Artifex's journey from boring to boosted...and more!
 

Welp, I suppose it's time to start documenting my adventures. I've been around here for a decent while and I'm finally getting around to starting a build thread. My hope with this build thread is to simply document everything I can while interacting with as many of you guys during the process.

First things first, I'll start with a little about myself. I know that none of you are here to learn about my boring self so I'll keep it short. My name's Jacob, and I am a recent Electrical Engineering grad at Tennessee Tech University. I currently work as a protection and controls engineer for a substation engineering contracting firm. I bought my Miata back in June 2017. Prior to purchasing this car, I only ever did basic maintenance work on my (not so) lovely '97 Toyota Avalon with 305k on the clock. She is still running strong to this day and shares the role of DD at a 50/50 split with the Miata.

Shew, I'm glad that's over, aren't you? Now back to the important stuff. I'll try my best to bring this thread up to speed with how the car sits today.

https://cimg0.ibsrv.net/gimg/www.mia...9313067467.jpg

https://cimg1.ibsrv.net/gimg/www.mia...4c48e752ab.jpg

Here she is. Your typical red '91 NA with 151k. This is what she looked like the day I bought her in June 2017. I bought it from an older gentleman for a very good deal. The car was completely stock except for the retro side mirrors. After the 5-6 months of scouring CL and Facebook Marketplace, this was the cleanest Miata I come across so I couldn't pass it up. The PO had the car resprayed and they did a pretty decent job with it. It has a few minor blemishes but I'd still call it an 8/10.

My goals with the car is a fun, clean, boosted street car with occasional autocross in the future. I'm trying my best to stick with the "buy it right or buy it twice" way of thinking. The downside to this is that, as a college student, saving up for the right parts took AGES. Therefore, it has all been a slow process.

I'm currently in the middle of my MKTurbo install so over the next few days I'll catch everything up to this point as I'm sure I'll run into troubles.

Yay, more boring picture dumps!

After getting this thing, I decided to simply enjoy the car for the time being. This was my first manual car so I was focused on perfecting the basics, rev match down/up shifts blah blah blah. I quickly fell in love with this thing. I've always engrossed myself with all things cars, but throughout high school and some of college I was stuck with no outlet for my passion for cars and wrenching in general. I may be wrong, but the last time I checked '97 Avalons aren't in with the cool kids.

https://cimg7.ibsrv.net/gimg/www.mia...2000edee30.jpg


https://cimg3.ibsrv.net/gimg/www.mia...21c4b34c3f.jpg


Before I dove into any sort of modifications, I worked on catching up on basic maintenance. Oil change, coolant flush, air filter, fuel filter, and spark plugs. Ya know, the real exciting stuff. Overall the car was in great shape and seemed to have been taken care of. However, when I went to flush the coolant, I discovered it was probably never changed. Gross.

https://cimg8.ibsrv.net/gimg/www.mia...1fb7d38e37.jpg

I probably flushed the coolant system 3 or 4 times to rid the rust-colored coolant. In the end, it improved but the coolant was still a bit murky. A new radiator was definitely in the cards soon.

Shortly after finishing up on the routine maintenance, my slave cylinder decided to shit the bed. Thankfully, it went out right as I was pulling into my driveway. I ordered a replacement as well as a SS clutch line and threw it on. WOO! first (boring) "upgrade!"

https://cimg0.ibsrv.net/gimg/www.mia...71a3f1814c.jpg


Upon changing out the slave and clutch line, I found this mess. The source seemed to be the CAS as well as a little bit from the valve cover. Woo, more boring stuff. I'm sensing a common theme here...I placed an order for the O-ring and VC gasket.

People claimed the SS line produced a little firmer clutch pedal. However, I experienced no improvements. It was easier to bleed, though. Soon after the slave replacement, my master started to go bad. Ordered a new one and replaced it and OH MY GOD my clutch pedal felt so much better. Think from Limpy-Flop-Johnson to Juice Head Gerald after his pre-workout. It's probably not a big deal to anyone else, but I found that replacing something and feeling a noticeable improvement is really what I'm after in this hobby.

After catching up with the basic maintenance on the car. I began throwing some new shiny parts at it.

