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My local dyno tuner was running a $100 off holiday special, and the temptation was just too great. I've always been chasing little boost leaks out of my charge piping, so this weekend I took it all off to re-clamp everything and pressure test it before hitting the dyno.
Got rid of the horrid T-bolt clamps and replaced everything with regular old screw clamps. Figured I'd get good pictures of my piping configuration while it was out of the car, for future newb questions.
I wanted to pressure test the piping while it was off the car; I figured out that spray paint cans are exactly the right size to block the ends of the 2.5" couplers. I cut up a can of compressed air and put a valve stem in it:
Then used another can to block the other end, and a highlighter marker to stop the IACV line, and pressure tested everything to 30 psi. All the joints are tight as a drum. The BOV leaks a bit over 20psi, which is irrelevant because the car will never see that much boost. My ghetto leak tester also shot out of the coupler like a cannon, and while it contributed greatly to comedic relief I cannot recommend that anyone else reproduce this stupidity. Nonetheless, I'm reminded of the saying "if it looks stupid and it works, it isn't stupid".
I put everything back on the car, doing some additional cutting/grinding as needed to ensure proper clearance around my charge piping and couplers.
Last edited by Schroedinger; 12-04-2018 at 03:42 PM.
Dyno day. Took the car into DBW Motorsports in Norcross, GA. It is really a first-class operation, I was very impressed and my tuner Doug was very knowledgeable.
And the results:
The dotted lines were my previous VladiTuneTM at 11.5psi. I need to take a moment to give big props to Vlad here; he really did an amazing remote tune on my car, and I would recommend his services to anyone. I happily drove the car that way for most of a year with great performance and reliability. My Virtual Dyno on this tune had it at about 183hp and 162 ft-lb, which is not far off of the 186/176 that the dyno shows.
Nonetheless, the dyno tune was very much worth it, especially with my crappy 1.6L motor. The solid lines are the new tune at 14psi: 205hp and 194 ft-lb on the "heartbreaker" Mustang dyno. That fat chunk of torque from 3500 rpm up is very noticeable, and greatly improves the driving characteristics of the car.
So back in the late 90's, my best friend had an E36 M3. I lusted after that car. Two years ago, when I decided to get into motorsports, I narrowed my choices down to Miata or M3. Obviously I chose Miata, but I've always wondered if I made the right call. So last month a buddy of mine picked up a squeaky clean E36 M3, then put $5k into maintenance and mods. Last weekend we went for a drive in the mountains and traded cars for part of the day. Man, what a sloppy pig that thing was. The steering was sloppier than my minivan, the suspension felt like it was full of marshmallows, the motor felt anemic, and it was just heavy and loose in general. Turbo Miatas for the win.
Lately I've been wanting more camber and less bump steer. I got up the motivation to deal with it when I cross-threaded one of my wheel studs, and figured I would just do everything. Ordered extended lower ball joints, R package tie rod ends, MT.net-approved Centric Premium front hubs without the machined step, and ARP studs. Removed the ABS ring and had the studs pressed in this week. Installed everything today; pretty straighforward project except for the ball joint bolts under the lower shock mount- big PITA there. Need to get a fresh alignment this week.
Got an alignment last week; wow, the car drives so much better. I have 3.5 degrees of camber in the front, but still plenty of caster so the steering doesn't feel twitchy. The R package tie rod ends work as advertised, bump steer is no longer an issue.
I'm at Road Atlanta this weekend with Chin Motorsports. I got tired of putting painter's tape on my doors, so I made some numbers with $5 of magnetic sheet from Amazon and some electrical tape.
I've only driven Road Atlanta three times, most recently last June. It is an intimidating track for me. This weekend I ran with Chin trackdays, whom I love. Yes, they are more expensive than the other groups and just about everyone is in a nice car except for me. However, each day you get four sessions that are 30-40 minutes long, and the 60 minute "happy hour" for all groups at the end. The run groups are small and the douchebags are few. That's honestly about as much track time as I can handle in a day and still keep a clear head.
Saturday was light misty rain all day; not as much fun to drive, but great for improving skills. I focused hard on cleaning up little things: brake points, looking down the track, indexing my entry speeds, etc.
Sunday was sunny and windy in the 50's, pretty much perfect. The car was great as usual, no issues. The new alignment (3.5 front camber, 3.0 rear) was great, very neutral and needed almost no tuning with tire pressure. The guy that did the alignment suggested a little front toe-in; I was skeptical, but I quite like it. The car still turns in well, but it feels much less sketchy at high speeds.
I was consistently lapping at 1:54-1:55, with my best time a 1:53:19. That is an improvement of 13 seconds (!!) over my times last June. I am solid middle of the Intermediate pack with the other groups I have run. In Chin, I'm a slightly fast Novice Solo. I'm still not a "good" driver, but I'm starting to feel like I'm less of a "bad" driver.
I got to ride along with a racer/instructor in this GT3. He was putting down 1:37's. Holy *****, what a car, what a driver.
Later he was instructing a novice in my group and watched me during the session. Said that my car rolls like a clown car in all the turns, and I'm basically sitting on the bump stops full time. Maybe that's the feeling that I've come to know as the car getting "settled"? I feel like I'm on two wheels coming through turn 12. I think I've reached the point where I'm outdriving my NB Bilstein/ FM spring setup. Sigh...
Last edited by Schroedinger; 02-25-2019 at 04:22 PM.
Turn 12 needs enough springs to keep it off the bump stops with your given tires. If you touch the outside curb on track out and are already on the stops it can unsettle the car. There's no compliance left to absorb the bump or irregularities.
And stickier tires will require more spring to keep it off the stops.
Mooch was excited about this box that arrived today.
I was more excited about the contents.
I was going to take apart my Bilstein setup and go with sleeves and something like 550/350 springs. When I added up the costs, and considered that those shocks probably aren’t well-valved for that spring rate, and saw these Xida GS’s listed in the classifieds brand new, it made it a pretty easy decision.
Last edited by Schroedinger; 03-21-2019 at 01:38 PM.
This is not a job for weaklings, or for the impatient.
Between the slide hammer/hub puller and the sledge, I felt like a gotdamn Viking warrior this weekend. Xida GS setup installed, along with Timken bearings and SADFab MR2 rear hubs.
I've got my ride set to 5.5" pinch weld height at all corners, and the Xidas dialed in to about 7 clicks from wide open. Wow- the hype around the Xidas is not exaggerated. It's more comfortable than the Bilstein/FM spring setup I was running previously, and the corners are much flatter and more composed. I spent the afternoon looking for potholes and dips in the road, this is really a superb suspension. As an added bonus, my front tires no longer rub on the fender liners in big dips or hard turns, and the 65mph shimmy is completely gone. I can't wait to get it on the track.
Track day at Barber today with Chin. After a big morning storm, the track was dry by 10am and it was game on. Beautiful day all around.
I did not get another alignment after installing the Xidas, as the ride height was almost the same as previous. That may have been a mistake. I spent most of the day tweaking and trying to dial out some not-too-good stuff. I noticed after the first session that I needed 2-3psi more tire pressure than before to stay off the sidewalls. The car felt very oversteery most of the day, by the end I was running 2.5psi less in the rears than the front and it felt pretty good. And I can’t understand how a different suspension would affect brake bias but I had too much rear brake again, and had to dial it back a couple times until it felt ok. My reward for all this was solid 1:53 lap times (1.5 seconds faster than my previous best) and a completely killed set of RE-71’s.
So... think I’m going to try RS4’s this time around. When they come in, I’ll take Rocinante to have the tires installed and balanced, alignment done, and corner weighting.
Scheduled TNIA for tomorrow night at AMP. I decided against corner weighting my new suspension install because the few places that do it around here wanted $$$. Got the RS-4's in yesterday and scheduled mount, balance and alignment for today.
One of my rear wheels was way out of alignment from the suspension install. That would explain the oversteer on my last track day, and the feeling that I had too much rear brake. While the wheels were off the car, I checked my brake pads and noticed my front pads were down to basically nothing on the inside. Rats. I ordered new PFC 14 compounds from OG, but they won't be here in time to run the event. I'm trying to reschedule for the event this Saturday at RA.
I heard so many good things about how the big brake kit and PFC 14 compound would last longer. I got four track days out of this set, less than 20 sessions. This probably doesn't speak favorably about my driving, and the Chin sessions are 30-45 minutes, but I expected more. Oh well, at least they were cheaper than the stock Miata pads.
The 225 RS-4's are installed. Hopefully we'll see how they run this Saturday.
Last edited by Schroedinger; 05-09-2019 at 07:55 AM.
I decided against corner weighting my new suspension install because the few places that do it around here wanted $$$. Got the RS-4's in yesterday and scheduled mount, balance and alignment for today.
It is expensive because it takes a ton of time, and scales and hub stands are expensive. I picked up a set scales last fall and I found it is way more time consuming to figure out then I had ever imagined.
Did you get the box I sent you? I left it out for UPS to grab last week and haven't checked on it.
I'd add brake ducts or go for a more aggressive compound like the 08. And always carry spare pads. Seen too many people lose track time due to brake pads.
Had a track day at Road Atlanta on Memorial Day weekend. 94 degrees and humid. It was pretty awful. This pop-up canopy I got for $40 at Costco was money though. Folds down to the size of a lawn chair, takes 30 seconds to set up. The Coolshirt system was also worth its weight in gold.
On a positive note, the RS4's and new suspension alignment were really great. I finally have enough camber that I'm not killing the outside shoulder of my tires, and it was nice to corner without sitting on the bump stops.
On a less positive note, I struggled with a few other things.
- On hard right turns (which is basically all of the turns at RA), there was a nasty loud vibration coming from the transmission tunnel. I could feel it right through my seat. It felt mechanical and was very disconcerting, so I wasn't really pushing hard lest I lose a drive shaft. I ran most of the day like this against my better judgement.
- I was close to overheating the entire day. I could get one clean lap, then I'd have to run a cooldown lap before going hard again.
- By the end of the day, I had cracked the brand new exhaust manifold I had just installed to replace the previous one.
The thing that pissed me off the most turned out to be an easy fix. The vibration was happening when the exhaust pipe would swing to the driver side and interfere with the seatbelt receiver alignment peg, which was poking through the floor pan. It probably wasn't an issue until I had the grip that came with new Xida's, new tires, and a good alignment. Twenty seconds with a cutoff wheel, no more issue.
The overheating and cracking manifolds... I'm frustrated. There are a thousand build threads here where people suffer from this stuff on turbo Miatae when they reach a certain level of speed/skill. Unfortunately I think I've hit that level. The next sequence of events needs to be 1.8L swap, upgraded radiator, and cast turbo manifold that can withstand track abuse. It's the middle of summer, and I'm currently lacking the time and motivation to deal with it.
Right now I just want to drive the car on the track without issues. I think I'm going to pull out all the turbo stuff, put the stock exhaust back on and run a stock drivetrain until the fall. It will be good for my driving skills to try to extract speed from a slow-*** stock 1.6L. I'm having fantasies about solving these issues with a new ZL1 Camaro instead.
Last edited by Schroedinger; 06-11-2019 at 08:07 AM.
I have all the parts collected for a swap. NA8 bottom end, BP4W head, flat top manifold, 95 header and downpipe, boundary oil pump, 99 fuel rail, etc. All I’m missing is the alternator. I was going to do a high power turbo build, but this whole turn of events has me very tempted to just slap it all together and put it in the car for a reliable 130-140hp and call it good.
The thing that pissed me off the most turned out to be an easy fix. The vibration was happening when the exhaust pipe would swing to the driver side and interfere with the seatbelt receiver alignment peg, which was poking through the floor pan. It probably wasn't an issues until I had the grip that came with new Xida's, new tires, and a good alignment. Twenty seconds with a cutoff wheel, no more issue.
Damn! I've been chasing that noise for months.... Now sorted.
12-04-2018, 03:27 PM
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