Scion tC Forums banner
1 - 13 of 13 Posts

·
Registered
Joined
·
742 Posts
Discussion Starter · #1 ·
Just wondering if they are deleting the first cat or moving it further back, etc as certainly not keeping it as stock.


My last car was a turbo Matrix and we moved the first cat back a bit and swaped it for a 3" high flow unit. The second o2 sensor wiring was taped into and a cat simulator installed to send a proper signal to the ECU. This was needed because of the aux fuel injection, etc, together the car ran great, plugs were clean and the right color, etc, etc.


We plan to build our own system and just trying to figure out what we will do for cat(s).

Rick
 

·
Former '05er
Joined
·
12,467 Posts
Planning on the presto chango for smog, or do you have other means available for passing smog?
 

·
Registered
Joined
·
742 Posts
Discussion Starter · #3 ·
Willing to make it back to as stock as possible;)

I have not checked on the Oregon or Washington laws yet, not sure which state I am moving to. In CA you get 4 years without a check due and in the county where I live you never have to get one done after you bring a car in from out of state. Silly thing is you have to get a brand new car done and they do a really simple test, not even run on a dyno.


Not worried about it to much, I did get a ticket once for my Matrix, had to make it pass smog at a referee station and go see the judge, fine suspended, one year probation, went home and put it all back on:)

Rick
 

·
Former '05er
Joined
·
12,467 Posts
You're lucky. I live in a Smog Check II area. I have smog every two years, and my Supra has been test only the last three times because the claim it has a "high emitter" profile. It always passes, but I haven't been able to do anything really fun with it other than turn up the stock boost.

I hope Scionspeed actually delivers on the CARB approved turbo kit for the tC. It would be nice to avoid official scrutiny.
 

·
Registered
Joined
·
742 Posts
Discussion Starter · #5 ·
I agree, legal is nice, why SC's are so tempting but the last factory one I had was a dog, problematic, would of cost more than the unit just to get some decent power, got rid of it, that was on our Tacoma.

My Matrix would of easily passed the test if they only did the acutal tail pipe test and let the visual go, dumb ass law anyway, I actually care about running clean.

I do not like the stock exhaust routing over the sub frame up near the intake manifold. I am looking at cutting out and welding in a pass through for the subframe or using some NASCAR style flatten tubing under neath it, I can squeeze in a cat and still have nearly the same overall ground clearance as stock plus alot fewer bends in the piping, cooler intake air, etc.

Rick
 

·
Registered
Joined
·
832 Posts
Up here in good ol' Whatcom County Washington there is no emissions testing or visual inspection except when you bring in an out of state vehicle. Down around seattle there are smog checks every year.
 

·
Registered
Joined
·
272 Posts
back on topic, i would put a high flow cat in the downpipe after the turbo. seems kinda pointless as the only reason u would add a cat is to pass emissions, and that wouldnt pass a visual inspection anyway.

idk what u plan to do about fuel management but make sure you arent running so rich you will fry the cat
 

·
Former '05er
Joined
·
12,467 Posts
If you just keep the OEM first O2, it's a wideband and will keep the cat out of trouble. Also, sitting after the turbo chops off about 200C from the exhaust temp, so it's tougher to hurt a cat with a turbo in front of it.
 

·
Former '05er
Joined
·
12,467 Posts
On page EG-41 of the New Car Features book, they call the O2 sensor an "Air Fuel Ratio Sensor (Planar Type)" and go on to describe how it works.
QUOTE
The air fuel ratio sensor outputs a voltage that is approximatelty porportionate to the existing air fuel ratio by converting the oxygen density to the voltage.
As a result, the detection precision of the air fuel ratio has been improved.[/b]
The other thing they brag about is a 10 second warm up time. Pretty cool for an O2 sensor. Unless you are unfamiliar with WB O2 sensors, you'll easily recognize this description as a wide band O2. Of course the graph of the sensor response voltage they included seals the deal. Is is undoubtedly a wideband O2.
 

·
Registered
Joined
·
742 Posts
Discussion Starter · #11 ·
I am liking what you are saying:)
I am looking into(not real intently yet as to many other projects, etc, right now) for the least costly yet very effective self tuning way of setting up our turbo system, having a built in wideband is one great way to attain these goals!!!


I have had alot of dyno tuning done with systems I was not allowed to have the programs for, not going that route again and we know it is a way to establish a base line but is not entirely transferable to actually driving the vehicle in many situations.

