New member - need some advice

[slowdown]

Decided to buy a car for a second car/track day car. Found this 2015 and it's pretty sorted out so why not - first Mustang for me. Original owner built it up - second had it for 11 months but then bought a C8 Vette so here I am with no contact to the original owner about any specs.

Got it in October and since have driven it on the streets occasionally over the NJ fall and winter so far and my first track day will be 4/21. It's got a mix and match suspension parts list. BC Racing BR series coilovers with Swift upgrade, Steeda front control arm tension links and bearings, Steeda bump steer kit, Steeda stop the hop, Steeda rear camber adjustment kit and rear billet shock mount. For aero it has a GT350 front end with an APR carbon splitter and also has an Anderson Composite GT350 rear spoiler.

What makes me nervous about the track is that I've done some pulls (100mph) in her and she does not react at all like my previous car (2012 STI) and gets very light footed and she's scary. I would think with the front lip, lower stance, and rear wing the car would plant hard. My STI on coilovers without additional aero mods was much more stable. And the thing is - at autocross speeds this car is the most balanced thing I've ever driven???? So the first thing I did was wrap her completely in new tires Continental Extreme Contact DWS (friend has them on his 350R so took his advice) for the street and this setup is 10 front and 11 rear (I have a set of Toyo r888r on Apex wheels as well and that is 18X11 squared) and it's now worse than when I got the car with drag radials in the rear. The last thing I want to have to do is get on the brakes (has the Billet upgrade with Gloc R8s) at speed into a corner and lose the tarmac.

So here's what I'm thinking.

My first guess is the tire shop did a crap balance and it may just be that simple. My second guess is I need an alignment. So I have an appointment (they are busy) with the best alignment shop around 3/24 to have both sets of wheels high speed balanced for the track and align the car to a conservative street/track setting as a baseline.

My question is - if this doesn't immediately alleviate the high-speed float what's next? Is this a common Mustang issue? I've poured over forums for this and not much. So I joined this forum.

Do I address aero? Do I rip all the suspension parts off and replace with a complete FR3A track pack so I'm starting from scratch with Ford parts?? If I do that do I also upgrade to adjustable front and rear sway bars?? (can't imagine that's a huge factor on the float issue)

Money isn't really an object.

Y'all have way more experience than me with these things so if someone handed you this car with this situation am I on the right track with my steps and logic?

Any and all feedback is appreciated.

Thank You - Doug (Howell, NJ)

 

[RES_22]

Nice car, Doug. Was not aware that BC was big in Mustangland.

The fact that you found drag tires on the rear makes me wonder - first - about the condition of your coil overs and spring rates...perhaps the previous owner spent time at the strip and specified drag-friendly springs? Do you know spring rates? Also wonder about damper settings...possibly aimed at promoting/maintaining rearward weight transfer while dragging? Do you have damper manuals...can you download???

Alignment, camber/caster and ride height balance are key factors, however the static stance of the thing in your pic isn't abnormal....so it might be a spring rate/type or damping issue that's causing what sounds like a rear biased balance issue...which could worsen as air packs under the nose when speed increases (like a speedboat).

Is your grille stock...or is it opened up a lot...could also cause front lift that increases with speed??

Alternatively, maybe that wing isn't cf...might be depleted uranium...could also explain a lot !

 

[slowdown]

Neither was I aware that BC was big either but that's what this guy installed. As far as I know the last owner had it to the strip once (car ran 12.2) but I think he liked the drag radials on the street because when we test drove the car he drives with no traction control and likes to have fun with the rear end.

I haven't touched rear damping at all and have only been playing with front. The front has 32 clicks and it was only 6 clicks from totally open when I got it. I'm running 16 clicks now and the front feels really good.

That's a good idea about getting a damping manual and seeing where I'm at in the rear.

The grill is stock but has a Velossa air duct on one side and it also has brake cooling ducts as well. The car is set up nice and for what I paid for it I figured it had a lot of potential to get dialed in properly.

I appreciate the advice and will hunt down a manual. And maybe I'll just contact BC and get some new rear springs.

 

[RES_22]

What's the general condition of the BC stuff? Steel or aluminum bodies? Are they ride-height adjustable?

Would be good to understand where BC recommends one should start with damper settings (or ride heights, if applicable). Would be better to call BC, describe your intended use and see what they recommend for spring rates...then try to get the rate codes off of the Swifts and compare their rates to what BC recommends...might explain a lot.

Ultimately...messing with damper settings, calling BC, checking spring rates is very cost-effective -free! Swapping to the Ford Perf track handling stuff could be something to consider if you find that the BC stuff is the primary cause of the issue and can't be adjusted/improved enough to meet your needs.

