The white-mess, my EM1 Si with a d16y8.

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The muffler is actually 2" input, but 2-1/4" output.

Downpipe is now connected to the midpipe. 255lph fuel pump is installed. Idle is stable once warmed up now that I fixed the exhaust leak from the PCV.

Now I need a 2" OD to 2.5" ID (2.4" OD actual) coupler to connect the mid-pipe to the stock-ish muffler temporarily until I can get around to making a 2.5" mid-pipe-back exhaust.
 
Spark plugs are in.
Muffler is connected.
Dump pipe is out of the engine bay.
Wideband O2 is calibrated.

I TIG brazed this piece, because, again, it's different metals/alloys and I didn't want to accidentally burn through either piece. I keep forgetting to take pics of the underside of the car.
IMG_20190615_200357.jpg


Now I can't get the ECU to work right, lol. Every cell is suuuuuuper rich, like 9.8 to 10.2, I suspect something is up with the ECU, because I can't seem to get it to not throw a limp-mode CEL now... :(

The ECU does have some spots I wonder if it's burned up, and that's why I got it for $65 shipped... Perhaps I'll have to try to find another somewhere cheap to test this possibility.
 
It has no CEL, idles, drives, builds boost, and has an exhaust leak somewhere...

AFRs are anywhere from 9.8-15. I still need to clean up the map a bit. Got it to idle at about 14.5 AFR, and I realized that for whatever reason crome gold's autowrite/realtime update isn't working... I wish I had known that a while ago, sure would have saved some frustration.

I think I'm going to have to ditch crome: nobody tunes it anymore and it's actually garbage.

It makes somewhere around 8lbs of boost on just the wastegate -- which is perfect. It doesn't really spool up until about 3300 RPM though.
 
I found the exhaust leak while cleaning up the garage... An unused turbo gasket. So, yeah, I forgot to install the turbo to downpipe gasket, that's where it's leaking exhaust.

Anyway, here's what Maddison looks like right now:
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It's hard to tell there's anything wrong but bad paint, and an ill-fitting hood, grille, and bumper.
 
Lol, trying to get the downpipe put back on after putting the gasket in there, I broke a bolt off in the turbo.

Luckily it was right at the head of the bolt, so a pair of pliers made quick work of it. Now I need to go buy some more stainless steel bolts, so they all match. Yay. One more day.
 
Lol, trying to get the downpipe put back on after putting the gasket in there, I broke a bolt off in the turbo.

Luckily it was right at the head of the bolt, so a pair of pliers made quick work of it. Now I need to go buy some more stainless steel bolts, so they all match. Yay. One more day.

It's always gotta be something. Lol.
 
A tip on the gauge cluster if you ever have it apart again.
A black piece of electrical tape laid over the automatic part of the cluster will make it almost invisible unless you know to look for it.

This project escalated quickly. Good read though. Brings back so many memories. Thanks for sharing.
 
Thanks for the feedback guys. After I get the downpipe bolts in, it's done for now.

I feel like the only thing I have left to do is tune it, but we'll see. I may have to implement boost control if 7/8lbs isn't enough to make the power goal.

I'm going to keep trolling facebook to see if I can find a d16y8 or a d16z6 and spare transmission to throw on an engine stand and rebuild for when I pop more than a head gasket.
 
Thanks for the feedback guys. After I get the downpipe bolts in, it's done for now.

I feel like the only thing I have left to do is tune it, but we'll see. I may have to implement boost control if 7/8lbs isn't enough to make the power goal.

I'm going to keep trolling facebook to see if I can find a d16y8 or a d16z6 and spare transmission to throw on an engine stand and rebuild for when I pop more than a head gasket.

What is the power goal again? Turbo specs?
 
What is the power goal again? Turbo specs?
The goal is to get about 250hp and 200 ft/lb. Either way, it should be doable with a good tune on stock internals.

Turbine A/R .63
Turbine Diameter Minor: 61.9mm
Turbine Diameter Major: 70.80mm
Compressor A/R .50
Compressor Wheel Minor: 58mm
Compressor Wheel Major: 76.15mm

I got some older rt615k (non-plus) Azenis the other day, gonna put them on the LS wheels at some point.
IMG_20190622_130825.jpg
 
The goal is to get about 250hp and 200 ft/lb. Either way, it should be doable with a good tune on stock internals.

Turbine A/R .63
Turbine Diameter Minor: 61.9mm
Turbine Diameter Major: 70.80mm
Compressor A/R .50
Compressor Wheel Minor: 58mm
Compressor Wheel Major: 76.15mm

I got some older rt615k (non-plus) Azenis the other day, gonna put them on the LS wheels at some point.
View attachment 27348

Nice! I missed the specs of the turbo earlier, I guess. But that should be a solid setup for 250whp.

I had RT615s on my hatch for a brief moment in time, they hooked pretty well at ~320 whp. :Thumbsup:
 
The more I ruminate on the tuning issue, the more I think maybe it's a fuel pressure issue. I didn't buy a walbro 255 pump until last-minute, and I didn't know why I didn't buy it initially with all the other stuff, then I realized why.

