Anyone ever use coilover in front, lowering spring in rear?

wildcat767676 · 06-08-2011, 01:41 PM

I have JIC Cross coilovers and the rears are driving me crazy. They clunk, ride rough, and I can't find instructions to adjust them anywhere..........

I'm leaning towards removing them and putting the lowering springs/stock shocks back in in rear. I like the front coilovers a lot though. Anyone ever try this? Any major issues doing it? Suggestions?

Thanks!

Focusedintntions · 06-08-2011, 01:42 PM

Maybe look at getting a different set of coil overs?? never heard of JIC...

wildcat767676 · 06-08-2011, 01:50 PM

JIC Cross was pretty big and a good brand. They are now called JIC Magic. www.jic-magic.com.

Had read a lot of positive reviews on the site about them beforehand....

Focusedintntions · 06-08-2011, 02:20 PM

I've never trusted reviews on a vendors own site as it's very easy for them to fake them. As far as I know you're the only person on here that's running them and you don't seem to happy with them as you're thinking about taking them out of the rear b/c of noise issues. Just sayin....

GaryS · 06-08-2011, 03:03 PM

Quote:

Originally Posted by wildcat767676

I have JIC Cross coilovers and the rears are driving me crazy. They clunk, ride rough, and I can't find instructions to adjust them anywhere..........

I'm leaning towards removing them and putting the lowering springs/stock shocks back in in rear. I like the front coilovers a lot though. Anyone ever try this? Any major issues doing it? Suggestions?

Thanks!

It's hard enough to get balanced f/r spring rates and damping when someone who is supposed to be an automotive engineer designs the whole system. If you are interested in calculating balanced rates and damping, check out the information under Springs and Dampers at this link: http://www.optimumg.com/OptimumGWebS.../TechTips.html

(IIRC the motion ratios are something like .92 front and .32 rear.)

wildcat767676 · 06-08-2011, 03:20 PM

What do you mean? Are you saying it's not set up right, thus the issues, or that aftermarket suspension is unbalanced?

GaryS · 06-08-2011, 04:12 PM

^^ I meant that mixing front springs and dampers from one system with rear springs and dampers from another system is unlikely to end up balanced; and if it's not balanced, ride and handling will suck.

wildcat767676 · 06-08-2011, 04:43 PM

Oh gotcha!

Ride in the rear pretty much sucks right now either way.....lol. Know how to set up the rear shock length by chance?

DriveHard · 06-08-2011, 05:22 PM

Quote:

Originally Posted by wildcat767676

Oh gotcha!

Ride in the rear pretty much sucks right now either way.....lol. Know how to set up the rear shock length by chance?

i know we are all lazy some times...but it took me 2 clicks to get this for you.. I would suspect that it is in fact in the set up.. ( ive never worked with theses so i am no help as to specific questions )

good luck !!

p.s. you may want to look at the installation instructions.. there may be an issue from the get go.. like a space mis placed or no bumstop or something like that .... just a thought
http://www.jic-magic.com/Files/FLT-A...y%209-7-05.pdf

http://www.jic-magic.com/Files/FLT-A...e%20height.pdf

wildcat767676 · 06-08-2011, 06:01 PM

I appreciate the help man but this isn't what I was trying to find. I've seen those links too. The rear of the 135i is a separate coil spring and shock. The shock body is adjustable in length. I am trying to find a guide to setting the shock length and no one seems to know the procedure. Thanks for trying!

wildcat767676 · 06-10-2011, 06:16 PM

Bump!

stevenc · 06-13-2011, 07:28 AM

Wildcat, if the rears are clunking, then the bottom of the shock tube may not be correctly seated in the cup. Same thing happened to me and i ended up uninstalling the rears and reinstalling and suddenly noticing how much better the shock seated the second time around, clunk gone.

Focusedintntions · 06-13-2011, 08:51 AM

Have you tried contacting JIC directly for instructions on doing so?

wildcat767676 · 06-13-2011, 10:56 AM

Quote:

Originally Posted by stevenc

Wildcat, if the rears are clunking, then the bottom of the shock tube may not be correctly seated in the cup. Same thing happened to me and i ended up uninstalling the rears and reinstalling and suddenly noticing how much better the shock seated the second time around, clunk gone.

