Steeda Dual rate mag ride springs and comp rear swaybar

[Stan Whitney]

After running all BMR on my GT500 for a few months (250/980 linear), over the new years break I installed the Steeda springs (350/1200) and later the big 1.5"/38mm front bar and skinny rear 19mm comp bar. I thought they might be snake oil, but I'm very happy with the change.

The springs gave about the same ride height as the bmr's but the higher rate keeps the car from bottoming out much better on track and on road surface heaves. Lap times stayed pretty similar, no break through there. They are better for street usage. The rear might be a tad easier to rotate mid corner and on exit, may have lost some power down capability.
Nice stance


A few weeks later I installed the massive front bar, and the comp rear bar with its relocation brackets. Very happy with it, the car is easier to drive now, and faster.
I have been fighting oversteer on trail brake/corner entry for a long time with this car. The setup I ended up with was BMR front 35mm bar at full stiff, oem base 24mm rear bar.
The Steeda 38/19mm bars in the mid settings improved the rear grip slightly on entry, without any additional understeer mid corner or exit.

Good parts - The rear bar mount relocation brackets work, check out the end link angles

The front bar ends have more clearance to the mag struts. BMR bar had the end links practically rubbing the struts.

Bad parts - front bar frame bracket needs a special tool to tighten the bolt under the alternator. An old gearwrench set I had worked, needed a low profile ratchet and socket.

 

[biggsy]

thanks for this review. I have been contemplating going from BMR handling springs to the Dual Rate Handling springs but I understand that linear springs are more predictable throughout range. Im not sure how that translates to difference in driving but I would like more rate without going to coilovers

 

[RES_22]

Dual rate springs aren't progressively wound...they have two linear rate parts. . You are in the main (high rate) portion unless you are transitioning....and then the secondary (low rate) portion works to maximize grip for the lesser-loaded corner of the car.

Same principle as a coil-over with a helper spring.

And as Stan noted...control at the lighter loaded corner/end improves (over a spring w/o a "helper" portion) b/c the softer portion lets the wheel track the surface better...

 

[RES_22]

Stan: Maybe try the Steeda bars @ full hard/full soft F/R, respectively?

Should help for sure on enrty, unless your driving style delays loading the nose OR loads the nose hard, early and pins it to the apex.

Should help center-off also...provides a bit more inside rear wheel grip on-power.

 

[biggsy]

Dual rate springs aren't progressive. You are in the (linear) high rate portion unless you are transitioning....and then the low rate (linear) part of the spring is working to maximize grip for the lesser-loaded corner of the car.

Same principle as a coil-over with a helper spring.

Thanks for explaining that. Now that you put it like that, it makes sense.

 

[Stan Whitney]

Thanks for explaining that. Now that you put it like that, it makes sense.

With these springs the car still responds in a linear fashion, I did not have to change any shock tuning or driving style for them compared to the BMRs. The platform just feels a little bit flatter and more stable (like 10-20%), but still rides curbs very well at the apex if I need to. I thought it was snake oil before that, but am happy after driving them.

 

[Stan Whitney]

Stan: Maybe try the Steeda bars @ full hard/full soft F/R, respectively?

Should help for sure on enrty, unless your driving style delays loading the nose OR loads the nose hard, early and pins it to the apex.

Should help center-off also...provides a bit more inside rear wheel grip on-power.

You read my mind, going to try it next weekend. Also am testing some different dsc shock tuning as well.

I did discover (in general - shock/spring/bar) - as I firmed up the front end more, the corner entry improved, but mid and exit started to get slightly more pushy and lose time. Especially mid corner between braking and going to throttle, trying to get the nose to finish pointing into the apex so that I could power out without waiting. Garmin data shows time gains on entry, but lost a lot of it on exit and down the straights. All tradeoffs.

 

[RES_22]

You've got 4200lbs of angry car - tough to slow it and turn it between the turn entry point and apex...especially as entry speed goes up and as the distance between TEP and apex decreases...tradeoffs for sure.

Try the new bar split...should delay the front outside corner wt transfer a bit on entry. Also, maybe consider backing up the braking marker a bit...get off of the brake a bit earlier...recover the nose, get all of the turning done a heartbeat or two earlier...slow in (just a bit - lol).

Finally - and it's likely something you've considered, with your experience.- your monster + improved suspension + higher entry speed *might* need a more capable tire, if you're still on the Nankangs. Energy has to go somewhere (without boiling the contact patch)...just a thought .

