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I have those same wets too. They wouldn't fit on my 18x8s, but I do have them mounted on a set of 18x9s, so 10s will work fine
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Well, I wasn't planning on buying any dry slicks until at least after I burn through this set of RS3's, but now I'm kinda tempted to stock up on some of those 285's while I can and just store them in the house for a few months :)
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exactly. one set is just a fraction more than 1 regular priced hoosier.
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I was reading up on the compounds and whatnot, those 285/645's are "GT-O", which is supposedly slower rubber than an R6, FYI (whereas their "GT-R" compound is faster, but no discontinued ones of that in the right size). Apparently GT-O was a special compound they did for the high banked oval courses like Daytona. But still, it's cheap, and it's not like I really care about my lap times. My first set of slicks is just going to be about learning whether I can handle driving on slicks or not :)
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Signed up for a NASA membership! Tentatively, I think my main schedule for TDE+NASA for the rest of the year looks something like:
Apr 5-6: MSR-Houston - The Driver's Edge Apr 26-27: Nismo Fiesta @ H2R May 17-18: TWS - The Driver's Edge June 21-22: Hallet - NASA Aug 9-10: TWS - The Driver's Edge Sep 6-7: TWS - The Driver's Edge Sep 20-21: NOLA - NASA Oct 4-5: MSR-Houston - The Driver's Edge Oct 11-12: TWS - NASA Nov 1-2: Eagle's Canyon - NASA Nov 22-23: TWS - The Driver's Edge I've only signed up for the first three so far. The rest are of course pending work conflicts and such as we get through the year. I'll probably ending up dropping one or two of those events, and I'll probably try to squeeze in a few more TWS visits that don't require as much notice where I can (PDS, PCA). Hallet's going to be a crazy-long trip for my first NASA event (~8hr drive each way). I had planned to start doing MSR-Cresson w/ TDE this year, which I'm not anymore. I really want to get into NASA's system this year and start working my way up to TT + Comp School there. So I figure that means squeezing in the only 4 NASA events I can reasonably hit this year, which means learning 4 other new tracks for the first time (H2R for NismoFiesta, + NASA @ Hallet, NOLA, ECR). I don't need a 5th new track all in this hectic year (I think I still get better skills-building out of working on known tracks at this point), so Cresson will have to wait for later! |
That is a lot of track time. Don't get burned out!
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That aside, I feel like I'm at a point where doing several events with less downtime between them will probably help me get over my next few hurdles in driving skill and get to a good comfortable point where I can relax my event pace again. I end up quizzing lots of track junkies, and that seems to be one of the common threads I hear over and over, variations on the theme of "I was kind of stuck at stage X for a little while, then I hit several events back to back in a short period of time and that really accelerated the learning curve and got me past that and my driving really took off". I think the ramp-up in the middle-late part of this year will probably fill that kind of role for me. |
For any of you other 7AT people out there looking at rear end stuff, I think I finally found the information on the real difference in the rear ends between 7AT and 6MT. This is all "what I think I know right now", it may change as I learn more (or worst case, it may change once I buy parts based on this and find out they don't work!)
Supposedly, the only difference is actually in the thickness of the ring gear itself and the mounting flange on the LSD carrier for that ring gear. Basically the 7AT's 3.357 ring gear is 10mm thicker than the 6MT's 3.692 ring gear, and the thus also the mounting flange for that ring gear is 10mm further to the inside on the 7AT's VLSD vs the 6MT's VLSD. If this information is actually true, then if you're putting an LSD unit into a 7AT rear end and leaving the stock gears in place, you need 7AT-specific LSD unit that's 10mm shorter at the gear mounting flange. But if you're upgrading to 6MT-size gears anyways, you should be able to drop a 6MT-model LSD (wider) + 6MT gears into the 7AT pumpkin without issue. Beyond that, it's a matter of figuring out which aftermarket and/or takeoff gear sets from various other Nissans are which thickness, but I think the general rule is that most are the same thickness as our 3.692 6MT rear gear, and the 10mm-thicker 7AT 3.357 is the "special case" (both for our car, and several other Nissan/Infiniti AT cars which have that exact same gear ratio). |
I don't think you will get burned out at all, but you will be in HPDE=4 by the end of the year with that schedule. Skill builds extremely fast if you can get out a couple times per month.
