combfilter

iTrader: (3)

So instead of the word "cats" should I have used the words "exhaust components"??? Last time I checked the cats would be considered an "exhaust component"??

Your comment:
There are hundreds (maybe thousands) of companies that make all sorts of exhaust components.
My comment:
He said there are 100's to possibly 1000's of companies that make aftermarket high performance cats

We know you are decorated with a degree covering "Economics, Marketing, Management & Finance", thus making you very intelligent. Please tell me that you honestly think that is a misquote?

newis350

can't we all just get along....

mikes rx

iTrader: (14)

Technically, Joe is right. But it's all a matter of semantics.

Joe's comment stated that there are a lot of exhaust companies out there, with lots of different products. Your comment implies that every exhaust company makes cats, which may not be true.

The cats could be made from 50 companies, the mufflers by 50 more, and piping by another 50. Hence, that would equal 150 companies that make all sorts of various parts COMBINED, but only 50 make one specific product.

Now...enough English for the day

Gernby

iTrader: (1)

Damn Troy, did someone **** in your Wheaties this morning? I've got to side with JoeZ on this since 95% of companies that manufacture "exhaust components" are probably just small shops like Mazzuri.

carchitect

iTrader: (1)

I've been away from this thread for a while.

My initial response to the thread starter was to inform them that the inquiry to these headers started in another thread and the thread was locked since it began with promotion of a non-sponsored (for CL) vendor. If it came of harshly I apologize for it but it wasn't meant to discourage Mazzuri or anyone else's headers from being published. As mentioned before I'm not a moderator or admin here but I am on our local forum and I understand how forums (and they could very well be considered businesses) work and I was making my point to inform the major public on here of what they maybe facing if this happens repeatedly.

Moving on....

Mazzuri (Daniel) congrats on making these and I would've done it no differently than you have done so. I believe the first 10-18", past the head ports, the gasses are simply comming out in pulses and having a poor quality merge or a tightly packed convertor substrate could significantly hurt exhaust gas flow. The only changes I could see making on them would be to have dyno comparison between the stock and them and make changes (primary lenghts or diameter) to have gains through out the entire RPMs. I'm also interesting in seeing the dyno graph of the vehicle's you've dynoed (both before and after) to compare the torque change across the entire powerband.

The primary cats are located close to the cylinder head to allow the spent gasses to heat them up quickly. Once the cats warmup they do their job. Since the IS300 had an inline-6 which didn't meet LEV standards Toyota/Lexus found it important to please the environment friendly crowd and help them win a few points with a performance vehicle. I believe engine ecu is programmed with an expected time for the convertors to warm up. The ISx50 has 4 convertors but only the first two are monitored. The primary are a/f sensors and are not the standard heated o2 sensors which are used after the primary cats. The a/f sensors are used for close loop control and the ecu makes changes in the fuel trims based on their input. The heated o2 sensors used after the cats are used to verify the performance of the cats. The engine ecu won't be using them for tuning even if either (one or both) of the a/f sensors were to fail.

Since these headers are made with a long tube design in mind the primary convertors have been elliminated. The may not have primary o2 sensor bungs but you can use the a/f sensors in the stock y-pipe where the heated o2 sensor would go. The secondary heated o2 sensors could be installed on new bungs welded after the secondary cats.

I informed Troy about the heat being important for the convertors to function. If we move the monitoring of the convertors from the OEM primary locations to the secondary location we may face a problem with the convertor monitoring since the engine ecu may find the warmup delay to take longer than its programmed thershold.

This doesn't mean it won't work. We may have to get creative with it. We could:-

1-eliminate all the convertors and install the secondary o2 sensors right after the primary sensors and use an electrolytic capacitor to delay and suppress the voltage from the sensor to the ecu to give a signal to the ecu that will keep it happy.
2-mount the convertors right after the flange from the headers but this could cause ground clearance on lowered cars or generate a lot of heat on both sides of the transmission (especially the transmission cooler on the right side)
3-thermotech (fiberglass/kevlar tape) wrap the manifolds all the way to the convertors to retain as much heat to increase the warmup of the convertors. this would be helpful at preventing the heat from deminishing the life of the starter which is located just below the left side manifold.

