RED MX5

We've had too many discussions about grounding kits already, and everyone has already made up their mind, one way or the other. I don't want to re-open the subject, nor do I want to argue with those who have a view that is different than my own. Rather, I want to ask a question to those who share my view.

Do me a favor guys; If you believe grounding kits offer some benefit please ignore the rest of this post. I understand your position and don't care what you believe or think about my position, and hope the feeling is mutual. It's all good. To those who see it as snake oil, I have a question ...

I've been eyeing the suspension pieces from a particular ("JDM") company for some time now, and it seems they have the most complete solution around (roll-center relocation for lowered cars, etc). However, I am also aware that they sell a grounding kit, and that they make claims that defy the laws of physics as I understand them. Given that, would you guys trust the claims they make for their suspension components? How can I be sure that their suspension components aren't just as "magical" as their grounding kits?

Has anyone here made any major changes to the geometry (roll-center, etc.), other than the simple BSK? I really need some advice I can trust.

xviper

I don't believe in grounding kits, but suspension is not my area of expertise, so I'll bow out on this one.

Race Miata

Red-MX5,

Have you found my posts on this thread? You may or may not find my info useful.

vtec9

post the site up, and I will take a peek. I have no experience with suspension geometry on the S2k, but I do have a good deal with other cars.

generally speaking though, I wouldn't trust a company that makes outrageous claims.

RED MX5

Thanks guys.

Vtec9, I have a little experience with suspension geometry on other cars too (probably just enough to be dangerous ), but the problem here is that I don't have the S2000 specific information I really need to make a decent evaluation. After using the term snake-oil, I'm not sure I want to name the manufacturer, and I need the same info regardless of which manufacturer is involved. Read on though, because with your experience you can probably help me sort this out.

XViper, that's ok man, I'll pick your brain later when I'm ready for a clutch upgrade.

Race Miata, good thread, but I'm looking at more than just roll center. I have yet to determine how much suspension travel I actually need (I'm counting on the data logging helping me with that once it is working), but ultimately the car is going to be lower than stock (and stiffer). As you know, lowering the car changes a heck of a lot more than just the static alignment, and there are parts available that are claimed to correct for every aspect of the cars geometry. Thing is, I don't have enough info on the dynamics of the geometry to figure out which ones are worth the money. Obviously I can get the car up in the air, remove the springs, and make measurements throughout the range of travel, and make a good guess as to what is needed, but that's a heck of a lot of work to repeat if someone else has already done it (and if the companies that make the parts are legit, they have to have done the measurements). According to the company who makes the components I'm looking at the issues that come with lowering include:

1) Bump/roll-steer is out of whack at both ends.

2) The roll-center drops faster than the CG, so the roll couple is increased.

3) Spacers are needed at the diff (and I don't understand why).

I'm sure there are other issues (with lowering) but 1 and 2 above are a given, and if the company isn't selling snake-oil then I can only conclude that 3 might make a difference too (not in handling, but in reliability).

I guess in the end I'm going to have to plot the suspension movement/geometry myself, but I was really hoping that somebody had already done it. I'm not really being lazy; It's a lot of work to repeat if it's already been done. On the other hand, I guess if I'm the first, at least I'll end up with some interesting data to post.

Wisconsin S2k

as xviper said. grounding kits are a joke. suspension is not my forte.

RED MX5

[QUOTE=Wisconsin S2k,Apr 10 2006, 03:58 PM]as xviper said.

Race Miata

PM sent.

Race Miata

I want to comment about grounding kit. I'm not a big fan of it and I have never got one on any of my cars, but I won't call it snake oil just yet. From my personal experience, one time I forgot to bolt on the ground wire to my miata cylinder head and the effect was significant. I'm not talking about totally electrically isolated cylinder head. The cylinder head was still electrically conducted to the ground thru' all the cylinder head bolts. Yet, my O2 reading went haywire and I lost significant hp (like 30%) at high end. I kept scratching my head for long doing diagnostics and couldn't believe I just missed one of the many ground wires. Even though the spark plugs got their ground thru' the cylinder head bolts, the added noise due to missing one of many ground wire was good enough to confuse the O2 reading and the ECU (even though at WOT ECU doesn't look at O2 reading). While grounding kit may have no effect on an S with good electrical noise isolation, it doesn't necessarily mean grounding kit is snake oil.

Ubetit

A few thoughts:

Leaving a purposely designed engine block ground wire off or loose is an entirely different thing than adding 6 more grounding wires to your car.

You are confusing electrical "noise" and conductivity.

Cylinder head bolts don't guarantee a ground. They may be conductive but that doesn't mean the circuit is complete.