What coil-overs should I buy? Poll inside

[2Fass240us]

pew pew pew!!!

 

[kcbrown]

I do not expect my word to be taken as gospel but when 7 people voted a Vorshlag Bilstein non-adjustable set-up as better than a JRI set-up, then I have to chime in because that is complete bullshit.

If the Bilstein setup were adjustable, then it might well be a better setup for the OP because the OP's requirements are primarily for the street. It would depend on the OP's durability versus performance tradeoff preferences (of course, this presumes that such a tradeoff would be necessary. What durability data exists for dampers such as the JRIs?).

I think it'll be interesting to see how well your JRIs hold up on the street. It'll be a testament to them if they hold up over a period of years or something without requiring a rebuild, but your personal requirements might demand a rebuild before then.

The JRI setup (from Maximum) is perhaps the only coilover setup that would meet my needs for my street car, because it's the only coilover setup I know of for which the vendor claims it can get me to stock ride height. The Konis and Boss 302 springs take my front as low as I'm willing to go. Even with this, I sometimes (not badly) scrape my front on the driveway.

 

[barbaro]

If the Bilstein setup were adjustable, then it might well be a better setup for the OP because the OP's requirements are primarily for the street. It would depend on the OP's durability versus performance tradeoff preferences (of course, this presumes that such a tradeoff would be necessary. What durability data exists for dampers such as the JRIs?).

I think it'll be interesting to see how well your JRIs hold up on the street. It'll be a testament to them if they hold up over a period of years or something without requiring a rebuild, but your personal requirements might demand a rebuild before then.

The JRI setup (from Maximum) is perhaps the only coilover setup that would meet my needs for my street car, because it's the only coilover setup I know of for which the vendor claims it can get me to stock ride height. The Konis and Boss 302 springs take my front as low as I'm willing to go. Even with this, I sometimes (not badly) scrape my front on the driveway.

I have a street / track car and my front height is enough to clear parking blocks and I have no problem with driveways as of yet. It is not stock height, but neither is it slammed. As for how long they will last before rebuild, we will see. The OP indicated he wanted to do some autocross and trackdays and he wanted full adjustibility and he did not care if he had to rebuild them periodically. JRI's fit that bill better than Bilsteins. BTW I like Bilsteins. Have had them before. But not in same league as a JRI or MCS set up.

BTW, I suspect those MCS shocks are probably pretty damn good and may be every damn bit as good as Terry suggests, but there is a weight of opinion about JRI's that was simply not being acknowledged.

 

[kcbrown]

I have a street / track car and my front height is enough to clear parking blocks and I have no problem with driveways as of yet. It is not stock height, but neither is it slammed. As for how long they will last before rebuild, we will see. The OP indicated he wanted to do some autocross and trackdays and he wanted full adjustibility and he did not care if he had to rebuild them periodically. JRI's fit that bill better than Bilsteins. BTW I like Bilsteins. Have had them before. But not in same league as a JRI or MCS set up.

BTW, I suspect those MCS shocks are probably pretty damn good and may be every damn bit as good as Terry suggests, but there is a weight of opinion about JRI's that was simply not being acknowledged.

My bet, actually, is that you have to be a professional caliber driver in order to be able to consistently see any real difference between the high end dampers on the track, once each is dialed in. And if that's the case, then other factors than performance should be the ones that determine the choice. Things like what the local support for the dampers on the specific car is like. For the Mustangs, we have Cortex and Maximum Motorsports on the west coast. In the south central U.S., we have Vorshlag. Dunno off the top of my head what's on the east coast, or up north, but I'm betting there are some reputable shops in each of those locations as well.

Since different shops have different favorite dampers, the choice of which damper to use may well end up being down to which damper the (relatively) local shop favors. After all, you may end up having to take your car to them in order to work through issues, and intimate familiarity with the dampers in question will be of benefit. And if they're relatively local, then might well show up at some of the track events you'll be going to, and I expect that'll be of great value for dialing in the car.

 

[2013DIBGT]

I've been throughly pleased with my front Cortex JRi DA setup in combination with rear Penske 7500 DA's. Night and day better with the JRi up front then it was with the Cortex Koni DA setup in the front before. You can go full retard at all times now with total confidence which is a good thing for someone like myself who see's red every time the road starts to get twisty

The tire clearance argument is a none issue IMO as seen in the pick below. This is the clearance with an 18x10 Forgestar and 275x40x18 RE-11 on my car. I have no doubt that a much larger Rim/Tire setup could fit with zero issues despite the Eye/Eye shock config in the back.