First, I swapped out the stock front swaybar for a FM front bar.

https://cimg5.ibsrv.net/gimg/www.mia...b18d8b7a98.jpg


https://cimg2.ibsrv.net/gimg/www.mia...b1bbda0646.jpg


I was excited to feel the improved handling characteristics. Sadly.. the car still felt like a boat with the amount of body roll still present. Bummer. I determined this was due to the front shocks being SUPER blown. I was practically riding on the springs alone. Naturally, I saved up my lunch money for some stock replacement front and rear shocks. Yes, the correct thing to do would have been to save up for some DIY Billies, xidas, etc. since that was the end goal, but It was all I could afford at the time. With how blown the shocks were, I couldn't have waited months to save for the good stuff.

Coming from only doing small maintenance on the Ol' Avalon, I was excited to take on a project of a more significant size. After the new replacement shocks were in, the car felt completely different. I was no longer driving a bounce house!

Now satisfied with how the car was driving, I spent the next few months simply enjoying it. Oh, and during this time I installed an R package front lip and a front tow hook. Tow hook is probably a little ricey but I like the look of it.

I took a few trips up to the Dragon since I only live about an hour away.

https://cimg1.ibsrv.net/gimg/www.mia...b49bdcdaa7.jpg

Surprisingly enough, with the (new) stock shocks and the front FM bar, the car handled the dragon pretty good! Granted, I only have a boat to compare it with.

More to come soon!

Update time. After spending time enjoying the car in stock form, I decided it was time for upgrades! First, I started with a Blackbird Fabworx Bar. Both for the added safety and rigidity and of course, the looks.

https://cimg3.ibsrv.net/gimg/www.mia...b960996c07.jpg

I even convinced my Pops for some assistance.

https://cimg4.ibsrv.net/gimg/www.mia...b89df754cd.jpg

Admittedly, the roll bar install was NOT very fun. I don't remember why, but I just sucked. I'm very stoked with the results though.

https://cimg8.ibsrv.net/gimg/www.mia...27cc7b7c8d.jpg

Up next, I wanted to try to get the car to feel a bit more comfortable while remaining stylish, of course. Being 6'1 and daily driving a small car leaves a lot to be desired in the comfort department. Headroom has always been fine but the area that need improvement was the leg room. My knees were only a couple inches from the steering wheel with the stock wheel.
https://cimg0.ibsrv.net/gimg/www.mia...af9c52dc7e.jpg


I opted for a 350mm deep dish Nardi Classic wheel. I absolutely LOVE this wheel. This was quite possibly my favorite addition to the car. The amount of additional leg room the small wheel and dish provided was simply amazing. It also helps that I really love the look of it. Please ignore my faded, purple floor mats.

https://cimg9.ibsrv.net/gimg/www.mia...89ffee0c3f.jpg

Over the winter break from school it was time to begin the slow and tortuous journey to boosted goodness. The goal all along was to try to do this right the first time even if it meant hearing the wonderful sounds of boost would be delayed by months or even years. What is (one of) the first steps to a reliable boosted miata? a standalone ECU! I saved and saved and purchased a MS3Pro from DIYAutotune.

https://cimg4.ibsrv.net/gimg/www.mia...bb18c2143f.jpg
https://cimg0.ibsrv.net/gimg/www.mia...7e73195f13.jpg


The initial wave of learning to tune was daunting, to say the least. But I was up for the challenge. Having the extra time between school semester was really nice because I was able to really take the time to learn to tune and really get the car dialed in on MS. The results were amazing! Even though the car was a bone stock 1.6 other than the megasquirt, the car felt so much more alive. 10/10 would recommend to someone willing to learn for an otherwise stock miata.

Alright, it's time to get this build thread up to date. A lot has changed so this will more than likely be a photo dump until I'm all caught up. Enjoy!


The plan all along was to keep with the 1.6 while I learned to tune and then toss in a VVT. 3 weeks later and a big package from across the pond shows up. EUDM VVT with 89k miles. Not bad! I didn't find out until after I placed the order that the EUDM VVT engines have the higher 10.5:1 CR. It was a bit of a bummer when I found this out since I planned to go turbo eventually. It is what it is though, The EUDM VVT comes with a square top so I'll count that as an overall win.

https://cimg6.ibsrv.net/gimg/www.mia...302024ebd1.jpg
https://cimg3.ibsrv.net/gimg/www.mia...1c11cf15ab.jpg

When this thing showed up, it was disgusting. I tried my best to clean it up as best I could without getting too crazy. First order of business, full front end maintenance. Timing belt, cam and crank seals etc.. Next, I threw in Flowforce 640 injectors and Supermiata Organic Sport Clutch. I also tossed in a new rear main seal, pilot and TO bearing while I was in there. I failed to snap a picture of the clutch setup but trust that since it's Supermiata, it's orange.