 

[Stan Whitney]

You've got 4200lbs of angry car - tough to slow it and turn it between the turn entry point and apex...especially as entry speed goes up and as the distance between TEP and apex decreases...tradeoffs for sure.

Try the new bar split...should delay the front outside corner wt transfer a bit on entry. Also, maybe consider backing up the braking marker a bit...get off of the brake a bit earlier...recover the nose, get all of the turning done a heartbeat or two earlier...slow in (just a bit - lol).

Finally - and it's likely something you've considered, with your experience.- your monster + improved suspension + higher entry speed *might* need a more capable tire, if you're still on the Nankangs. Energy has to go somewhere (without boiling the contact patch)...just a thought .

Good tips, it is a lot of angry car energy to dissipate and redirect. I am stuck on the nankangs because of 200tw requirement, but they are decent to good for what the car is asking for. Will try the new bar split next weekend, and try not to 'hot dog' in as hard.

 

[biggsy]

Thanks for all the info gentlemen.
Even though I’m on lesser rates(250/980), I may try putting my BMR front bar to fill stiff and replacing my 350R rear with a convertible rear (19 or 22mm).

 

[mavisky]

I just placed an order for this exact same combo for my GT350 so good to hear your feedback.

 

[Ewheels]

Damn it.....
I just came across this thread and now I want dual rate springs
I also have the BMR 250/980 springs and they still feel like a boat on track. Not sure if the dual rates are worth it for me at this point being $350 when I should just save up for some coilovers.
I will be trying full stiff on the front bar next track day though.

 

[biggsy]

Damn it.....
I just came across this thread and now I want dual rate springs
I also have the BMR 250/980 springs and they still feel like a boat on track. Not sure if the dual rates are worth it for me at this point being $350 when I should just save up for some coilovers.
I will be trying full stiff on the front bar next track day though.

you and me both. And I currently am replacing the camber plates so it’s the best time to do it because I don’t feel like hammering out those strut bolts again.

 

[Ewheels]

you and me both. And I currently am replacing the camber plates so it’s the best time to do it because I don’t feel like hammering out those strut bolts again.

Looks like you have to buy the springs

 

[Stan Whitney]

you and me both. And I currently am replacing the camber plates so it’s the best time to do it because I don’t feel like hammering out those strut bolts again.

Don't run and swap, at the track it is a nice but not earth shattering difference. I like them better on the street where the bumps and dips are more severe. Also the mag shocks , when you get them working well, help make these softer-than-coilover rates workable.

 

[biggsy]

Don't run and swap, at the track it is a nice but not earth shattering difference. I like them better on the street where the bumps and dips are more severe. Also the mag shocks , when you get them working well, help make these softer-than-coilover rates workable.

My bank account thanks you kind sir.

 

[johnnyh788]

Don't run and swap, at the track it is a nice but not earth shattering difference. I like them better on the street where the bumps and dips are more severe. Also the mag shocks , when you get them working well, help make these softer-than-coilover rates workable.

Thanks for the review again, great info. I see you are going even faster in your Youtube video! anything in particular you change/ upgrade since? How is the dual rate ride vs stock spring? I have 2019 gt350 with whiteline sway bar kit. Looking for better control.

 

[Stan Whitney]

The ride is just a little bit stiffer. It is not as noticeable as the change between normal and sport shock settings. Either BMR or Steeda will help your gt350, reduce the pitch under braking, and the flop side to side in transitions. I ran BMR on my 350 for 2 seasons with great success.

 

[johnnyh788]

The ride is just a little bit stiffer. It is not as noticeable as the change between normal and sport shock settings. Either BMR or Steeda will help your gt350, reduce the pitch under braking, and the flop side to side in transitions. I ran BMR on my 350 for 2 seasons with great success.

Thanks for the speedy info. Sounds like Steeda will fit me better since it has better street manner. Did you notice major improve in transitions even with sway bar upgrade or you upgrade everything at once ?
I am interested in upgrading the DSC as well, did you have a custom tune map just for your BMR/Steeda ? Did you tune the DSC when you change to Steeda ?

 

[Stan Whitney]

Thanks for the speedy info. Sounds like Steeda will fit me better since it has better street manner. Did you notice major improve in transitions even with sway bar upgrade or you upgrade everything at once ?
I am interested in upgrading the DSC as well, did you have a custom tune map just for your BMR/Steeda ? Did you tune the DSC when you change to Steeda ?

Sway bars alone did not help much. Spring change made the difference. On the DSC map, the current Billy Johnson Gt500 map is really good. I make some small tweaks, but even out of the box it was an improvement in stability on corner entry and over curbing.