Kingcof22

I am a pretty big noob and i just got my first sr20det swap in my coupe. Ive only installed a PBM cobra flex downpipe and tomei ti exhaust with ti test pipe. The turbo is one of the S15. Everything else is completely stock. No other engine modifications. This is my first car that has a test pipe and I was told that the exhaust would smell rich. After some aggressive pulls and spirited driving, Ive noticed that my rear bumper is yellowing and becoming burnt. Does that mean my car is running really rich to be doing this to the bumper? Everything is stock so im unsure what to do. is this normal or what should i check?

Thank you for any helpful advice

Mikester

If you are running an S15 turbine on a stock-tune S13 SR, chances are you are running lean. My advice is to be careful and buy a wideband. AEM UEGO is plug & play installation (minus power/ground for gauge) and will tell you all you need to know.

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Kingcof22

alright, thank you for your response. I will try to get a wideband asap. Will that require a new ECU/engine management because the sr ECU probably cannot account nor correct for a wideband02 sensor?

Mikester

No. Wideband runs completely independent of engine management. All it does is measure your AFR... so you can see whether or not you are rich or lean during hard pulls, cruise, parked etc. It's just a sensor that taps into your downpipe... Basically an O2 sensor.

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5280VertDET

What he said, but if you are running a S15 turbo, you REALLY should look at supporting mods (injectors, MAF, ECU) to take full advantage and allow your engine to last longer.

Ethalpy
NismoTronic
AEM
Apexi
Even a ROM tune from JK tuning.

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S13 Vert | SR | PE1420 | 5-Speed | 15x9.5 - 0 |

Kingcof22

hmm, yea I didnt realize that. Im surprised the shop didnt recommend that since the turbo came with my swap. I appreciate it, ill get a wideband and really see whats going on.

angel mkiv

If it came with the swap it might already have bigger injectors/maf and a tune.what color are your injectors? And look up what a z32 maf and a s13sr20 one looks like and let us know what you have. Also +1 on getting a wideband.

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Kingtal0n

Use a re-circulated bypass,
make sure its tuned right


I have seen this happen to cars with atmospheric blow-offs running maf sensors, and with poorly tuned engines.

Kingcof22

I honestly couldnt pull the injectors out... they should be the regular purple ones 370cc. i took some pics.. i apologize if i didnt do this correctly, i have a bad back and its very painful for me to bend over for more than 45 seconds.. this wont be a sob story though.



This is a pic of the maf... i think its actually a Z32 maf




this is the Blow off valve. im hoping that a recirculated bypass is the same thing as a blow off valve? I also think its a greddy type BOV

Kingtal0n

Show me how the maf is routed to the turbo inlet. your bypass is recirculated, which only leaves improper maf placement, and tuning, as your two logical explanations, assuming the computer is stock the only leaves placement. Your maf is probably too close to the turbo, and recirculation fitting.

It is also likely your engine is running lean during boost if you are using the S15 turbo, with a factory redtop ecu and 370cc injectors. that is an OEM maf btw.
Running lean under boost has nothing to do with the bumper getting black. The blackening bumper is likely poor voltage stability at the maf sensor due to perturbations in the linear flow that should exit, because of maf placement.

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Kingcof22

Im hoping im providing enough information at this point. All i want is a healthy reliable blacktop. At this point, i know i need, aem wideband, some sort of engine management which im torn between nistune or haltech. I just want to be able to not possibly burn my paint of my car or even cause a bumper fire. Should i even be boosting it hard. I dont have a boost guage hooked up since it was wire incorrectly so i have no idea what my boost levels are.

Mikester

First and foremost- get a boost gauge. Not knowing your boost levels on an unfamiliar engine is a recipe for disaster. S

Good news: short of pouring lighter fluid on your bumper and lighting it with something far hotter than your exhaust, your bumper will not catch fire. If you don't want soot on your bumper, put a stock exhaust, catalytic etc. back in and keep your boost at stock (.5-.7bar). Opening exhaust piping, deleting cat (increasing flow) means that more different types of particles are going to leave the tailpipe- no getting around this- Well I suppose you could get a small bend and have it point at the ground, but that'd look kinda silly lol.

Second, If the wiring was done incorrectly, #1 easiest fix to avoid tail-chasing is a drop-in harness for your swap by Wiring Specialties. Fresh, properly pinned upper/lower harnesses are worthwhile to have. Depends on budget. I rely on the time/money/reliability equation when thinking of these things. Also, I use the KISS concept- If there is something plug & play, and idiot-proof that will get me what I need reliably, then I'm all over it. This is one of many reasons I sincerely admire fabricators and 'true' auto mechanics/gurus.

Mike

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Kingcof22

Mike, Thank you! I have a gauge line up in my mind because they are suppose to be very accurate and ive read many positive things about them but its just gonna take awhile to save up for them since i only truly want to do it right the first time.

Thank you for the reassurance that im not gonna catch my car on fire because of my hot exhaust. Ive just never seen a car turn black and yello from having a straight pipe before when all the settings should be stock. I guess its not unusual to have black soot or yellowing of the paint even on stock settings

I really prefer spending good money the first time so if i have a true wiring problem, ill elect to go with an rywire harness Thanks again for your help and responses

Kingtal0n

when you get your wideband installed in the downpipe (make sure its installed in the downpipe, not where the factory O2 sensor goes, and at the angle specified in the instructions), and start driving...

You may notice when you let off the gas, the wideband will swing rich for a split second(11:1).

This is because your turbo is too close to the maf sensor, and this is 74% of the reason why the bumper is blackening up.