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J STOCK springs are BACK!!!!!!!!!

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  • mwagner10702
    replied
    Now that I see you have a non-M3 E30 the fender-to-wheel measurements I provided are probably not valid as I have an M3 which as you know has different fenders and cutout profiles. You mentioned "Using full length front strut assemblies with the billy sport inserts" confuses me (easily done) as I know the GC coil over conversion sections the front struts.

    Here is a link to a video showing this done. My apologies if you have seen this. Not sure what Bilstien cartridge the guy is using, however I noticed he is using 6" springs.

    https://www.youtube.com/watch?v=8Q7xUSNRyLI

    Whatever Bilstein cartridge he is using it is shorter than a standard E30 cartridge as he uses a spacer to bring the top of the cartridge in line with the top of the strut housing. This is the same procedure GC uses with the Koni inserts.

    Not sure any of this is helpful to you or not.

    Leave a comment:


  • kevnj
    replied
    Hereís pics of the front passenger corner.

    The strut has maybe a little over 2 inches of travel but when you factor in the internal bump stop itís less then that.

    Thereís close to a 2 inch gap to the fender from the top of the tire. Iíll need to recheck my measurements from the pinch weld. I should be able to go much lower without having the control arms go beyond parallel.

    When I was using the 440ís up front vs the current 700ís the car was over an inch lower. The increase spring rates and dampeners raised the car up over an inch. Makes sense but surprised it made that much of a difference. Car weighs 2412 with me, my gear and a full tank of gas.

    Leave a comment:


  • kevnj
    replied
    Hereís the best pic of have of the struts assemblies with inserts. The camber/caster plates attach to the piston without any type of external bump stop.

    Leave a comment:


  • mwagner10702
    replied
    Originally posted by kevnj View Post
    Iíve read from internet experts that GC konis cant handle 1000 lb springs and max out around 700.
    GC told me they valve their Konis for a range between 400lb to 900lb.

    Originally posted by kevnj View Post
    Do you think the konis are a better choice then fooling around with the Billys?
    Not sure. From what I gather reading this and other forums, some people prefer the Bilsteins and others prefer the Konis. I believe GC uses strut inserts from the VW Corrado (G60) in their shortened M3 struts. They also use a small length of tubing at the bottom of the strut as a spacer. This piece of tubing is cut to fit in order to properly align the top of the strut with the top of the shock body. But if you have full length struts then it is doubtful you can use a shorter strut.

    Does Spec E30 have ride height minimums? I know PRO3 does (car can't be lower than 5" from pinch weld to ground). Maybe GC configured their Spec E30 setup to not be able to be adjusted lower than the minimum ride height for the class.

    Does your setup look like this? (This is from an e36 but its the same on the E30)

    Click image for larger version  Name:	Suspension.JPG Views:	0 Size:	26.5 KB ID:	1281195

    Leave a comment:


  • kevnj
    commented on 's reply
    I think your spot on, thank you for the feedback.

  • kevnj
    replied
    Originally posted by mwagner10702 View Post
    I think the length of the J-Stock springs is irrelevant since the J-Stock spring sits in the OEM strut perch. Like you I have a Ground Control coil over setup and my spring lengths are:

    Front = 6.5"
    Rear = 5.0"

    So it would seems like your spring lengths are probably OK. Regarding ride height, I took some measurements of the front and the back of my car.

    Front:
    Top of wheel arch to center point of wheel = 12.5"
    Pinch weld (just behind jack point) to ground = 5.5"

    Rear:
    Top of wheel arch to center point of wheel = 12.0"
    Pinch weld (just behind jack point) to ground = 6.5"

    Looking at my front strut I definitely have enough threads to lower the car an additional .5". Looking at my rear ride height adjusters probably the same (around an additional .5") so I am curious how you can be maxed out on your adjusters. Are you running any helper springs? (That would increase stack height).

    I assume you are running Ground Control front camber plates. I ask because I've read where some brands add to the overall height.

    While not a direct comparison, I have the SA Konis (rebound only) and at a recent track day had some rear end bounce coming out of turn 2 and turn 7 at PIR. In both cases you are hard on the throttle just past the apex of the corner where it is a little rough. I adjusted the Konis to full still and backed off a 1/4 turn. The next time out the rear end was solid with no little to no bouncing. Based on my experience I would say the suggestion regarding your rebound settings being too light are probably spot on.
    Thanks for sharing all this. Iíd like to get the car about 1/2 an inch lower for it to be ideal. I am using a Ground Control Coilover kit that was the predecessor to the now Spec E30 set up. Using Ground Control Camber/Caster plates. Not using tender nor helper springs.

    Using full length front strut assemblies with the billy sport inserts. I have not measured but Iíd be surprised if I have more then 1-2 inches before Iím into the bump stops that weíre trimmed. On the passenger side Iím maxed out on the adjuster to full low. The real solution is going to be to shorten the assemblies and find Bilsteins that are shorter or go with Konis. I love how durable Bilsteins are and the low cost too. MCS is the ticket for sure but the price of entry is over my head.

    Iíve read from internet experts that GC konis cant handle 1000 lb springs and max out around 700. I have been meaning to talk to Jay but have been swamped at work. Do you think the konis are a better choice then fooling around with the Billys?

    I agree with you regarding the rebound. RE does allot of circle track setups and also asked about how much aero I had. Looking at the calculations that were done there was a mistake made for sure. Thereís definitely some improvements to be made but even in the current state the car is an absolute hoot and is perfectly neutral.

