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It's just one I've pieced together from ones on here. It's pretty close to the one you sent me, although it might be even more conservative. Before I rebuilt the engine I was running something a lot more aggressive, but also wasn't monitoring knock. I'm hoping to be more calculated this time around.
FWIW I've got 9:1 pistons and am running 91 octane, which is the best we get around here. Ambient air temps right now are ~0-10* C (~30-50* F), but those are going up soon.
Added 2 degrees and got some pulls in. The fuel table corrections put me on target. I might richen up the lower RPM a bit.
Honestly I'm surprised that I don't seem to have picked up any power. Both tables seem to have centered right around 150 HP. I've now got a map with 2 degrees less timing from my base, so I'll try to get some logs with that map today.
I'll post some photos (or just the whole tune) when I'm back at my tuning laptop.
One thing to note is that barometric pressure for me is about 90 KPA, so even with 1 "Boost PSI" I'm still under 100 KPA. So I suppose 150 HP doesn't seem unreasonable considering I'm basically running 4-5 PSI above Atmospheric.
If my understanding of that is wrong feel free to correct me.
That bottle is pretty frugal and slick. Almost as much so as my buddy’s redbull can with a hole drilled in the lid.
In all seriousness, good work all around. As much as I love the look of a dialed in engine bay with lots of shiny things, I feel like mods such as your bottle give our little cars character. I ran a Gatorade bottle all summer for my exhaust side breather and it got as much attention as the turbo itself haha.
+1 on this comment, I had a good chuckle at it, it works and provides a good talking point when you pop the hood.
You'll likely replace it with a more rugged solution one day but, until then, happy "Macgyverin".
The car passed tech, blender bottle and all. At this point I see no reason to remove it. Its definitely in the spirit of the car and seems to be functional enough. I am not seeing any accumulation in it so far, so that seems to be a good sign.
I've done a bit more fiddling with virtual Dyno and my spark map. I'm currently running at wastegate which is ~6 psi at 132 KPA. I tried adding 2 degrees and taking out 2 degrees.
I did a bit of averaging and it looks like peak power is shown below. If I pull the low 161 and 142 values, then baseline and +2 are within a HP of each other.
Not the most scientific, but makes me feel pretty good about running the timing that I started with. I circled the area I've been looking at.
The values in the picture are the "baseline" values.
I've enabled my boost controller again and am going to move up to the ~180 KPA range and see what I find there. I also want to spend a bit more time in the lower RPM medium load areas to keep listening to what I thought was knock. I'm still not sure about what I'm hearing though.
I'm starting to think about little ways to reduce weight around the car and am wondering about peoples thoughts on the white bar here. I'm not sure how much it's really helping and figured maybe I'd pull it out.
I know AC, PS, battery would really be the way to drop weight, but I'm not committed to going full race car with the thing. I likely will go LifePo when the current battery dies.
Went out and got some data last night. I'm not sure what's going on, but at ~180 KPA it looks like VD is putting me around 185 HP. I'm no mathematician, but that's a gain of 30 HP on 7 additional pounds of boost which seems wrong.
I have run the car around this level of boost earlier and remember seeing similar numbers. I also realize that VD is not perfectly accurate, but even taking the lowest numbers from my previous data and the highest numbers from this data we're talking a 45 HP gain, which still seems quite low.
I checked over my spark map again and realized I'm running more timing in this area than some reputable maps. For what its worth, I didn't hear knock last night with the headphones.
I pulled 2 degrees out this morning, so we'll see what the data looks like.
That aftermarket brace is only adding weight when you've already got a much beefier roll bar bracing the same area and bolting directly to the frame rails rather than the seatbelt tower. At first I thought it was a harness bar. Beyond the factory front and rear subframe braces, I don't think there's a good case to be made for adding the weight of bracing to lower lap times. I just removed my NB2 Sport models factory underbody brace and strut tower brace purely to cut some fat off my car.
Even if I had to parallel park every day, I'd still love my depowered steering. My first Miata was a factory manual steering car and power steering felt completely numb in comparison.
I pulled the strut brace a couple weeks back to help with routing the rad hose for the reroute. That's what got me thinking about removing them in the first place. Between the bar and the mounts it seemed like a good amount of weight.
My rear subframe brace is aftermarket and seems really heavy for what it is. Maybe someday I'll swap that out for something different.
Likely I'll pull that seatbelt tower brace once the hardtop comes off (going to be around 70 here soon).
My roommates NA has manual steering which I drove for a run at the last autocross event last year. I know what you mean about the power steering feeling dead. Manual steering feels a lot like some of the sim racing I do, the edge of grip is just so much more apparent. We will see...
