Koni sports in conjunction with Boss 302 springs?

[kcbrown]

save your money

What else has the wet boiling point that Castrol SRF does?

My intention is to avoid having to replace the brake fluid every day or two at the track. There's no real savings if I have to replace the brake fluid often with, e.g., Motul, while not having to do the same with Castrol.

 

[csamsh]

What else has the wet boiling point that Castrol SRF does?

My intention is to avoid having to replace the brake fluid every day or two at the track. There's no real savings if I have to replace the brake fluid often with, e.g., Motul, while not having to do the same with Castrol.

From Jason@Vorshlag

"First, yes on the brake fluid. But there is a tradeoff. The higher temp brake fluids will absorb humidity into the brake fluid faster than low temp fluid. The super-high performance brake fluids will need to be changed every month. But the moderately high performance fluid will last as much as a year as long as it isn't overheated. It's performance will drop off as it absorbs water, but for street use that usually isn't an issue. For track use it is and you will want to flush the fluid every three months or so if you are doing a track event every month. In our own testing we've settled on Motul 600 as a good compromise between initial cost, performance and longevity. There are higher temp fluids, like Motul 660, which have a higher cost and performance, but also require more maintenance."

 

[kcbrown]

From Jason@Vorshlag

"First, yes on the brake fluid. But there is a tradeoff. The higher temp brake fluids will absorb humidity into the brake fluid faster than low temp fluid.

But Castrol seems to be an exception to all this, hence (or, perhaps, because of) the high wet boiling point.

What fluids was Jason looking at in his comparison?


If Castrol didn't have some major advantage, it wouldn't be able to command the price it does on the open market, and Castrol would take it off the market for lack of sales. If the stuff is snake oil, I've not seen any indication of that.

 

[csamsh]

It's expensive because it's really great fluid. You just need to replace it often. To pro race teams, and to people with no money concerns, this isn't a big deal.

It's like a Hoosier A6. Nothing beats it, but, you buy new ones all the time.

 

[NoTicket]

But Castrol seems to be an exception to all this, hence (or, perhaps, because of) the high wet boiling point.

What fluids was Jason looking at in his comparison?


If Castrol didn't have some major advantage, it wouldn't be able to command the price it does on the open market, and Castrol would take it off the market for lack of sales. If the stuff is snake oil, I've not seen any indication of that.

I think the reason this is not a good idea is that you are going to end up with vapor in your lines after every track day regardless. That has been my experience. After 3 track days on the same fluid you will probably want to replace it no matter what the wet boiling point is.

In either case it is a lot cheaper to start with Motul and experiment than do SRF and then decide it wasn't worth it.

Sent from my XT907 using Tapatalk

 

[kcbrown]

It's expensive because it's really great fluid. You just need to replace it often. To pro race teams, and to people with no money concerns, this isn't a big deal.

But if its dry boiling point isn't really any better than that of the others (in fact, it's less than that of Motul 660), then what makes it so great?

I don't understand. If they're having to replace the fluid often, then what advantage could Castrol SRF possibly have over Motul 600, much less Motul 660?

It's like a Hoosier A6. Nothing beats it, but, you buy new ones all the time.

Well, yeah, but tire wear will tend to force you to do that.

 

[SoundGuyDave]

Here's my view on brake fluid...

1) For the occasional track day, with a non-aggressive driver, stock fluid will be fine AS LONG AS IT'S FRESH. $5.00/half-liter.
2) Castrol SRF is an absolutely awesome fluid, with very high dry AND wet boiling points. It's still hygroscopic, though, and after roughly a year, it's trash, and needs to be completely flushed. $35.00/half-liter.
3) Motul RBF600 also has a very high dry boiling point; hygroscopic. After roughly 6 months, it's trash. $14.00/half-liter.

The way I look at it, SRF lasts about TWICE as long as the RBF600, but costs MORE than TWICE as much... If ultimate performance is the only object, then yes, it's a superior fluid. If you're in an "extreme duty" scenario, like maybe endurance races over 6 or 8 hours, then the better fluid may allow you to stretch your braking performance a bit. If you're a track-day guy and want bragging rights, this won't hurt. If you want/need a better fluid than the stock stuff, and don't want to break the bank (like MOST track junkies), RBF600is probably the best bang for the buck out there.

Hoosiers, now, that's just straight-up purple crack!

