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  • RE Suspension, as in Roehrig Engineering? Yeah, probably fine to send your stuff there. PSI out in Sonoma is for sure legit; so is Roehrig.

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    • Originally posted by Ant's m3 View Post

      So in short so far it is possible to send in B8 Front and rear dampers (i know non inverted rears but what are our choices) to RE Suspenion and get them revalved for these springs?

      Only if you have and older set of B8 rear dampers. You will need to confirm that they are serviceable (look for a lack of "crimp" marks on the body, as showin in the picture posted previously in this thread)

      I am not sure on the front, I believe those are still serviceable. I ended up buying the pre-valved 300/175 J-stock dampers from Turner.

      Comment


      • Originally posted by irdave View Post
        RE Suspension, as in Roehrig Engineering? Yeah, probably fine to send your stuff there. PSI out in Sonoma is for sure legit; so is Roehrig.
        Not exactly, but Roehrig engineering is mentioned on their "About us" blurb.

        https://www.resuspension.com/


        Per RE, another good option is the AK1198 shock, which is designed for 4cyl mini-stocks. Its about $160 with any valving desired, has a 10mm shaft, a 5/8 lower hole (close enough to 12mm), and is slightly shorter than the B8/Econolines. I think that is what I am going with, just debating what rates to go with now based on my car's weight and balance.

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        • Update on the Ground Control J Stock Replica project.

          RE suspension is awesome to work with. They rebuilt and re-valved my Billy Sport dampeners and turned them back to me in a few days, very good service. I ended up going with a 6 inch, 700lb spring up front and 1000, 5 inch in the rear. This has increased my ride height by almost an inch and my adjusters are pretty much maxed out. Now evaluating getting shorter springs.

          Can someone measure the J stock springs Front and Rear? Curios what length they are when they are not under load....

          Will be running my car at Summit Point this weekend, going to put some zip ties on the dampers and springs to see how much compression I'm getting and if coil bind is an issue with these high rates.

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          • See you at Summit!
            it is going to be a little warm...100deg...


            Instructor group #122
            Red 2002 with S14.
            Marshall
            75 M2
            88 M3

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            • I'll be there as well! Marshall I just heard you were going.
              Silver E30M3 (also with S14 LOL)
              Instructor Group #130
              jimmy p.
              87 E30 M3 Prodrive British Touring Car
              88 E30 M3 Zinnoberot - Street
              88 E30 M3 Lachsilber - Race (#98 SCCA SPU)
              92 E30 M Technic Cabrio - S14 POWERED!
              98 318Ti M44, Base - Morea Green
              04 Ford F350 - V10

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              • Originally posted by mlytle View Post
                See you at Summit!
                it is going to be a little warm...100deg...


                Instructor group #122
                Red 2002 with S14.
                Awesome, Iím running pit-out so Iíll have to make sure and get out so we can run a session or two together.

                Love your car, have seen you run before. Iím driving a Non M Orange E30.

                Comment


                • 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
                  1990 M3

                  Comment


                  • 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

                    Comment


                    • 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

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                      • kevnj
                        kevnj commented
                        Editing a comment
                        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.

                    • 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
                      '69 Datsun 2000 Roadster vintage race car (Street driven on a regular basis :taz
                      '59 Alfa Romeo 101 Sprint (HUGE project :uhoh
                      '88 M3

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                      • kevnj
                        kevnj commented
                        Editing a comment
                        I think your spot on, thank you for the feedback.

                    • 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.
                      1990 M3

                      Comment


                      • kevnj
                        kevnj commented
                        Editing a comment
                        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.

                    • 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.
                      1990 M3

                      Comment


                      • 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

                        Comment


                        • 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.

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