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Quick update:
Oil leak popped up again after the first drive in a couple weeks, but this time I was able to verify the Mishimoto sandwich plate is leaking when warm. So I ordered a speed factory racing sandwich plate in hopes the design differences will stop this madness once and for all. lol
I think the shape of the sealing gasket might make the difference. Square vs round.
Not sure if my Mishimoto sandwich plate is leaking or if it's the RSX oil cooler. One single drip of oil on the bottom of the filter but never seems to get worse than that. Interested to see what you find.
So far so good, my dudes! No leaks over 50ish miles in varying driving conditions.
But here’s the interesting part. Again, the center of my oil filter was empty when I swapped it out. I have a working theory that these mishimoto sandwich plates are not only leaky, but for our cars and probably others, potentially harmful to the motor.
So the mishimoto plate in the most basic terms, feeds engine oil from a pressurized “pool”, between the block and the oil filter. This area is where the tapped ports for oil pressure and temp sensors, along with turbo lines live.
Our oil filters flow from the outside-in. Oil feeds through the little holes, and out the larger middle passage. If you look at a Honda “small” oil filter, you will notice an orange gasket under the inlet holes. These holes work a lot like a diaphragm on a wastegate. These require engine oil under pressure to actuate. This means as oil pressure rises, the flaps open and the pressure the equalizes. In a perfect world, that’s where you should see some of the highest oil pressures in the system, since it must be forced through the filter element.
Notice an issue here with mishimotos design, at least on a d-series application? Any feed line, or leak associated with that sandwich plate will cause a flow restriction to the oil filter.
Now before someone claps at me and says something about “the pressure will eventually overcome the filter”, let me respond by using some logic here. The last 3 filters have had very little oil inside them when uninstalling. if we know oil flows from the outside in, then that pressure should have overcome the filter and pooled in the center.
That means any contaminants whether it be from a new build, or dirty oil are being fed back through the turbo and ending up right back in the oil pan, while your motor is starved of clean oil.
A more correct design would feed the engine oil after filtering. Speed Factory Racing and a couple other manufacturers make this style.
This isn’t a post bashing mishimoto, as this has been the “standard” for a long time. I just wonder how many big power D series cars have failed due to this silly little adapter.
TLDR: Don’t run a mishimoto sandwich plate on your turbo d series Honda. Oil starvation and contamination may occur.
The problem I have with mine is there are two oil feed ports on the sandwich plate. I believe both are pre-filter. My turbo oil feed comes from here. Normally, the check valve in the filter stops oil from draining back through the filter when the engine is shut off. This should also stop oil from draining back down the pump feed and into the pan since there is no way for air to replace the oil. However, since my turbo feed is pre-filter, this means air can back-feed up the turbo drain, through the turbo and oil feed, all the way back to the sandwich plate allowing all the oil from the pump up to the filter to drain down over time. This leads to low oil pressure for a second after starting when the car has been sitting for a while. I can hear piston slap and it pains me. I need to relocate my turbo feed to somewhere post-filter.
Im so glad this thread is still a thing. I had to resurrect my old account to jump back on. Similar to you I did the same thing. Took my years of improved mechanical knowledge and got my d17 turbo build running in 2020 and have kept making it better since. Really interested to see some details on your turbo and what your spool up looks like. I have a log manifold right now. Bw s200 56sx 20psi.
The problem I have with mine is there are two oil feed ports on the sandwich plate. I believe both are pre-filter. My turbo oil feed comes from here. Normally, the check valve in the filter stops oil from draining back through the filter when the engine is shut off. This should also stop oil from draining back down the pump feed and into the pan since there is no way for air to replace the oil. However, since my turbo feed is pre-filter, this means air can back-feed up the turbo drain, through the turbo and oil feed, all the way back to the sandwich plate allowing all the oil from the pump up to the filter to drain down over time. This leads to low oil pressure for a second after starting when the car has been sitting for a while. I can hear piston slap and it pains me. I need to relocate my turbo feed to somewhere post-filter.
I would recommend teeing off the low oil pressure light port. I installed a tee type fitting here. Its a 1/8” npt thread so you can get the adapter with 1/8 thread on one side of the tee then open hole on the other 2 sides. Then I used 1/8npt to JIC fitting for my turbo feed line and put the pressure light back straight in. Best solution I’ve found.
Im so glad this thread is still a thing. I had to resurrect my old account to jump back on. Similar to you I did the same thing. Took my years of improved mechanical knowledge and got my d17 turbo build running in 2020 and have kept making it better since. Really interested to see some details on your turbo and what your spool up looks like. I have a log manifold right now. Bw s200 56sx 20psi.
Honestly, my turbo is the "weak link" in my build, seeing how its an ebay special T3. However I do see full boost (whether its a wastegated 5 lbs, or an unrestricted 17 lbs) by about 4000 rpm. Based on my datalogs, power isn't dropping off at the top end, so I might just have an efficiently matched turbo for the motor.
Honestly, my turbo is the "weak link" in my build, seeing how its an ebay special T3. However I do see full boost (whether its a wastegated 5 lbs, or an unrestricted 17 lbs) by about 4000 rpm. Based on my datalogs, power isn't dropping off at the top end, so I might just have an efficiently matched turbo for the motor.
very interesting. I'm at 17 around 4600rpm. My other car makes 17 around 3100. Would be nice to get my civic into the 3000's. Been eying up the pulsar 4849g and doing a t3 to vband low profile adapter but concerned about clearance to the clutch slave cylinder and everything else in that area. there's just not much space behind the rad support. How's everything else going?
Well I got the Datalog and High/Low boost switch wired in, and I made the changes for that in KManager this evening. Once the weather calms down out here, ill be testing it all out.
very interesting. I'm at 17 around 4600rpm. My other car makes 17 around 3100. Would be nice to get my civic into the 3000's. Been eying up the pulsar 4849g and doing a t3 to vband low profile adapter but concerned about clearance to the clutch slave cylinder and everything else in that area. there's just not much space behind the rad support. How's everything else going?
That's why I cut my center bar out of my radiator support, and swapped to a 96-00 civic mishimoto half size radiator. It's snug, but I have room to get a bigger turbo, assuming I orient it with the cold side towards the driver's side of the engine bay. Currently mine has the cold side on the passenger side of things.
Edit:
Why not spray nitrous to get that turbo spooling at little earlier? Also, what are your quick spool settings in kpro?
Last edited by chozobody; Feb 29, 2024 at 12:23 PM.
I ordered tires today, since I keep breaking loose on low boost. Got some Toyo r888R's in 225/45r17, running them on the same wheels I have now. Just 2 tires, since i'm keeping my daily 205's in the rear (conversation for another day). Should be a good fit for the strip this spring.
Mini update. 3/25/2024
Got the new tires installed. 225/45R17 Toyo Proxes r888R. Seems to fit with no rubbing. I'm hoping these will hook a bit better. Too bad the high today was 34 and way too cold to test. The warm weather can't come soon enough.
I took the civic out for a spin today. The new tires will be a game changer. Not too big, not too small. On the high boost setting, 18 lbs has me skating along, fighting actively having to "drive" the car. I have broken through my boredom plateau and am proud to announce the civic scares me once again.
4/26/24
I got some logs this past weekend, and made some time to work on the tune again. However she loves boost so I have to start tuning in the >= 20psi boost pressure areas of the table. 😈
