Hello

Struggling to decide on best springs to use for autocross and HDPE events. I drive the car on the street but willing to give up some ride comfort for better times. 2013 GT Track Pack. Just picked up a set of Potenza RE-11's and looking to do camber plates, panhard bar, springs, and struts/shocks.

Have 3 options in mind

1. P-Spring/Koni Yellow - I have heard that 1 inch drop is good as it allows lots of suspension travel and I assuem thats why its part of Ford Handling kits

2.K-Spring/Koni Yellow - Like the look of and I beleive has a little more spring rate

3. BMR Handling springs/Koni Yellow - Highest spring rates I have seen 240/200 in a linear spring. I haven't seen much on these but description sounds right.

Thoughts?

I think of it as personal choice for how low you're willing to go on the street.

Have you also considered H&R race springs or Steeda Boss springs?

What width are you running for the RE-11s?

For not much more money you could also consider the CorteX Koni fronts and another brand spring/perch system for the rear springs or BMR rears can be purchased separately. Woudn't cost too much more, considering the separate cost of Koni yellows, camber plates and springs. JMO, if you're considering all your options.

265/35/19 on the factory Brembo wheel

I don't think I want to go any lower than 1.5 as I have a Stillen splitter on the front of the car that limits driveway ability.

I have seen both H&R and the Steeda Boss springs frankly confused on best to get at this point.

Have a baby on the way so trying to keep cost somewhat in check here so Cortex is out of the league even though it would be my first choice if no baby .

If clearance is a concern for the street, I'd go with the Steeda Boss springs. From the stock GT height it should net you about -.7" in the front and about an inch in the back. 1.5" drop with a splitter might be hard to live with.

For street, I liked the P springs, for our roads the K springs would be to much of a drop. Buddy has a 2013 GT with Koni yellows and my old P springs and he is just about as fast as my Cortex Koni setup. With A7s he is a little faster then me with my semis.

IMO autocrossing has very little to do with HPD events, the biggest issue is because of tires, in the auto-x (and I've done a bunch) the tires have no way to warm up and never get to the desired temperature, for this reason I've run rain tires and tires that have been "soaked" in softening liquids, things that you are way less likely to get away with on track events, for those same reasons, you would probably want much softer springs and sway bars.
I'm sure you can find an compromise and even adjust the sway bars for autocrossing, this and adding 3 psi extra air into the tires will help.

Also take a look at Vorshlag's Bilstein options.
http://www.vorshlag.com/index.php?cPath=141_142_179
If they fit your price range, give them a call and tell them your goals. I bet they can put together a strut/spring combo for you.
That being said, several years ago I picked up a used Koni yellow/Steeda Sport spring system with MMC plates installed, and overall, it works pretty good.

500 front , 250-300 rear springs, Ford blue bar up front, and the 18mm or no bar in the rear.
That setup is like the general..can't mess it up, works for most people deal

I do not recommend BMR handling springs with Konis. Currently running those with RE11s. They were acceptable up until I upgraded from MPSS to RE11s. Now they need to be cranked almost all the way up to get good turn in response and the ride is intolerable. These springs would be much better paired with Bilstein shortened struts like Vorshlag sells.

I am very happy with my Cortex Koni setup with F600#/R350. But on street the rear 350 coil overs are too hard (maybe a little too hard for track as well), I think a 250 rear spring would be great.

What I was most surprised about was that my present Cortex setup is more comfortable then the P springs and Stock Boss shocks on the stiffest setting. Is that just from better shock valving??

Mad Hatter said:

I am very happy with my Cortex Koni setup with F600#/R350. But on street the rear 350 coil overs are too hard (maybe a little too hard for track as well), I think a 250 rear spring would be great.

What I was most surprised about was that my present Cortex setup is more comfortable then the P springs and Stock Boss shocks on the stiffest setting. Is that just from better shock valving??

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That might be because I'm refering to a separate spring, coil overs are different, and your numbers sound about right for that.

I was trying to understand the physics involved with the different spring diameters, but got now where..... Why would a spring rated at 200# with a 5" diameter feel stiffer then a 500# spring with a 2.5" spring. I get that coil overs will be lighter and have more wheel space etc... But the rest is beyond me so far.

It's the location of the springs that matter. Coilovers will have a different effective 'wheel rate' vs. in the stock perch on the axle tube.

'12 Boss. I've at one point or another tried all of the springs listed on either my Boss or the '12 GT I had. I ended up with Maximum Motorsports Road & Track springs. Slightly softer at the track than the H & R Race and not quite as low. Because they are progressive the street ride quality is better that the stock springs or any of the others IMO. My setup: Koni yellows, MM caster camber plates, MM Road & Track springs, MM front bar, 18mm rear bar, Fays 2 watts link, FR rear lower control arms and relocation brackets, poly bushings at all these points. This is with 18 x 10 275/ 40/ 18 NT-01's square. For the money I think a very fun setup. Really transformed the car.

