OntarioMark

I hope I have a suffiently evolved topic to warrant a new thread.

Since an earlier post regarding custom valved Bilsteins, I have followed up on some of the suggestions received. In speaking with one of the recommended shock gurus, I have learned I could put a great Moton system on my 89 911 that is to be used for vintage racing and PCA stock class racing. Unfortunately, that is beyond my budget. It has been suggested to me that another option at about half the price would be to run custom valved Bilsteins on the front and JRZ double adjustables on the back. More costly than 4 custom valved Bilsteins, but I am told a better set up. It appears to be a legal set up for PCA. Any comments on that set up vs. going with custom valved Bilsteins all around?

Mark

924RACR

JRZ ought to be able to recommend a starting point for the adjustment setting to be close to your desired Bilstein rear valving.

I must say, I'm surprised that the JRZ's would be cheaper! I guess the rear Bilsteins wouldn't be an off-the-shelf shock? Adjustability sure is nice, the only downside of the Bislteins. My teammate made a similar choice; on his car ('79 924 ITB) he chose DA Carrera/QA1 PromaStars instead of the Bilsteins I have - but running Bilsteins up front same as me. However they just went on the car, he's still getting used to them, newer driver, and no longevity data (I've heard that this is the weak point of the Carreras), so can't say how well they're working.

Larry Herman

That really doesn't make a whole lot of sense to me. I do not see the logic in having fixed front valving, and adjustable rear valving if it means that you will need to adjust the rears to match the fronts and then leave them set as is. Either run the Bilsteins and know that your shock valving will be right for some tracks, and wrong for others, or just buy the JRZ package and eat beans for a while.

OntarioMark

Vaughn, The JRZ are not cheaper than the Bilsteins, but are cheaper than the Motons.

Larry, I think one JRZ issue may be that they have adjustable spindles, and I could only use them if I weld them, and then I have really committed to them. When I looked into the Fox Shox adjustable system, I know that issue arose with their front shocks and was told that for that reason in PCA stock racing you have to weld the spindles to make them legal. And while I like beans, I can't eat enough of them to afford all JRZ or Moton. I see your concerns about the logic of the set up. I think I will raise that issue with the guru.

Mark

Peter Zimmermann

I always think back to my own personal experience with PCA when I built my '81 SC. I knew that I wouldn't be able to afford a crew, let alone an engineer, so I decided that I wanted to keep it as simple as possible. I selected the T-bars and S-bars that I wanted, bought monoballs for all points that they were available for, bought the best bushings I could find for the rest of the car, and installed Bilsteins valved to a set of specs that myself and the Bilstein people in San Diego came up with. When the sorting process began I concentrated on suspension settings (fortunately with plenty of experience I came darned close out of the box) that would deliver the pyrometer readings that I wanted. After that, adjustments were largely confined to tire pressure adjustments and small changes to the sway bars, which delivered the goods with noticeable, usable handling changes. It might not have been the optimum way to do it, but the car was extremely drivable in high speed corners, and I just adjusted to it in the slow stuff. I tried my best to keep it simple, and make every effort to keep from wearing myself out keeping track of all the adjustments that I might have been able to make. I'm organized to a fault, but without help I fear that I would have been like a dog chasing its tail if I had added adjustable shocks to the mix.