Not sure if this is related but took it apart to check yesterday and noticed the threaded spring perch is not even mounted to the body! I can pull it away from the car with the screwdriver. No wonder spinning the adjuster also spins the threaded mount! Not sure if that's the clunk since they are under pressure when its on the ground but seems not right, don't you think?

When you say shock cup, do you mean top or bottom? The top bolts just spin when you try to check tightness. Lower bolts are tight for sure. If I shorten the length of the shock the clunk gets quieter.....???

tinnsoldaten · 05-21-2012, 05:12 PM

Working on my JIC Cross install and needed some help from JIC Cross, here is some of the info I got from them, more to come

From JIC Cross Tech:

On your application it is best to re-use the stock rear dust boot so that is okay that you used the oem unit, We use the OE bump stops at full length no reason to cut these because with proper adjustment you will have plenty of stroke in the rear.

The front upper strut bolt as well as the rear should be tightened with an impact wrench there is no way to tighten these sufficiently with hand tools because as you stated the shaft will start to spin before they are tight.

Rear ride height is adjusted by the spring no the damper, the damper adjustment is to set spring preload and stroke. By lengthening the damper you are only causing it to loose stroke in the back without also lengthing the spring. You do not need to remove the lower mounting bolt on the damper in order to adjust damper length in the rear just loosen the lock ring and turn the damper in or out of the lower mount. To raise the car you want to loosen the spring perch and lengthen the adjuster, then you want to set damper length so there is aprox ~10mm preload on the spring when the car is in the air this will ensure that the spring is captive and not ratting if the wheel lifts off the ground.

Please if you have any further questions feel free to email or call.
thank you

Tech
JIC-Magic USA Suspension / Ziel Motorsports Inc

syenisch · 05-21-2012, 08:55 PM

Definitely check that the shock is seated properly in the lower cup. When I installed my Performance Suspension I had this problem and experienced thumping noises over the slightest bumps. Very easy to check this.

int2str · 05-21-2012, 09:49 PM

Quote:

Originally Posted by wildcat767676

I appreciate the help man but this isn't what I was trying to find. I've seen those links too. The rear of the 135i is a separate coil spring and shock. The shock body is adjustable in length. I am trying to find a guide to setting the shock length and no one seems to know the procedure. Thanks for trying!

Just to clarify:
Shock length is not adjustable. The ride height is determined by the spring tension, length and the mounting position.

06-08-2011, 01:41 PM	#1
wildcat767676 Private First Class 17 Rep 199 Posts Drives: 2008 BMW 135i Coupe Join Date: Dec 2010 Location: Phoenix, AZ iTrader: (0)	Anyone ever use coilover in front, lowering spring in rear? I have JIC Cross coilovers and the rears are driving me crazy. They clunk, ride rough, and I can't find instructions to adjust them anywhere.......... I'm leaning towards removing them and putting the lowering springs/stock shocks back in in rear. I like the front coilovers a lot though. Anyone ever try this? Any major issues doing it? Suggestions? Thanks! __________________ 2008 135i AT, iDriveNAV, Remus quad exhaust, A.P. DP/MP/IC, Custom Oil Cooler, BMS JB4/Meth/DCI, JIC Cross Coilovers/Camber Plates/STB, BMWP rotors, EBC Track pads, Motul Fluid, CF Hood, BMWP Kidneys, black painted roof/mirrors, BMWP CF rear spoiler, Roof Spoiler. VMR V710 18" Wheels.
	Appreciate 0 Tweet Quote

06-08-2011, 01:42 PM	#2
Focusedintntions Colonel 107 Rep 2,696 Posts Drives: 2011 135i M-Sport :D Join Date: Nov 2010 Location: NoVA iTrader: (1)	Maybe look at getting a different set of coil overs?? never heard of JIC... __________________ Faster, faster, faster, until the thrill of speed overcomes the fear of death… – Hunter Thompson
	Appreciate 0 Quote