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More tire porn! I went ahead and picked up a single set of the 285/645-R18 GT-O's from Hoosier/Conti. Can't beat $110/tire for sticker slicks!
https://lh3.googleusercontent.com/-1...327_110416.jpg They're a little taller than the 265/645-R18 Wets, but appear to be exactly the same width unmounted. Go figure, but works out good for me :) I probably won't mount these until my RS3's die sometime in the mid-late summer. |
nice! let us know how the switch from street tires to slicks go! can't believe it was just a year or two ago you were on continental DW's -> RS3's -> full competition grade rains and slicks!
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Oh I imagine it will be a little dicey at first, but I'm thinking by the time these RS3's die I should be close enough and be able to deal with it and adapt. Worst case if I can't, I'll pull them off and run through a set of NT01's or something first, then put them back on and try again :)
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You'll love it and won't want to go back. :) They call them black crack for a reason.
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funny story, I have mine stacked in the garage until after the last freeze, when they will go to my storage unit. I was looking at them, compared to a stack of my unmounted 295 hoosiers and they were much taller. I later realized I have them stacked 5 high!
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I missed the Apr 5-6 MSR-H event already, had some personal things to deal with that weekend, and I won't make the NASA Hallet event either. I'm already on a roll with screwing up my aggressive schedule :) I think I might try to do the Edge Addicts COTA thing at the end of June, though. Karen rocks, I'm sure her event will kick all other COTA events' asses.
In other news, work sent me to Athens last week. If you ever get the chance, go. I've been many places, and it was by far one of the best cities I've visited. Well worth the trip, and pretty cheap there due to the current economic situation. I'm almost tempted enough to just sell all my stuff and move there, even housing is pretty cheap there right now :) |
Revised upcoming schedule (subject to work/life cancellation/interference!):
Apr 26-27: Nismo Fiesta @ H2R May 17-18: TWS - The Driver's Edge June 21-22: MSR-Houston - The Driver's Edge June 28-29: COTA - Edge Addicts Aug 9-10: TWS - The Driver's Edge Sep 6-7: TWS - The Driver's Edge Sep 20-21: NOLA - NASA Oct 4-5: MSR-Houston - The Driver's Edge Oct 11-12: TWS - NASA Nov 1-2: Eagle's Canyon - NASA Nov 22-23: TWS - The Driver's Edge |
Back from NismoFiesta w/ the Houston Z's crowd, which was awesome. Got to chat with a bunch of vendors/sponsors (Nismo, Z1, etc, even a Motul rep!). The trackday was only 4x 15m sessions, but still tons of fun. I really like Harris Hill even though it's a bit bumpy. You get used to kinda skipping along the bumpy parts :)
Video links are over in a post in the NismoFiesta thread: http://www.the370z.com/texas/84689-n...ml#post2798479 |
Got the EC-WETs mounted this morning. 18x10 is not ideal for these 265/645R18's. I think they should really be on 9.5's, maybe even 9's. They're not like, ricer-stretched or anything, and they're mounted well enough to not be a safety hazard on the track, but the rim edge is wider than the tire sidewall, so you get zero rim protection while manhandling the wheels around the trailer/paddock/car. They'll probably look a little better with proper pressure and the car's weight on them, but still :shakes head:
Pics: https://lh3.googleusercontent.com/-E...509_093823.jpg https://lh6.googleusercontent.com/-w...509_093838.jpg https://lh5.googleusercontent.com/-R...509_093847.jpg |
TWS Recap!
I did a Red-group check-ride Saturday and got myself into Red w/ Driver's Edge. It wasn't as scary as I thought it would be. I thought they'd be running me down all session and I'd have my arm hanging out the window the whole time, but I'm actually on pace with them pretty well (although certainly not in the faster half of the group). The simple corner passes I'm pretty used to now, but I can tell it will take a while to learn how the rules of "etiquette" work in a pass-everywhere group. For example, in the "pass on straights only" groups, usually if I see a car closing on me fast in the corners but he's still not quite on my bumper, and I know he's not as fast in the straights, I'll lift for him on the straight so he doesn't get stuck behind me for a 1/3 of track in the next twisty section. It seems like the opposite social rules apply here: if they're not on your bumper coming into the straight (*and* faster than you on the straight), go ahead and stay in the throttle and pull away, because when/if they do catch you in the next twisties, you can always let them pass there as well. No point in losing laptime over trying to be pointlessly-polite. Also, I broke my car this morning. As I laid into the throttle for a pass, the car went into some kind of limp mode and I had no real revs or power left. I coasted down through the next corner and then eventually pulled off the side of the track. Tried to restart the engine, but it was running rough and limiting at like 2K with a SES light on, so I gave up and let them tow me in :/ SES was for a faulty Crankshaft Position Sensor. Restarting it in paddock, the engine seemed to run ok at idle and very low RPM, so I doubt there's any internal damage (well, it was a little rough, but I think that's probably the limp mode's un-tuned timing and/or lack of good sensor input, etc). There was a funny rattle off and on though, and it sounded like it was coming from the bellhousing area. Jacked the car up and pulled the crankshaft sensor, and it has some physical scratches and wearmarks on the tip of it like the flywheel nicked it. With the sensor back in I was able to drive it back up into the trailer at least, with that bad rattle sound. At this point my best guess is a cracked flywheel/flexplate, or maybe a flywheel<->torque converter bolt backed out, or both. Parts cost on the sensor and flywheel is pretty cheap, but it will be a bitch to drop the trans to install the flywheel. Next events are June 21-22 and 28-29, so I need to figure this out relatively quickly. Tomorrow I'll pull the access covers/plates and/or the starter motor so I can actually look at the edge of the flywheel or tap it with a hammer and see how it sounds or something. I may just call a Nissan place too and see what they'd do. The shorty lift in my garage doesn't have open access under the trans, so I know I can't (easily) drop it here. |
Made a video from datalogger recordings on the flywheel thing. Youtube desc copied for embed:
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Dropped the car off at Baker North today to let them sort it out :)
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If I was below 1K and in drive or reverse, the car would bog down and stall. I thought I was gonna have to have the car towed home, but I managed to get the car rolling by revving to 4k and 5k in neutral and then dropping it into gear. The momentum got the car moving, RPM's stayed high enough to prevent the car from stalling. Shifting, especially downshifting manually seemed to aggravate the transmission and would cause the "stalling" symptom to return. I was able to reproduce the problem on demand, all i had to do was drive it like a manual Anyway, dealer has my car...says they're gonna replace the transmission under warranty. They haven't said what the problem is and I doubt they are going to diagnose it to figure it out. I want to prevent this in the future but I don't know if this is my flex plate or something else. So I'm hoping your experience might help point me in the right direction so i can spend my money wisely on this. This is actually my second transmission, the 1st one got replaced Sept 2013. The way this is going, I'm sure it will happen again. I pinged Megan370z and he seems to be in the same boat with the 7AT, except i think he's gonna throw in the towel on fixing it and just swap it out for a 6MT. I called GTM about the flex plate seems it's just checmically treated to better withstand the heat, I ahve no idea if it will fix my problem or if I need their torque converter or maybe something else. |
Honestly, I have no idea what's wrong with your transmission, sorry! This is the only AT I've ever owned, and I know next to nothing about the internal mechanisms of one (at least, not enough to diagnose based on symptoms like that).
My trans has been fine so far, and it's been through a lot of abuse. I basically never used the normal "D" mode even when it was a street car, and at the track it's M-mode and high revs all day long. I don't *think* my trans is currently broken, just the flexplate. Worst case, could be related issues at the pilot bushing and/or torque convertor (e.g. loose bolt), but who knows at this point. I'll know more once the guys at Baker starting looking at the car. The only non-standard things I've done with my 7AT really is up the line pressures slightly via UpRev, and switched fluid to Motul Multi-ATF. I've done a mostly-complete fluid swap on this trans twice now with the Motul. Hot track days can really destroy fluid pretty quickly, and bad fluid could lead to all kinds of problems. There's a PDF chart from GTM somewhere about trans fluid temp vs miles-to-change... I'll probably put a stock flexplate back in mine for now, assuming that's the main thing that's broken. As long as the first one lasted, I'm sure something bigger will break before another one does. |
Would you say the symptoms I'm experiencing are similar or are they just totally different?
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Sorry don't mean to thread jack your journal. I called the dealer and they confirmed it was the torque convertor, they said it was actually coming apart
Sent from my SPH-L720 using Tapatalk |
Totally different, for the record :)
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Also, while the diagnostic investigation over at Baker North probably isn't complete yet, it's looking like more than just a flywheel+sensor on my car. There's a good chance there's damaged crank bearings or something along those lines. I'm not sure how sure they are yet as to cause and effect. Looks like the 7AT may have outlived the engine! I'm sure I'll know more in a couple of days.
