SR20DE ecu in SR20DET

[azreark1]

Has anyone ever seen a #60 ecu running an SR20DET without a tune/daughterboard?! As i'm digging deeper into just what i have on my hands i'm finding some serious irregularities on my car. It is an SR20, that much i know for sure, it has all the workings of an S13 redtop EXCEPT for the fact it is running a SR20DE ECU and distributor...crazy thing is there's nothing to indicate the ECU has been tuned to accept the boost, but the damn thing runs great! Only problem i've come up with is the fact it's wired with a Z32 MAF because it looks like there WAS an SAFC on it which made the MAF work right (not anymore :( ). I've got 52F markings on the head and block but the oil drain from the turbo doesn't go to a fitting on the bottom of the block (because there isn't one) it goes to a fitting welded into the lower oil pan...and there aren't any oil squirters (fresh rebuild)...i'm just completely lost with all the mix and matched parts on this car...

[japslapsilvia]

Sounds like you have an SR20DE and someone put a turbo on it.

[azreark1]

Yeah seems you're right, no oil squierters means DE block...yay. Oh well, the thing builds boost fast and runs great so i'll drive it like i stole it lol

[TurboTiger]

Did you buy your car already swapped or did you buy this engine from someone?

[azreark1]

Bought it already swapped, had to rebuild the engine though.
I'm just baffled at how the car is even running boost if the ecu isn't programmed for it, I thought it would go crazy if it detects the forced air.

[5280VertDET]

I ran a G20 P10 ECU with a SR20DET and a SAFC. Ran great. Interesting how well it runs...

Have you opened the case and looked for a ROM tune chip?

[azreark1]

Yeah, opened it up last night...bone freakin stock.
Guess people weren't kidding when they say it's a very durable platform...

[Croustibat]

Bought it already swapped, had to rebuild the engine though.
I'm just baffled at how the car is even running boost if the ecu isn't programmed for it, I thought it would go crazy if it detects the forced air.

It drives != it works correctly.

These ECU (and MAF systems) don't care about boost. They calculate a load (TP) that is basically the amount of mass of air entering the system. On boost = this number is high.

When not mapped and this number exceeds the max defined in the table, the ECU extrapolates from the last column, until it hits the defined max TP value allowed and hits you with what people call "fuel cut" (fuel cut is something else in these ECUs).

If you want to understand better, nissan has a patent on TP that you can find online. It is actually quite interesting and simple to read.

A MAF sends a 0-5V signal that represents the air mass that goes through it. That value is relative to the diameter of the pipe it is in, and a table in your ECU converts it to an absolute value. This is called VQ map (or VE map, depends) .

What happens here is that your VQ map does not match your MAF, which is actually surprising as it would bog severely down. There are 2 possible reasons for this:
1/ you have the correct VQ map in the ecu (unlikely)
2/ you have bigger injectors that somewhat compensate the Z32 VQ map (very likely - although the ecu cannot factor the latency)

Either way, you need a remap. Unless you want to melt your pistons, as the timing on a turbo engine MUST be retarded compared to a non boosted engine. It will run better of course, but it will det like hell (unless you are using e85, but then this require fuel adjustments too).

If you have a wideband AFR & an EGT sensors and gauge, take a look at them.

Without oil squirters nor remap, that thing is going to need another rebuild very soon.

[azreark1]

^^^ stock purple injectors, thought of that last night too...

[azreark1]

I still have my truck so this isn't my daily yet, so I'm probably going to try and find an EMS so I can just cure all the ecu problems and any future ones I come up with

[5280VertDET]

If you have a wideband AFR & an EGT sensors and gauge, take a look at them.

Without oil squirters nor remap, that thing is going to need another rebuild very soon.

This, you NEED an AF gauge or at a minimum take it to a dyno and get it read there. Plus, a tune will likely unlock some more ponies.

[Croustibat]

I still have my truck so this isn't my daily yet, so I'm probably going to try and find an EMS so I can just cure all the ecu problems and any future ones I come up with

Nistune is a cheap way to go too, it depends on what you can get your hands on, and who is going to tune it (don't buy an ECU or a daughterboard if no one knows how to map it - and don't try to map it yourself if you don't already know how to do it, error = dead engine, plus dynoruns are expensive).

Forget SAFCs, these are piece of garbage that tricks your ECU by modifying the MAF signal. While it can work to tune AFRs, your timing values will be everywhere ( => performance problems and melting pistons again)

Can you add oil squirters? I know this would be a lot of work, but nissan did not add them on the DET engine for fun.

[azreark1]

Can you add oil squirters? I know this would be a lot of work, but nissan did not add them on the DET engine for fun.
Other than the tearing the motor apart...again...Not really that much work, Hell I already have the tools since I had to fix a bunch of F'd up crap on the motor and car as I was rebuilding it, but I've seen guys with DE-T build post their mileage so I'm not really worried about the oil...it's the ECU that would blow my engine up first. AFR and boost gauge are first on my list when I get paid, it builds boost really freakin fast (1900 rpm) and I don't know what kind of internal wastegste is on there so I need to know how much boost it's pushing.

[5280VertDET]

AFR and boost gauge are first on my list when I get paid.

Bought this, for the price of a good the AEM UeGo and a good Boost Gauge you can buy it.

http://www.amazon.com/gp/product/B007ZAQLF6/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1

Plus does data logging and some other neat stuff.

[azreark1]

Wow that thing is pretty badass, thanks I'll put it on the list

[Sills]

Hey, im trying to set up a de-t and im curious where your turbo oil feed comes from on the engine you got??

[azreark1]

Hey, im trying to set up a de-t and im curious where your turbo oil feed comes from on the engine you got??

http://imagizer.imageshack.us/v2/640x480q90/540/WySQHI.jpg

So on the passenger side of the engine, by the oil filter, is the fitting for the oil sending unit, my setup looks almost just like the pic, hose then runs around the front of the engine and around to the top of the turbo.

[Croustibat]

If i had to do it again, I'd get this one (AFR + EGT)
http://www.race.fi/en/product/12927a/vems-wbo instead of my 2 gauges, in a 60mm size, and an electronic boost controler. Boost gauge is useless once you get an EBC ( they have an integrated boost gauge).

i have bad experience with aem uego widebands, so i'd stay away from it, but that is down to personal opinion.

[azreark1]

So out of curiosity...if it's stock DE ecu...i should be able to run it without turbo piping and it run fine right? In theory at least? Once i get a stock MAF i could just hook MAF to the end of the throttle body piping till i get the tune or EMS.

EDIT: I don't know why i am having such a problem understanding this car...Stock ECU (at least that's what the numbers on the board say...and no daughterboard added), SR injectors (AFAIK cuz purple neck), T28 turbo (HOPEFULLY stock wastegate), Z32 MAF, either DE or DET head (stock AFAIK) with distributor not coil packs...and no fuel cut or detonation when in boost...very much a conundrum.

[azreark1]

Update: so get this shit, took the car to a local shop to stick it on their machine. Got everything hooked up and at idle, AFR hovers around 16.2, but when on the gas it's boosting to 12psi and AFR of 13.5...wtf?! Does JWT or one of those companies flash ECU without adding anything to the board? Thought they had to add a way to hook up a datalink.