able to get away with only installing Eibachs springs up front and coding the rear air down just a hair to match. Ideally offering an OEM like ride with minimal fender gap and added comfort from taller tires. If it doesn't pan out this way then ponying up for KW coilovers is next. Pricey but worth it IMO. I have ran them on all 3 of my vehicles.

I test fit a 285/45/21 up front and unfortunately it didn't clear the upper spindle joint (and it probably would have rubbed on the liner at lock) but it gets me fired up for the meatier tires. IMO a little 1-1.2" drop would be all it needs to look proper.

More pics in my build thread:
https://xoutpost.com/bmw-sav-forums/...og-m57-x5.html
As for sway bars there are only 2 companies I know of that make a rear sway bar (no fronts). I run the Ultra Racing rear sway. I minor improvement over stock, the E70s could use much more robust sways.

Evan