pdexta's build: round 3
Thread Starter
Elite Member
iTrader: (17)
Joined: Aug 2007
Posts: 2,954
Total Cats: 184
From: Knoxville, TN
I can't wait to take it down the 1/4, but realistically I doubt I'll be ready before summer. I'd love to meet you guys there. I've got a little pdexta that's scheduled to arrive in July so hopefully I can get up there before then, I don't feel like I'll have much time afterwards.
Read from start to finish and all I have to say is Wow! Scott if your anything, you are persistent and looks like it has payed off because it looks great and sounds like its on its way to running even better than it looks. Keep up the great work!
Thread Starter
Elite Member
iTrader: (17)
Joined: Aug 2007
Posts: 2,954
Total Cats: 184
From: Knoxville, TN
Since I was getting random intermittent sync loss issues on the cam sensor I spent a few weeks miserably failing at trying to get the car set up on a crank sensor. As seen: https://www.miataturbo.net/mspnp-55/...l-setup-77167/
Last weekend I gave up on the crank sensor and rewired the stock cam sensor so the car will run at least. I'm still getting the sync loss errors occasionally, but at least I can drive it.
Took a few crappy pictures last weekend with a friend's gto.



Last weekend I gave up on the crank sensor and rewired the stock cam sensor so the car will run at least. I'm still getting the sync loss errors occasionally, but at least I can drive it.
Took a few crappy pictures last weekend with a friend's gto.



Thread Starter
Elite Member
iTrader: (17)
Joined: Aug 2007
Posts: 2,954
Total Cats: 184
From: Knoxville, TN
I took the car out last night and got in a few runs. The car ran pretty well for a change. It's still spooling really slow which kills it in 1st/2nd gear, but once I'm into 3rd it stays high enough in the powerband that it's not a big issue. The timing sync issue seems to be healing itself, it's only showing up with I start the car or load a tune. I'm hoping that's normal, I never really paid attention to it until I started having my recent issues.
I ran a turbo/built motor/bandaid 1.6 miata. I took him pretty easily, probably 4 car lengths from 20-100. He's got a megasquirt and injectors ready to go in that I'm going to help him install next weekend.
Then I got beat up on pretty good by a bolton/cam LS1 Camaro. I'd run him before dead even in my NB so it was nice to see how far off I am now. The first run he got me easily, the 2nd run I jumped him a little bit (which helped to compensate for the slow spooling) and he ended up a car ahead from 20-100. Videos:
The last run was against a bolton/tune 2013 V6 mustang. I was probably 4 car lengths ahead of him.
Really hoping it continues to run decent so I can clean up the tune and add some more boost. I'm at the point that I'm ready for this thing to work right or blow up so I can part it out and move on with something else.
I ran a turbo/built motor/bandaid 1.6 miata. I took him pretty easily, probably 4 car lengths from 20-100. He's got a megasquirt and injectors ready to go in that I'm going to help him install next weekend.
Then I got beat up on pretty good by a bolton/cam LS1 Camaro. I'd run him before dead even in my NB so it was nice to see how far off I am now. The first run he got me easily, the 2nd run I jumped him a little bit (which helped to compensate for the slow spooling) and he ended up a car ahead from 20-100. Videos:
The last run was against a bolton/tune 2013 V6 mustang. I was probably 4 car lengths ahead of him.
Really hoping it continues to run decent so I can clean up the tune and add some more boost. I'm at the point that I'm ready for this thing to work right or blow up so I can part it out and move on with something else.
Thread Starter
Elite Member
iTrader: (17)
Joined: Aug 2007
Posts: 2,954
Total Cats: 184
From: Knoxville, TN
It's just some well hidden deadend sideroad. I'm assuming they used it for cleaning out the stripe machines, or practicing, or when changing colors, or someone was just bored/drunk/high. Whatever it was, it makes for an interesting picture spot.
Curious though, what would you get if this thing blew up and you parted it out?
Thread Starter
Elite Member
iTrader: (17)
Joined: Aug 2007
Posts: 2,954
Total Cats: 184
From: Knoxville, TN
I don't think I'd replace it, I'd just downsize. I daily drive an RSX that I'd probably end up messing with a little more but for the most part I think I'm just done with cars in general.