https://cimg1.ibsrv.net/gimg/www.mia...f413a9c147.jpg
https://cimg4.ibsrv.net/gimg/www.mia...16132f1334.jpg
https://cimg8.ibsrv.net/gimg/www.mia...8a491c5bf3.jpg

I always liked the simple look of wrinkle black with red lettering. I was pretty happy with how it turned out. With all of the maintenance items taken care of. Out came the boat anchor 1.6 and in went the VVT!

https://cimg4.ibsrv.net/gimg/www.mia...978efc251b.jpg
https://cimg0.ibsrv.net/gimg/www.mia...792f7b3029.jpg

With the fresh VVT being now in the car, now came the daunting task of wiring it in.


https://cimg3.ibsrv.net/gimg/www.mia...8b1d052e38.jpg
I finished up the swap a few days before my local Cars & Coffee so I was able to tune out a few of the gremlins beforehand. Boy, this thing felt great. It was a really proud moment for me. This was by far the biggest project I have underwent and it ended up going very smoothly! VVT plus the 4.10 diff made this thing feel so much more alive. I was on a stock exhaust and NA8 headers, so it was pretty choked still though. I think VD said I was at roughly 125 hp. Yes, I was the scumbag at C&C with his hood up. I didn't care, I was really proud of myself at the time. This was the summer of 2019 so just before COVID hit.

For the next year, I drove the car as is while I finished up my Senior year of Electrical Engineering classes. That's all the time I have for now, more updates to come soon!

Alright, time to fast forward to how the car sits today.

Long story short, my motor decided to self-install some windows on BOTH sides of the block. It was completely random when it happened. I was just cruising on the interstate in 5th at less than 15% throttle then... BOOM.

https://cimg5.ibsrv.net/gimg/www.mia...194dbb5247.jpg
https://cimg6.ibsrv.net/gimg/www.mia...06b5ddd69d.jpg

How is this for carnage pics?

https://cimg3.ibsrv.net/gimg/www.mia...0eebeefd5a.jpg

I found a decent deal for a replacement VVT motor with 150k miles a couple of hours away so I scooped it and brought it home. The PO claimed all of the front-end service was very recently done. TB, WP, pulleys, front & rear main seals, and both cam seals. perfect! I ripped the junk motor out swapped the necessary parts to the new long block and tossed it back in.

https://cimg7.ibsrv.net/gimg/www.mia...80063c8830.jpg
https://cimg4.ibsrv.net/gimg/www.mia...7015fed05b.jpg


The biggest bummer to blowing up the previous motor was that it wasn't 'rebuildable.' If it were rebuildable I would have thrown in rods, 8.6 CR pistons, and pushed for 280ish hp on the MKTurbo kit.

That's right, I haven't mentioned that last part yet. Before the old motor blew, it was turbo for about 8k miles running 10.5 psi on what I believe to be conservative timing. It was a 10.5:1 EUDM VVT and a base timing map was extremely hard to formulate. I made a very crude manual Det can and never heard any pinging. VD was showing it was making ~220hp. The car felt great.

Anyway, to make all of this work in swapping the new motor worth it to me. I decided to upgrade to the Supermiata Lightweight Flywheel and their Hybrid mounts.

https://cimg1.ibsrv.net/gimg/www.mia...d6418e4bdc.jpg
https://cimg1.ibsrv.net/gimg/www.mia...37636be96c.jpg
https://cimg8.ibsrv.net/gimg/www.mia...b2813ec121.jpg
Ready to drop in!

Ok, now we are up to date. This is where I need some help. After I got everything hooked up to the new drop-in motor and got it running, it's making a strange noise. On initial rev up, it makes a ticking/clicking noise that sounds like it coming from up in the head. The sound doesn't occur at idle, constant throttle, or when the RPMs fall. At first, I attributed it to some noisy lifters from the motor sitting for a time but after letting it idle to burp the coolant the sounds still persists. I'm aware that this may be an expensive noise but I would really like some confirmation on it before I begin tearing it back apart to rebuild.

I'm hoping others can chime in here with some advice. Here's a short video of the sound.


Things I have tried:

• bolt checked lots of stuff
• ensured the wastegate was fully closed and not rattling
• probed around with a stethoscope everywhere - nothing
• compression test - cylinders 1-4 were 170, 165, 165, 168 respectively

My leak down tester just came in the mail today. I will test this as soon as I can find an air compressor to borrow.