 

[frank s]

[...]
I know of no springs that reduce the car height by so little, except perhaps the Boss 302 front springs combined with the Brembo50 springs in the rear.

[...]

SCreemer mentioned his "P" springs lowered his car by a "modest 1" drop"; on my 2009 GT with Koni yellows the P-spring drop was just ½ inch front and ¾ inch rear. I experienced significant improvement in "handling" sensations, and very little deterioration in ride quality (full soft on the Konis).

Not the fastest possible solution, but an occasional track day was much more satisfying without a lot of sacrifices.

 

[kcbrown]

Here's my view on brake fluid...

1) For the occasional track day, with a non-aggressive driver, stock fluid will be fine AS LONG AS IT'S FRESH. $5.00/half-liter.

I've no idea how aggressive a driver I'll be on the track. Probably not terribly, especially at first.

Then again, I keep crashing the car in GT5 due to going too fast.

2) Castrol SRF is an absolutely awesome fluid, with very high dry AND wet boiling points. It's still hygroscopic, though, and after roughly a year, it's trash, and needs to be completely flushed. $35.00/half-liter.
3) Motul RBF600 also has a very high dry boiling point; hygroscopic. After roughly 6 months, it's trash. $14.00/half-liter.

The way I look at it, SRF lasts about TWICE as long as the RBF600, but costs MORE than TWICE as much... If ultimate performance is the only object, then yes, it's a superior fluid. If you're in an "extreme duty" scenario, like maybe endurance races over 6 or 8 hours, then the better fluid may allow you to stretch your braking performance a bit. If you're a track-day guy and want bragging rights, this won't hurt. If you want/need a better fluid than the stock stuff, and don't want to break the bank (like MOST track junkies), RBF600is probably the best bang for the buck out there.

I think I can handle an additional $30, or even $60, per year in my budget for brake fluid (assuming I have to change the SRF twice a year due to going to track events several times a year), especially since heavy braking into a turn is the last place you want your brakes to fade on you. Brakes is an area I'm not skimping on. The only reason I'm not running anything higher temp than Stoptechs (1300F) to start with is that I want to use the same pads on the street so that my experience in one arena translates directly to experience in the other. Between the fluid, the FRPP brake duct kit, and the Stoptech pads, I suspect I'll be okay on brakes since I'm remaining on street tires.

Hoosiers, now, that's just straight-up purple crack!

 

[barbaro]

Konis plus Boss Springs Good for me.

First, preferred spring rate is very subjective. I built my car for both street and track performance. It is a compromise. And it seems to me that if you are interested in a street/track vehicle, the compromise you are suggesting can be an excellent one for most people.

Many people have opined, however, none have actually used the combo you are suggesting. I have and it works great for me and I will be tracking the car again on November 19 at Willow Springs.

At Sam Stranos' suggestion I changed My Brembo Package to a a Steeda Sport / Koni Sport package. I live in Los Angeles, which has recently been confirmed by NHTSA has having the worst roads in the U.S.. The Steeda Sports were too stiff. The ride was uncomfortable even on full soft. Too many bad roads to tolerate that set up. In one year, I had already blown out a ball joint and a set of Koni yellows that I am now having rebuilt. That is how bad the roads are. If I lived in Northern California or San Diego where the roads are better, it would have been fine. However, the rear Steeda Sports still do not give you enough suspension travel. And on rough roads at high speed the car became stiff and bouncy and dangerous.

I switched to Boss Springs and Koni yellows and it was a match made in heaven. Much more suspension travel. Less driveway scraping. Much more compliant on the road. Not quite as stiff as I would like at the track, but the compromise is well worth it and the car is still much faster than I am. It is not the Springs holding me back.

Also, we need to give Ford Engineers a little more credit. The compromises they made between performance and comfort are sensible. They have tested these cars more than everyone on this forum has collectively. There is a good reason the Boss springs are softer in the front then in the back and I am totally down with it. To give up liveablility for some incremental increase in theoretical track performance makes no sense. If you are interested in track and only track performance, spend $2600+ on coilovers. Otherwise Boss springs and Koni yellows are a good combination.

 

[kcbrown]

I switched to Boss Springs and Koni yellows and it was a match made in heaven. Much more suspension travel. Less driveway scraping. Much more compliant on the road. Not quite as stiff as I would like at the track, but the compromise is well worth it and the car is still much faster than I am. It is not the Springs holding me back.

