RPMs are best for the MS6 (currently unavailable, check mazda 6 club for details).
What I get from this thread is that there are no existing spring setups for the MSP6. Can't really claim that the best are RPM's since they don't exist, right? Or do they exist and initial production has sold out?
Anybody trying to do suspension mods that WORK - For less money than a Haynes manual:
http://www.soloperformance.com/Shop...Make+Your+Car+Handle/selection/0/Default.aspx
Hitting the bump stops at either end of the car is a really bad thing, and will put you in the trees or into the oncoming lane when you least expect it. Very aggressive spring rates are necessary when lowering to as much as 1.5" or more. More aggressive springs require more aggressive damping.
Mazda6 aftermarket, lowered springs applied to an MSP6, here's a rundown of what you might expect, based on armchair engineering estimates of weight distribution:
Any Mazda6 application - Springs will not work well with stock anti-roll bars since they are engineered for AWD configuration, and springs are for a FWD vehicle. Damping will be incorrect for reduced suspension travel, contributing to bottoming out, especially in rear. Ride height specification of springs will be innacurate due to different weight distribution on MSP6. 262 lbs is a LOT of weight to consider when setting up springs. Any Mazda6 spring set will produce increased, earlier understeer. Ability to controll over/understeer with the throttle will be greatly diminished, if not completely lost.
Mazda6i - Front rates might be ok, but rears will be too soft due to the added weight of the rear diff and axles. Expect more understeer much sooner in the corners. Severe bottoming in rear.
Mazda6s - Front rates (higher due to weight of V6) will be too firm and rears too soft. More understeer, and sooner than with 6i springs. Bottoming in rear same as with 6i set.
Any setup that changes the ride height and rates unequally will change the car's center of gravity and roll center. This will further adversely affect the anti-roll bars. What effect it has depends on the bias produced by the inequity of change. Rate changes should be equal percentage front & rear, and height changes using rate correct springs will be a trial & error process, and depend on the length of the spring. Info from everyone here running aftermarket springs could be compiled to try and match up springs from different sets. We'd need the specified rates and real-world height numbers from drop measurements on springs actually installed on MSP6's. If we got lucky we could actually stumble across a good combination.
I'd say that until a specific MSP6 aftermarket setup is available, effective spring mods will also take research into spring rates available for all the cars using the platform, providing the mounting hardware is uniform. Fords, Volvos and Mazdas use the same platform but are different weights, right? With a test car and funds to purchase the available springs or at least the likely candidates, a usable set could be assembled. Theoretically it could work. A lot of old school hotrod setups were worked out the same way. Production numbers of MSP6's might be low enough to discourage development of proper sets, and could leave us on our own or paying really high prices.