I'm open to any and all suggestions. Did I get burned from Facebook marketplace?

If the wood stick/stethascope test doesn't indicate any excessive lifter tick (which it shouldn't? If memory serves BP-Z3 heads don't have the hydraulic lifters that make that noise?) and the VVT actuator isn't all noisy, next place I'd probably check is an exhaust leak? Can you get your hands on a good straight edge to check the flatness/straightness on the head and the manifold? Seems to me like the noise is only happening when cylinder pressures are > atm (i.e. on throttle), but not with every ignition event, so I'd probably look there before checking the turbo-manifold or turbo-downpipe connections.

Also holy shit dude that motor really didn't want to stay in one piece did it? Did it just send a rod through the oil pan or did you get some new speed holes in the block as well? Might want to rethink those lower compression pistons...

I forgot to add. I did lightly drive it around my neighborhood and while on throttle uphill I noticed it made the noise rather constantly with each rev. It made me think it was my EBC ticking at first but nope. That's a good thought on a potential exhaust leak at the manifold. I'll try to dive into that this weekend along with the leakdown test.

I did poke the stethoscope all the way down to the bottom of the block in case it's bearing related but I couldn't hear the noise at all.

As far as the old motor goes I believe injector #1 started leaking heavily causing that cylinder to run very lean. There's nothing left of rod #1. I was so surprised by it it took me a few seconds before I thought to put the clutch in. therefore, the broken bits had a little extra time to wreak havoc. I haven't had a chance to fully tear down the old motor to inspect.

This is what leads me to believe the injector was leaking.
https://cimg6.ibsrv.net/gimg/www.mia...64d0996c7a.jpg

The weird ticking sound is fixed! Thanks to Spiff for the suggestion, I looked into the possibility the sound was coming from an exhaust leak at the manifold. I really had a hard time fathoming a sound like that coming from a simple exhaust leak. It just sounded too metal-clanky-ey for me to think that was the problem. I pulled off the turbo and manifold and sure enough, the old gasket looked like it was leaking like crazy.

https://cimg7.ibsrv.net/gimg/www.mia...eedfefae34.jpg
Now the next item on the list to figure out is a slight pinhole coolant leak around the water pump pulley. Where ever it is coming from, the face of the WP pulley is slinging it all over the bay. You tell because the face of the pulley looks like those trendy art paintings they make using a canvas attached to a drill.

I loosened and retightened the coolant lines coming from the waterneck that's just behind the T-Stat. After driving for a few to get it up to temp it seems to have fixed it. I'll keep an eye on it the next few drives.

Since the USDM VVT I swapped in is slightly lower compression than the EUDM, I switched timing maps to the one Brain has on Trubokitty.net. Hoooooly cow the difference! His map is about a blanket 5-8 degrees more advanced than my uber-conservative timing map. I still pulled about 2-3 degrees from peak torque to redline in boost because I'm scared. I also pulled some in the cruise area for the same reason. The car feels so much better now. Even out of boost I can tell the car picked up a lot of power.

I'm currently running on wastegate (8psi) until I get more confidence it won't explode on me again. I'm also waiting for my catch can to come in the mail.

Here is a snip of my old timing map from my EUDM VVT with 10.5:1 compression. It was very tough to find a base timing map to the higher compression VVTs . I ran it for almost a year at 10.5 psi until injector 1 leaked and it windowed the block.

https://cimg5.ibsrv.net/gimg/www.mia...1afa61f40f.png


And here is the updated timing map from Brain's Trubokitty.net base map for 01-05 miata. Like I said, I pulled some timing in boost and cruise from his base map because I'm a panzy. If anyone would like to comment on my old or new timing map, I'm open to any advice!
https://cimg6.ibsrv.net/gimg/www.mia...5dfd5ec741.png


Lastly, while I was out today I took a quick VD pull in 2nd gear. I know 2nd isn't ideal but it's showing I'm at about 204 hp at 8psi. If I can find an old VD from the previous VVT I'll upload it later.
https://cimg6.ibsrv.net/gimg/www.mia...172a312e5c.png

Hate to bring this to you but the eudm vvt has the same 10:1 as the usdm. Only JDM had 10.5:1.

That is news to me. When I was conducting my initial research for the vvt swap, I saw that jdm bpz3 had the higher compression like you said. Perhaps I assumed jdm and eudm were the same? Who knows.

