swat518

iTrader: (5)

I will buy a set of OEM shocks and test it again in late June autox event, if the noise goes away, then it's definitely shocks. Will do the research in June and try to get car ready for July events.

I don't participate in any racing, and not intend to do so in the future. Very enjoy in DE4 or adv. group in HPDE or random non-competition TT. I focused much more on my driving skill rather the car setup, kinda adapt to the car rather asking the car fit for my needs. After tuning V3 to a decent setup, compared to my old cheap non-adjustable shock & lower springs, not really get much quicker. Currently, the max I can afford is kw clubsports or some brand less than 3k.

I'd like to ask for the advice/suggestion from the people have more knowledge and experience, it can lead me to more effective research, especially for this type of question that it's very personal opinion based.

rustyschopshop

May concider going with koni shock/struts with sprint springs. You will lose some adjustability but from what i have been seeing on here for years much more realiable and precise. Plus the cost will be half of what you are concidering running now.

swat518

iTrader: (5)

Same taste here, I will most likely go with Koni yellow. The difficulty is to select the springs, after spending hours to do research, just realized I can continue using kw v3 springs (not sure if front will fit). I double anyone had this combination. Checked the spring database, V3 progressive spring rates Front 485lbs to 525Lbs Rear: 240Lbs to 548Lbs

rustyschopshop

Sprint actually makes OE style lowering springs, lower approximately the same as eibach prolines. So definitely not about stance, Concidering removing my sportlines for the sprints myself.

rustyschopshop

sprint lowering springs, OE style

swat518

iTrader: (5)

that's the one I plan to go next if kw springs don't fit.

swat518

iTrader: (5)

just to give an update. Finally have shock and spring installed tonight. but the issue still exists.

The driver side rear shock is worn, rebound is gone. I installed the koni shocks but kept kw spring, the 'bang' sound still exist and no change at all. I suspected it's the 3 tabs that hold the upper spring mount was bent, which cause the mount unstable. I adjusted the tabs, make sure the rubber upper mount seats tight, installed swift springs. The noise still exist but isn't as loud as using kw spring. It feels like the noise comes from the unstable springs, but no idea what is the next I should try...

rustyschopshop

if you have the stock springs or know someone that has a set to barrow, might not hurt swapping them in to see if it cures the issue or not.

rustyschopshop

looking at that rubber isolator at the top of the KW you could try to make a replacement out of a rubber mud flap. Yours looks pretty worn and could be making the noise when the spring shifts while binding.

swat518

iTrader: (5)

The rear shocks & springs are new, put OEM rubber spring top mount back, 3 metals tabs holding the rubber mount are all adjusted and rechecked after testing the car. I have to correct myself, the noise after replacing the rubber mount doesn't change.

What I noticed today, when I drove over a 2-inch tall curb at my driveway entrance, the bang noise came up, but only happened if entry from the left side, no noise if entry from the right side. And noise occur after rears wheel ran over the curb. But my wife stood outside of the car and insisted the noise came from the front. I asked her to sit inside the car, did slalom and drove over the curb, she thought the noise is from the passenger front. I wanted to replace the front shocks and spring but Koni required OEM shock boot, need to order it. But from every evidence, I still think the noise should come from the rear.

This is so annoying.. My plan for the next week is to replace all front shocks and springs, if the noise still exists, I will ask my friend come over on the weekend to drive my car, I will try to hear where is it come from.

rustyschopshop

I would look at the front for giggles, if the mrs thinks she heard something there might not hurt to look. Doesn't take long for sure.

swat518

iTrader: (5)

New front shocks and springs installed, sway bar disconnected, checked lower control arm bushing. Noise still there

Will ask a friend to come this weekend, need to hear where the noise come from...

260DET

Haven't read all this again but I'd carefully check the rear axles making sure the stubs are not popping out of the diff and then going back in. At this stage it sounds like a drive train thing. Checking the car up on stands is one thing but with the car high on a hoist it's much more likely to be able to spot a problem.

swat518

iTrader: (5)

I removed and reinstalled the diff, replaced driver side axle, checked the passenger side outside nut. Noise remains before and after, so couldn't be the connections. The car is not road illegal, so has to be towed to the shop and have a high possibility that cannot find anything. Next try is to have my friend drive the car, I need to hear where the noise comes from.

swat518

iTrader: (5)

FINALLY!! found the issue, it's the engine mount. The driver side mount is completely worn..

rustyschopshop

so your wife was right
glad you finally found it and now it can be resolved

swat518

iTrader: (5)

I don't believe the noise came from the front end until I heard it outside of the car. Thanks everyone's help, will order the part tonight, plan to fix it in 2 weeks.