That's ultimately the question: is the car sufficient for your needs and capabilities. I won't get an answer to that except through experience, but my expectation is that the car will be plenty for me. I'm already impressed with its handling, and that's in purely stock form.

Also, we need to give Ford Engineers a little more credit. The compromises they made between performance and comfort are sensible. They have tested these cars more than everyone on this forum has collectively. There is a good reason the Boss springs are softer in the front then in the back and I am totally down with it. To give up liveablility for some incremental increase in theoretical track performance makes no sense. If you are interested in track and only track performance, spend $2600+ on coilovers. Otherwise Boss springs and Koni yellows are a good combination.

If I were interested in only track performance, I wouldn't be driving a Mustang at all. I'd be driving a Formula Ford car or something of that sort, which I expect would destroy even the best Mustang you can find here on the track for the same or less money.

We're here precisely because we're willing to make compromises of one sort or another. It's not a question of if there's a compromise involved, it's a question of what and why. I suspect most, if not all, of us are in this for the fun, and not strictly the competition. It then becomes a question of what it takes to have the most fun overall.

Frankly, I think this is going to be an interesting and fun journey of discovery!

 

[kcbrown]

By the way, having seen the photos of people in heavy braking with the stock suspension on their Boss 302s, it looks to me like the rear end is lifting. Doesn't that mean that the AS% isn't high enough, and that the stock rear suspension needs LCA relocating brackets?

 

[Whiskey11]

By the way, having seen the photos of people in heavy braking with the stock suspension on their Boss 302s, it looks to me like the rear end is lifting. Doesn't that mean that the AS% isn't high enough, and that the stock rear suspension needs LCA relocating brackets?

%AntiSquat is only an instantenous force responding to acceleration (in the car sense, not phsyics sense) and the force that causes squatting. The rear side view instant center location defines the %AntiLift which is what you are thinking of. Cant help you with how that value trends on these cars with respect to %AS.

 

[kcbrown]

%AntiSquat is only an instantenous force responding to acceleration (in the car sense, not phsyics sense) and the force that causes squatting. The rear side view instant center location defines the %AntiLift which is what you are thinking of. Cant help you with how that value trends on these cars with respect to %AS.

I thought the two were directly related (i.e., essentially the same), but if not, then how does one compute %AntLift?

 

[SoundGuyDave]

Couple things:

Brake fluid: If you've decided on SRF, cool, I won't try to change your mind. Realize that it takes a bit over a full liter to flush the system, and when doing the initial change, you should probably plan on running at least 1.5L through the lines, and work on purging the ABS block as well (flush, panic stop on gravel; then repeat a few times).

The rear-end lift is really a function of spring rate, with a dash of front anti-dive angle thrown in as well.



The ONLY changes between the two runs were springs, dampers and bars. Front 350lb/in, rear 300lb/in, and as you can see, the dive under braking is dramatically reduced, as well as rear-end stability under braking. Yes, the dampers in question (AST 4100s) are coil-overs, however with the rebound set to full soft, the ride is actually quite decent. Also note that I have NOT altered the front-end anti-dive geometry.

The rear lift under braking is a result of chassis motion under weight transfer, and by increasing the spring rates, the transferred weight will not compress the front nearly as much. Yes, the load still transfers, and yes, the rear still gets "light," however it's not moving nearly as much around the side-view roll center.

As was pointed out, "ride quality" is subjective, but you're going to be (apparently) setting up a dual-purpose car, and that spells "compromise" any way you look at it. What is best for the street will have negative impacts on track performance, and vice-versa. What winds up being "best" for your application will be the happy medium where neither is overly impacted.

I've ridden in (instructing) and driven more than a handful of Boss cars, and they are quite a bit better behaved than the stock S197 chassis, but they still pitch-pole quite a bit in the braking zones. I just really don't want you (or anybody) thinking that there is ANY similarity between the Boss 302 and a Boss 302S/R in terms of spring rates and damper curves. The 302S and 302R come with "proper" spring rates and very high-end coilover dampers. 'Nuff said.

 

[kcbrown]

Couple things:

Brake fluid: If you've decided on SRF, cool, I won't try to change your mind. Realize that it takes a bit over a full liter to flush the system, and when doing the initial change, you should probably plan on running at least 1.5L through the lines, and work on purging the ABS block as well (flush, panic stop on gravel; then repeat a few times).