That's not terrible gains for 7 additional PSI. I expect 5-10hp/psi, depending on how close you are to the limit of your turbo or any other components, such as exhaust or intake. Once I start to see close to 5hp/psi, I stop increasing boost pressure and start looking for restrictions. Try unbolting the exhaust and do 1-2 VD pulls, it's obnoxious and your neighbors will hate you, but it's for science. If it doesn't help at all, you may have a boost leak, or your turbo sucks. If you do indeed have a FM kit from ~2000, it may be that hideous intercooler setup.
Yeah... part of the problem with buying a car from a questionable PO is that know, as I go through the car, I feel like I need to redo everything that I haven't touched yet.
The intercooler is on my list. My thinking was, get the car running with what I've got, then I'll enjoy it and be more motivated to upgrade and work on it. I've been looking into doing an over the radiator setup, which I think I should be able to piece together for a couple hundred bucks. I just need to pull the trigger on ordering the parts.
My exhaust is also going to get some love here soon. The PO had a cat cobbled in to try to pass emissions to get the car registered. It's something like 2.25" slipped into 2.5". It's pretty horrible. There's an older couple I autocross with who codrive an old Mustang II. They own a muffler shop a ways out of town, but it's on my list to talk to them and get something less restrictive fitted.
For now I'm just trying to remind myself that the car is running and driving, and while it's not perfect, there's nothing that should prevent me from enjoying it right now and fixing things as I go.
...But yeah, there's this photo on TDR's website where they compare their intercooler to the setup that I've got to theirs. 34 pounds and it runs like 3 mm away from the crank pulley.
On a positive note, I got Ye Old Chevy out to the tire store yesterday and got fresh rubber for the street wheels and race wheels.
Nitto Neo Gen's for the dailys @ 205/50/15
Falken Rt660's for the race wheels @ 245/40/15
IC piping and exhaust have been on my mind more and more lately.
I'm looking at something like this, but haven't done my research on IC sizing yet, so I haven't pulled the trigger.
The core seems a bit small to me. All of the ones I've found on ebay are this size. Again, I need to do my research.
I think TDR's setup is 14 lbs, so if I could get down to that I'd be saving 20 lbs over my current setup.
The Chevy is going to get a new turn signal flasher soon, because I think the old one died on the trip home from the tire store. I'm not sure I could get it to lose traction on the clapped out tires it has on it currently unless I lost my brakes. The thing is basically a tractor, straight 6 and 4 on the floor. It's been fun to go back and learn how to tune the distributor and carb in that thing after learning how to tune an ECU. The core concepts are the same, just implemented differently.
The exhaust is almost definitely your lack of power up top. You're going to notice a huge difference if you can do proper 3" the entire length. I wouldn't be surprised if you see a 20-40hp gain from that alone. I might eat my words until you also upgrade the intercooler, they're probably both holding you back.
The TDR setup is decent on an NB, although keep in mind you'll have to weld a 3/8npt bung to it for the typical GM IAT sensor. It's SS, heavier than the typical aluminum piping, but it's so short, who cares. Easier to find a welder that'll add the bung, but since it's stainless, I'd still suggest finding a decent motorsports or similar shop to TIG it, not some random muffler shop.
I'll keep that in mind Curly. I have been planning to just get the midpipe sorted out for now (probably 2.5"), but it probably would be better to do it properly the first time. I had another friend running a 2560r recommend that I go straight to 3". It seems like the way to go.
I do know a guy who seems to be a pretty good tig welder. He's offered to help me with some welding projects in the past. I've seen his aluminum intercooler piping that he welded up for his turbo rabbit, and as far as I know he hasn't had any issues with that since he got it put together. I can't imagine I'll actually buy the TDR kit though, just run a similar routing to it. It's a nice piece, but I'm not going to shell out $1100 for an intercooler.
I've been driving the car just about any time I leave the house and it's feeling great. I'm hoping to cobble together some ducting for the radiator this weekend or next. My front bumper doesn't have anything underneath it and the temperatures I'm seeing are higher than I'd like. Ambient today is 11 C (~50F) and sunny, I was able to get my coolant above 95 C when getting the engine into some heavy load mixed with stop and go traffic. The fans are keeping the idle temps at 90 C, which is where they kick on, so I'm not worried about that, but airflow when moving will become an issue in a month or two if I don't get on it.
