******j m r s n e e k p e e k ******
Rookie
Joined: Jan 2011
Posts: 79
Likes: 1
Answers and Updates
Why is the coil almost fully compressed?
The coil in the picutres is almost fully compressed due in part to the weight of the bumper (about 180 lbs). The coil spacer does not compress the spring, though it appears that it would. The spring is compressed due to the weight of the vehicle. The distance that the spring compresses is directly related to the weight that is applied to it. For example, a 600 lb spring means that if 600 lbs of force is applied to the spring, it will compress 1 inch. If 2400 lbs is applied to that same spring, it will compress a total of 4 inches. The spacer only works by lowering the level that the spring sits, and thus works as a "leveling/lift" for the vehicle. Coil spacers work almost the same as lowering the point at which the coilover is mounted, yet they slightly take away from upward wheel travel. All lift kits work by lowering the mounting of the suspension. Since the truck sits on top of the suspension, "lowering" the suspension really means lifting the truck. Therefore, with a heavier bumper, more weight is applied to the coilover, and it compresses more. When I first installed the coil spacers the coils on the truck were very close together, even with the coilover fully extended. In addition, if the bumper weighs 180 lbs then 180/2=90 lbs per spring. Because the bumper's weight is not directly above the coilover, leverage causes more than 90 lbs to be placed on each coilover. For "safe" calculations, we could say that 180 lbs is applied to each coilover. Therefore, 180/600= 0.3, and therefore should only compress the coilovers about 1/3 of an inch. So the fact that the coil was closer together before the coil spacers and before the bumper in combination with the theoretical calculation shown above, my best guess is that my coils were unusually compressed from the beginning or compressing the coil 1/3 of an inch makes a big difference in the appearance of the coil assembly.
In conclusion, however compressed your coilover is before the JMR lift kit is how compressed it will be after the kit.
Are all the tests done with stock wheels?
Yes, the wheels seen in the pictures are stock 16" alloy wheels that came with the 2005 Dak. The test truck had previously been in a minor accident, in which the driver's side tire scrubbed the side of another vehicle. After installing the JMR kit, the brake caliper on the driver's side did slightly rub on the inside of the driver's side wheel when the brakes were applied. However, this did not happen on the passenger side. Could this difference be a result of the accident? Possibly. However, if this occurs on other vehicles, the amount that the caliper rubs is so insignificant that you can either deal with it rubbing for a couple days til it wears itself down (which is what happened to our test vehicle), you can grind the top of the caliper about 1mm, or you can use 17" wheels.
Many lift kits require aftermarket wheels that are larger and have less backspacing than stock. Our kit is a little better but still does not work perfectly with stock wheels. For backspacing, we are running 1.5" spacers. Therefore, the IDEAL setup would be to run 17" or larger wheels with reduced backspacing (we will measure required backspacing in the near future).
Update:
We have just finished installing Fabtech's Dirt Logic 2.5 coilovers on the front. They were difficult to install because the coilovers needed to be compressed in order to install them, even after backing the coil nut all the way out. With the truck sitting level with it's weight on the suspension, the Fabtech coilovers are more compressed than we were hoping for. Though spring slap will not occur, the shock inside the coil only has about an inch and a half of compression. The good news is that the ride height of the vehicle is the same with the Fabtech coilovers as it was with our coilover drop brackets. Next, we will test this setup off road (Fabtech Dirt Logic 2.5 coilovers in front and Dirt Logic 2.25 shocks in the rear). Following this, we will have ICON build custom coilovers and test them with the Rancho 9000 rear shocks.
The coil in the picutres is almost fully compressed due in part to the weight of the bumper (about 180 lbs). The coil spacer does not compress the spring, though it appears that it would. The spring is compressed due to the weight of the vehicle. The distance that the spring compresses is directly related to the weight that is applied to it. For example, a 600 lb spring means that if 600 lbs of force is applied to the spring, it will compress 1 inch. If 2400 lbs is applied to that same spring, it will compress a total of 4 inches. The spacer only works by lowering the level that the spring sits, and thus works as a "leveling/lift" for the vehicle. Coil spacers work almost the same as lowering the point at which the coilover is mounted, yet they slightly take away from upward wheel travel. All lift kits work by lowering the mounting of the suspension. Since the truck sits on top of the suspension, "lowering" the suspension really means lifting the truck. Therefore, with a heavier bumper, more weight is applied to the coilover, and it compresses more. When I first installed the coil spacers the coils on the truck were very close together, even with the coilover fully extended. In addition, if the bumper weighs 180 lbs then 180/2=90 lbs per spring. Because the bumper's weight is not directly above the coilover, leverage causes more than 90 lbs to be placed on each coilover. For "safe" calculations, we could say that 180 lbs is applied to each coilover. Therefore, 180/600= 0.3, and therefore should only compress the coilovers about 1/3 of an inch. So the fact that the coil was closer together before the coil spacers and before the bumper in combination with the theoretical calculation shown above, my best guess is that my coils were unusually compressed from the beginning or compressing the coil 1/3 of an inch makes a big difference in the appearance of the coil assembly.
