hi! from a newbie in canada. rb25det neo, in 240sx

[Matt]

Under Operations > Active Tests, there is a Valve timing solenoid in the drop down. You can select this on or off (greyed out) and start test. It sohuld click

VCT will only work on NEO engines if you have a speed input, since this is an engine conversion, you may not have a speed signal. Patch this from the 240SX dash loom (to the old ECU plug) into the NEO loom and it will work again

Tach might be out with the difference too, compare it against Nistune tach

[polemite]

awesome. i know i've seen the ecu speedo signal come back through consult, (wiring specialties conversion harness), but its still worth checking. i wouldn't know what it feels like to be with vs. without vtc

i'll have to figure out a good way of mounting the laptop while driving. another winter project.

[polemite]

so i've gathered up the parts for the next phase of my build.
plazmaman top half plenum, sinco exhaust manifold, custom built turbo, and a diy kit for the downpipe.

when it comes to fabbing up the downpipe, i'm just wondering if i need to retain the oem o2 sensor? i've heard of guys getting rid of it, but haven't really seen how they've done it, or if it's something that you would only do on a track car perhaps?

is it recommended to keep it, or is it easy enough to get rid of? i just need to know if i should be shopping for one or not.

[Matt]

You dont have to keep the O2 sensor unless you want it to keep closed loop during cruising (emissions, economy etc). Otherwise if you are running a wideband, and have a 0-1V narrowband output you can put that into your O2 sensor wiring and use that

[polemite]

oh! that would be a great feature, but it doesn't look like the aem wideband has a narrow band output. oh well, it's not a whole lot more work to keep the oem sensor in the loop.

thanks.

now i just have to figure out how to do a remote mount iacv with this plazmaman plenum... no flange for it on the plenum, and no instructions for what i'm supposed to do with it! haha

[tsuokun]

oh! that would be a great feature, but it doesn't look like the aem wideband has a narrow band output. oh well, it's not a whole lot more work to keep the oem sensor in the loop.

thanks.

now i just have to figure out how to do a remote mount iacv with this plazmaman plenum... no flange for it on the plenum, and no instructions for what i'm supposed to do with it! haha

The AEM UEGO from way back had 0-1v narrow band simulation. It worked quite well in my PS13 Silvia, but for example the Tech Edge NB sim did something strange to my HCR32 ECU and it would fail the emissions test. I haven't tried it with NEO ecu though.

But about that plenum, I am slightly shocked that it doesn't come with a flange adapter for the IACV. I have been trading some emails with Plazmaman people about it and they quite straight up failed to mention that. They only said they substituted the flange with a hose barb, but what I thought was that they'd instead provide the flange as separate with a hose barb in it so the IACV can be placed where ever one pleases. That is quite a killer for me, as I cannot fabricate much where I am now. Do update if you found a solution. Did you also get the IC piping or such?

Sorry for the slight thread hijack.

[polemite]

no problem!

my apologies. it did include the flange. it had been a while since i went through the box. it's in there as a separate piece, and it's meant to be remote mounted.

however, it doesn't include the gasket for the iacv, throttle body, or the plenum base.

i didn't get any instructions, but they tell me that was a mistake. easy to fix, as they just emailed them.

the instructions suggest that sometimes the original gaskets can be reused. i kinda wish they wold have just included new ones. the r33 base gasket is a thick rubber thing, but the r34 is metal, with crush rings around the runner openings. the iacv gasket is just paper for either, but totally different from r33 to r34. they might include a tb gasket if you buy their tb, but i'm using an oem r33 (r34 tb is massive and doesn't fit).

the instructions don't suggest a good place to remote mount the iacv, but in our emails, it was suggested that the right shock tower is a good spot. seems a bit busy there for me, so i'm going to try to find a spot on the firewall.

for anyone in north america reading this, the plenum fits just fine under the hood of my s13.5, with at least 1.25" clearance at the highest spot. i assume it would be close to the same with the pop up hood. i am using the mckinney engine mounts. i mention all this because i was told that hood clearance can be tight on s13 swapped cars. not sure if their design has been updated, or if that is only an issue on aussie cars? not sure what engine mount design you guys normally use.

i will have to come up with a totally different fuse box mount though. and there is a fair amount of hose work to do, for the coolant and fuel lines. (i plan to keep the stock fuel rail).

i did not opt for the plazmaman intercooler plumbing. i'll be fabbing that up myself.

[polemite]

still plugging away at this. remote mounting the iacv turned out to be a much bigger job than anticipated. i'll post pics of that later on.


for now, i just have a question about the boost sensor, if anyone can help. there is something inline with the feed for it. i assume a check valve or damper of some kind. i assume it's best to keep this thing, but wanted to ask, if it's something i can get rid of.

[tsuokun]

That black/orange plastic thing is labled as "vacuum tank" in the service manual and I am guessing it serves to dampen the pressure "signal" the sensor sees. I was unable to locate mine at the time, when I was plumbing the sensor back and substituted it with slightly more aesthetically pleasing see-through vacuum line filter I had at hand.

I have since found the factory part but haven't replaced it yet. I do get some warnings about the boost sensor not being correctly plumbed but I somehow doubt that has anything to do with there being a clear filter instead of the vacuum tank, because the sensor seems to work fine.

[Matt]

To verify VCT make sure
1. Consult View window - neutral is off
2. VCT TP enable pull that to 0 and it should turn on , put it upto something like 50 and should turn off

[polemite]

thanks guys.

[polemite]

so now i'm currently working on building the downpipe. i'm planning to do a pumbed-back external wastegate, and i've got a question about that, in relation to the o2 sensor.

i'm guessing it doesn't really matter if the bung is upstream, or downstream of the wg re-rentry, since some people vent to atmosphere.

but would there be any benefit, from a tuning standpoint, to be reading, or not reading, the gases passing through the wastegate?

[Matt]

i'm thinking the mixtures should be the same once all 6 cylinders are combined into one pipe in the manifold, assuming there is no fluctuation due to airflow turbulence before/after wastegate

Given the narrowband o2 sensor is normally reading in cruise conditions, then we would not expect turbulence anyway, so it should not matter I would think?

[polemite]

yeah, it should all be the same mixture, i would imagine. there would just be less of it being seen by the sensors if the wg is bypassing them.

my oem sensor is definitely going to be bypassed, but i could potentially do it either way for the wideband.

probably overthinking it, as there are lots of guys running the wg to atmosphere. definitely bypassing their wideband.

[polemite]

hey guys,
found some interesting info about turbo clocking on the garrett website. they say 20 degrees off of vertical gives you a nice cooling effect, if your coolant outlet is on the high side. scroll about half way down the page to get to the relevant section of this article https://www.garrettmotion.com/racing-an ... our-turbo/


so now i'm just wondering if anyone can confirm the coolant flow direction for the turbo?
does it go
block>turbo>intake runners
or
intake runners>turbo>block
?