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jamal posted:Well, they are definitely not the same pad, even though they will both work at about the same temps. The -30 is likely going to have a higher and more consistant coefficient of friction, and will make more noise, dust, and wear faster. And it will probably handle high temps better but work worse while cold since it is actually designed to be a race pad. From a lot of third hand reports, it sounds like the compound is the same, they just added chamfering and the shims to the Street Race pads. Apparently. Pad opinions are like assholes though, so who the hell knows.
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May 27, 2016 18:32
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Assuming a lot of things, yeah, the friction vs temperature charts Hawk and Wilwood (and nobody else I've found) help. *quickedit* And according to those charts, DTC30 and Street/Race are the same, apparently, maybe. The issue comes when you start asking questions like "OK, but how would PF01 or Raybestos ST43 compare?" or are looking at modulation or release of pads... or whether any published data is remotely, you know, accurate.
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May 27, 2016 18:48
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Cheap and easy to install? Normally open switches for pressure and temperature set to go closed at some reasonably "OH poo poo!" value, wired in parallel, to a big red light on the dashboard. Light goes on, shut down car. I really do like the Longacre AccuTech SMi gauges though.
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Jun 24, 2016 21:21
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um excuse me posted:My post was followed up by info saying my tires won't really get hot enough to get real results. It kind of leaves me wondering how I can objectively tune my suspension. Objectively? Lap times. No, seriously. Even if you're running a soft enough compound to get it hot and get good pyrometer measurements, the pyrometer will tell you if you're under or overinflated, but it won't necessarily tell you what you should be doing with camber. Pyrometer at the pit lane after a session will tell you what the average heating of the tire is, but what's actually important is how it's loaded in more important corners - for example, you might see a nice even heating across the tread on the pyrometer, but there's a sharp right hander before a straight where the left tires are running too far to the outside. Or maybe by loading the inside shoulder "too much" you're actually getting better heat into the tires and working everything better. This is not to say that pyrometers are bad, but there's limits to what you can get out of them. ... this is also why I'm working on data acquisition systems...
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Jul 11, 2016 19:15
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um excuse me posted:This is a solid suggestion. However it doesn't apply nearly as well with autocross. I got 8 runs on that course. First 3 were duds and 4 and 5 were good. 6, 7, and 8 were on a wet track as it rained during those runs. Completely unreliable for tracking times. Even under ideal conditions I'm not nearly good enough to stay consistent. My times generally go down as the day goes on. Also since courses aren't used more than once, I only really get one data point if I start using average times. Hell, it's hard enough to do with club level road racing. What I'm trying to say that "objective" is hard, especially with autocross, especially with drivers who aren't really consistent. Frankly, I'd argue that other than the lap time metric, it's almost impossible to objectively tune many things without a data system. So don't worry so much about "objective" metrics other than bad warning signs (tire pressure too low or high, temperature lower or higher in the middle than the shoulders, chunks of the shoulder leaving the party) and focus on subjectively making it easier to drive at the limit.
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Jul 11, 2016 20:11
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G-Force harness here; the 2 inch dealie. I swear I'm like the only one in the world that doesn't like 6 point harnesses though.
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Jul 11, 2016 22:57
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I guess it *is* just me - in stuff I've tried it in, the wider harness end on the 6-points dig into my thighs. May just be a "10 pounds of drive in a 5 pound car" thing though.
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Jul 12, 2016 17:54
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Oh yeah - AIM Solos are great things. Couple hundred bucks for something that datalogs GPS and accelerometers and does predictive lap timing? Worth it. Of course, I'm the nut trying to make his own DAQ...
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Jul 13, 2016 01:44
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NitroSpazzz posted:We've never bothered to pull the data and really look at things but it is great for lap time bragging rights. It's pretty cool to be able to throw math channels at the data to do various things, though it's kind of an annoying teaser in a way. "Hey, here's a suspension analysis tab... OH WAIT, NO SHOCK POTS!" Then again, I work with DAQ stuff for my day job so 1: I geek out over acquired data and 2: I bet I could kitbash together hardware and software to do whatever I want. Predictive lap timing is great though. What I really want is a box that hooks into the Race Monitor data to give you split time to the guy in front of you. Race Monitor wants cash to hook into their API though, so oh well.