In terms of ride height adjustment with that setup, me thinks it's another none issue unless your Snoop Dog trying to flip switches for the bitches on a Friday night in the mall parking lot.

I'm dropped 1.5" or so in the back and 1.25" or so in the front (going by memory) and still have threads on the shock body to play with if need be.

 

[Pentalab]

I've been throughly pleased with my front Cortex JRi DA setup in combination with rear Penske 7500 DA's. Night and day better with the JRi up front then it was with the Cortex Koni DA setup in the front before. You can go full retard at all times now with total confidence which is a good thing for someone like myself who see's red every time the road starts to get twisty

The tire clearance argument is a none issue IMO as seen in the pick below. This is the clearance with an 18x10 Forgestar and 275x40x18 RE-11 on my car. I have no doubt that a much larger Rim/Tire setup could fit with zero issues despite the Eye/Eye shock config in the back.

In terms of ride height adjustment with that setup, me thinks it's another none issue unless your Snoop Dog trying to flip switches for the bitches on a Friday night in the mall parking lot.

I'm dropped 1.5" or so in the back and 1.25" or so in the front (going by memory) and still have threads on the shock body to play with if need be.

Those penske rear coil overs appear to be inverted..vs the front JRI coil overs. If you look at his pix..on page 2, starting 1/2 way down the pix, you will see additional pix of the rear coil overs. It looks like the coil is at the bottom, sitting inside the wheel rim barrel, while the top end of the shock goes to the oem rear shock mount. End result is loads of clearance..at least with his 10" rims + 275 rear tires. Dunno whether it would be enough to handle a 11" wide rear rim, even with optimum offset..and say a 305 or 315 rear tire? Looks like from the above pix, and the pix directly below it,(p2), that there is a lot more tire width to be had. It's a unique configuration at any rate. I'm assuming the curved plate connection, between bottom of rear spring seating assy..and axle is strong enough? https://www.flickr.com/photos/125697112@N03/page2

If the oem rear shock tower was a concern, with a rear coil over installed, the rear shock tower could be beefed up somewhat, with additional plateS installed above and below. The pair of rear shock towers could also be braced, with either a single brace between them, or a X brace, or both.

I see the rear bump stops are still retained..and the axle tubes have been welded. The watts link looks bullet proof. Judging from the various pix, the entire package...front to back has been well optimized.

 

[Norm Peterson]

The tire clearance argument is a none issue IMO as seen in the pick below. This is the clearance with an 18x10 Forgestar and 275x40x18 RE-11 on my car. I have no doubt that a much larger Rim/Tire setup could fit with zero issues despite the Eye/Eye shock config in the back.

Thanks for the picture. Saves me a lot of trouble.


The inboard flange of an 18x11 will sit well inboard of that, and ride height probably plays a small part as well (at stock height, there can be light contact between the tires and the shock boots under some circumstances). Dunno exactly how much further in (and I wouldn't say if I did), but I'm thinking in terms of more than a whole inch. 11's would never work with non-inverted coilovers without offsetting/spacing them back outboard (and outside the sheetmetal).


Norm

 

[Norm Peterson]

BTW, I suspect those MCS shocks are probably pretty damn good and may be every damn bit as good as Terry suggests, but there is a weight of opinion about JRI's that was simply not being acknowledged.

Not immediately acknowledged to your "greatest thing since sliced bread" standards, perhaps. But OP's purposes sounds like a new market for them, and it'll take time before the kind of recognition they deserve makes it way around the HPDE/autocross/serious dual purpose community***.

But even that might still come up short of your standards, where you have this tendency to see as substandard everything you aren't currently running (especially if it's something that few others are using). At least that's how it reads. Consistently. You wanted to know where it came from . . .

If it makes you feel any better, I wouldn't have listed the non-adjustable Bilstein setup as an alternative either. Though I sort of understand how it ended up there. The fact that the rear springs are divorced from the dampers (in the MCS) affects your choice of rear spring and bar stiffnesses, and the damper settings required as a result, but I don't see any order-of-magnitude magic hiding in making the springs and dampers concentric here. Feel free to convince me otherwise, if you can do so in terms of pure/flat/unemotional relevant tech and not via product names and testimonials.