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After dropping him off I left the engine idling and didn't shutdown the car, probably for 5 to 10 minutes at least. I also left the hood up so it could ventilate a bit more Sent from my SPH-L720 using Tapatalk |
So, it looks like I did spin a crank bearing (in addition to (probably as an after-effect of) having flywheel damage). Nissan won't warranty the engine, of course, but I can hardly blame them on a car like mine. Even asking was mostly a shot in the dark.
So, I've got some heavy thinking to do on options here. The factors in play are money (of course!) and time (two events I really wanted to make in the latter half of June, not blowing the rest of the schedule for the year, and in general not spending months off the track with fading skills). The first routes that come to mind and/or are useful for comparison:
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Man that's a tough spot. If it were me I would probably go with option 3. It's far cheaper to buy a built car than to build one yourself and having a car you can write off without such a big loss is nice (I wrecked my 350Z race car this weekend and still managed to smile for a photo of it in the trees since I don't have nearly as much in it as my 370.).
Option 4 might be the wisest but at least in my case I don't think I could give up racing. That Peter Egan quote - "Racing makes heroin addiction look like a vague wish for something salty" says it all. |
I would do 2A. You already have a track car that you know well, and have top shelf parts in it. You'll end up with having a bullet proof VQ motor.
Buying another track car. Who knows what you might get in to with it. It could be more $$$ then you think in the long run. Doing the GM motor swap. Sounds good when you talk about. But it will take time and $$$ to finish it. And you could lose your feeling for the sport while doing the swap. You will never get you money back out of it when selling your parts. And time you've put in to it also. Unless you want out of the sport all together. You and everone else that tracks a car should know that broken parts is part of the game. You always hope that it will never happen to you. But when it does. Be prepared to bit the bullet. |
Forgive my ignorance, but was the failure due to the AT transmission? Do the same issues exist with the 6MT? I just haven't heard of many Z's with engine failures.
I'm sure you could quickly source an engine and transmission. Nissan Unlimited usually has stock. (Near 290 and Beltway 8) So my vote is 1b. If it was my car I'd do that. You are a better man that me if you can walk away from this sport without some kinda rehab program. On the flip side, owning a miata is cheap :) you can probably sell off your Z stuff and use a fraction of it on a built miata. |
I don't think the failure is really 7AT-related, but I guess the answer to that question is a matter of opinion.
Keep in mind nobody's opened up the engine or even the bellhousing yet, this is all based on an experienced, trustworthy 370Z mechanic's opinion that a main bearing is spun based on the sound, and that the flywheel is damaged by looking through the bellhousing access holes. I 99% trust he's right on both counts. Given the audio data from the datalogger late Saturday (where the engine was operating fine in terms of revs and performance, but there was a buzzing/grinding noise), I think the flywheel failed first, and then the imbalance/drag from that affected the crank and caused the eventual spun crank bearing within a couple sessions after the flywheel got bad. The flywheel *is* different on the 6MT and the 7AT, obviously (the 7AT has a "drive plate" that the torque convertor bolts to, it's a different part number than the 6MT flywheel). I've seen reports of cracked driveplates on 7AT's elsewhere (e.g. Megan's here: http://www.the370z.com/engine-drivet...wner-look.html ). The 7AT itself is supposedly still in good shape right now, but perhaps there's a weakness in the 7AT-specific driveplates under heavy loads at the track. |
BTW, Option 1b with a salvage block is in the ballpark of $7K installed (~$5K of that in parts). Better than ~$11-12K for the new block, but still a lot of cash, especially for an engine of unknown durability going forward. Next thing I want to look into is what an engine rebuild shop would charge to rebuild mine and make it stronger, and how long the process would take assuming no unexpected parts damage.
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I think I might be able to find a cheaper salvage engine than they did. The plan that's starting to form here is throw a cheaper salvage engine in for right now, maybe get the cost down to ~$4-5K installed, and I could still make my June events (one of which is expensive and non-refundable). Then keep my old engine and work on tearing it down and rebuilding it slowly as a stronger replacement for down the road when the salvage one dies.
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Saw your car at Baker today hiding in the corner.
I think you can find the engine plus parts for a lot less used, I think the salvaged engine plus re-building the current in spare time is the best option. |
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