Lots of positive feedback/love for the Ford stuff from TMO members...

 

[slowdown]

Yeah - I'm going to call BC this week and see what they say. They can likely recommend exactly the springs for my needs and how much preload and that could be useful to have the shop do before it is aligned.

I did get in touch with last owner and he did soften the damping a bit in the rear so I'm going to add a few clicks to that and see what she does.

 

[RES_22]

Good stuff...confirm optimum spring rates, then mess with damping.

Write down what you have now for damper settings..and then record any changes you make. Make 6 or 7 click changes per bite...big enough so the impact of the change is easily felt. iterate to a baseline that serves your needs if possible.

Good luck.

PS: Chances are that your rear spoiler is actually cf...not depleted uranium. Inside (nuclear power) little joke .

 

[blacksheep-1]

what's BC?
I agree with the above, I suspect the shock/ springs/ bars are no where near where you need to be for a road course.
As you have experienced, I always recomend a single supplier of suspension products, preferably Ford Racing.. Cortex.and then others. This way the pieces should complement each other, but, you have what you have so you might as well work with it.
There is really no comparison between an STI and a Mustang, two totally different animals. I have some experience with them, 2 engine changes a weekend gets old real quick.

 

[RES_22]

BC is a Japanese (I think) suspension outfit.....big in the JDM for Supras, STi, Evo, etc...range is from "inexpensive" to "yikes".

Never bought it but have driven/tracked it....you get what you pay for, more or less.

 

[JDee]

replace with a complete FR3A track pack

+1 to that. Absolutely transforms the car on track and is still quite liveable on the street. Who would know better than Ford engineers what their car really needs for the track for the non-professional driver?

 

[slowdown]

BC is a Japanese (I think) suspension outfit.....big in the JDM for Supras, STi, Evo, etc...range is from "inexpensive" to "yikes".

Never bought it but have driven/tracked it....you get what you pay for, more or less.

Yeah I wouldn't have bought them myself. Have never had them before. They seem ok and are very damp and the car is planted but what good is that at speeds under 80mph?? The car feels horrible after that.

I may just order the complete FR3A kit and be done with it. Rather have that on the car before it goes to the alignment shop.

This is why I came here for advice. I'd prefer to spend the money and be solid rather than chasing my tail with stuff I don't know. The kit isn't that expensive at all.

 

[RES_22]

And it's all about confidence in the car, the driver and most importantly....having fun!

Poke our frozen buddy @JDee for some intermediate alignment settings...lotta knowledge there so be prepared to take notes.

And visit our friends at Vorshlag for (the best) camber plates asap...can't achieve a decent track setup window without them.

 

[funksouljon]

Is it possible that all the random parts were just tossed together without a plan and it never worked and the original owner just got rid of the car? No amount of fiddling and testing is going to make the mismatched set up work? You mentioned Steeda and BC, are there other mismatched manufacturers or are some of the parts drag oriented and others road race oriented?

 

[slowdown]

Is it possible that all the random parts were just tossed together without a plan and it never worked and the original owner just got rid of the car? No amount of fiddling and testing is going to make the mismatched set up work? You mentioned Steeda and BC, are there other mismatched manufacturers or are some of the parts drag oriented and others road race oriented?

Yes and no. The original owner did all the mods. The second owner is a drag guy and has a 10.8 GT he built but bought this car as a fun weekend car. He had plans to supercharge it and take to track but it ended up not getting much use as the drag car was getting all his time so then he decided to buy another car and sold this. Pretty much everything on the car for the track is Steeda with the exception of the coil overs. Steeda sells these BC Racing BR series for the GT on their website so perhaps they recommended to the original owner.

I've pretty much decided I'm going to pull it all off and have the Ford Track Pack installed. I'll swap out the camber plates too. This way I'll know it's all Ford suspension with proper spring rates for my car and Ford sway bars and endlinks. I think it comes with bump steer as well.

If, after that, I still have a problem at high speed I will have to figure it out. I took her out today for a half hour. Honestly the car is phenomenal and corners as well as I'd want with my experience level. She would autocross like a beast. Maybe it's just a feeling I'm not used to but today once I hit 90mph it's like the car goes quiet as the airflow changes so much because the aero kicks in and she doesn't feel connected to the road. Like she's going to take off. You can instantaneously feel it. It's exacerbated the faster she goes after that. But it's not necessarily the rear that feels loose it's the whole car - it's like I'm driving my boat fast rather than a car because she's floating.

I'm just wondering if there's too much downforce up front and the Anderson spoiler isn't keeping up in the rear. Perhaps an APR adjustable wing could sit her down. Or is the front aero actually causing air to lift the car at speeds over 90. Obviously aero does nothing at lower speeds so the issue is not noticeable and the car drive beautifully.

I'm starting to think it's bad aero and when I do the suspension remove the splitter and leave the spoiler and see how it feels. Then remove the spoiler.

I just don't know and it's very frustrating.

Good news is my first day is a Beginner paced lap course at NJMSP so I can work with the pros at the track and stay at the back of the group if she's acting up on the fast straights. I'm sure the instructors will be very helpful and knowledgeable. Plus their pace cars are all Mustang GTs.

 

[funksouljon]

Yes and no. The original owner did all the mods. The second owner is a drag guy and has a 10.8 GT he built but bought this car as a fun weekend car. He had plans to supercharge it and take to track but it ended up not getting much use as the drag car was getting all his time so then he decided to buy another car and sold this. Pretty much everything on the car for the track is Steeda with the exception of the coil overs. Steeda sells these BC Racing BR series for the GT on their website so perhaps they recommended to the original owner.

I've pretty much decided I'm going to pull it all off and have the Ford Track Pack installed. I'll swap out the camber plates too. This way I'll know it's all Ford suspension with proper spring rates for my car and Ford sway bars and endlinks. I think it comes with bump steer as well.

If, after that, I still have a problem at high speed I will have to figure it out. I took her out today for a half hour. Honestly the car is phenomenal and corners as well as I'd want with my experience level. She would autocross like a beast. Maybe it's just a feeling I'm not used to but today once I hit 90mph it's like the car goes quiet as the airflow changes so much because the aero kicks in and she doesn't feel connected to the road. Like she's going to take off. You can instantaneously feel it. It's exacerbated the faster she goes after that. But it's not necessarily the rear that feels loose it's the whole car - it's like I'm driving my boat fast rather than a car because she's floating.

I'm just wondering if there's too much downforce up front and the Anderson spoiler isn't keeping up in the rear. Perhaps an APR adjustable wing could sit her down. Or is the front aero actually causing air to lift the car at speeds over 90. Obviously aero does nothing at lower speeds so the issue is not noticeable and the car drive beautifully.

I'm starting to think it's bad aero and when I do the suspension remove the splitter and leave the spoiler and see how it feels. Then remove the spoiler.

I just don't know and it's very frustrating.

Good news is my first day is a Beginner paced lap course at NJMSP so I can work with the pros at the track and stay at the back of the group if she's acting up on the fast straights. I'm sure the instructors will be very helpful and knowledgeable. Plus their pace cars are all Mustang GTs.

Dude. Get a second opinion on day 1, some stuff is hard to diagnose via internet. Esp since the people here only know what you are saying vs seeing the car. I'm doing exactly that this upcoming weekend depending on who shows up for a local practice day. Both from a "as a baseline how does this feel and why?" but also a "What are changes could I make and what would that do?" Knowing that we all like it a little different, but getting an actual second opinion might help, esp if they can feel the issue.
Another thought, if it's all Steeda, get them on the phone and talk to them. Most of my parts are either Steeda or purchased through them. And every time I call, they have been very helpful. A number of their folks also drive, so when you call, you likely won't just get "here is the part you need", in my experience, they have been very helpful with suggestions and even some how to tips for doing the work. Too bad you don't have the name of the original owner, they might be able to look up the parts.

 

[slowdown]

Dude. Get a second opinion on day 1, some stuff is hard to diagnose via internet. Esp since the people here only know what you are saying vs seeing the car. I'm doing exactly that this upcoming weekend depending on who shows up for a local practice day. Both from a "as a baseline how does this feel and why?" but also a "What are changes could I make and what would that do?" Knowing that we all like it a little different, but getting an actual second opinion might help, esp if they can feel the issue.
Another thought, if it's all Steeda, get them on the phone and talk to them. Most of my parts are either Steeda or purchased through them. And every time I call, they have been very helpful. A number of their folks also drive, so when you call, you likely won't just get "here is the part you need", in my experience, they have been very helpful with suggestions and even some how to tips for doing the work. Too bad you don't have the name of the original owner, they might be able to look up the parts.

Yeah that brings me back full circle and do I even bother with the alignment I have scheduled for 3/24 and just track the car as is on 4/21. The car handles great it's just this high speed issue. But I did call Steeda and they were the first ones to say high speed balance the tires and get an alignment before you start chasing any ghosts. So I suppose I'll feel better if that is done and just go from there.