*** 50 years ago, Bilsteins and Konis weren't exactly household names either.


Norm

 

[csamsh]

I think concerns about unibody strength at the rear shock tower are very valid. I would also say that whoever built/designed the factor S197 race cars did too. Otherwise, you're just bolting to sheetmetal. IIRC, there is no bracing, gusseting, triangulation, or anything in an S197 where the shock top mount goes.

This is a picture of the trunk of a Boss 302S- note that the cage takes the load from the spring mounting point. Whether this is by design or accident, I do not know for sure, but I would suspect the former.

For anybody who needs a refresher on the 302S suspension setup, it used a concentric coil over shock rear.

Most of the series of which I am aware that the 302S could be used in mandate a small tire (IE, a 275 in NASA AI), so the wheel clearance thing is probably rarely a concern, unless you want to use the car for a different series. Which...if you're somewhere with unlimited tire and can afford a 302S, you an probably afford to flare the car and buy big wheels.

 

[barbaro]

I think concerns about unibody strength at the rear shock tower are very valid. I would also say that whoever built/designed the factor S197 race cars did too. Otherwise, you're just bolting to sheetmetal. IIRC, there is no bracing, gusseting, triangulation, or anything in an S197 where the shock top mount goes.

This is a picture of the trunk of a Boss 302S- note that the cage takes the load from the spring mounting point. Whether this is by design or accident, I do not know for sure, but I would suspect the former.

For anybody who needs a refresher on the 302S suspension setup, it used a concentric coil over shock rear.

Most of the series of which I am aware that the 302S could be used in mandate a small tire (IE, a 275 in NASA AI), so the wheel clearance thing is probably rarely a concern, unless you want to use the car for a different series. Which...if you're somewhere with unlimited tire and can afford a 302S, you an probably afford to flare the car and buy big wheels.

You say valid. I say show me the data because there are dozens of cars running this setup and I have not heard or seen one failure. These vehicles are being driven on the road and being tortured on the track. Show me the failures? There is not one that I know of. You often put me down because you say that I don't have the data to back up what I say and yet here you are making a pretty strong statement with absolutely no data behind it. And that is because there is no data. Because failures if they occur at all and it's not clear that they do, are so few as to be inconsequential.

 

[barbaro]

Cortex says this:

Taken fron Boss Mustangs online:

Reply #2 on:*November 24, 2014, 01:55:06 PM »

"Failure of the rear upper shock mounting point of the S197 chassis is extremely*unlike.* We have never seen it happen and there is good reason.* The upper mounting pad is tied directly into the rear unibody frame rails with steel that is quite thick.* The upper pad that the OEM shock bushings bolt to approximately 0.200" thick and it is surrounded by multi-wall heavy duty vertical reinforcements on all sides. The CorteX Racing upper shock mounts have a large pad area that spreads the loads and feeds them directly into all of the vertical supports surrounding the bushing pad area.* Because the shocks are nearly vertical there is essentially no side loads (horizontal). For those that are not convinced, you could always retain the OEM bump stops that are bolted to the top of the axle tube and shorten them as needed to ensure adequate bump travel. We do this on the majority of our installs mainly because it is easier on the shocks over time.* If retained, the OEM bump stops would take loads from a large hit such as jumping the car instead of the shock mounts. We have spent a fair amount of time thinking this through and testing our design on daily driver and dedicated race cars of a number of years.* The benefits of a much improved motion leads to better ride quality and much improved handling. Properly setup full coil-overs on an S197 are amazing and we highly recommend them for all serious enthusiasts."

I believe them I don't believe you.

 

[barbaro]

Not immediately acknowledged to your "greatest thing since sliced bread" standards, perhaps. But OP's purposes sounds like a new market for them, and it'll take time before the kind of recognition they deserve makes it way around the HPDE/autocross/serious dual purpose community***.

But even that might still come up short of your standards, where you have this tendency to see as substandard everything you aren't currently running (especially if it's something that few others are using). At least that's how it reads. Consistently. You wanted to know where it came from . . .

If it makes you feel any better, I wouldn't have listed the non-adjustable Bilstein setup as an alternative either. Though I sort of understand how it ended up there. The fact that the rear springs are divorced from the dampers (in the MCS) affects your choice of rear spring and bar stiffnesses, and the damper settings required as a result, but I don't see any order-of-magnitude magic hiding in making the springs and dampers concentric here. Feel free to convince me otherwise, if you can do so in terms of pure/flat/unemotional relevant tech and not via product names and testimonials.


*** 50 years ago, Bilsteins and Konis weren't exactly household names either.


Norm

As for relevant tech I will point to the fact that you can't show me one case of rear shock tower failure on an S197. As for the benefits of concentric outboard coilovers See Cortex response above.

As for everything else. I do my research the best I can. And I put my money where my mouth is. And what you see is the results of that research. So why would I advocate for something that I myself cannot vouch for. Because that's what you're doing Norm. Or do you want to tell me about the sweet set of MCS coilovers you're driving around on? You have not seen data and you don't have personal experience and so you don't know anything either.

 

[zeroescape]

I run the sachs FR500S rear shocks with FRPP upper shock mounts and vorshlags F14 18x11 BFG Rivals 295/35/18 rears. I measure about .50 to .65 inches between shock body and wheel. Enough to reach my hand around from the top and place it between.

As for bracing, if the rules allow it, why wouldnt you attach the rear diagonals. Adds rigidity with a cage you are already going to put in. So its hard to say theres a lack of strength just because it was incorporated into design.

It does look stout and I plan to use the same idea.

 

[Norm Peterson]

I looked up the shock mounts (M-18197-A) and it looks like they might buy you a little extra room.


barbaro - I don't recall getting involved with tower strength here. In fact I went out of my way to avoid it. Not that I couldn't discuss the matter with some intelligence - after all, I only spent nearly 40 years doing structural strength and fatigue calculations, sometimes involving resiliently mounted equipment (think shock bushings here). Oddly enough, mostly in the same industry that Filip worked in, pre-Cortex.

The matter of shock tower strength aside, the

But anyway, the stock S197 has none of the additional structure shown in the FR500S picture, and given that that's an all-out competition car, if it's there at all it's because it needs to be there. Horizontal loads from a C/O assembly isn't going to be the reason (I agree, those loads will be small), and there isn't going to be any suspension geometry benefit to be had. It's going to be more about the flat-sheet trunk floor structure making for poor-ish structural continuity between the other cage bars and fixing that.

I do have some idea what's going on with the OE divorced spring/damper arrangement, and I suspect that the difference in "feel" with coaxial springs/dampers is going to be more noticeable than the divorced setup maybe being relatively overdamped in roll compared to ride. Dunno, maybe there's enough added composure to be had by dialing back the roll damping at some point, but it'd take more testing than I'd ever take on personally to identify it. Retired, y'know . . . fixed income and all that.


Norm

 

[Pentalab]

Cortex says this:

Taken fron Boss Mustangs online:

Reply #2 on:*November 24, 2014, 01:55:06 PM »

"Failure of the rear upper shock mounting point of the S197 chassis is extremely*unlike.* We have never seen it happen and there is good reason.* The upper mounting pad is tied directly into the rear unibody frame rails with steel that is quite thick.* The upper pad that the OEM shock bushings bolt to approximately 0.200" thick and it is surrounded by multi-wall heavy duty vertical reinforcements on all sides. The CorteX Racing upper shock mounts have a large pad area that spreads the loads and feeds them directly into all of the vertical supports surrounding the bushing pad area.* Because the shocks are nearly vertical there is essentially no side loads (horizontal). For those that are not convinced, you could always retain the OEM bump stops that are bolted to the top of the axle tube and shorten them as needed to ensure adequate bump travel. We do this on the majority of our installs mainly because it is easier on the shocks over time.* If retained, the OEM bump stops would take loads from a large hit such as jumping the car instead of the shock mounts. We have spent a fair amount of time thinking this through and testing our design on daily driver and dedicated race cars of a number of years.* The benefits of a much improved motion leads to better ride quality and much improved handling. Properly setup full coil-overs on an S197 are amazing and we highly recommend them for all serious enthusiasts."

I believe them I don't believe you.

Good info. However the sheet metal between the shock mounts is paper thin. When I helped the local race shop weld in my rear steeda STB, while welding on the shock tower, it was glowing red inside the wheel well. I had to put a lot of water on the wheel well area to keep things in check.