    Leave a comment:


  • kevnj
    replied
    More food for thought, while there are some more adjustments that could be made the non-M e30 with a stock M50 was able to keep up and pass much faster machinery at Summit Point In instructor and advanced groups

    I pointed by a factory built M2 turn key race car and a well driven 400 hp GT3, thatís it. So again, Iíd like to make some adjustments but itís fair to say the suspension changes made werenít a complete waste of money.

    Sorry if my posts have annoyed anyone, just an enthusiast trying to learn and share my experiences with the community.
    Attached Files

    Leave a comment:


  • mwagner10702
    replied
    I think the length of the J-Stock springs is irrelevant since the J-Stock spring sits in the OEM strut perch. Like you I have a Ground Control coil over setup and my spring lengths are:

    Front = 6.5"
    Rear = 5.0"

    So it would seems like your spring lengths are probably OK. Regarding ride height, I took some measurements of the front and the back of my car.

    Front:
    Top of wheel arch to center point of wheel = 12.5"
    Pinch weld (just behind jack point) to ground = 5.5"

    Rear:
    Top of wheel arch to center point of wheel = 12.0"
    Pinch weld (just behind jack point) to ground = 6.5"

    Looking at my front strut I definitely have enough threads to lower the car an additional .5". Looking at my rear ride height adjusters probably the same (around an additional .5") so I am curious how you can be maxed out on your adjusters. Are you running any helper springs? (That would increase stack height).

    I assume you are running Ground Control front camber plates. I ask because I've read where some brands add to the overall height.

    While not a direct comparison, I have the SA Konis (rebound only) and at a recent track day had some rear end bounce coming out of turn 2 and turn 7 at PIR. In both cases you are hard on the throttle just past the apex of the corner where it is a little rough. I adjusted the Konis to full still and backed off a 1/4 turn. The next time out the rear end was solid with no little to no bouncing. Based on my experience I would say the suggestion regarding your rebound settings being too light are probably spot on.

    Leave a comment:


  • kevnj
    commented on 's reply
    Wasn’t looking to reinvent the wheel. Had Coilovers already. There is no turning back to stock spring perches when they are cut off.

    Does anyone have the dyno graphs for the front dampeners? Want to share them with RE to get the valving corrected.

  • mwagner10702
    replied
    Perfect example of why you don't re-invent the wheel when all the real parts are readily available. Springs are the incorrect length, dampers incorrectly valved. Complete waste of money IMO.

    Leave a comment:


  • RAD2LTR
    replied
    I'm guessing your compression damping is too stiff, and the rebound is a little on the light side. If you back the compression damping off, that will allow the springs to do more work without the dampers trying to keep them from compressing. On the other end, if you don't have enough damping on the rebound, the back end is going to bounce.

    Will

    Leave a comment:


  • kevnj
    commented on 's reply
    Thanks for the feedback Redneckvtek. The technician did a conversion to inch pounds from the rates Will shared. Wonder if there was a disconnect in the conversion.

    Looking at my rear shocks at rest installed there isn’t allot of travel available and I’d like to lower it another 1/2 inch ideally with some room to spare for corner balance if. I’ll snap some pics and share later.

  • redneckvtek
    replied
    Looks like your dampers are too stiff. Definitely in compression. I canít really see which ones are front and which are rear on my phone, but the compression numbers seem very high specifically. The ones not starting at zero are odd too - thatís preload I guess?

    Bilsteins numbers are at 20.5 in/sec, but your chart only goes to 10 in/s and your damping is much higher than the numbers that were posted before.

    1250 Newtonís is 281 pounds, which is where the force should be at 20 in/s. Yours are past that at 10 in/s.
    Attached Files

    Leave a comment:


  • kevnj
    replied
    Thanks mwagner10702. Had a great weekend at Summit. Overall the car felt great. Immediate turn in, with a very neutral car.

    Only issue I am having now is on sweeping turns greater then 90' degrees, the rear of the car is bouncing when approaching the traction limits on bumpy tarmac running Hankook 214s. When I backed off a smidge it was fine. I'm running full length Bilstein sports so thinking the dampener maybe too compressed and it's not working in the sweet spot. We also thought possibly the trailing arm was moving so much that the spring was not under constant tension but looking at pictures of the car through the corner it looks like the tire was pretty loaded and there was minimal lean Also want to get the car lower.......Ride height is about 5.5-5.75 inches from the front pinch weld. Looking to get closer to 5.

    Here's the shock dyno for the re-valved dampeners if anyone can comment or knows how to read this.
    Click image for larger version  Name:	Dyno_Plot.JPG Views:	0 Size:	68.0 KB ID:	1281099

    Leave a comment:


  • mwagner10702
    replied
    Originally posted by kevnj View Post
    Can someone measure the J stock springs Front and Rear? Curios what length they are when they are not under load....
    Front is 8"
    Rear is 7"

    FRONT:

    Click image for larger version  Name:	Front.jpg Views:	0 Size:	197.0 KB ID:	1281030

    REAR:

    Click image for larger version  Name:	Rear1.jpg Views:	0 Size:	196.3 KB ID:	1281031

    Click image for larger version  Name:	Rear2.jpg Views:	0 Size:	172.4 KB ID:	1281032

    Leave a comment:

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