06-08-2011, 01:50 PM	#3
wildcat767676 Private First Class 17 Rep 199 Posts Drives: 2008 BMW 135i Coupe Join Date: Dec 2010 Location: Phoenix, AZ iTrader: (0)	JIC Cross was pretty big and a good brand. They are now called JIC Magic. www.jic-magic.com. Had read a lot of positive reviews on the site about them beforehand.... __________________ 2008 135i AT, iDriveNAV, Remus quad exhaust, A.P. DP/MP/IC, Custom Oil Cooler, BMS JB4/Meth/DCI, JIC Cross Coilovers/Camber Plates/STB, BMWP rotors, EBC Track pads, Motul Fluid, CF Hood, BMWP Kidneys, black painted roof/mirrors, BMWP CF rear spoiler, Roof Spoiler. VMR V710 18" Wheels.
	Appreciate 0 Quote

06-08-2011, 02:20 PM	#4
Focusedintntions Colonel 107 Rep 2,696 Posts Drives: 2011 135i M-Sport :D Join Date: Nov 2010 Location: NoVA iTrader: (1)	I've never trusted reviews on a vendors own site as it's very easy for them to fake them. As far as I know you're the only person on here that's running them and you don't seem to happy with them as you're thinking about taking them out of the rear b/c of noise issues. Just sayin.... __________________ Faster, faster, faster, until the thrill of speed overcomes the fear of death… – Hunter Thompson
	Appreciate 0 Quote

06-08-2011, 03:20 PM	#6
wildcat767676 Private First Class 17 Rep 199 Posts Drives: 2008 BMW 135i Coupe Join Date: Dec 2010 Location: Phoenix, AZ iTrader: (0)	What do you mean? Are you saying it's not set up right, thus the issues, or that aftermarket suspension is unbalanced? __________________ 2008 135i AT, iDriveNAV, Remus quad exhaust, A.P. DP/MP/IC, Custom Oil Cooler, BMS JB4/Meth/DCI, JIC Cross Coilovers/Camber Plates/STB, BMWP rotors, EBC Track pads, Motul Fluid, CF Hood, BMWP Kidneys, black painted roof/mirrors, BMWP CF rear spoiler, Roof Spoiler. VMR V710 18" Wheels.
	Appreciate 0 Quote

06-08-2011, 04:12 PM	#7
GaryS Colonel 37 Rep 2,084 Posts Drives: 2009 135i 6MT Join Date: Feb 2010 Location: Maryland iTrader: (0) Garage List 2009 135i [6.50]	^^ I meant that mixing front springs and dampers from one system with rear springs and dampers from another system is unlikely to end up balanced; and if it's not balanced, ride and handling will suck.
	Appreciate 0 Quote

06-08-2011, 04:43 PM	#8
wildcat767676 Private First Class 17 Rep 199 Posts Drives: 2008 BMW 135i Coupe Join Date: Dec 2010 Location: Phoenix, AZ iTrader: (0)	Oh gotcha! Ride in the rear pretty much sucks right now either way.....lol. Know how to set up the rear shock length by chance? __________________ 2008 135i AT, iDriveNAV, Remus quad exhaust, A.P. DP/MP/IC, Custom Oil Cooler, BMS JB4/Meth/DCI, JIC Cross Coilovers/Camber Plates/STB, BMWP rotors, EBC Track pads, Motul Fluid, CF Hood, BMWP Kidneys, black painted roof/mirrors, BMWP CF rear spoiler, Roof Spoiler. VMR V710 18" Wheels.
	Appreciate 0 Quote

06-08-2011, 06:01 PM	#10
wildcat767676 Private First Class 17 Rep 199 Posts Drives: 2008 BMW 135i Coupe Join Date: Dec 2010 Location: Phoenix, AZ iTrader: (0)	I appreciate the help man but this isn't what I was trying to find. I've seen those links too. The rear of the 135i is a separate coil spring and shock. The shock body is adjustable in length. I am trying to find a guide to setting the shock length and no one seems to know the procedure. Thanks for trying! __________________ 2008 135i AT, iDriveNAV, Remus quad exhaust, A.P. DP/MP/IC, Custom Oil Cooler, BMS JB4/Meth/DCI, JIC Cross Coilovers/Camber Plates/STB, BMWP rotors, EBC Track pads, Motul Fluid, CF Hood, BMWP Kidneys, black painted roof/mirrors, BMWP CF rear spoiler, Roof Spoiler. VMR V710 18" Wheels.
	Appreciate 0 Quote