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Jul 14, 2016 15:33
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Well that's awesome. I was just going to use a trio of the Melexis single point ones. My basic intent is to have a little box at each corner transmitting to a central DAQ over serial or CAN or something; everything can be sampled at 10hz except for shock pots so it shouldn't be that hard.
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Jul 17, 2016 13:14
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Maybe the track designer didn't like racers? Then again, it sometimes seems like modern tracks have too much runoff - the Kink at Road America is awesome, for example. I dunno.
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Jul 19, 2016 00:18
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I'd be really tempted to just step up to PF11; it's not like they're that much more than Carbotech. Hawk DTC60 front, DTC30 rear has also been done by a lot of Spec Miata guys.
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Aug 4, 2016 02:14
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Maybe a dumb question, but did you look underneath the padding and stuff?
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Sep 8, 2016 16:56
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kimbo305 posted:I moved around the padding that I could move easily, but the side pieces seem to be glued, not velcroed or otherwise reversibly mounted. A lot of the padding should come out; I'd expect to find it on the hard foam, under the soft foam, in the back. I just know that tech inspectors for roadrace stuff anyway will verify SA rating by finding the sticker. *quick edit* Note I said should - what I'm seeing yeah, the sides on that are glued but the some of the rest should?
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Sep 8, 2016 17:08
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Penskes are excellent but from what I've heard from pro race engineers, even with pro drivers and such, triples are almost impossible to tune without a data system. And 8760s are bank. 7500DAs are much cheaper and still good, but frankly there's nothing wrong with Bilsteins valved properly. Similarly, monobloc calipers will be a bit stiffer but I think you're not going to have a very heavy car, and any of those should be dead solid.
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Mar 31, 2017 04:25
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jamal posted:Not always. The steel bolts holding a two piece caliper together often make them stiffer than a monoblock. Yeah, if you listen to Stoptech, who markets exclusively two piece calipers, that certainly is the case.  Sorry, I shouldn't be flippant about that... basically, if you can make the piston bores, it's pretty easy to have 3x the area of aluminum than the area of the bolts in the area where you'd sink cross bolts into, which takes care of the tensile stiffness, much less bending. The Stoptech article everyone goes towards is also making you assume a lot about bolted joints. Their points are true for some of the 60s vintage AP calipers, but that's why they don't make them like that any more.And to stave off the predictable "people getting butthurt"... Stoptech makes good stuff, I'm looking at getting some of their STR42s for the front of my Miata project, and the rears I have I think are private label manufactured by them, and any differences between bolted or monobloc calipers are pretty wanky below the pro level. They're a business though and under no obligation to call people's attention to the assumptions they make in their tech articles.
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Mar 31, 2017 12:51
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Oh sure. If I were megabucking I'd be looking at Formula 3 calipers or something for a Miata, but in the real world I'm looking at Afco's Dynalite clones or maybe the Stoptech Dynalite clones.
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Mar 31, 2017 14:42
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jamal posted:I think I heard that from essex parts about their kits using new AP calipers as well, even for their new "radi-cal" shape optimized deal. Yeah; bolted joints have limitations but honestly they work well enough. Of course, if I had a chance of them fitting I'd run PFC ZR34s but they're Superlite size, which is an issue on a Miata.
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Mar 31, 2017 19:24
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Oh yeah, I should maybe post here too. Did my driver's school and got my Midwestern Council novice wheel to wheel competition license last weekend! I've done track days and what MC calls high speed autocross (time trial basically) but this was the first green flag racing for me. loving tits. https://www.youtube.com/watch?v=QoAqH1cRwI8 One of my morning sessions before the GoPro crapped out. It was a school and I wasn't confident in the car yet - I got better over the course of the day and was deliberately not focusing on braking points or using all the throttle yet, also because I wasn't always 100% sure that other people were seeing me. I guess what I'm saying is that I know a lot of experienced people could tell me how to go faster, but that wasn't quite the point yet anyway.