Now, since the OEM a/f and heated o2 sensors have fairly small wires from the connectors you would need to either make longer harnesses adapters (mail and female connectors) or cut and lenghten the wires on them. The heating of these sensors is handled from their individual heated circuits and the ecu controlles the grounds (and the current) so location of them won't directly affect their performance.

Gernby has mentioned this already but I'm being as through as possible to help you guys understand how the emissions analysis criteria is so important for the ecu.

Of course this involves a little bit of trial and error in order to find the best combo to keep the ecu content with our mods.

-Joe

newis350

what about just making a bung hole on the headers in the approximate same location as the OEM bung hole? Would this avoid the CEL light? Would this cause problems with the monitoring of the fuel injection?

lobuxracer

iTrader: (2)

Longer wires will upset the heater current (which is monitored) because they will necessarily be spliced, and longer wire has more inherent resistance. Five wire WBO2 sensors don't like too much run because the currents are in microamps. Heaters are tad more powerful, but remember, the ECM can infer exhaust temperature from heater current. If it falls out of acceptable parameters, UH OH, CEL time. So, moving the sensor with longer wires, or significant temperature loss might be a big PITA.

It would be so much easier to crack the ECM code and have it ignore the secondary O2 input.

carchitect

iTrader: (1)

Yes since you won't have a convertor in between them and the ecu will determine convertor's efficiency way below the thershold.

carchitect

iTrader: (1)

You won't be lenghtening the wires enough to affect the resistance unless it was done poorly. I've built several engine harnesses from scratch and have run wires all sort of directions and have yet to have them create issues in the resistance of the wires. And most of the engines I've put together have been engines under high boost and run full loop wideband 5-wire NTK sensors.

Toyota ECUs are definitely the most difficult to hack and even if you do they won't have the control of a standalone. I can get my hands on the ecm file but sorting thru and finding out how to change the parameters in it and making it work is definitely out of my league. These newer ecus aren't as easy as using an unscramble chip and board as you can on the MKIV supra and program the 27C256 chips to change the injector delay values, ignition timing values, idle or/and redline and tuning away. They are so much more involved than that with multiple maps per 10 deg of crank timing and a map designated just for the cam control via load and rpms. Not to mention the dual stage injector control and fuel pressure control for the direct injection.

IS35O

How much are we looking at for installation?

newis350

I'm guessing installation at your local muffler shop would run a couple hundred dollars at the most, assuming the headers can be installed to the existing exhaust without major welding.

I read that it took Daniel about twenty minutes to install on a IS250 with stock exhaust.

lobuxracer

iTrader: (2)

I know. I have a good friend who works for an aftermarket tuning company writing engine management code. He told me there are hundreds of tables in the current VW/Audi/Porsche engine management software. But there is software to solve the problem of identifying which table to tweak.

Gernby

iTrader: (1)

I find this a bit hard to accept. The ECM has to have some amount of tolerance or minor environmental / hardware variances would cause bogus CEL's. I'm sure there is a significant chance that relocating the secondary O2 behind the secondary cats might not work, but I don't believe for a second that it would be "so much easier to crack the ECM code". That's basically like saying it is impossible since nobody has been able to crack anything in the ECM.

Regarding the wiring of the O2 sensors, the added resistance of the extra foot of wire could easily be overcome by hard wiring and soldering the connections instead of using the OEM plugs.

combfilter

iTrader: (3)

You sure about that?

combfilter

iTrader: (3)

From the sounds of what mazzuri said and also talking to carchitect, the driver side is very tight. Not sure what the total time would be on this install? Probably a lot.

glad i have a friend with a lift who likes to help out with projects like this.