576 said:

'12 Boss. I've at one point or another tried all of the springs listed on either my Boss or the '12 GT I had. I ended up with Maximum Motorsports Road & Track springs. Slightly softer at the track than the H & R Race and not quite as low. Because they are progressive the street ride quality is better that the stock springs or any of the others IMO. My setup: Koni yellows, MM caster camber plates, MM Road & Track springs, MM front bar, 18mm rear bar, Fays 2 watts link, FR rear lower control arms and relocation brackets, poly bushings at all these points. This is with 18 x 10 275/ 40/ 18 NT-01's square. For the money I think a very fun setup. Really transformed the car.

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Doing that might also put you into an entirely different class. We've tried the PHB set, the Watts link and about everything else, both of our drivers always ended up running the stock style suspension (PHB) with the stock locating points. It's probably a matter of preference but they always gravitated back to that setup.

blacksheep-1 said:

Doing that might also put you into an entirely different class. We've tried the PHB set, the Watts link and about everything else, both of our drivers always ended up running the stock style suspension (PHB) with the stock locating points. It's probably a matter of preference but they always gravitated back to that setup.

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Your experience got me to put on hold my Watts link plans. My buddies GT has all the cortex tricks (Watts, torque arm etc) and am waiting to run with him to see how it does on our bumby less then perfect tracks. Good old PB is way cheaper!

It's kind of funny, with the car on the hauler lift people would come by and ask if they could look at the car, we always said yes because Phoenix is in the business of racing and they race what they sell, and to prove that our stuff is actually a lot more conservative than people think. There's pretty much nothing you can't ask AJ or Kurt and get a legit answer. That bit us at the runoffs a few years ago at Laguna Seca when we showed someone the car and they lodged a protest, which was thrown out. So barring the occasional vagina move, we are very open about what we do.
Joe Aquilante has probably done more, with less, than anyone else I know, he spends money wisely.

This thread is a couple months old. But rather than start a new thread about the same subject, I will add my own spring setup question.

I am looking for advice to upgrade or stiffen the spring setup I now have since I am going to switch from BFG Rival 295/35/18 tires square on 18x10 Apex wheels to BFG R1 315/35/18 tires square on Forgestar F14 18x11 wheels. Philosophy; Tire grip sets spring rates, spring rates set damper setting,l etc, etc.

Background info on my S197 Mustang; 2007 Saleen Parnelli Jones Edition with SuperShaker, Cortex Koni coilover setup, Cortex Watts Link, Cortex Torque Arm, 35mm adj fr bar, 24mm rear bar with alternate 18mm rear bar, current springs 475lb 8x250 front and 275lb 8x250 rear, 14" Stoptech front and 14" Baer rear, Torsen T2R diff. My Saleen is only for track use, no daily driving. Setup is NASA TT3 with 3863 min weight and only run at Utah's Miller Motorsport Park/UMC track.

I figure with the added grip of the new tires and wheels I need to move up in spring rates and hope to buy hit the target rate with just one new set. (550-600 front ? 300-350 rear ?) I would appreciate any experienced input. zajac

P.S. I have already read hundreds of postings on TMO and learned quite a lot! Thanks guys!

Welcome to TMO.

I’m of no help with your spring question other than talking to one of the mechanics at the Ford Performance Racing School as they have setup quite a few Mustangs for that track.

You have all the right stuff on your car already and depending on your budget I’d look to go straight to either a MCS or JRi coilover setup.

Thank you.

Yeah, I have most of the right "stuff" as I like buying and installing "stuff". The Ford Racing School at Miller has been very, very helpful in the past. For instance, when a sway bar bracket broke and punctured the oil filter and blue smoke billowed out everywhere. The Ford school GAVE me new heavy duty sway bar brackets, new poly bushings and new hardware all for free. I just had to install the stuff but got back on track for the next NASA session.

The main problem with the Ford school at MMP is that their work involving the S197 is with the school modified S197 Boss 302 which weighs about 3400lb and dynos at 417hp at 7000 rpm at our 4500 ft altitude. So I have to adjust any school advice with my Saleen 3863 TT3 weight.

Yes, the Cortex JRI DA setup is what Filip recommends I switch to....... in my future budget. I think my springs answer is somewhere between the 550-600 and 300-350 (475/275 current) and the choice will have to be compatible with my current Cortex Koni track valved coilover setup.

I am inclined to go for the 600/350 springs and take a chance on overshooting the optimum spring selection unless recommended other wise.

zajac