Hopefully you didn't just replace the gasket. After 8k of turbo miles, once you remove the manifold, it'll need to be surfaced. Put it on a flat surface and I can almost guarantee it'll rock.

Thank you for pointing that out. I admittedly had no idea that the manifold needed to be resurfaced that often. I only replaced the gasket, however, It seems to be free of leaks for now. Next time the manifold comes off, I'll definitely check this.

On another note, I've been thinking about my misinterpretation of the EDUM VVTs having the same 10.5:1 compression ratio as the JDM VVTs. Considering my previous timing map was quite conservative in all areas of the map, could this have possibly contributed to a slow death of the previous motor? I don't think I've heard of that being much of an issue from others. I'm more or less thinking out loud.

There are lots of imported jdm miata's being scrapped in the uk. So there is a slight chance that if you bought a vvt engine from a uk-source that it will have the 10.5 pistons.

That's comforting to know that my concerns may have not been in vain!

I do have a question to ask the masses or the greybeards around here. So with the updated timing map, the car definitely picked up power everywhere. However, after searching around and reviewing other maps I'm concerned mine may be too hot in boost. The easy answer would be to run DIY's 01-05 base timing map and be done with it but everyone knows it's REALLY bad. I'd really rather not send another rod to the moon any time soon.

As stated above, my map was taken from Brain's basemap he uses for 01-05's with a few degrees taken out in boost because I'm scared. From the other maps I've seen from looking around, Brain's map seems pretty aggressive. I hate to ask this question but could someone give me some advice on my timing map? Here's a more up-to-date map. I'm running 10 psi and don't intend to turn it up any more than maybe 11.

https://cimg7.ibsrv.net/gimg/www.mia...b38803367d.png

I have an OEM knock sensor but it's not wired up. I'll tackle that this weekend. I don't hear any knock but these supermiata hybrid motor mounts are pretty buzzy.

Also, while I'm on the topic of sanity checks. I've noticed that my VE table is settling at less than 100 VE in the majority of the boosted cells. To me, that seems theoretically wrong. Any ideas? The car runs well otherwise. This is just something weird I've noticed. Injectors are FF640s. I've attached my .msq for your viewing pleasure.

https://cimg2.ibsrv.net/gimg/www.mia...72267a487a.png
I'm still in the process of auto-tuning the VE table but I'd say it's 90% good to go.

I'll make it quick:

Spark map looks a little hot for my taste with 10:1 on pump gas transitioning into boost. I'd pull 1-2° until your knock sensor is running or you have some good knock ears.

Your VE-table looks pretty much like mine, as long as your car runs right and you have enough resolution and don't go to low or high (255), it's okay. If you've set req fuel and dead times, fuel pump/pressure right, no worries.

Nice build!

As mentioned in pm AFR's are too rich and too soon (junior!) for my tastes. Suspect that's why your FF 640s are seeing 90% injector duty cycle at 10psi.

Get that knock sensor properly set up as a matter of urgency. It'll save your motor.

Oh and double check your injector dead times & fuel pressure are correct. :likecat:

Hey, thanks again for all of the information in the PMs! I'll do back to back VD pulls and target a slightly leaner AFR in boost to check if I gain anything.

I finally have access to my VD plots you were asking about. I'll also toss in the data log of the VD pull showing the 90% duty cycle.

In an attempt to bring my mass following (ha!) in here up to date. The car is currently running 10 psi tapering to just a hair over 11 psi at redline. When looking through the VD datalogs, I noticed my FF640s are touching 90% duty cycle. According to others on here, that should put me close to 300hp. The car feels great but not that great. VD puts me at a somewhat puny 225hp. Somethings funky here.

I've checked the Barometric correction and it's not affecting it. I also don't believe the problem to be fuel pump related. If I command more fuel in the top end my AFRs change accordingly. Allofit suggested I check that my fuel pressure and injector dead times are input correctly in TS. I'm using the stock NA6 FPR so it should be 43.5 psi. TS is showing 42.9. I can't see that small difference making a huge impact. The injector dead times were input with data straight from Flowforce. So I'm still at a loss here. I'll try changing the fuel pressure from 42.9 to 43.5 to see if there's a difference and report back.

In the meantime, here's an updated 3rd gear VD pull and the associated datalog. I'll get off my ass and install the knock sensor real soon I promise!

https://cimg8.ibsrv.net/gimg/www.mia...6a59647831.png
https://cimg9.ibsrv.net/gimg/www.mia...2b65a1531f.png

Edit - Before anyone comments, I fixed that 11psi spike on the initial spool-up. The VD plot shows me hitting 11.8 AFR towards the top end at 10 psi. Nowadays I'm consistently hitting 11.5 AFR.

