775LikesMugen MTC2
12-05-2021, 05:13 PM
#857
Originally Posted by Typeone
What spur did you use to achieve those final drives?
12-06-2021, 11:21 AM
#860
Tech Adept
iTrader: (4)
Originally Posted by Typeone
Do you guys no what site to get stainless steel set screws instead of the stock ones that come with the kit.
12-07-2021, 10:15 AM
#861
Tech Regular
wouldn't it be best to replace the setscrews with regular screws?
12-07-2021, 10:31 AM
#862
Tech Master
iTrader: (15)
Originally Posted by chumanji
wouldn't it be best to replace the setscrews with regular screws?
12-07-2021, 11:27 AM
#863
Is there a chart that shows the rates of the springs? I got a used kit and have a tone of springs, some new, just don’t know the progression from soft to hard, and the description on A-main of the progressive springs is just a cut and paste job.
even better if there is a chart that shows comparison to X-ray springs to give relation to a known “standard”
even better if there is a chart that shows comparison to X-ray springs to give relation to a known “standard”
12-07-2021, 11:59 AM
#864
Tech Master
iTrader: (15)
Originally Posted by theproffesor
Is there a chart that shows the rates of the springs? I got a used kit and have a tone of springs, some new, just don’t know the progression from soft to hard, and the description on A-main of the progressive springs is just a cut and paste job.
even better if there is a chart that shows comparison to X-ray springs to give relation to a known “standard”
even better if there is a chart that shows comparison to X-ray springs to give relation to a known “standard”
progressive~
OPTION PARTS FOR MTC2
linear~
OPTION PARTS FOR MTC2
The MTC2 spring rates are much softer than what Xray uses. The numbers on the springs indicate coil count. Larger number is softer in the order.
12-07-2021, 12:35 PM
#865
Originally Posted by BobW
I will try to explain.
First the Mugen springs are much softer than what we are accustomed to with other chassis. Since Xray springs have the same inside diameter and the same wire diameter its' only the number of coils that is different. More coils softer spring. The spring rate is directly related to the number of "Active Coils" so using the Xray spring as a base the Mugen spring rates in N/mm are 5.75T - 2.4, 6T - 2.25, 6.25T - 2.12, 6.5T - 2.0 and 6.75T - 1.89. These values are quite a bit softer than the Xray springs at 2.5 - 2.9. I inquired about getting actual values from Mugen but didn't receive a reply so until someone can accurately measure them this is what I will use.
To determine how the spring force translates to a force at the wheel you need to look at the Motion Ratio (MR). Ignoring the shock angle this is simply the ratio of the length from the inner arm mount to where the spring connects divided by the length of the arm. For the Mugen the MR is .75 and for the Xray it is .64. To determine the spring effect at the wheel (Wheel Rate or Ride Rate) the spring rate gets multiplies by the Motion Ratio squared. So at the wheel a 2.5 Xray Spring becomes 1.0 N/mm and for the Mugen with a 1.89 spring is 1.06 N/mm. So even though the Mugen spring is softer the effect it has at the wheel (which is the important part) is the same.
First the Mugen springs are much softer than what we are accustomed to with other chassis. Since Xray springs have the same inside diameter and the same wire diameter its' only the number of coils that is different. More coils softer spring. The spring rate is directly related to the number of "Active Coils" so using the Xray spring as a base the Mugen spring rates in N/mm are 5.75T - 2.4, 6T - 2.25, 6.25T - 2.12, 6.5T - 2.0 and 6.75T - 1.89. These values are quite a bit softer than the Xray springs at 2.5 - 2.9. I inquired about getting actual values from Mugen but didn't receive a reply so until someone can accurately measure them this is what I will use.
To determine how the spring force translates to a force at the wheel you need to look at the Motion Ratio (MR). Ignoring the shock angle this is simply the ratio of the length from the inner arm mount to where the spring connects divided by the length of the arm. For the Mugen the MR is .75 and for the Xray it is .64. To determine the spring effect at the wheel (Wheel Rate or Ride Rate) the spring rate gets multiplies by the Motion Ratio squared. So at the wheel a 2.5 Xray Spring becomes 1.0 N/mm and for the Mugen with a 1.89 spring is 1.06 N/mm. So even though the Mugen spring is softer the effect it has at the wheel (which is the important part) is the same.
Originally Posted by theproffesor
Is there a chart that shows the rates of the springs? I got a used kit and have a tone of springs, some new, just don’t know the progression from soft to hard, and the description on A-main of the progressive springs is just a cut and paste job.
even better if there is a chart that shows comparison to X-ray springs to give relation to a known “standard”
even better if there is a chart that shows comparison to X-ray springs to give relation to a known “standard”
12-07-2021, 04:13 PM
#866
Awesome explanation! Thanks!
Edit… I have questions looking at set up sheets. Every one of them has harder springs in rear than front. I’ve never seen that on setups before. I know this suspension design is “new” but it still is a hard pill to swallow after 20+ years of harder front than rear
Edit… I have questions looking at set up sheets. Every one of them has harder springs in rear than front. I’ve never seen that on setups before. I know this suspension design is “new” but it still is a hard pill to swallow after 20+ years of harder front than rear
Last edited by theproffesor; 12-07-2021 at 04:24 PM.
12-07-2021, 08:15 PM
#867
Originally Posted by theproffesor
Awesome explanation! Thanks!
Edit… I have questions looking at set up sheets. Every one of them has harder springs in rear than front. I’ve never seen that on setups before. I know this suspension design is “new” but it still is a hard pill to swallow after 20+ years of harder front than rear
Edit… I have questions looking at set up sheets. Every one of them has harder springs in rear than front. I’ve never seen that on setups before. I know this suspension design is “new” but it still is a hard pill to swallow after 20+ years of harder front than rear
Don’t trip on it though, car is wicked with the softer front. Kit springs are good on carpet, the 7.0p front makes it that much better. You could even just get away with grabbing a single 1.0 bar and a set of the 7.0p springs for the front and you’d be good. If your track slicks off throw a 1.0 on the rear and you’ll be good.
I’ve ran the kit springs and bars for awhile and it’s still money though!
12-07-2021, 10:40 PM
#868
Despite harder springs in the front, the ride stiffness is softer for the front of the car. This is due to a more inward lower damper attachment at the front (to clear for steering). So thanks to BobW for helping us understand, the motion ratios are 0.45 for the front and 0.59 for the rear. (Motion ratio = ratio between coil spring rate and resulting ride stiffness at the wheel).