On any lowered car....at the rear, the oem bump stops will have to be shortened, that's par for the course. Ok, will 11" rims fit on the rear, with the inverted shock /coil over assy ? The rim would sit inboard a full inch more than a 10" rim. I think it would be a squeaker, even if optimum offset was used on the 11" rim... or a small 3-5mm spacer used.

Does anybody know what the C-C spacing is..of the oem springs ? They sit well inboard of the oem rear shocks. The inverted rear coil overs, being located a lot further apart vs oem springs....would change the rear suspension geometry a bunch... I suspect like apples + oranges.

 

[Norm Peterson]

Does anybody know what the C-C spacing is..of the oem springs ? They sit well inboard of the oem rear shocks.

I measured something like 34" on my '08. But I don't remember taking any measurements between either the axle side or body side shock pickups.

The inverted rear coil overs, being located a lot further apart vs oem springs....would change the rear suspension geometry a bunch... I suspect like apples + oranges.

The relationships between spring deflection and shock piston movement for the various body motions will change (and won't change by the same amount), so the forces will change. Things like axle roll steer and anti-squat will not change at all assuming that you maintain the same ride height and LCA/UCA/PHB linkage pivot points - which is really where the suspension geometry part is.


Norm

 

[DocB]

@zeroescape- On your Vorshlag F14 18x11 wheels, do you happen to know what the backspacing is?

 

[JerryZ]

You just asked the question that some people on here consider classified info including guys that own them.
For me, I chose a bit more conservative route with 18X10ET43 which has sold a zillion and works well. As I see it, the clearances of concern are the struts to inner side of rim for the front and the rear is avoiding excessive poke on the outer rim side with inner clearance sufficient enough to not be a concern (at least up to 11").
Using the 18X10ET43 as reference, to maintain the same front inner clearance and same outer clearance in the rear, you merely adjust offset 1/2" in opposite directions and I think you would have to be extremely close to as good as the magic Vorshlag numbers.
I would bet that a 30F & 55R would be very close to correct assuming some amount of negative front camber beyond Ford Spec. You guys that have been sworn to secrecy tell me I'm not very close. Every individual setup may take a bit of tweaking with any offset is why I chose not to push the limit.
I do not claim to be any kind of expert; I just don't see it as rocket science. Just adjust the numbers based on a tried and true unclassified setup.

 

[Pentalab]

You just asked the question that some people on here consider classified info including guys that own them.
For me, I chose a bit more conservative route with 18X10ET43 which has sold a zillion and works well. As I see it, the clearances of concern are the struts to inner side of rim for the front and the rear is avoiding excessive poke on the outer rim side with inner clearance sufficient enough to not be a concern (at least up to 11").
Using the 18X10ET43 as reference, to maintain the same front inner clearance and same outer clearance in the rear, you merely adjust offset 1/2" in opposite directions and I think you would have to be extremely close to as good as the magic Vorshlag numbers.
I would bet that a 30F & 55R would be very close to correct assuming some amount of negative front camber beyond Ford Spec. You guys that have been sworn to secrecy tell me I'm not very close. Every individual setup may take a bit of tweaking with any offset is why I chose not to push the limit.
I do not claim to be any kind of expert; I just don't see it as rocket science. Just adjust the numbers based on a tried and true unclassified setup.

1/2" = 12.7mm 43+12.7 = 55.7 mm offset. Use 42mm with a 10" rim as ur baseline. 42+ 12.7 = 54.7 mm So 55mm may well work..at least with a 305 /315 rear tire.

I can't see how a 30mm offset with a 11" wide front rim would work, even with a lot of neg camber. It would be poking out past the wheel well.

 

[DocB]

@JerryZ-Since the Vorshlag wheels in that size have been out so long, I didn't think that was classified info any longer. If so, I apologize for asking an inappropriate question. It just seems that other manufacturers have already roughly copied or did their own designing.
I realize that Vorshlag does a lot of testing, and I respect what they do to bring a product to market first and what they do for us in the Mustang community. It's just that I have never actually seen one of these wheels, nor measured one.
Additionally, I am not out to copy this wheel. It won't work for me. I need a way different setupfor the series I run in.
I need an 18x11 wheel wrapped in 315s. X4 that are rotatable.
Running the thinnest spacer possible* in the front and don't poke out the fenders.
I am performing my own calculations to determine the mods I need to do to make this happen. Was just looking for a rough idea of what others were doing, even though it's a narrower tire.

*By thin front spacer, I mean 3/4" or less.