I've had a look through your log and tune again.


https://cimg8.ibsrv.net/gimg/www.mia...662469b676.png


Your VE table makes a pretty big jump in the 180kpa row as you move from the 6100rpm cell to the 7000rpm cell. That's where your injector duty cycle shifts from 80% to 92% in the transition between those cells.

Expect the general shape of your VE table to be similar to the shape of the engine's torque curve. By which I mean it will start low, increase and peak, and then begin dropping as rpm increases.

My VVT motor and tune has the VE table numbers level off around 6000-6500rpm and then start falling beyond that. Your VE table numbers are rising exponentially well beyond your engine's torque peak as shown in the Virtual Dyno plot.

And I still think a target AFR of 11.5 is too rich for just 180kpa! :)

I apologize, I should have uploaded an updated version of my tune with that datalog earlier. The tune and subsequent VE table you are referring to are pretty out of date. I think I was only on wastegate at the time.

Last night after work I took the car out for back to back VD pulls. The first pull was with my current target of 11.5 AFR in boost and the 2nd pull was targeting 11.8. As you can see, there is a noticeable gain however the 2nd pull peaked at 12 psi vs 11.5psi from the first run. /shrug

I also adjusted the fuel pump pressure in TS from 42.9 to 43.5 but no noticeable difference was made. The duty cycle on the FF640s is still in the 90s at redline at only ~225 hp. I'm still stumped on this one.

https://cimg7.ibsrv.net/gimg/www.mia...ad44dd21ac.png

Both pulls were taken within 10 minutes of each other on the same stretch of road in the same direction. Side note, I'm not concerned with the hp/tq numbers. I had my girlfriend in the car with me and I wasn't about to ask what her weight was. :rofl:

Current tune and datalogs of both pulls are below.

Since NB2 has a higher pressure system (60psi vs 43), your input of injector flow at the req fuel table is wrong. Should be in the 720's if I'm not mistaken.
But that still doesn't account for such high injector duty. It should be in the 30s or 40s in your case.
Also I noticed your alternator control is set to "off", while MS should control it to the best of my knowledge.

Your fuel pressure is probably tanking at higher RPM. Hook up a fuel pressure gauge and go for a drive.

Can we have some more details about your '91 FPR setup? Are you using a 1999-2000 fuel rail with it?

Yes this.

I'm using an NA8 alternator so voltage regulation is handled by the alternator.

That's a very good thought, I'll see if I can find a pressure gauge locally. I'm assuming If I'm losing fuel pressure this would point to a bad pump, correct?

Absolutely. Since I'm NA VVT I'm using a 99'-00' fuel rail with the stock NA6 FPR flipped upside down. Exactly how It's outlined in the VVT megathread.

On the topic of fuel pumps, I hear DW100 pumps are fine but DW200 may overwhelm the FPR. The 200 seems to be more common than the 100, however. I'm wanting to push the car towards the 300hp number in the future. Would the DW100 still handle that power level? The current fuel pump in the car may be the same one that rolled off the showroom floor. I may order up a new one anyway. I'm just trying to decide which of these two would be best for my long-term goals.

30 year old OEM fuel pump with 150k miles wear and tear? Yeah that might be your problem. :likecat:

From: https://www.miataturbo.net/engine-pe...er-logs-91349/

Thanks for the link, I actually happened upon this when I first researched my issue. I figured since my AFRs in boost reacted accordingly to a change in commanded fuel, I could rule this out. On the same coin, a drop in fuel pressure in the top end resulting in an increase in injector duty cycle to compensate makes perfect sense to me. A DW200 will be here sometime next week!

I'm hoping to get out to the garage tomorrow to install my 2nd catch can and finally wire up the OEM knock sensor.

On paper, the oem pump is just about sufficient, but after 30 years of wear and tear, they often don't flow quite enough and it's better to upgrade. DW200 is a good choice.

If you look at your logs, you go from ~70% injector duty cycle at peak torque of ~5700rpm to over 90% injector duty cycle by ~6700rpm. That's a clue.

After the new fuel pump is installed, spend some time working on your VE table. Those fuelling numbers should be flattening off around 6000rpm with a square top and VVT head. I'll upload my VE table later for reference.

Btw, your 'VD1 rich' log AFR's are getting down into the 10s at 170-180kpa. :ugh: