Possible issue with mountune springs??

[Flaco]

I installed the Mountune Sport Springs about 2 months ago, it takes them a while to settle. In the front I have a 1 1/4 inch drop and in the rear about 3/4 inch drop. Also on the right rear the drop is only 1/2 inch, so weird. Took out both rear springs and the right spring is 1/4 inch longer than the left. No weight in the back so maybe that would account for them not to have finished settling.

 

[shelbydave]

I installed the Mountune Sport Springs about 2 months ago, it takes them a while to settle. In the front I have a 1 1/4 inch drop and in the rear about 3/4 inch drop. Also on the right rear the drop is only 1/2 inch, so weird. Took out both rear springs and the right spring is 1/4 inch longer than the left. No weight in the back so maybe that would account for them not to have finished settling.

That's odd because I had an uneven rear also

 

[BuiltforSin]

Looks good, I just put Swift and B8’s on mine

Pic?

 

[me32]

I installed the Mountune Sport Springs about 2 months ago, it takes them a while to settle. In the front I have a 1 1/4 inch drop and in the rear about 3/4 inch drop. Also on the right rear the drop is only 1/2 inch, so weird. Took out both rear springs and the right spring is 1/4 inch longer than the left. No weight in the back so maybe that would account for them not to have finished settling.

That would cause one side not to lower as much as it should. Have you contacted them?

 

[DaveG99]

Sounds like the mountune springs have some issues. Weird. Im going to go with the swift spec R springs.

 

[Dirttwurk]

I have the exact opposite situation. Have a '17 and Mountune, and the rear sits a full inch higher than the front (front 24", rear 25"). Sure hope it settles soon. Don't like the raked look.

Hey did you ever have any resolution with this? My 17' is the same way.

 

[BRGT350]

Remember that the rear wheel arch is lower than the front. How much change did you see between stock F/R and Mountune F/R? You need to measure the difference from stock to know how much you lowered the car.

 

[Dirttwurk]

Remember that the rear wheel arch is lower than the front. How much change did you see between stock F/R and Mountune F/R? You need to measure the difference from stock to know how much you lowered the car.

Yeah, I should have been more clear. I took reference measurements before I started anything. I ended up with an .750" ride height reduction up front, which is within what I expected. This is where it gets weird. My rear measurement show an even .250" ride height increase side to side.

I'm currently working with Mountune to resolve. They have told me that they have had reports of the rear being a bit too low, but this is the first instance where they've heard of an increase in ride height. My next step is to remove the powerflex spring insulators and try out the stock insulators to see where it lands. I could see the poly insulators possibly adding maybe .250" of preload to the spring.

 

[730iACSchnitzer]

It seems that the Mountune Spings are only an issue with later model 2017 Fist. Maybe because of the softer suspensions given to the later models which might share some of the characteristics of the ST200.

 

[Flaco]

My next step is to remove the powerflex spring insulators and try out the stock insulators to see where it lands. I could see the poly insulators possibly adding maybe .250" of preload to the spring.

I just did this last weekend made no difference in how the rear sits. Still my right rear sits 1/2 inch above the left rear. Got under the car and measured the springs both were compressed to aprox., 8 inches. I think maybe the rear of the car is not quite square. Gonna talk to my body shop guy and see what he thinks

 

[Dirttwurk]

It seems that the Mountune Spings are only an issue with later model 2017 Fist. Maybe because of the softer suspensions given to the later models which might share some of the characteristics of the ST200.

Yeah I noticed that as well and was thinking something similar. Mid-16' and up have a different beam axle so I'm wondering if the lower spring cups are in a slightly different position, although this I don't really hear of this issue with other brands of spring, so who knows.

I did put the stock upper insulators back in and it measured out right at 1/4" drop from where I was. So now I'm back to my stock height in the rear.

I've seen inconsistencies with other eibach springs in the past. I think that the most likely issue at this point is that rear springs were manufactured out of spec in some way.

 

[ThaiFiesta]

If you swap them side to side you will be able to determine if it’s the springs or the car.

 

[BRGT350]

Yeah, I should have been more clear. I took reference measurements before I started anything. I ended up with an .750" ride height reduction up front, which is within what I expected. This is where it gets weird. My rear measurement show an even .250" ride height increase side to side.

I'm currently working with Mountune to resolve. They have told me that they have had reports of the rear being a bit too low, but this is the first instance where they've heard of an increase in ride height. My next step is to remove the powerflex spring insulators and try out the stock insulators to see where it lands. I could see the poly insulators possibly adding maybe .250" of preload to the spring.