In conclusion, however compressed your coilover is before the JMR lift kit is how compressed it will be after the kit.
Are all the tests done with stock wheels?
Yes, the wheels seen in the pictures are stock 16" alloy wheels that came with the 2005 Dak. The test truck had previously been in a minor accident, in which the driver's side tire scrubbed the side of another vehicle. After installing the JMR kit, the brake caliper on the driver's side did slightly rub on the inside of the driver's side wheel when the brakes were applied. However, this did not happen on the passenger side. Could this difference be a result of the accident? Possibly. However, if this occurs on other vehicles, the amount that the caliper rubs is so insignificant that you can either deal with it rubbing for a couple days til it wears itself down (which is what happened to our test vehicle), you can grind the top of the caliper about 1mm, or you can use 17" wheels.
Many lift kits require aftermarket wheels that are larger and have less backspacing than stock. Our kit is a little better but still does not work perfectly with stock wheels. For backspacing, we are running 1.5" spacers. Therefore, the IDEAL setup would be to run 17" or larger wheels with reduced backspacing (we will measure required backspacing in the near future).
Update:
We have just finished installing Fabtech's Dirt Logic 2.5 coilovers on the front. They were difficult to install because the coilovers needed to be compressed in order to install them, even after backing the coil nut all the way out. With the truck sitting level with it's weight on the suspension, the Fabtech coilovers are more compressed than we were hoping for. Though spring slap will not occur, the shock inside the coil only has about an inch and a half of compression. The good news is that the ride height of the vehicle is the same with the Fabtech coilovers as it was with our coilover drop brackets. Next, we will test this setup off road (Fabtech Dirt Logic 2.5 coilovers in front and Dirt Logic 2.25 shocks in the rear). Following this, we will have ICON build custom coilovers and test them with the Rancho 9000 rear shocks.
Rookie
Joined: Jan 2011
Posts: 79
Likes: 1
Update!!!
http://www.youtube.com/watch?v=Jam-sHsFKCM
We tested the truck again with Fabtech Dirt Logic 2.5 coilovers in the front and Fabtech Dirt Logic 2.25 non-resi shocks in the rear. Skid plates were not used in this video.
Our conclusion: the Fabtech rear shocks are great on the road and descent off road. The Fabtech coilovers, on the other hand, are too long. For small bumps and rollers they feel good but only allow for 2-3 inches of upward wheel travel and bottom out on the rubber bump stop (no spring slap).
As a result, the next thing we are going to test is:
Custom length ICON coilovers in front and Rancho 9000 shocks in rear. The ICON coilovers must be ordered and shipped, then installed so testing of these will be at LEAST 3 weeks out (1st of November).
We tested the truck again with Fabtech Dirt Logic 2.5 coilovers in the front and Fabtech Dirt Logic 2.25 non-resi shocks in the rear. Skid plates were not used in this video.
Our conclusion: the Fabtech rear shocks are great on the road and descent off road. The Fabtech coilovers, on the other hand, are too long. For small bumps and rollers they feel good but only allow for 2-3 inches of upward wheel travel and bottom out on the rubber bump stop (no spring slap).
As a result, the next thing we are going to test is:
Custom length ICON coilovers in front and Rancho 9000 shocks in rear. The ICON coilovers must be ordered and shipped, then installed so testing of these will be at LEAST 3 weeks out (1st of November).
Rookie
Joined: Aug 2011
Posts: 50
Likes: 0
From: Boulder, CO
Absolutely awesome! Looks like you guys brushed up on your video editing skills too. 
And come on guys, you are crazy for not wearing helmets during that extreme off-roading with the dirt bike at the end!
But seriously this is looking great and I can't wait to get this set up on my Dak.
And come on guys, you are crazy for not wearing helmets during that extreme off-roading with the dirt bike at the end!
But seriously this is looking great and I can't wait to get this set up on my Dak.