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May 2, 2017 16:13
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I was never too keen on the idea of the head/neck thingies that go behind your back and strap on... seems more awkward.
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May 9, 2017 19:33
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Ziploc posted:It's essential. It barely limits your head movement. And the benefits in a crash are immense. ... compared to a HANS which sits on your shoulder, I guess I should have been more clear. I have a HANS and find it completely inoffensive, ones like http://www.ogracing.com/simpson-fia-hybrid-head-and-neck-restraint look uncomfortable.
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May 10, 2017 22:21
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I note that if you poke around, a real HANS III is the same price from that seller (not that I have any ojection to the Scroth one) I suspect it's one of those things where Brexit is loving exchange rates up, people can't revise the UKP price so the dollar price ends up temporarily small. Or something like that. Which is to say, good find.
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May 11, 2017 13:08
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Huh. Well, six of one, half dozen of the other, I guess - makes sense overall. I guess I was trying to speak to the "this is better than that because it's cheaper or more expensive" aspect. My dad found an older HANS Pro (or whatever they called it back then) with sliding tethers and even though it's taller than the newer ones I haven't had any trouble. Of course, because I'm a weird mutant that barely fits in the race car and we had to pull the seat cover off the Ultrashield seat for my driver's school to get my helmet down enough, I feel like a hard thing on my back (like the Hybrid dealie) would suck. Maybe other people race cars with padding though, I dunno. *quickedit* I should note that I have no doubt that the Simpson Hybrid ones are also safe. Also, it amuses me that one of the gentlemen behind the HANS is Jim Downing, an oldschool rotary road racer who's still at it in SCCA. Met him a few times, nice guy.
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May 11, 2017 15:15
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Heh... maybe this is just me being a test engineer, but my brain keeps skipping over the "incorporate data and video into one thing" step. I guess I'm just used to squiggly lines?
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May 11, 2017 20:14
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No but from what I've seen, tech doesn't like it if you've avoided washing it long enough that it's probably flammable from being dirty. There was this one guy... 3.2A1, A5 or what?
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May 16, 2017 01:05
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Street/Race is a newer compound - basically DTC30.
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May 23, 2017 15:46
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Roman Rambo posted:DTC30 may stop fine, but DTC60 squeaks more and that lets everybody in the paddock know you mean business. I swear, the DTC60 is so much nicer than the oldschool Blues or Blacks.
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May 23, 2017 16:17
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Are RS4s (or any of those really) usable as budget street tires? I've heard tell that Z2s are only a couple seconds slower than Hoosiers in the dry, and usable in the wet... it would be nice to have an intermediate tire instead of just chunking Hoosier H2Os.
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May 25, 2017 19:27
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crazzy posted:I mean, if you don't drive much they are usable, but will have pretty short life spans, be loud as hell, really stiff ride, etc. I'm running wheel to wheel - I'm up against Hoosier R7s being about $300-400/weekend; this is a price I'm resigned to. I would occasionally like to do shakedowns on public roads without worrying about getting a rock through the R7s, and I would like something better than R7s if the track gets wet. At the same time, I don't want to shell out the $1200 for something that mostly just sits, and apparently will only live for a session or two before chunking.
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May 25, 2017 19:51
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crazzy posted:If that's the use case, the re71r/rs4/z2ss are completely usable, and are a hell of a lot better than an r7 in the rain. Someone with fresh 0 heat cycle hoosier h2o's will be faster, but as a compromise the 200tw tires are fantastic. Yeah, it's basically for a "poo poo, they're not going to refund my entry fee now, might as well go on track" scenario. I did my driver's school in R7s in the rain, I do not want to repeat that.
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May 25, 2017 20:30
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FatCow posted:Do the R7s really fall off that fast? SM7s are about a 15 heat cycle tire before they really go off. Define "fall off"? In my experience, after about 3-4 heat cycles they won't get up to optimum temperature anymore, but that doesn't mean they're dead, just not as fast. I don't have any data on how many heat cycles until they're slower than lesser tires. I'm thinking about trying to play with some of those tire treatments on the set I have that's about 15 heat cycles in to see what happens since otherwise they're garbage.