We should swap springs! I am trying to raise the rear of my ST by .25" for better tire clearance. Did you check to make sure both springs are seated properly? That is very odd about your car with the springs. I do appreciate the clarification since that indicates for sure there is a problem.

 

[Dirttwurk]

We should swap springs! I am trying to raise the rear of my ST by .25" for better tire clearance. Did you check to make sure both springs are seated properly? That is very odd about your car with the springs. I do appreciate the clarification since that indicates for sure there is a problem.

Definitely not a problem with how they are installed, that was the first thing that I checked. I've already ordered a set of swift springs. So I'll test with those once they arrive and see what happens. Obviously if I can get to the approximate advertised drop with the swift springs, I think it would prove my hypothesis that there is something amiss with the mountune springs. If I end up significantly higher than the advertised drop on the swift springs, then I think that it would be reasonable to conclude that there is something different about the spring mounting points on the 17+ cars.

Have you installed the powerflex insulators yet? If you need .250" i think those might get you there, or at least fairly close.

 

[BRGT350]

Definitely not a problem with how they are installed, that was the first thing that I checked. I've already ordered a set of swift springs. So I'll test with those once they arrive and see what happens. Obviously if I can get to the approximate advertised drop with the swift springs, I think it would prove my hypothesis that there is something amiss with the mountune springs. If I end up significantly higher than the advertised drop on the swift springs, then I think that it would be reasonable to conclude that there is something different about the spring mounting points on the 17+ cars.

Have you installed the powerflex insulators yet? If you need .250" i think those might get you there, or at least fairly close.

I am going to be making a set of shims to fine tune the ride height in the rear and see how that works. I can do those cheaper than the urethane isolators. Reports say there isn't a noticeable change in ride height.

I think your conclusion that there is something different with the model years is probably valid. However, I do have an interesting story that nobody has been able to solve. My dad's 1985 Saleen Mustang sat nose high on lowering springs. He added a set of Ford Motorsports springs and it still sat high, so he had a coil or so removed to level the car out. The ride wasn't great, so he swapping in some Eibach springs. Again, the car sat nose high. Cut the coils down and the car sat level. I took his old Ford Motorsports springs and put them on my 1984 Mustang and the front sat scary low. It sat way too low with the 2.3L engine and even lower when I installed the 302. The K-members, control arms, and front structure were the same between the cars, yet his car always sat nose high with lowering springs. Nobody could ever make sense of it.

 

[Dirttwurk]

I am going to be making a set of shims to fine tune the ride height in the rear and see how that works. I can do those cheaper than the urethane isolators. Reports say there isn't a noticeable change in ride height.

I think your conclusion that there is something different with the model years is probably valid. However, I do have an interesting story that nobody has been able to solve. My dad's 1985 Saleen Mustang sat nose high on lowering springs. He added a set of Ford Motorsports springs and it still sat high, so he had a coil or so removed to level the car out. The ride wasn't great, so he swapping in some Eibach springs. Again, the car sat nose high. Cut the coils down and the car sat level. I took his old Ford Motorsports springs and put them on my 1984 Mustang and the front sat scary low. It sat way too low with the 2.3L engine and even lower when I installed the 302. The K-members, control arms, and front structure were the same between the cars, yet his car always sat nose high with lowering springs. Nobody could ever make sense of it.

I remember back in my fox body days the eibach springs were all over the place as far as lowering or even raising the cars. I recall similar stories to yours where people were swapping the same set of springs between cars and ending up with wildly different results. That was the main reason I went with H&R springs in my 89', they were spot on to the advertised drop from day one and stayed within 1/4" of my day one measurements for the 7 years they were in the car.

 

[Adub]

Yeah I noticed that as well and was thinking something similar. Mid-16' and up have a different beam axle so I'm wondering if the lower spring cups are in a slightly different position, although this I don't really hear of this issue with other brands of spring, so who knows.

I did put the stock upper insulators back in and it measured out right at 1/4" drop from where I was. So now I'm back to my stock height in the rear.

I've seen inconsistencies with other eibach springs in the past. I think that the most likely issue at this point is that rear springs were manufactured out of spec in some way.

Different beam axle? I thought they just softened the dampers and added a stiffer 21mm bar in the front.

 

[Dirttwurk]

Different beam axle? I thought they just softened the dampers and added a stiffer 21mm bar in the front.

Apparently the beam is thicker by 1mm.

 

[Adub]

Interesting have link to info?

 

[Dirttwurk]

Interesting have link to info?

http://www.fiestastforum.com/forum/threads/16138-Stock-Front-and-Rear-Suspension-Changes-Between-Early-Late-Production