JMortensen

This looks like a thread jack. What does Tein have to do with this particular issue? For the record I've never seen Tein springs advertised or talked about...

Yes, good to have you back!

I think you guys are confusing drag and downforce, and also the effects of hood vents vs belly pans. Hood vents can vent under hood pressure, and under hood pressure can cause a large amount of lift. So comparing similar cars, one car with hood vents and a belly pan to a car with hood vents to a car with a belly pan to a car with neither would be a better way to clarify what is causing what. If you look at wind tunnel testing like the Lotus test done in Racecar Engineering last year, you'll see that a car with a flat bottom and a diffuser didn't start to really work to produce downforce until the outer diffuser fences went down to about 2" off the ground. The flat bottom car is not the best design for downforce either. It's what most forms of motorsport were left with after ground effects cars were banned. In order to make it work to produce any significant amount of downforce the car is going to have to be LOW.

That has happened a bunch of times to my BIL Matman. I've been telling him to just put stuff on ebay and advertise it here, that way at least it gets sold and most likely paid for.

Eh, if you figure the outer layer is exposed to the air during a cool down lap, I think the probe really is the way to go. This coming from a guy who has used an IR up to this point...

110' huh? Why bother???

Changed title.

Good point. Similarly it's probably worth mentioning that splitters can be a bit touchy when it comes to pitch sensitivity. If you're using soft front springs and the nose dives under braking that can suddenly get the splitter closer to the ground and increase downforce in the front.

In the US.

Shoot it first. I thought it was looking pretty promising until I shot one. Compared to the others that I shot, I just didn't like the way it felt. I think the one I shot was brand new, never fired which may have had something to do with it, but it wasn't very accurate, at least with me behind the trigger.

I did some reading on sigforum.com and found a couple posts dealing with this issue. Apparently most people find that the .40 spring works fine, but there is a different 9mm spring and so I went ahead and ordered it. $20 after shipping isn't too bad...

Just the man I want to talk to! I tried the Sig out yesterday, and I had no problems at all with the .40 barrel's accuracy and no issues with feeding, etc. When I swapped in the conversion barrel I'd guess that about 40% of my shells stovepiped. It was very annoying. Also, the slide never locked back at the end of a magazine. It was like there just wasn't enough recoil to operate the slide. I'm wondering now if this is a fitment issue with the Bar-Sto barrel. From what I've read the recoil springs for the .40, .357 Sig, and 9mm are all the same, so that shouldn't be the cause. I just can't figure anything else out. For what it's worth, I did find the Bar-Sto barrel to be at least as accurate as the Sig barrel with the ammo I was using.

If you're talking about the big hunk of metal that some Z's have bolted to the front of the diff, I suggest you scrap it.

Go look under a Viper and I'll bet you that the underbody is recessed or the trans tunnel is large enough to accomodate a flat floor. Go look under a Z and you'll see that it is not. It's a great idea, I just don't think there is room in a Z.

How would a diff appear "not OE"? Pull the cover, the ring gear will be stamped with the tooth count for ring and pinion. 4.11 might say 37:9 for example. As far as the LSD goes, take a picture and we can identify it. It is very common for Z's to spin both wheels and guys who are used to solid axle cars tend to assume that this means that their diff has an LSD, when that is not the case.

Also check the big bolts in the control arm at the inner pivot. The 24mm ones.

Verrrrrrrrrrrrrrrrrrrrrrrrrrrry nice.

Not really. It was in CP, which became GT2, which is a much faster class than EP. But those cars were allowed more modifications, so they had more hp and chassis modification options than the EP cars. An old, properly sorted GT2 car "should" spank an EP car. ITS is a slower class than EP, and when Z's race in ITS they are allowed significantly less modifications, but they're racing with against BMW 3 series that simply have better suspension designs and stronger motors. I suppose ultimately the Z has been relegated to slower and slower classes in that it doesn't compete in GT2 anymore, but what it does compete well in is based on how much modification can be done. Or to say another way, the Z can be slow in a slow class or faster in a fast class, it all depends on what modifications are allowed. The rules determine whether or not it is competitive, not the age of the car.

Slow day for work, so here are some pics: