BMR Suspension SP083 Handling Springs, REVISED and Better than Ever!

CoolRod · Jul 18, 2018

BmacIL said:
The Konis are a little harsh. They handle amazing but are somewhat crashy. The Ford Racing soaks up imperfections better and still is very responsive. I'd say for a car that sees less street time than track time, the Koni are awesome. For the opposite, the FRPP are the ones to have. They just match to the springs so well

The more street miles I put on the car, the more I've come to realize this is the truth. I've got three autoX events on this spring/shock combination and the handling is great, car is well planted, the grip is tremendous and it transitions well thru slaloms. But I am begining to not like them on the street. Fortunately, she is not a daily driver, but I am starting to hate railroad crossings and large freeway expansion joints. The front handles everything great but the rear really bounces and if I didn't wear my seat belt, my head would hit the roof!

I have both F&R Koni's at 1.5 turns. Should I soften the rears? Do I need to trim my bump stops a little more (I followed BMR's directions).

I also reclocked the bushings by using a transmission jack (car was on a lift). I compressed the spring with the jack until weight of the car was slightly off the lift, then tightened all the bushings. Did I do this incorrectly??

Any other suggestions?? New struts/shocks are pretty much off the table. Mods are in signature below.

BMR Tech · Jul 18, 2018

CoolRod said:
The more street miles I put on the car, the more I've come to realize this is the truth. I've got three autoX events on this spring/shock combination and the handling is great, car is well planted, the grip is tremendous and it transitions well thru slaloms. But I am begining to not like them on the street. Fortunately, she is not a daily driver, but I am starting to hate railroad crossings and large freeway expansion joints. The front handles everything great but the rear really bounces and if I didn't wear my seat belt, my head would hit the roof!

I have both F&R Koni's at 1.5 turns. Should I soften the rears? Do I need to trim my bump stops a little more (I followed BMR's directions).

I also reclocked the bushings by using a transmission jack (car was on a lift). I compressed the spring with the jack until weight of the car was slightly off the lift, then tightened all the bushings. Did I do this incorrectly??

Any other suggestions?? New struts/shocks are pretty much off the table. Mods are in signature below.

I drive on Koni Yellows and SP083s often.

My personal preference for street driving is 1.25 turns up front and 1/2 to 3/4 turn out back.

Try that and see how it feels.

Everyone is different and suspension settings are subjective for street use, but I have found the above to be "perfect" for me on our car that is modded similar to yours.

Also, everyone is all over the map with this...but I personally like to run my street tires at 26-27psi on the streets. I have done A LOT of testing with tire pressures on mine and BMR S550 cars and I prefer all at those pressures.

Good luck.

BmacIL · Jul 18, 2018

CoolRod said:
The more street miles I put on the car, the more I've come to realize this is the truth. I've got three autoX events on this spring/shock combination and the handling is great, car is well planted, the grip is tremendous and it transitions well thru slaloms. But I am begining to not like them on the street. Fortunately, she is not a daily driver, but I am starting to hate railroad crossings and large freeway expansion joints. The front handles everything great but the rear really bounces and if I didn't wear my seat belt, my head would hit the roof!

I have both F&R Koni's at 1.5 turns. Should I soften the rears? Do I need to trim my bump stops a little more (I followed BMR's directions).

I also reclocked the bushings by using a transmission jack (car was on a lift). I compressed the spring with the jack until weight of the car was slightly off the lift, then tightened all the bushings. Did I do this incorrectly??

Any other suggestions?? New struts/shocks are pretty much off the table. Mods are in signature below.

Try the rears at 1 or 3/4 turn from soft. At 1.5 turns it'll jack the car down and will be more crashy. A little less rebound will let the spring keep the tire in contact with the ground better. Don't go too soft though, as then it'll get bouncy and easily perturbed.

I would say that your method for clocking the bushings isn't necessarily the best but is probably not far off from doing at ride height. If you verified that the wheel center is in the same or nearly the same position when you jacked it up as it is at ride height, then you're ok.

jbird60 · Sep 26, 2018

So it might be a bit premature (still have to get the alignment done), but I recently installed the SP083 set (with the revised fronts, rev. C if I'm not mistaken @BmacIL , same setup as talked about here: https://www.mustang6g.com/forums/th...ith-the-ford-performance-track-shocks.105570/). On top of this setup, also added on the CB005 cradle lockout kit.

Pretty much all my feedback is 100% in-line with what you'll see in that other post I linked to, with special emphasis on the fact that this setup surprisingly irons out speed bumps and other harsh road surfaces quite nicely, much better than you might expect. It offers a very connected feel with the road surface and inspires a lot more confidence in the handling capabilities of the car. That being said, you'll feel road undulations a lot more. Doesn't bother me one bit, but I know some may object to this.

More to come once the alignment is done and I can wring this thing out around the roads north of Ann Arbor...

Bluemustang · Sep 27, 2018

jbird60 said:
So it might be a bit premature (still have to get the alignment done), but I recently installed the SP083 set (with the revised fronts, rev. C if I'm not mistaken @BmacIL , same setup as talked about here: https://www.mustang6g.com/forums/th...ith-the-ford-performance-track-shocks.105570/). On top of this setup, also added on the CB005 cradle lockout kit.

Pretty much all my feedback is 100% in-line with what you'll see in that other post I linked to, with special emphasis on the fact that this setup surprisingly irons out speed bumps and other harsh road surfaces quite nicely, much better than you might expect. It offers a very connected feel with the road surface and inspires a lot more confidence in the handling capabilities of the car. That being said, you'll feel road undulations a lot more. Doesn't bother me one bit, but I know some may object to this.

