5thgen

Thanks. I should have documented all the wiring changes. Would've have made some things a lot easier over time.




Car is driving now, everything is loud, everything vibrates lol. I have basically went from all stock mounts to "hard" mounts all the way around (motor, trans, diff). Under zero load (no fan, ac, etc) the idle is decently quiet. It is definitely louder than the stock trans. When you add load the noise gets a lot worse...a lot more "clunky".

As far as NVH, we'll call a stock s2000 a "0"....and a "hard" mounted s2000 with open wastegate dump a "10". Being in a metal trashcan with 50 kids beating on it with sticks is probably also comparable to a "10"

Driving the car it feels like there are 3 different vibration ranges during acceleration.
1000-1500rpm has a trans vibration/noise (4)
2500rpm has the sidewinder/turbo/engine vibration/noise (5)
3500-4000rpm has another trans vibration/noise (5)

Deceleration can have a decent amount of noise too. Most of it noticeable from 4000-1500rpm. It make a cyclical whirring/vibration.
Decel in 2nd/4th/6th gear isn't really too bad. The NVH will have a range .... probably 4 to 3
1st gear decel I haven't experienced.
3rd gear NVH range is a little higher than 2/4/6 at about 6 to 4
5th gear decel is an easy 10. The noise is LOUD...the vibration feels like the front end is shaking apart. This is the worst NVH of the swap.

When cruising It makes the same noises as decel, but the harshness of it is a lot lower.
3rd and 5th gears are probably a 3-4. Certain spots will be louder, and others will be softer.
2nd and 4th are a touch better than 3rd and 5th at around a 2-3.
6th gear is by far the best gear for cruising. Probably a 1-2 for NVH. Unfortunately you can only use it at 45+ mph (with a 3.73). And it is kind of useless for casual acceleration until 65-70mph.



Although the NVH is pretty bad for a street car, it isn't too hard to avoid it while driving. All driving can really be done with gears 1-4. 5th gear has become my most avoided gear. And 6th gear is nice for highway driving. At 70mph in 6th gear, the engine sits just under 3000rpm (again, with a 3.73).



I am having a speed related vibration issue and have narrowed it down to the rear end or the driveshaft. It starts around 65mph and just gets worse the faster the car goes. Super disappointing considering they are new parts.

The driveshaft is included in Fullblown's kit. I believe they outsource it, but I'm not sure. I will take it to a local shop to see if they can find anything. I'm hoping the issue is with the driveshaft as it is easier/cheaper to address. I'd rather not have to tear the rear end apart again.

Always something.

Spoolin

I wonder if your diff angle/alignment with the trans could be off causing the vibrations? This was an issue with Stew from Tony Palo's shop when he had the Stock trans with PPG gears and his angle/alignment was off. Do a search, his thread wasn't too far back.

I think it may be in this thread. https://www.s2ki.com/forums/s2000-fo...ought-1187555/

5thgen

So the driveshaft angle (vertical) is about 2.75° relative to the rear end and the engine. I have adjusted it to .5° vertically with no change in the vibration. And the motor (measured on the crank pulley) and the rear end (measured on the face of the pinion flange) are parallel, within .1°.

Hoizontally I cannot change the angle, but it should be around 1.5°-2°.

I think its about as good as I can get it. I'll just be crossing fingers that its as simple as the driveshaft needing balanced.


Thanks for the link, a decent amount of good info in there. It kind of amazes me that the pinion angles aren't addressed more when designing a "diff kit".

Spoolin

Yeah, it sounds like you have the angles where they need to be. I think you had mentioned this in a previous post that I forgot about.

No problem on the link help and I agree, these designed kits should be getting those angles dialed in before release. Especially with the cost of them..

5thgen

Here is a crappy vid of the moving driveline parts. The axles look wobbly, but the cups and shafts don't move too much. I think its just the boots and clamps that make it look worse.

This was being held at about 60mph. I can't do anything under load obviously, but my vibration issue is just at speed, no matter the load on it.





Driveshaft should be back in the car tomorrow, we'll see if it is fixed.

Spoolin

You running a steel or aluminum driveshaft? Mine is the carbon fiber with the IP super 8.8 diff kit.

What mounts are you running and is the diff solid mounted? I'm wondering if you have dissimilar mount material durameters that could be exacerbating the issue, like hard at the engine, softer at the trans and hard again at the diff. For instance, I'm running the Vibra-technics engine mounts that are billet and use rubber, then the T56 trans mount is harder poly and the diff is solid mounted. Wondering if I will see vibration issues with this setup when I get things finished? I figured having the engine cushioned the most and then the trans cushioned a little less with harder mounts and lastly having the diff solid mounted would make things run pretty smoothly since things start out "softer" at the front of the car and then become solid at the back, kind of a slow transition.

5thgen

I'm using a steel 3" driveshaft. Its back on the car and 95% of the vibrations are gone. There is still a minor vibration from 65-70mph, but it is night and day from before. I have taken the car up to about 110mph and it is pretty smooth.

The expressions from the guy at the shop suggested it was pretty bad. He said it was built poorly. Needed a bit of straightening and obviously a rebalance afterward. Price for the work was really reasonable at $65.

My engine mounts are the same Vibra-technics. Trans mount is a rubber vibra-technics. And the rear diff mounts are 85a innovative mounts. I think the 85a diff mounts transmit some of the NVH I'm feeling. The difference of play from the oem mounts to a more solid mount is pretty drastic.



Now its on to retuning the car here and there.

Spoolin

Very Nice! Glad that worked out well for you. Is it a DSS driveshaft?

5thgen

Yeah I'm glad it was cheap to fix the problem.

I doubt its a DSS driveshaft. It shipped from a shop in Orlando, FL (DSS is in NC I think).

5thgen

Some pictures I forgot to load of altering the downpipe.

I had some shielding gas issues. It could have been the argon, or it might have been sucking in air with the argon somehow. Issue is fixed now, but the color definitely looks off. Inside was shielded and looked normal so I just went with it. The diameter changes right before the flex from 3" to 3.5".











This flex is from JMD. I had been having issues with vibrant's "shiny" flex tubes cracking on me. This flex felt a lot more sturdier. The flex wall is probably much thicker.










For me it is always easier to weld slip joints as late as I can. It makes it a little more forgiving when trying to fit tubing in between two existing parts that aren't straight.



















The last piece needed to join new downpipe to existing exhaust. Not the most perfect way to do it, but probably one of the easier ways to do it for me and not really compromise flow.









Normal gas coverage vs the horrible coverage







Also made aluminum shields to cover the downpipe. I got it done on the first section of downpipe....and then about half of it done on the third section of downpipe (just passed the flex). This was one of the most time consuming things to do on this setup. I also should have had the downpipe and shields coated at this point. Maybe during the winter I will try and address that.










Standoffs to bolt the shields on.








The pieces were cut long, welded, and then trimmed to a nice contour (not in the pics). I still need to finish the shield on the other side.






Also just got the car back to using ethanol (about 75% at the pump). The difference in feeling always amazes me. Makes it feel like winter air during the summer.