Coilover Recommendations

[PDC]

This is great info and gives my a good idea of what range of spring rates to look at. This spring, I will get under the car and see what my current set up is. She actually does feel pretty good right now, but that sure doesn’t mean improvement isn’t within reach.

[PDC]

May need a recommendation after all - more info: Took the car out yesterday and noticed a small puddle of thick oil in the area of the rear passenger tire. Sure enough, the rear passenger shock is all wet and dripping.

Figured out these are JRI 'Base' (non-adjustable) shocks with the Detroit Speed logo. #041301 Rear @ $329 a piece. The fronts are the same 'Base' shocks part #030313 DS Detroit Speed sells the rear shocks individually, but only sells the front shocks as a complete coil over kit @ $1003.95 for the pair. As I surfed around, that seems to be not an unreasonable price range for a pair of front coil overs with the springs - and it looks like most manufacturers sell the fronts that way.

I 'could' grab one rear shock for $329, replace the one that is leaking and forget it. But I am wondering if driving this car around with no nitrogen charge in the shocks for as long as I did contributed to the failure of the passenger side rear shock - maybe replace both and have a fresh set of new shocks in the rear?

As far as my previous post indicating that I was told that the shocks I have are not intended for street use, I learned today that advice was not based on the fact that they are nitrogen filled - but because they are comparatively stiff and designed for flat cornering on smooth roadways. Lots of quick jarring on bumps / irregularities in regular street driving will have a tendency to wear them out faster. Maybe that's what I am seeing now with the passenger rear shock leaking oil?

Going back to the discovery that the nitrogen chamber was empty on all 4 corners and had to be re-charged - I have to wonder if that also contributed to the current failure of the rear shock. This build has just under 2,000 street miles since completion - but only a few hundred since diagnosing and re-filling the shocks.

I am pretty much sold on replacing both rears - maybe leave the fronts alone since they are not leaking and appear to be holding the recent Nitrogen charge just fine.

At the same time, if there is an alternate brand of shock that I am overlooking that may be better suited to street driving as opposed to competitive driving, I'm all ears. I'm not pinching pennies and I don't mind spending money once for the right part - I just like to avoid spending money twice when I can.

Thank you all very much.

[FORDvsCHEVY]

kinda a fun engineery thread....
but it is still an everyone's is best thread, I have JRI so its best, I have ridetech so its best, I have QA1 so its best....

I have air ride it’s definitely the best!

[cpd004]

Curious about this.

If the front of the car seems to ride over a bump (peaked line for example) instead of absorbing it as much as the driver would think it should would likely be the lack of enough compression (in this example ridetech single adjustable coil over preset compression) alone or is a combination of the compression ratio/speed and the spring rate?

[dontlifttoshift]

It is the springs job to allow the suspension to move and absorb the bump. It is the shocks job to control the speed at which the spring and suspension move. To divide it up even further, compression controls the movement of the unsprung weight and rebound controls the movement of the sprung weight.

This whole thread is really about NVH, though, and there is so much more to it. Britt touched on it earlier, with no compliance in the front suspension bushings, the initial impact of the tire hitting the bump is transferred directly into the chassis before the shock or spring has even started to move. That is a thing you will never be able to get away from with most pro-touring suspensions. If you ever get a chance to compare Roadster Shops FastTrack chassis to their RideLine chassis pay close attention to the bushings that they use in all the control arms. The RideLine isn't delrin.

I still think ridetech are the best shocks for money. Period. I have made them work very well in several applications but there is something in their valving that is different than even off the shelf JRi shocks, let alone the custom built ones from Ultimate Performance* JRis don't hammer over expansion joints or cracks in the road to the extent that the ridetech's do. This especially shows up at lower vehicle speeds, less than 50 mph. The difference between the two shocks is more noticeable the slower you go. Even triple adjustable ridetech shocks with the high and low speed adjusters on the canister have this issue.

It doesn't really show up on the dyno sheets either, I have made that comparison and the numbers and curves are similar enough to me.......but there are soooo many ways to make force numbers look the same on the dyno and act completely different in use.

To answer CPD's question, I don't think it is a function of too little compression valving or spring rate for that matter. It is a lack of compliance in the suspension bushings coupled with the way RideTech makes their compression numbers.....which is fine for probably 95% of the aftermarket.


*The last couple times I talked to JJ @ https://upspeedshop.com/ He reminded me that he will also revalve shocks other than JRi. I have never used him for that so I can't say if this will solve CPD's issue or not but I think it is certainly worth a call.