Thinking about it today that makes the most sense. One track day on the car and then I can make some adjustments.

 

[bnight]

Is it possible that all the random parts were just tossed together without a plan and it never worked and the original owner just got rid of the car? No amount of fiddling and testing is going to make the mismatched set up work? You mentioned Steeda and BC, are there other mismatched manufacturers or are some of the parts drag oriented and others road race oriented?

BC makes not very expensive set of coilovers for the car and according to the spec it's 395f/895r springs. But what are the Swift springs is not known nor is dumping. Ether way it might be bed aero setup or some rake not dialed in properly. I would start with getting ride hight measurements both front and rear. See where the car is rake wise. Then found someone to get me a good alignment like -1.4f and rear camber. 0.0 Toe up front 0.2 toe in on the back and see how it feels with this changes. Then find what the spring rates are and dial that in to something that I like. BC Coilovers are cheap but will do better than FP TP or at least on par so no need to trow parts at the car just yet sounds like it just need to be dialed better.

 

[funksouljon]

Yeah that brings me back full circle and do I even bother with the alignment I have scheduled for 3/24 and just track the car as is on 4/21. The car handles great it's just this high speed issue. But I did call Steeda and they were the first ones to say high speed balance the tires and get an alignment before you start chasing any ghosts. So I suppose I'll feel better if that is done and just go from there.

Thinking about it today that makes the most sense. One track day on the car and then I can make some adjustments.

Good luck.

Makes it even more impressive when you see guys fast AF in one type of car hours and hours in that specific vehicle. Then they jump into another type of car do a couple laps, make a couple adjustments and can set blistering lap times in a totally different set up.

 

[slowdown]

BC makes not very expensive set of coilovers for the car and according to the spec it's 395f/895r springs. But what are the Swift springs is not known nor is dumping. Ether way it might be bed aero setup or some rake not dialed in properly. I would start with getting ride hight measurements both front and rear. See where the car is rake wise. Then found someone to get me a good alignment like -1.4f and rear camber. 0.0 Toe up front 0.2 toe in on the back and see how it feels with this changes. Then find what the spring rates are and dial that in to something that I like. BC Coilovers are cheap but will do better than FP TP or at least on par so no need to trow parts at the car just yet sounds like it just need to be dialed better.

The car as it sits now with the Conti tires front 265/35 R18 rear 285/35 R18 is sitting 1/4" (.25") positive rake with a front tire that is .3" lower at the axle. The car also has a set of matched squared toyo r888r that I have yet to put on it but now that's an issue since if I play with ride height on this setup it will completely change if I put the track setup on the car. It would, in theory, have the slightest negative rake of 0.05". I once it warms up a little here in NJ and I get the first warm weekend day I should just slap the Toyos on and see how she feels. It will be a hair over a quarter inch more negative rake. I should know pretty quick how the front and rear react to that. This will potentially give me some sort of baseline where I'm at.

 

[bnight]

The car as it sits now with the Conti tires front 265/35 R18 rear 285/35 R18 is sitting 1/4" (.25") positive rake with a front tire that is .3" lower at the axle. The car also has a set of matched squared toyo r888r that I have yet to put on it but now that's an issue since if I play with ride height on this setup it will completely change if I put the track setup on the car. It would, in theory, have the slightest negative rake of 0.05". I once it warms up a little here in NJ and I get the first warm weekend day I should just slap the Toyos on and see how she feels. It will be a hair over a quarter inch more negative rake. I should know pretty quick how the front and rear react to that. This will potentially give me some sort of baseline where I'm at.

So your rake is fine with my square setup I have a bit of negative rake (rear lower than the front) but car is ok balance wise. Nothing like you describe though I don't have any aero to worry about. Thinking about it can it be that your rear is to soft for the wing ? Maybe is creating more downforce and putting the car to the ground raising the front in the process ? Also adding lift with the big air scoop. I guess you can try adding more dumping to the rear but this will make the car oversteery though probably will help with high speed lift. We need to know what spring rates you have in order to sort that out.

 

[Scootsmcgreggor]

Welcome and sorry to hear the car is unstable at speed. That’s def not normal.

I would also be surprised if it were from the aero as what you have is not capable of that much DF. You can test that though. Pull the wing and splitter off and try it out. If the problem persists my money is on alignment.

also go through all the suspension bolts and make sure torque is good.

BC coils are not great but unless they’re completely blown they would not create a floaty feeling at speed in a steady state (damping wise).

Also it getting worse with the new tires makes me think alignment. These cars can “tram line” badly with certain tires and alignment settings.