I do like piggy back system since it allows the stock ECU to manage the more mundain daily driver issues. Reflashed ECU's would be cool as well and of course changing rev limits, where applicable and deleting speed govenors are something cool to address.

If I could get a decent reflash to fix a few things and run a good fuel sytem, timing is also really nice to tune, that would be my idea of the ideal way to boost a modern vehicle.

I like the Unichip overall, if only I could have access to the software, I would probably go that route, Jack was going to do a custom dual map setup on my Turbo Matrix once the engine was built, 1100 mile trailer trip to get it done. Now that we will be within 30 miles or so from them, maybe we will end up with one again;)

The last plan was to have a high and low boost setup that controlled timing, fuel, boost onset and offset at super high RPM, 8,600 redline, delete the speed govenor(the last two hard ware mods to the stock ECU), a GT25/40 turbo, totally built engine, this project was well on the way when I sold off everything to help my disabled buddy out.

The plan was this: 10:1 compresion with forged pistons and billet rods, .300 longer than stock, Darton sleaves(had them custom made). fully ported and polished, flow benched head, custom cams(if needed), knife edged, lightened and rebalanced crank, 5 angle intake, radius exhuast valve job, etc, etc.

This was based on a lessor built but very well put together engine that put out over 300 WHP and over 280 ft lbs from a 1.98 liter 1ZZ. Stock head and 7k redline, 12PSI, 91 Ocatane.

1) Low boost, 12PSI, 300+WHP, nearly 300 ft lbs, 91 octane. Unichiped tuned to control the onset of boost for a smooth bottom end to avoid excessive wheel spin out of corners then drop of boost at super high RPMS to protect the engine and allow less shifting between corners. A very wide powerband of approx 6k RPM:) The unichip would also control the Aquamist Met/water injection I was already using, also timing and fuel.

2) Remote on steering wheel, only used when race gas in the tank, once hooked up well in a drag or out of a corner, remaps the fuel, timing, boost to come on immediately and stay on to redline, Aquamist, etc, etc. 17PSI, expected well over 400WHP and nearly that much torque.

Though this sounds a bit fare fetched, believe me, several very sharp and experienced minds were involved in this plan and all the hard parts were on track to be custom built, alot of partial and some full sponsorship, all well known and respected parties except the main engine idea guy I learned what could be done with a 1ZZ from, not so well known Japanese engine guru.



OK, now we have a tC instead and the goal is a daily driver 300WHP reliable machine which from all I have read is really easy to do and far more cost effective:)

Rick
 

·
Former '05er
Joined
·
12,467 Posts
Why the water/meth mix? Why not straight meth? Supra guys have been doing this for awhile now with great success. Yeah, you still have storage issues, and refill issues for two fuels instead of one, but you have that with the H2O/meth set up anyway.

2.4 liters is enough displacement to make a LOT of power. My only concern is the open deck block. I asked Jayson at Scionspeed if he had hydrotested the block to know what the maximum allowable cylinder pressure is, but he never replied. We never worry too much about it with Supras because they are a high nickel content cast iron block. Heavy, but sustain 40 psi boost with the right additional hardware.

I think stretching the rods in the 2AZ will be difficult. You'll obviously need custom pistons with very thin rings and a very tight ring stack with the pin encroaching on the bottom of the oil rings. That's how HKS does the pistons for their 2JZ stroker. A friend of mine who bought that kit sent me all the measurements, and it's really obvious they squashed the ring pack. They still ended up shortening the rods to get the stroke they needed for 3.3 liters.

The last thing the 2AZ needs is more stroke. The block has cast in liners, and there are no factory overbores. I haven't seen the wall thickness and I haven't looked at the bore spacing to know what potential there is to drop in bigger buckets. Still lots more questions than answers.
 

·
Registered
Joined
·
742 Posts
Discussion Starter · #13 ·
Just to be clear, I plan on running as is, no internal mods at all with the exception of possibly a bit of porting at some time down the road. This is going to be on the cheap, as much reliable power possibly and without an Aquamist setup as well.

Just want a nice wide powerband, oriented toward the low to midband range where 90% or more of the driving will be anyway:) I call this more effectively usefull power, more fun than a pipey high RPM power band for real world use:)

Rick
 
1 - 13 of 13 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top