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May 27, 2017 15:51
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FatCow posted:Let's say 1s on a 2min course I'll get back to you when either my dad or I are consistent enough for me to have data on that. There's a reason I'm talking in terms of getting up to temperature or not.
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May 27, 2017 20:00
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mekilljoydammit posted:I'll get back to you when either my dad or I are consistent enough for me to have data on that. There's a reason I'm talking in terms of getting up to temperature or not. Anecdote - practice session tonight. Measured after a cooldown lap and drive through the paddock, the R7s (this set has at least a dozen sessions on it) were at between 135 and 160F. Going to try to get real temperatures tomorrow - Hoosier says they're supposed to be at 180-200 or so but like I said, who knows how much they cooled down. Car's about 4 seconds off lap record for class - 1:25.x vs 1:21.2 at Blackhawk Farms.
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May 28, 2017 02:21
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Two things I'm thinking of. Number one, had an annoying end to a race weekend when a cloudburst meant my dad put the car off the track on the first lap and spent the whole race watching stuff go past in his rear view mirror from 20 yards into a swamp, and I had to go bike around the track to figure out WTF happened when he didn't come around again. Between this and various other reasons, we're thinking about radios now - not pro grade worldbeating radio setups yet, kinda between http://www.sampsonracing.com/The-Starter-5watt-Package-for-2way-driver-to-crew-p/starter-plus.htm http://clubracingradios.com/Budget-5-Watt-Radio-System-5WATTAFF.htm or http://www.racingsafetywarehouse.com/product/600080141.html and yes I know, Chinese radios aren't going to be as good as something where I'm paying more. Right now it's between "go cheapish to prove out the usefulness" or "don't do this at all". And yes I know I'm supposed to get a license for GMRS. Secondly, I sat and looked at the run group listing for my local org (Midwest Council) and realized I can squeeze the NC MX-5 into 2, maybe 3 (though potential backmarker in the third so probably not) different run groups / races per day. Given the price of Hoosiers and their falloff, and Midwest Council not actually caring if I throw bigger wheels on, I was thinking of going with Toyo RRs. It would be 235/40/17 Toyo RRs on 17x8 or 17x9 wheels, vs the Hoosier R7s in 225/45/17 on stock 17x7 wheels. How much lap time am I likely to lose on a 1:25ish lap, and will I be able to keep that going for more heat cycles?
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May 31, 2017 15:02
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From experience, Blackhawk Farms has lovely cell reception around a lot of it. Ordered a setup using HYT radios. It might prove to not be good enough, but it's a place to start.
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Jun 1, 2017 20:46
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FatCow posted:Just keep in mind you're playing pirate radio with just about every race radio system. That linked system will be stomping on HAM bands. I actually *was* going to get a license... from what I'm seeing, the 5 watt stuff is GMRS which isn't that expensive or hard to get a license for.
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Jun 2, 2017 02:24
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Just got back from the SCCA June Sprints at Road America. Took some pictures - should I post them here or in my own thread?
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Jun 18, 2017 03:10
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... ok... well, here! I only took my Fuji X100 so it's just stuff around the paddock I thought was cool, or sometimes technical stuff I was interested in... whatever, look at the pics or not. http://imgur.com/a/k7yvO
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Jun 18, 2017 18:39
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It's a great walking around camera. I (my wife) has a Nikon and I have a decent long lens for it, but if I'm not trying to get pictures of stuff on track, enh.
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Jun 18, 2017 18:58
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1500quidporsche posted:Any info on that two stroke flat six? Kohler flat 6 from a drone program. That car is run by Jason Miller who's an engineer at Kohler, and his dad was on the program originally and first adapted it to SCCA sports racers. Off the top of my head. Actually this: https://grassrootsmotorsports.com/articles/two-strokes-genius/ BlackMK4 posted:The cheap-rear end Fuji 50-230 is hilariously good for what you pay for one used. Works great for trackside shots... Continuous high shooting with continuous auto focus makes it so easy. (I have an XT1, I know the x100 is fixed but you can move to a 23 + xt p cheap My long solution is a Nikon D5100 with a 70-300 - good enough for my purposes, tbh.
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Jun 18, 2017 20:39
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)