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Dan Baldwin

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Dan Baldwin last won the day on June 17 2005

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  1. Perusing the 'stang forums, found multi SoloII champion who has used the T2R in the past, but then they started failing on him. Now he's apparently back to clutch-type (Auburn or Eaton). Wavetrac doesn't make sense to me. Seems like a mild locker/torsen combination. For there to be any differential action, the 4x convex/concave interacting faces have to be worked apart, presumably against a spring preload. But after 1/8 of a turn, the convex feature is being indexed against the next concave feature, with the preload *adding* to slip. Seems like it would act like T2/TrueTrac with a
  2. Thnks, Jon! Doh... Really want to avoid ridiculous preload. LOVED the clutch R200 in the Z. No probs holding 250hp on Hoosiers, picking up the inside front exiting corners, with next to no breakaway torque (bought with ~23 lb-ft, 18 lb-ft last time I'd checked it). Supposedly the TrueTrac is between T2 and T2R in terms of torque bias. Seeing a range of 2.5-3.5 for it. Good enough, maybe? Is the Yukon a direct enough copy of the Eaton Posi to also have at least a smidge of additional lockup under load? Still on the fence... What about Auburn cone-type?
  3. Long time no post! Z is gone, but I need a new LSD for the current ride: ~530hp LS2 FD RX-7 The T2R that was been in it is worn out Apparently it's not unheard of. Looking at options for a new limited slip carrier, got it down to: Eaton Posi (clutch-type) Yukon Duragrip (supposedly an Eaton posi clone for less $$$) Eaton Detroit TrueTrac (helical gear type similar to T2). Definitely like the rebuildability aspect of the clutch-type units after a helical wore out on me. But apparently these clutch types don't employ ramps like the old R200 clutch LSDs which increase
  4. FTR, I was running 35degrees (i.e., full) advance back when I was running the stock N42 head (with ~.010" shave) with stock cam, stock SU carbs, stock everything, at 10.25:1 CR, on pump gas, no problemo. Stock N42 with flat-tops should be 9.8:1. I dunno, maybe a 3.1 with N42 and KA24E pistons is somehow less detonation-prone than the same head with L28 flat-tops... PA, actually, SP rules don't allow a different number of cylinders! Kinda arbitrary if you ask me... I went 0.8 seconds SLOWER in the monster RX-7 in October than my best time there in the Z Power steering
  5. If you run it hard while it's detonating away, bad things... But you wouldn't do that I hope. If you get detonation/pinging, back the ignition timing off and you should be OK. If there's any chance at all you'll be tweaking this motor (cam, triples, headwork, etc.), I'd go with the flat-tops. If you just want a no-worries stock build, with less potential for building n/a power, go with the dished. That would probably let you run 87 octane, too.
  6. Dropped in to see what's shaking and plopped myself right into the same P vs. N "discussion" that's been ongoing for eons now! I drove the Z down to Atlanta last week, to be shipped from there to its new owner, fellow HybridZ-er Bob_H. So, end of an era for me, but it's going to a very good home. The Z was partial trade for his (now my) '94 RX7 with 500+ LS2 V8 horsepowers. Wheee!
  7. I wouldn't bother with dished pistons... FWIW, I ran my 3.1 with a stock N42 at 10.25:1 CR for years with a stock cam, at 35deg advance. Currently at ~11.5:1 with the N42, with a 310deg/.550" cam and some headwork (minor bowl reshaping), running pump gas with no problems. Last dyno runs it made the same power from 34deg to 38deg total advance. That said, I am aware of at least one stock N42/flat-top build where ignition timing had to be backed down to 26deg, so ymmv... Me? I'd go with the N42/flat-tops, particularly if future mods are planned (cam, porting, etc).
  8. There isn't any gyroscopic precession because the braking torque is on the same axis that the wheel is spinning on. No, you won't. For one thing, "momentum" is mass multiplied by velocity. When you hit the brakes, "momentum" will decrease as speed decreases. It won't INcrease. It may seem like where you locate the caliper will affect how the wheel is loaded/unloaded, but in reality it doesn't matter where the caliper is clocked, the load on the tire will be the same for a given level of deceleration. If you locate the caliper such that when you hit the brakes, the caliper is pu
  9. The unsprung part of the car is indeed *part of the car*! Having them clocked at 6:00 does lower the c.g. Optimal placement would be a bit off the 6:00 position (aft of 6:00 for the fronts, forward of 6:00 for the rears) in the interests of minimizing polar moment. For my perfectly optimized car, I have the front left caliper at 4:30, front right at 7:30, left rear at 6:45, right rear at 5:15.
  10. The key word being "look". Many have been able to run decent compression ratios with the N-heads, and it's easier to get higher c.r.'s with the N-heads (less shaving, no need to shim cam towers). Again, here's my N42-head 3.1's history: 3.1 liter, stock N42 head (shaved ~.010 from previous rebuild), stock N42 cam, unshaved KA24E pistons, 2mm gasket, 240Z carbs. 10.25:1 CR, timing had to be knocked down to 10* initial/35* total advance to eliminate ping (I had stupidly and wrongly been running +15* initial/+43* total) 290*/.490" Schneider cam, 2" Jag carbs 10.25:1 CR, timing
  11. It's not the kind of thing that's going to be "resolved" via discussion on this forum. JMort's link gives some insight: http://forums.hybrid...846#entry914846 Here's another link I came across last night (which references the author of the above link): http://cgsuspension.com/ackerman.htm From which: My takeaways: 1) What you set toe for and whether you want pro- or anti-ackerman is going to be driven by how the tires you're on respond at the load levels they're subjected to (rough estimate, a decently set-up 240Z should be loading the outside tires to on the o
  12. I glanced over it. I understand the concept of more ackerman generally helping with turn in on lower-speed corners. I can appreciate that for a given amount of turn-in respones, more ackerman would reduce the amount of static toe-out. At road courses, for higher-speed corners, whether ackerman helps or not will depend on how the tire lateral grip vs. slip angle curve and how it varies with load. If at lower loads the tire develops maximum grip at a lower slip angle, I want anti-ackerman. If at lower loads the tire develops maximum grip at a higher slip angle, I want pro-ackerman (gene
  13. The problem is that you don't have a basis to say what direction is the "right" direction. You *FELT* the change it made? For one thing, it is possible to *feel* a change that doesn't exist (placebo effect). For another, what *feels* better isn't always faster. I would think you might want to maximize lateral grip for smaller-diameter lower-speed corners as well! You are *assuming* that it has a significant negative effect. The engineers who are responsible for the Corvette's steering geometry might beg to differ... OK, I just did the geometry, and for a 30ft ra
  14. Look at Figure 1 in your link which shows lateral force vs. slip angle for different normal force or load on a tire. This would argue for anti-ackerman. Now look at the plot of lateral force vs. slip angle for different tire loads you posted previously in this thread. That one argues for pro-ackerman. Who ya gonna trust?! I think you're knocking yourself out for very very little, EVEN IF you did testing to figure out what the grip vs. slip angle vs. load relationships are for the exact tire you're going to be using under the exact conditions and range of loads you'll be usi
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