Thread Starter
Elite Member
iTrader: (17)
Joined: Aug 2007
Posts: 2,954
Total Cats: 184
From: Knoxville, TN
^ Thanks man, I appreciate it. I'm so glad the stupid thing is finally coming together.
I swapped out a wastegate spring to add a little more boost. Green was last Sunday, Red was tonight. Still needs a lot of work, but it's amazing how much better it feels with the extra ~4psi.
I swapped out a wastegate spring to add a little more boost. Green was last Sunday, Red was tonight. Still needs a lot of work, but it's amazing how much better it feels with the extra ~4psi.
Did you adjust the AFRs? It goes leaner above 6k.
Yeah, a 64whp jump is more than most supercharger guys get with a whole m45 kit added to a stock Miata, and you got it by adding 4psi to your WG spring! What is the current pressure?
Yeah, a 64whp jump is more than most supercharger guys get with a whole m45 kit added to a stock Miata, and you got it by adding 4psi to your WG spring! What is the current pressure?
Thread Starter
Elite Member
iTrader: (17)
Joined: Aug 2007
Posts: 2,954
Total Cats: 184
From: Knoxville, TN
Yeah, I added fuel up top. This was my first tuning run at that boost so it was a little leaner than I like, I prefer to keep WOT toward 11:1 rather than 12:1. You can see the boost curve in the screenshot; it's still coming in late, then creeping up, peaking at 210kpa and 240kpa respectively.
Thread Starter
Elite Member
iTrader: (17)
Joined: Aug 2007
Posts: 2,954
Total Cats: 184
From: Knoxville, TN
I drove the car a good bit last weekend. At one point I rolled into it and heard some crazy horrible detonation. I pulled 5 degrees of timing and it was still exactly the same. Yesterday I filled with E85, adjusted my fuel map, and it's still detonating. Plugs 2 and 3 look lean, a good bit leaner than 1/4. The car also started to stumble occasionally with AFR's going lean.
I'm suspecting it may be a wiring issue with my COPs since it looks like cylinders 2/3 are the issue. I'm thinking maybe a wire is working its way loose and they're firing really weak or something. Next time I have a chance I'm going to pull the COP harness apart and redo it, hopefully I find something screwed up and it hasn't done any damage to the motor.
Also spent a ridiculous amount of time scraping sound deadening out of the trunk. Several hours work, a bag of dry ice, and a can of goo-gone later and the car is now 7oz lighter, great victory!
I'm suspecting it may be a wiring issue with my COPs since it looks like cylinders 2/3 are the issue. I'm thinking maybe a wire is working its way loose and they're firing really weak or something. Next time I have a chance I'm going to pull the COP harness apart and redo it, hopefully I find something screwed up and it hasn't done any damage to the motor.
Also spent a ridiculous amount of time scraping sound deadening out of the trunk. Several hours work, a bag of dry ice, and a can of goo-gone later and the car is now 7oz lighter, great victory!
Last edited by pdexta; Feb 20, 2014 at 05:23 PM.
Thread Starter
Elite Member
iTrader: (17)
Joined: Aug 2007
Posts: 2,954
Total Cats: 184
From: Knoxville, TN
A fuel issue was my first thought as well. Actually the first thing I did was swap in a new fuel filter and checked fuel pressure, which is still right at 70psi where I set it.
After looking at the plugs I felt like the cylinder pairing pointed more toward a spark issue. It's possible that 2 injectors on opposite ends of the motor are clogged or something, but that seemed unlikely. Then considering how shoddy my wiring/soldering skills are and how many times I've pulled the COPs off to swap plugs I was leaning toward that being the issue. If I don't see anything in the wiring I'll definitely pull the injectors and look at them.
Thanks again for the input on the E85. I was surprised how easy it was to just fill up and go on my way.
After looking at the plugs I felt like the cylinder pairing pointed more toward a spark issue. It's possible that 2 injectors on opposite ends of the motor are clogged or something, but that seemed unlikely. Then considering how shoddy my wiring/soldering skills are and how many times I've pulled the COPs off to swap plugs I was leaning toward that being the issue. If I don't see anything in the wiring I'll definitely pull the injectors and look at them.
Thanks again for the input on the E85. I was surprised how easy it was to just fill up and go on my way.






