ROTARYROCKET7

Im looking to put on my headers and presilencer to complement my Racing Beat Cat back. My heatshield came off recently after a night of racing cars and want to see the gains with the header/silencer.

Now i might as well put a new o2 sensor in the header and heard that i have to extend the wires cuz its in a diff position.

I use to work at autozone and i know they got the BOSCH ones for $35.00. Can i use this one or just use a Universal one.

Also if mazda sells there own, what if any would be the benefit to use the stock one.

Thanks

Jason NYC

ilike2eatricers

bosch or borg warner ones are fine. OEM one is $$$

ROTARYROCKET7

iight cool guess ima get teh OE TYpe Bosch one, its like $35. But just for to know who makes the OEM one Mazda or Nippon or someother company

Sideways7

iTrader: (7)

Yep, I have the OE style bosch and it works fine.

socalrx7racer

i believe the actual o.e. from the manufacturer is a denso unit.....usually a couple bucks more.

ilike2eatricers

mazdatrix prices... more than a couple bucks
s4 http://mazdatrix.com/getprice.asp?partnum=18-8610-N326
s5 http://mazdatrix.com/getprice.asp?partnum=18-8610-N350

tandolla

iTrader: (1)

i just bught my Universal Boch at Shucks for it was either 10 or 20 dollars i dont remeber. .

FIBREMAZ

AC Delco make them also from memory

Sideways7

iTrader: (7)

Just read the whole post. Anyway, the RB header comes with an additional wire to make it long enough to fit.

ROTARYROCKET7

yeah i got the header from someone and they gave me a package with the ACV block off plates and he mentioned something about a wire in there for o2 but i didnt think of it till you just mentioned it.

Autozone sells a o2 sensor from nippon for like $53 or so. But ima get teh bosch one, pockets aint heavy right now lol

Thanks guys for the replies

Jason NYC
NYRA PREZ
www.nyrotary.com

SpooledupRacing

IMO bosch sucks, I sell Denso and will only use them on my vehicles... I have had nothing but problems with bosch sensors going out prematurly on turbo vehicles, so I wont use them on any car..

I sell bosch items daily and if I can sell another brand I do.. bosch is JUNK!

ROTARYROCKET7

I read that after 3000 RPMs you dont use the o2 sensor anymore is this true.

Aaron Cake

iTrader: (1)

The O2 sensor is only used for closed loop which occurs under light throttle and cuts off around 4K or so.

ROTARYROCKET7

when you say closed loop meaning it no longer needs the input from the oxygen sensor and it runs off its own "made up" readings about what its getting from the o2 sensor.

The o2 sensor reads how much parts of air are exiting the vehicle right, so isnt that for emissions. So that sends a signal to the ecu/afm to adjust the amount of air in?

Or am i totally just off

My5ABaby

iTrader: (7)

I think it adjusts the amount of fuel being put into the engine. The AFM is just a flapper so it's not really adjustable.

Training Manual 4 pages 42 and 43 have a decent overview of the system.

ROTARYROCKET7

Training manual meaning haynes? Well i guess after 4k it tries to stick to its AFR of 14.7:1

My5ABaby

iTrader: (7)

Someone put up a RX7 Training Manual from Australia which is basically an overview of how the RX7 works. It's more in laymans terms. It doesn't cover testing near as much. You can find it in one of the FAQ FSM links.

I've printed the FSM and Training Manual and also own a Hayne's Manual.

gerrychuck

Rotary Performance (Rx7.com) have the direct factory replacement O2 sensor right now for the same price ($40) as their aftermarket unit, with the OEM connector already there, so no soldering needed.

ROTARYROCKET7

so i check out the O2 sensor, gerrychuck on rx7.com. They got two types one is just the wire and the other is this one http://rx7.com/store/rx7/RPOEO2sensor.html

If Universal is $25ish and $35-40 for the one with the factory connector. Are they the same o2 sensor or is the OE type one special for the rx7. Or are they just charging $10-15 for the connector being added for you.

Jason NYC

jgrts20

I got mine from the local autoparts place here in VT, partsamerica has them. I think they are bosch.

SomeGuy_sg

Any one knows where to buy the denso O2 sensor and/or the part number for it ?

ROTARYROCKET7

Check autozone they actually sell the denso OEM type , it goes for like $53 off the top of my head. They dont stock it so it must be ordered. But if its only works under 4k, then just get a uni or a bosch and save half the money.

Jason NYC

Tofuball

I got my last narrowband for $7 at Olympic Auto Parts about two years ago.


The reason O2 sensors go out early on TIIs is because rotaries put out an amazing amount of exhaust heat. The turbo certainly doesnt help, and the stock O2 sensor location of being right next to the turbo outlet isnt so cool either.

If you want it to last longer, you can buy one of these O2 sensor heatsinks. They just happen to cost more then your narrowband does :P

Though, they're manditory for widebands on rotaries, especially turbos, and especially in the stock location (IMHO).

Since you're replacing your O2 sensor anyway, a wideband O2 sensor really isnt that expensive at $200 (http://www.diyautotune.com/catalog/i...nsor-p-41.html)

Though, I've killed three of these already, Innovate was decent in replacing them (Took them a while though)

I belive the TechEdge is a much more roadbust unit.

HAILERS

I attached a graph of RPM and AFR. It shows the 02 sensor when it's in the Loop and when it is not. When it is not, the jagged line is more or less smooth/straight.

The jagged lines represent the fuel injectors trying to keep the AFR at a afr of approx 14.7. The top of the spikes are around 15.2 and the bottom is around 14.3 afr.

The smooth line represents no 02 sensor influence and that line is at approx 14.5 afr.

Read the part of the Training Manual cited in the post above. It does this to try to keep CO and HC down.

Closed loop is not used during any idle condition, only while driving and at a steady pace.

Oh, that's a four year old, twenty dollar Bosch oxygen sensor.

ROTARYROCKET7

Summit Racing has NGK O2 Sensor, who knew, and there around the same cost as BOSCH

http://store.summitracing.com/partde...5&autoview=sku

What do you guys think. I gota get speedbleeders from em anywho i might just order them

Jason NYC