06-10-2011, 06:16 PM	#11
wildcat767676 Private First Class 17 Rep 199 Posts Drives: 2008 BMW 135i Coupe Join Date: Dec 2010 Location: Phoenix, AZ iTrader: (0)	Bump! __________________ 2008 135i AT, iDriveNAV, Remus quad exhaust, A.P. DP/MP/IC, Custom Oil Cooler, BMS JB4/Meth/DCI, JIC Cross Coilovers/Camber Plates/STB, BMWP rotors, EBC Track pads, Motul Fluid, CF Hood, BMWP Kidneys, black painted roof/mirrors, BMWP CF rear spoiler, Roof Spoiler. VMR V710 18" Wheels.
	Appreciate 0 Quote

06-13-2011, 07:28 AM	#12
stevenc Coming Soon 256 Rep 960 Posts Drives: 2015 BMW M4 Alphine White MT Join Date: Apr 2008 Location: Houston, TX iTrader: (0)	Wildcat, if the rears are clunking, then the bottom of the shock tube may not be correctly seated in the cup. Same thing happened to me and i ended up uninstalling the rears and reinstalling and suddenly noticing how much better the shock seated the second time around, clunk gone.
	Appreciate 0 Quote

06-13-2011, 08:51 AM	#13
Focusedintntions Colonel 107 Rep 2,696 Posts Drives: 2011 135i M-Sport :D Join Date: Nov 2010 Location: NoVA iTrader: (1)	Have you tried contacting JIC directly for instructions on doing so? __________________ Faster, faster, faster, until the thrill of speed overcomes the fear of death… – Hunter Thompson
	Appreciate 0 Quote

05-21-2012, 05:12 PM	#15
tinnsoldaten Captain 34 Rep 715 Posts Drives: e92 335i coupe Join Date: Dec 2008 Location: Bergen iTrader: (1)	Working on my JIC Cross install and needed some help from JIC Cross, here is some of the info I got from them, more to come From JIC Cross Tech: On your application it is best to re-use the stock rear dust boot so that is okay that you used the oem unit, We use the OE bump stops at full length no reason to cut these because with proper adjustment you will have plenty of stroke in the rear. The front upper strut bolt as well as the rear should be tightened with an impact wrench there is no way to tighten these sufficiently with hand tools because as you stated the shaft will start to spin before they are tight. Rear ride height is adjusted by the spring no the damper, the damper adjustment is to set spring preload and stroke. By lengthening the damper you are only causing it to loose stroke in the back without also lengthing the spring. You do not need to remove the lower mounting bolt on the damper in order to adjust damper length in the rear just loosen the lock ring and turn the damper in or out of the lower mount. To raise the car you want to loosen the spring perch and lengthen the adjuster, then you want to set damper length so there is aprox ~10mm preload on the spring when the car is in the air this will ensure that the spring is captive and not ratting if the wheel lifts off the ground. Please if you have any further questions feel free to email or call. thank you Tech JIC-Magic USA Suspension / Ziel Motorsports Inc __________________ Vargas S2 turbos\|VAC S3 Cylinder head\|RR DPs\|RR MPs\|Supersprint X pipe\|Remus Quad Sport mufflers\|aFe Stage 2 Si with scoops\|Forge DVs\|ER CP\|BMS meth elbow\|Aquamist HFS-4\|Walbro 450 E85 LPFP\|AA FMIC\|BMS OCC\|MHD\|P3 Boost Gauge\|Ohlins Road & Track + camberplates\|M3 sways F/R+ Ground control endlinks\|Vorsteiner v303 19"\|Michelin PS2 sport\|Quaife LSD\|Vorsteiner V35 CF hood\|CF CLS trunk\|Duke Dynamics quad diffusor
	Appreciate 0 Quote

05-21-2012, 08:55 PM	#16
syenisch Captain 111 Rep 810 Posts Drives: 2015 435i Gran Coupe Join Date: Jun 2008 Location: Winter Garden, FL iTrader: (1)	Definitely check that the shock is seated properly in the lower cup. When I installed my Performance Suspension I had this problem and experienced thumping noises over the slightest bumps. Very easy to check this.
	Appreciate 0 Quote