And you know how to access them? The VAG port!

 

There isn't anything in this thread that changes my thoughts about it. I am aware of the heater circuit that is controlled via the ECM. If the ECM decides that the heater circuit is requiring more current than it should, it will cause an error, but I wouldn't really call that a "temperature sensor".

 

i read that Daniel removed the steering shaft an the installation took less than one hour...

 

Nice Work on the R&D Daniel!!!


But, for all who haven't read in between the lines yet...

There is NO DYNO on an IS350 yet.. the "30 whp gains" is just a guestimate ...

Does anyone read entire post/threads anymore??

When we mis-quote things like this it just starts a whole discussion on something that's not done or tested yet...

ALL the info I see is based on an IS250 Manual Transmission.

Just clearing the smoke for those who are not aware of this fact.

 

I would be very surprised to see a 30rwhp gain from headers alone on the IS350. I'm not knocking the design of Daniel's work but I just don't see a 30 rwhp gain happening on these cars with out tuning and other mods.

Maybe if you started with a stock IS350, then did the headers and a full exhaust, better intake, etc, and were able to tune it I could see that as a possibility.

But then again I'm not up on the internet hp gains

No question the Mazzuri headers will make better power than the JUN stuff. I would say the Mazzuri stuff is way below "well priced" in my opinion! Nice work.

Would be interested to see a before/after dyno on a Dynojet logging cyclinder head temps for repeatability...

 

If I have a table with engine load and expected current +/- allowable error, I'd call that a temperature sensor. The whole reason for the heater is so the O2 sensor will work consistently.

A long time ago the sensor manufacturers discovered the single wire units were worthless as soon as they dropped below 700F. So they put in a heater to make them work faster and better. The ECM knows how much current should be needed for a given load. If it has to run more current, it thinks the exhaust is colder than it should be for the load it is calculating with all the other engine's operating parameters. I'd call that as close to a temperature sensor as a whole lot of other measurement equipment.

 

What is the downside of the CEL being lit all the time, other than the annoyance factor?

 

Taylor, Have you looked at the stock manifolds? After looking at them, I think your opinion would be different. They look like they came off a '70s Chevy pickup.

 

lobux, I would find it hard to believe that the ECM would calculate an actual exhaust temperature as much as it would just go into an error state if the current is out of range. Honestly, what benefit would there be to do otherwise? Do you think this would be part of the closed loop tuning data (other than to monitor the cat's performance)?

Regarding the CEL being on all the time, I noticed in my S2000 that my fuel mixture ran extra rich when its CEL was on. In the 2IS, we would also loose traction control.

 

Haha, haven't really had a good look at them. Still 30rwhp is a large figure for a modern technology small displacement engine. I guess you will have to be the first local guy to do a before/after

 

Since I have access to OEM scantool and the datalist via OEM CAN protocal I can assure you the heated o2 sensors are not turned on and off repeatedly. The ecu simply leaves then constantly on. The a/f sensors on the other hands do indeed work by rapidly cycling the heater circuit on and off and when the circuit is turned off the resistance of the heater is measured to allow the engine ecu to determine the temperature of the sensor. This won't necessarily alert the engine ecu of the temp of the exhaust. There are a lot more factors that determine that and the ecu uses this input to determine sensor degradation and makes changes to the a/f sensor heater and sensor circuits to conpensate for the wear and make use of more accurate measurements. As far as I know, only Motec ecus and PLM widebands are capable of this type of compensation across the 5-wire units and is the main reason why I only use Motec standalones. Unfortunately they won't work on these cars.

 

The current is just data. Whether it gets converted to a temperature is academic. It measures current, compares it to an expected value based on known good parameters and sets a DTC/CEL if it is out of range. The current is based on temperature, so it would be simple to calculate it if you needed to. I doubt they waste the cycles on it though, they just compare it to a look up value table.

 

Agreed.

Apparently, semantics are really important on these forums.

Lets look back to post #22 where I originally stated that was what one of the problems would be. Everything I said in that post was correct, it's just what some might call a heat sensor/circuit/temp sensor, others would call it whatever else. It still boils down to the ecu expecting the cats to heat up to a certain temp in a certain amount of time. They determine this via the o2 sensor talking with the ecu and telling the ecu "i have these measurements within this range, does it fall within the parameters you have set?" ecu says "yes or no". If i am wrong, i am sure greg will tell me, but my original point is/was correct in concept.

You guys can nerd out all day long, but sometimes its best to explain things on these forums to where anyone that would be a potential buyer would understand. This was exactly what i was trying to do in post 22. It was a response to greg, but written to where others could understand.

I appreciate all your opinions and discussions, I truly do. These discussions with carchitect/mazzuri/lobux/jeremy/taylordp/joez/ and yes you greg help us figure out what hurdles there are to overcome. We are working towards the same goal. However, if you are all going argue (including me) about what something is called technically it's not going to help out us all in the end.

lets figure out what we need to do to make this work. There are only a hand full of us that are actually willing to take this project on right now. mazzuri took the lead with developing the headers. At 650 per unit, it's a good deal.

 

right on dude!

 

I agree that this argument is moot at best. My definition of a sensor is different from yours. To me, a sensor measures something directly, not indirectly. This method of measuring electrical current, then looking something up in a data table for a best guess is not a sensor at all in my opinion. That would be like calling the traction control system a road wetness sensor. If you guys think the ECM should consider the roads to be wet just because the wheels spin at 20% throttle, then I guess you would call it a wetness sensor. However, it could also be called an ice sensor or gravel sensor.

I'm sure there are many things that will effect the accuracy of the ECU's ability to monitor exhaust "temperature" like sensor age, humidity, altitude, ambient tempurature, etc, and I think that would work in our favor. That's why I mentioned in post 30 that we might be able to solve this problem by insulating the exhaust all the way to the secondary O2's with wrap, shields or Jet Hot. It might also help to remove the little heat syncs that they have.