More to come once the alignment is done and I can wring this thing out around the roads north of Ann Arbor...

I agree with your assessments. It definitely makes you feel the road undulations more and I take that as it just being more responsive.

What dampers are you using?

jbird60 · Sep 27, 2018

Bluemustang said:
I agree with your assessments. It definitely makes you feel the road undulations more and I take that as it just being more responsive.

What dampers are you using?

Ah yes, forgot to mention, Ford Performance Track Shocks (M-18000-F, https://performanceparts.ford.com/part/M-18000-F). Should probably also mention that I threw on BMR's caster/camber plates as well during the install (CP001).

Bluemustang · Sep 27, 2018

BMR Tech said:
I drive on Koni Yellows and SP083s often.

My personal preference for street driving is 1.25 turns up front and 1/2 to 3/4 turn out back.

Try that and see how it feels.

Everyone is different and suspension settings are subjective for street use, but I have found the above to be "perfect" for me on our car that is modded similar to yours.

Also, everyone is all over the map with this...but I personally like to run my street tires at 26-27psi on the streets. I have done A LOT of testing with tire pressures on mine and BMR S550 cars and I prefer all at those pressures.

Good luck.

@BMR Tech - With respect to your comment about tire pressures -- wouldn't running street tires at 26 or 27 psi cause the tires to wear excessively on the outside edges? Currently I am running mine at 30 psi cold.

Also, what difference did you notice running lower pressures?

I still have my KONI yellows sitting the in garage from my previous setup. I plan on keeping them for when my Ford Racing track dampers wear out. I have a feeling the KONIs are sharper than the Ford Racing dampers. But nevertheless I enjoy the handling of the Ford Racing shocks and the ride quality is quite nice with them compared to when I ran the KONIs paired with SP080s.

Thanks for your valued insight as always.

jbird60 · Oct 1, 2018

Alright, I finally had a chance to have a tiny bit of fun on Huron River Drive between Ann Arbor and Dexter over the weekend (not too much though, too many kayak-filled pickup trucks and cyclists), so here are a few more observations about the BMR SP083 springs paired up with the FP track shocks and the CB005 lockout kit (for a full list of what's now on my car, see my signature):

As I indicated in my previous post, I can definitely affirm that there's a much more "directness" in terms of road feel. Undulations and road camber changes are felt through the seat much more (i.e. this setup is much more communicative than the stock PP suspension items). I think a lot of this has to do with the FP damper rates being very well tuned to match the BMR spring rates, both in low-speed and high-speed suspension movement.
I somewhat recently made the switch from the stock PP Pirelli P-Zeros to the Firehawk Indy 500 tires and noticed a marked drop-off in initial turn-in crispness (perhaps the only thing the Pirellis were good for), but much more predictable and linear grip levels further through turns. With this suspension setup, this initial bite appears to be restored without sacrificing grip through the corner. Win-win
It's become slightly easier to detect the rear end of the car slipping out under excessive corner-exit throttle. Admittedly at low slip angles, it's very hard to feel this in our cars (my opinion, might be unpopular). I think the spring/shock/lockout combination in the rear is definitely critical to transmitting more of that feel to the seat. I have a set of RLCA bearings that may get installed in the near future; these will probably improve this feel even more.
The only negative point thus far: increased road noise, especially over harsh surfaces (which Metro Detroit is certainly not lacking). Given that I only drive my car maybe once or twice a week, this isn't really an issue for me, but I could understand this being problematic for people who may not be as track-oriented. It's worth noting that much of this may come from the CB005 rather than the spring/shock setup. All that being said, I've had no issues daily driving on this setup. Even made a Trader Joe's run in it yesterday and it was perfectly comfortable.

Ideally I'd be able to test this setup a bit more as I think there's lots more to uncover, but the car's scheduled to go into storage tomorrow until Spring :crying:

Bluemustang · Oct 1, 2018

@jbird60 In my experience the RLCA bearing helps low speed corner traction. Those + the FRPP toe bearing allows me to step away hard in a turn from a dead stop with much less inside wheel chatter.

It definitely communicates even more what the rear is doing. Also can introduce a little bit of bounciness in the driver seat because it transmits more of the forces through the chassis. It basically removes the vagueness in rear left even after doing CB005.

Glad you’re enjoying your setup and sad that she has to get put away for awhile.

BmacIL · Oct 6, 2018

Another happy camper in @MTECH6G with these springs and FP Track dampers! Such a great combo.

MTECH6G · Oct 7, 2018

I’m not exaggerating here but the car handles just as good as my old E92 M3 with the Ford Performance FR3 dampers and BMR SP083. Just absolute precision and response.

BmacIL · Feb 17, 2019

SP083s going FAST! First and lap record in Street class.

BMR Tech · Apr 23, 2019

Alessandro continuing to win with SP083s and FP Dampers.

axios · Dec 8, 2020

@BMR Tech, what bump stops do you recommend for SP083s and FP dampers?

Stang55 · Dec 9, 2020

axios said:
@BMR Tech, what bump stops do you recommend for SP083s and FP dampers?

It isn't mentioned but FP dampers ( M-18000-F ) already come with orange bump stops. :thumbsup:

BMR Suspension SP083 Handling Springs, REVISED and Better than Ever!

CoolRod

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BMR Tech

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BmacIL

Enginerd

jbird60

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Bluemustang

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jbird60

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Bluemustang

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jbird60

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Bluemustang

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BmacIL

Enginerd

MTECH6G

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BmacIL

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BMR Tech

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axios

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Stang55

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