[KC30]

Ok, I do realize that these may be a couple of basic and or dumb questions for the SR20DET... But I know RB's better and the SR's all new to me. Also so far searching I haven't found any clear answers. Anyways, on with the questions:

First, I have a black top from a 95ish 180sx... so it's really a red top. The stock O2 sensor is the skinny titanium type, which my Apexi turbo timer doesn't read. I have bought a new turbo outlet elbow (Megan) and the original plan was to keep the skinny O2 sensor (I've got the adaptor and everything) and add a second O2 bung for the fat type O2 sensor for an independent AFR reading. I just wanted to verify that I can't use the fat type O2 sensor in place of the skinny one. I would assume so as the signal seems to be different as the Apexi TT can read the fat one, but not the skinny one.

The second question is about the MAF. I have the restrictive (smaller opening sensor) and would like to get the later one. I know I could easily do it with a piggy back system, but I'm just wondering if there are any other options that I haven't considered since I don't want to do that. I'm not sure how much difference there is in the signals between the two MAFs.

 

[RikRong]

Well, it's not really a redtop, it's S13 blacktop, they are just slightly different. As for MAFs, if you change the MAF you will probably have to get some sort of tune to accomodate. If you go with the larger Z32 MAF, you will definitely have to get a tune for it to work. I think SR MAFs are all pretty much the same size.

http://www.240sxforums.com/forums/sr20de-det/133167-sr-mafs.html

 

[KC30]

Yikes, I was completely screwed up about the MAF thing. I got my two vehicles confused, of all things my Amigo's 4ZE1 2.6 engine with the SR's MAF. The older Isuzu 2.6s use a smaller opening MAF that the later. And funny enough, the opening area looks just like the SR's, but the exterior of the housing is different. Here's the old Isuzu 2.6 MAF:
Old Isuzu MAF
And a common upgrade was to install the later MAF, here's a comparison:
Old vs new MAF
It's an approx. 2" opening vs 3"! And since the MAF's signals were found to be within 5% of each other (in the richer side), it was a bolt on upgrade... no ECU reprogram.

So, just for the hell of it I was looking at the part number on my Isuzu's MAF vs my SR's. And I come across that I have the CA18's 22680-58A10 MAF with my SR... Sometimes you just have to love the mix of parts you get off of a japanese drifter's car.

 

[Joel 180]

Not sure your Apexi turbo timer will read either early SR type o2 sensors.

If it worth it to you I ran the fat sensor from an S15 for years. Car worked fine but I couldnt tell you if it was having some internal issues with the sensor. I didnt throw any codes if thats what you are after.

 

[BoostinIX]

If you're just going with the fat to feed the Apex'i, don't bother. Get a wideband at that point and make it worth it.

 

[KC30]

Well, after searching around the last day I finally found that the 62 ECU (what I have) does not read the fat O2 sensor. So I'd have to get the E6 ECU if I wanted to run it... not worth it.

BoostinIX: That's the plan down the road to run a separate wide band O2 sensor on the second bung. But in the meantime I have a fat O2 sensor and the Apex'i TT, so I'll run that until I get to the wide band one. Unfortunately I have several other things to work on the engine/car before I'll get to that.

As far as the MAF, luckily (for me) a friend's waiting for his SR wire harness for his S13 and was able to loan me his MAF which is the one I should be using. Wow what a difference! So I have the correct MAF on it's way now.

 

[BoostinIX]

Narrowbands make for pretty light shows But that's about it.

 

[driftsyndicate]

i ave a 62 ecu with fatty o2 and my Nissan consult says it reads fine

 

[SRinside]

for the 30 seconds it takes to try it out. you could have tried it out instead of starting the thread and by the time you've read this post you could have switched it back if it didn't work.. plugs are cheap

 

[BoostinIX]

^Nothing wrong with asking. It's not like he asked a bad question.

 

[KC30]

Thanks all for the info. I haven't been able to test it out yet since the old turbo outlet's fat vs skinny adaptor has been previously stripped on the nut part and is completely seized. Also when I pulled the turbo elbow off, there was a broken stud that took two days of soaking to get it to free up and get it out. So in the meantime, I've dropped the new turbo outlet off to get the second o2 bung installed. Since I have both sensors, I'll just keep the skinny one for the ECU and run the fat one for the Apex'i timer. If the fat sensor is the same as what my Skyline had, that was actually very good at reading the AFR with the Apex'i TT. That's the combo I had in that. Plus having the two O2 bungs now means I can get the wideband at any point down the road and it'll be already setup for it.