Amazing what a mild spring rate increase and beautifully matched dampers can do. You can eat your cake.
Funny that you call it a mild spring rate increase. Front is 50% stiffer than PP and the rear is about 30% stiffer. I agree that it feels mild, though.
Relative to what most run for their track-only cars (450-600 lb front, 1200-1400 rear in stock location), they're pretty mild.
That's amazing!
I finally got to install my suspension. I bought the parts last fall. Between work and home projects I didn't get a couple days to work on it.
Try the Konis at around 3/4 turn up from soft for the street. They rode better to me there than at 1/4 turn (basically full soft).
Flip a coin! Go with your gut on the height. If it were me, now, I'd go with the SP083 set, as the 0.5" drop 980 lb/in rear handling springs that I have are no longer available. IMO, SP083 is slightly better than the GT350R spring setup, but it's really close. If you felt stronger about not lowering that bit extra, I'd say R springs.Hi All!
I'm new here, and there's a lot of great information on this thread and across this forum. Hopefully this is the right place to post this!
I'm looking to stiffen-up my car and make the steering more responsive - while still being daily-drivable.
I daily drive a 2017 Mustang GT PP completely stock (with the exception of the Steeda clutch assist spring and a Corsa Sport cat-back)
I currently do a lot of spirited driving through Bay Area backroads and in the future I plan on taking my car to auto-cross events.
Based off of research gathered from this forum, my build proposal so far is as follows:
I am holding off on the RLCA bearing for now due to concerns over NVH.
- APEX SM-10 19x10 + Michelin Pilot 4S @ 285/35r19
- FRPP Track Dampers
- Steeda Tension Link with Bearing
- Steeda Roll Center Correction Lateral Link + Bumpsteer kit
- Steeda Stop-The-Hop Kit (IRS Alignment, Brace, Bushing Supports)
- FRPP Knuckle to Toe Link Bearing
- BMR SM760 Rear Shock Mount
The only decision remains is what springs to choose, namely GT350R springs or BMR SP083 springs.
I am hung up on the following reasons:
- GT350R - 240f/920r lb/in @ .7/.3 inch ride height drop
- SP083 - 250f/980r lb/in @ .88/.75 inch ride height drop (or .5 inch rear if used with a Steeda 1/8 inch spacer)
- The GT350R has less of a drop front and back, but Steeda's Extended Ball Joint is *ideally* designed for a 7/8 inch drop; the joint is .625 inch more than stock whereas a GT350R ball joint is .5 inch more than stock. Given the design of a McPherson strut cg to rc drop ratio is roughly ~3:1, I would be raising the roll center probably .6-.7 inches higher than Steeda and/or Ford deems is ideal, and I am not sure how far off from 1:1 the motion ratio would be. I am also not sure what other unintended effects this would have, such as increased camber gain under braking or faster tire wear from scrub during suspension travel if the motion ratio is far off from 1:1. Seems like @BmacIL runs GT350R fronts with this and doesn't have issues, I would love his input
- The BMR SP083 front spring matches PERFECTLY with Steeda's Extended Ball Joint @ a 7/8 inch drop. However, the rear drops too far for my liking and I would probably want to run it with a 1/8 inch spacer to raise it 1/4 inch (total .5 inch drop). I'm still worried that this may be too low of a drop in the rear, as the rear roll center drop is worse than the front roll center when lowering the same distance. I know @Bluemustang runs this without a spacer and loves it, I would love to hear more on his thoughts
- The BMR SP083 springs are 5% stiffer, but this is probably unnoticeable and a non-issue.
Please tell me if I'm over thinking this too much and I should simply choose one or the other!
My gut is also telling me I would probably also not notice the difference, which would mean I should choose the GT350R springs for the extra .2 inch of ride height gained, as I'd prefer to lower as little as possible.
Thanks!
I totally agree with @BmacIL. Not much to add because he pretty much summed it up.