At some point, I found a post on Honda-Tech stating that the 99-00 Civic Si had a 135lph fuel pump. Google search history tells me that I already saw this post and I must've done the math at some point too, because when I calculated the number of CCs per minute the 135lph fuel pump can flow and divided it by injectors, I came up with 562.5, which seemed to stick in my head. Granted, I don't need 550cc/min of fuel, I only need somewhere around 425cc/min, which means I need 102lph of fuel -- this gives me a safety margin of about 30%.

So, I think I'm gonna remove my daughter's car seat, remove the back seat, and re-replace the fuel pump with the stock fuel pump. I'm still going to throw a gauge on it, just to make sure the theoretical universe lines up with reality, but I think it will just this once.

EDIT:
Hondata has a good page on this:
https://www.hondata.com/tech-fuel-pumps


fuelpumplitresmin.gif


This means that the fuel pump can flow enough fuel for large amounts of power if the the fuel pressure is kept low. This means that large injectors will need to be used.

What is important to note is that this pump (and most others) has an internal bypass valve that opens at 75 psi.

So from this graph, Hondas running the stock pump, and a rising rate regulator top out at 75 psi and about 200hp. So, this is not a good solution.

But, if you run your stock fuel pressure (say 40 psi) and this stock fuel pump, 650cc injectors will easily provide you fuelling for low 300 wheel HP. Honda computers will easily idle a 1600cc engine on 720cc injectors.

So, damn. I wasted the money on a 255lph pump.

I probably wouldn't have figured this out if it hadn't been for a post on the HunterTuned facebook group where someone asked something about fueling and someone responded with some questions about their fuel pressure at idle, which got me thinking.
 
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Correct me if I'd wrong but I think most people run the Walbro with stock injectors and a FMU.

Now I'm curious if I needed a Walbro. I had the larger injectors and a Chrome tune in the 90 hatch with a D16z6.

If you are running larger injectors and tune, why not leave the walbro in?
 
Well, I swapped out the walbro 255 with my stock Si pump. Immediate difference in the response of the tuning to AFRs. I think that was it. I may upgrade to an aftermarket fuel rail, regulator, and lines at some point, but it's not going to happen yet. I'm not 100% sure what the issue was, but I want to get an alright tune on it, then I'll play with it a bit more. As it stands right now, I think I could drive it to a tuner. I need to pull a bunch of fuel, and add timing pretty much everywhere, but it's safe now.

I got some good rips in, it's making 5 PSI with a super-restrictive muffler, and I think it's leaking from the downpipe to the turbo still, because I need to fix the bolts. You can definitely feel when the boost comes in, so that's good. It still feels as quick as it did before the turbo, but now it comes more alive when wound up. I've gotta get rid of this 2" muffler.

Most people did use an FMU with a walbro 255, then used an AFC hack to lean out everything 25% or so when not in boost, so they were looking to increase the fuel pressure to get more fuel into the engine under boost. My issue is that it ran great in boost, but couldn't do anything out of boost. Now it's alright in and out of boost, I just need time to drive and tune it.
 
Received the fuel pressure gauge, it's all within specs at idle and at key-on. No issues there now.

I got the downpipe removed, the mounting bolt holes fixed a little bit, gasket replaced, and tightened down and now it doesn't leak. I also got the midpipe tightened, rotated, and cut down a bit more so it'll fit the intermediate pipe now. Now I just have to figure out the muffler situation, for now it's just an angled turn-down dump. Once I get some stainless steel rod, I'll make better hangers, right now it's just welding rod holding the end of the intermediate pipe.

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How much boost are you generating now with the leak fix and muffler removed?
 
Got it prepped for paint. I sprayed a little of the driver's door, roof, and the first part of the rear quarter panel last night, and it came out pretty nice, so I'm gonna go with this.
IMG_20190703_124110.jpg



Don't worry, I'm actually prepping the surfaces, lol. I've scuffed with brillo, cleaned with degreaser, etc. It's not bad paint, other than it doesn't lay down "wet" so you can't see what you've already covered easily. I should have dusted with a primer so I could see what I was covering, but I don't want to see-through the paint... Maybe I'll just put a bunch more lights in the garage and maybe I can see it better...

Anyway, car looks like this right now:
IMG_20190703_133744.jpg


Hopefully I'll have the fender and the rest of the body paint done tonight, after I paint the office/playroom in my house like I told my wife I would before I bought the car. So, gonna get the paint to do the car at the same time as I get the paint for the office.

Picking up a stainless exhaust and straight through muffler tonight, it's cheaper than having a shop bend up a muffler/axle-back piece for me. So, yeah, more money I didn't expect to spend, but it's not bad.

I got some other ancillary bits, like a front traction bar, solid engine mounts, fuel lines, and a new throttle body to hopefully fix the "throttle sticks closed" issue I'm having. It seems like it's the TPS side that's binding, so $53 on eBay and I got a TB with sensors on it. Woo.

I bought BMTune, because they're running a 40% discount right now, and I've got what seems like it might be a run-able basemap. It is actually actively being developed, so it's got some legs-up on crome. I'll get to play with the tune later this week. I'm hoping to have everything running decently well by the 24th of July, so I can bring this thing to a car show. I've still gotta get those wheels finished though, so that doesn't leave much time. We'll see...


More updates as they happen.
 
Now I'm curious if I needed a Walbro. I had the larger injectors and a Chrome tune in the 90 hatch with a D16z6

I have an old, unused Walbro I can send you. I'll check the part number to see what it works on or if it's car specific.
 
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