Not the best photo, but might give you some idea of what it looks like right now. I did experiment a bit last weekend and have a couple ideas of how to make something that should work well. Note that there's nothing sealing the bumper "mouth" to the cooling stack or preventing air from going under everything.
Yesterday I ran down to Home Depot and grabbed one of their storage totes to cut up and turn into an undertray. Behind the mouth of my bumper there was nothing to prevent the air from going straight to the ground.
I've seen people do similar things with a cement mixing tub from the hardware store, and these storage totes were just a bit more expensive. Around $12.
As an experiment I think it worked out pretty well, however I would find a slightly wider tote if I were doing this again. Another 2-3" on the bottom would be really beneficial and fix having to bend the sides out so much. The top of the tote is the right size, but the taper on the sides makes the bottom a bit narrow.
My roommates stock bumper tray compared to the top of the tote. The tote tapers down, so the size isn't quite right, although orienting the tote a different direction might work.
Yesterday was pretty warm. I took the car out to our nearest fun road and gave it a rip. It could be placebo, but the temps seemed to be similar or lower to what I've been seeing on some of the colder days lately.
It was about 20 C (~70F) ambient yesterday and very sunny.
I was able to get the coolant to peak at 100C (212F), although averaging 12 seconds of the datalog around that peak shows 95 C (~203 F). I have an 80 C thermostat and fans switch on at 90 C at idle.
Intake temps peaked to 35 C (95 F) when going up a small hill after beating on the car. Averages looked closer to 25 C ( 75 F) when the car was moving.
I will likely be doing a bit more research and ordering new intercooler components soon, both to get newer components and simpler routing.
What I'm finding right now is that most kit's seem to be in the 360-380 cubic inch range for core size. I'm estimating the core on the ebay IC that I was looking to be 363 cubic inches, so on the smaller end of the spectrum. I'd take another inch or two in either direction on the core if possible, but the sizes in that style seem to be limited.
As always, if something I've said seems wrong, or I'm headed in the wrong direction, feel free to correct me and save some headache.
That was my second attempt at making an undertray that way and honestly I'm still not super happy with the result. Maybe once I get around to redoing the intercooler I'll revise the undertray. I do think it's helping, but could be improved a lot.
I'll try to get some photos showing the fitment soon.
Pulled the hardtop off yesterday now that we're warming up. Enjoy the craftsmanship of the PO's soft top install.
Again, I'd like to emphasize that the soft top install was not my work. And yes, those are self tapping screws holding everything together. It's actually held up better than I would've expected, but the fitment is... rough.
Got the car washed yesterday at lunch. Noticed that the passenger side door card was a bit loose so I pulled it to add some new clips in.
I found these clips when researching for some to use for my drivers side door card a while back. Someone who makes aftermarket door cards for Miata's said that these were the best ones. They seem to work pretty well to me. I think I paid $15 for a box of 50.
I'll be damned if I'm going to take the weight penalty of a soft top without enjoying the benefits. Driver's seat at night with the top down is seriously one of my favorite places to be.
Slapped on the RT660s this morning to try and heat cycle them at lunch. I doubt I'll be able to get too much heat into them but I figure it's better than nothing.
Unfortunately Saturday will see a huge drop in temperatures and a 30-40% chance of rain for the autoX season opener. We're looking at 5-10 C (40-50 F) for the day. I suppose it'll be a good opportunity to see how the cooling system holds up.
Still fiddling with the timing adjustments.
Also, I removed that seatbelt tower brace. Only weight about 3.5 lbs, but it cleared up a lot of space in the parcel shelf, so I suppose that's a win as well.
Every few track days I walk around checking how many NA/NB Miatae have their radiator sealed up. Most of them still have the massive gap between the radiator and the undertray that comes stock, which lets a ton of air shoot right past the radiator and go into the engine bay and under the car. I can't tell if you've addressed this in your pictures, but make sure air can't bypass the radiator.
What's wild to me is that this is still often the case for cars with front splitters! They've spent enough time down there to see the radiator isn't sealed to the nose. I've seen two K24 powered and splitter equipped cars like this. It seems a lot of people only care about sealing the radiator when they run into cooling issues, but there's gains to be had even on a naturally aspirated, stock car. Better cooling, lower drag, less lift - all this can be yours for the cost of a piece of foam you find in a dumpster, in 10 minutes or less.
Thanks! Again, I would do this differently on the next attempt. I'd either find a tub with a larger base, or put the tub on its side so the undertray tapered down as it went from bumper to radiator.
Gave me something to do on a Sunday though, and might be doing something so I'm going to say it was a successful learning experience if nothing else.
03-08-2024, 02:03 PM
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