Good to know. Thanks! I would be more inclined to consider the other brake fluid options if the cost difference were truly massive or something, but in this case, the cost difference is just low enough that I'm willing to go with what seems to be the best I can get my hands on.

The rear-end lift is really a function of spring rate, with a dash of front anti-dive angle thrown in as well.

I would have thought that the rear suspension geometry would have a major impact on this, actually. I mean, what's the difference between anti-squat and anti-lift as regards the rear end? If the rear suspension geometry has a major impact on anti-squat, why wouldn't it similarly have a major impact on anti-lift?

The rear lift under braking is a result of chassis motion under weight transfer, and by increasing the spring rates, the transferred weight will not compress the front nearly as much. Yes, the load still transfers, and yes, the rear still gets "light," however it's not moving nearly as much around the side-view roll center.

Right. And the same would be true of squat under acceleration. Yeah, I know that the springs are going to have more of an impact on this than anything else but if that were the only major consideration, then why would anyone care about relocating the LCAs in the rear after lowering the car?

As was pointed out, "ride quality" is subjective, but you're going to be (apparently) setting up a dual-purpose car, and that spells "compromise" any way you look at it. What is best for the street will have negative impacts on track performance, and vice-versa. What winds up being "best" for your application will be the happy medium where neither is overly impacted.

I've ridden in (instructing) and driven more than a handful of Boss cars, and they are quite a bit better behaved than the stock S197 chassis, but they still pitch-pole quite a bit in the braking zones. I just really don't want you (or anybody) thinking that there is ANY similarity between the Boss 302 and a Boss 302S/R in terms of spring rates and damper curves. The 302S and 302R come with "proper" spring rates and very high-end coilover dampers. 'Nuff said.

Oh, believe me, I'm under no illusion that the stock Boss 302 setup is anything like the racecar setups. I'm just after the best handling I can get within the limits of my specific requirements, and the Boss 302 setup (with Koni Sports instead of the Tokico Illuminas that come with the Boss 302) may be about as close to that as I can reasonably achieve.

We'll see. It's going to take some experimentation on my part. There is, sadly, no substitute for experience when making subjective determinations like that of ride quality.

 

[SoundGuyDave]

I would have thought that the rear suspension geometry would have a major impact on this, actually. I mean, what's the difference between anti-squat and anti-lift as regards the rear end? If the rear suspension geometry has a major impact on anti-squat, why wouldn't it similarly have a major impact on anti-lift?

I'm sure other people can answer the question better than I can (paging Norm!!!), but suffice it to say that anti-squat geometry does not necessarily translate into an anti-lift tendency. Also, keep in mind that fixing one end of the car frequently requires a change at the opposite end.

About spring rates:

Right. And the same would be true of squat under acceleration. Yeah, I know that the springs are going to have more of an impact on this than anything else but if that were the only major consideration, then why would anyone care about relocating the LCAs in the rear after lowering the car?

Because the LCA relocation affects a LOT more than just anti-squat. Roll steer would be another consideration...

We'll see. It's going to take some experimentation on my part. There is, sadly, no substitute for experience when making subjective determinations like that of ride quality.

Exactly right, particularly when there aren't solid metrics that can be applied. What two people can tolerate in terms of "ride quality" can be vastly different. The Steeda Sport spring with Koni yellows is a proven general all-around performer, but in the end, I still lean towards good quality coil-overs for a variety of reasons. In the end, though, yes, it will take some experimentation to hit the bullseye, particularly if the desired target might just move.

I'm on my third complete set of dampers and springs, and I'm kind of eyeing the fourth...

 

[kcbrown]

I'm sure other people can answer the question better than I can (paging Norm!!!), but suffice it to say that anti-squat geometry does not necessarily translate into an anti-lift tendency. Also, keep in mind that fixing one end of the car frequently requires a change at the opposite end.

Which is probably why making changes can cascade into something very expensive if one is concerned about doing it right...

About spring rates:
Because the LCA relocation affects a LOT more than just anti-squat. Roll steer would be another consideration...

That's a darned good point.

Exactly right, particularly when there aren't solid metrics that can be applied. What two people can tolerate in terms of "ride quality" can be vastly different. The Steeda Sport spring with Koni yellows is a proven general all-around performer, but in the end, I still lean towards good quality coil-overs for a variety of reasons. In the end, though, yes, it will take some experimentation to hit the bullseye, particularly if the desired target might just move.

I'm on my third complete set of dampers and springs, and I'm kind of eyeing the fourth...

Would you mind sharing your thoughts about the combinations you've been through so far, if you haven't already? If you've already discussed them, links to the messages would be greatly appreciated.

 

[SoundGuyDave]

You're entering into the world of chassis setup, and at least for me, it was easier to think of the car as a blank page, than to try to band-aid specific problems. The best bet (ALWAYS!!!) is to drive the car as-is, assess what you have that you like, and what you have that you don't, then try to figure out what to change to affect what you don't while leaving the rest alone. If the car rolls too much, then maybe bars are the answer, for example. However, if the car pitches too much in braking, squats too hard under acceleration, AND rolls too much, then it becomes obvious that the spring rates are just too low to constrain the chassis to the degree that you want. Of course, to properly control those higher-rate springs, you'll need dampers that are up to the task, hence the "supporting mod" conundrum. Best bet is to really look at your final target, plan out what you THINK you'll need to hit it, then buy only what fits the plan. Buy once, cry once... Adjustable dampers are pretty much the key to any suspension tuning, since they can control a pretty wide range of spring rates, allowing you to tailor the rates to taste without having to recurve or replace the dampers. The big thing for me with "coilovers" is that you have a MUCH wider range of spring rates available (at a lower cost) than you do with the OE perch setup. You also then have the ability to adjust ride-height without monkeying with the rate.

As for my setups:


Setup one: Bone stock. It sucked, as we all know...

Setup two: Tokico D-Spec, BMR springs and bars: You saw them on the first half of that vid that I posted.

Setup three: AST4100 dampers, Hypercoil springs, Strano's bars. You saw them on the second half of that vid.

The AST setup is still on the car, but I've just about hit the limits on them as far as what I want them to do for me, and want to do some experimenting that goes beyond what they can do in "stock" form. DISCLOSURE: I was a VERY early adopter of the 4100's, and they are all stock length, which reduces my ability to drop the car without getting into the bump-stops more than I want to. The cost for a rebuild, plus the custom work of shortening the rods and housings is approaching the point where replacement makes more sense. If I do replace them, I'm kind of leaning towards remote doubles or triples, which is quite a bit higher in price point than anything you've been looking at. They're also a bit much in terms of tuning for the casual track-goer to want to deal with.

 

[Sky Render]

First, preferred spring rate is very subjective. I built my car for both street and track performance. It is a compromise. And it seems to me that if you are interested in a street/track vehicle, the compromise you are suggesting can be an excellent one for most people.

Many people have opined, however, none have actually used the combo you are suggesting. I have and it works great for me and I will be tracking the car again on November 19 at Willow Springs.

At Sam Stranos' suggestion I changed My Brembo Package to a a Steeda Sport / Koni Sport package. I live in Los Angeles, which has recently been confirmed by NHTSA has having the worst roads in the U.S.. The Steeda Sports were too stiff. The ride was uncomfortable even on full soft. Too many bad roads to tolerate that set up. In one year, I had already blown out a ball joint and a set of Koni yellows that I am now having rebuilt. That is how bad the roads are. If I lived in Northern California or San Diego where the roads are better, it would have been fine. However, the rear Steeda Sports still do not give you enough suspension travel. And on rough roads at high speed the car became stiff and bouncy and dangerous.

I switched to Boss Springs and Koni yellows and it was a match made in heaven. Much more suspension travel. Less driveway scraping. Much more compliant on the road. Not quite as stiff as I would like at the track, but the compromise is well worth it and the car is still much faster than I am. It is not the Springs holding me back.

Also, we need to give Ford Engineers a little more credit. The compromises they made between performance and comfort are sensible. They have tested these cars more than everyone on this forum has collectively. There is a good reason the Boss springs are softer in the front then in the back and I am totally down with it. To give up liveablility for some incremental increase in theoretical track performance makes no sense. If you are interested in track and only track performance, spend $2600+ on coilovers. Otherwise Boss springs and Koni yellows are a good combination.

I've driven around on Koni Sports and Steeda Ultralite springs for a few years now. Even with the rebound turned to full soft, it's a very stiff ride. I've driven in LA before, and I wouldn't want to do so in my Mustang's current setup.