My Latest Aurion Mods

[mkay]

Been a while since I've played around with my Aurion. I lost a bit of interest after failing to lower it with king springs a couple of years ago due to scrubbing. At the time I had a cat back system made up by D&T exhaust in Darwin. I have finally got around to getting a K&N intake kit and had success getting a custom made mandrel bent Y-Pipe and High flow Cat installed by a performance shop in Perth. I was extremely suprised to find the custom Y-Pipe has actually eliminated the exhaust drone I used to get with just the Cat back system. The car seems to rev a lot more freely and the sound is awesome now too (surprisingly, a lot different to just the Cat back system)

The shop that did my exhaust has a Dyno so next chance I get (hopefully next week) I will get it tested and post the results. I know I should have got before and after Dyno tests done but did not have the extra cash to burn.

I can't believe Toyota released this car with such a pathetic exhaust, the engineer who designed the original Y-Pipe should be sacked. Must have just been a cost cutting thing and for ease of assembly.

Next on the list is a set of BC Racing coilovers (before X-mas) and Toyota has just ordered me a new Transmission ECU to remedy my Transmission flare.

Toyota's attempt:

Custom Y-Pipe:

Tail Pipes:

Intake:

Edited December 4, 2009 by mkay

[DJKOR]

Good stuff mate. It's good to see someone finally attack that y-piece. Would be curious to see the dyno results. At least the ECU will be given a week to settle in to see if it adjusts in a good or bad way.

I was considering maying the y-piece like that, but I've also heard of things like equal header length and all that. Would be curious to see if that has an effect on the dyno.

[httttt]

Nice work. I am very curious to see the results.

[1stKill]

Well done,i think it might be the 1st Y piece mod on here B) ...very interested to see how it all goes,keep us updated.

[chicken]

hi mkay nice work there. where did you get the exhaust done?

[mkay]

hi mkay nice work there. where did you get the exhaust done?

I had the recent work done at The Performance Shoppe in Wangara, by the owner (Harry) who has been in the trade for over 10 years. I was very happy with the quality of workmanship.

[CHA54]

did the put both o2 sensors in the one bank??

[DJKOR]

did the put both o2 sensors in the one bank??

It sure looks like it.

[mkay]

did the put both o2 sensors in the one bank??

It sure looks like it.

The wiring loom for the rear Heated Oxygen Sensor was not long enough to reach the rear pipe of the modified set up and the wires can not be lengthened. All the post cat o2 sensor does is fine-tune the air-fuel ratio to maximize catalyst efficiency. So both sensors on the same pipe should have no effect (unless the other cat stops working, she'll be right)

Edited December 5, 2009 by mkay

[cranky]

i am curious of the dyno results too, look good

[SCOOTA44]

Been a while since I've played around with my Aurion. I lost a bit of interest after failing to lower it with king springs a couple of years ago due to scrubbing. At the time I had a cat back system made up by D&T exhaust in Darwin. I have finally got around to getting a K&N intake kit and had success getting a custom made mandrel bent Y-Pipe and High flow Cat installed by a performance shop in Perth. I was extremely suprised to find the custom Y-Pipe has actually eliminated the exhaust drone I used to get with just the Cat back system. The car seems to rev a lot more freely and the sound is awesome now too (surprisingly, a lot different to just the Cat back system)

The shop that did my exhaust has a Dyno so next chance I get (hopefully next week) I will get it tested and post the results. I know I should have got before and after Dyno tests done but did not have the extra cash to burn.

I can't believe Toyota released this car with such a pathetic exhaust, the engineer who designed the original Y-Pipe should be sacked. Must have just been a cost cutting thing and for ease of assembly.

Next on the list is a set of BC Racing coilovers (before X-mas) and Toyota has just ordered me a new Transmission ECU to remedy my Transmission flare.

Toyota's attempt:

Custom Y-Pipe:

Tail Pipes:

Intake:

thats awsome with the Y pipe, I did the same with my previous camry, now I have seen this I will be seeing my exhaust man this week to do the same, what mufflers are you using ? they seem very small.

[Ingres]

Nicely Done Mkay... Anyone from Brisbane trying that??

[DJKOR]

Nicely Done Mkay... Anyone from Brisbane trying that??

I'll wait for the dyno results first to gauge some figures. I was thinking more of modifying it but keeping equal header length which means having a bend in the pipe still. Anyone with more knowledge on the subject care to explain if there are any advantages to equal header length?

[SCOOTA44]

Nicely Done Mkay... Anyone from Brisbane trying that??

I'll wait for the dyno results first to gauge some figures. I was thinking more of modifying it but keeping equal header length which means having a bend in the pipe still. Anyone with more knowledge on the subject care to explain if there are any advantages to equal header length?

hi daryl, when I did the same mod on my v6 camry, I did not worry about the different length of the header pipes, it did not cause any performance problems and it did free it up. cant see any problem doing the same on the aurion.

[DJKOR]

hi daryl, when I did the same mod on my v6 camry, I did not worry about the different length of the header pipes, it did not cause any performance problems and it did free it up. cant see any problem doing the same on the aurion.

I mean more like "does equal header length provide a greater increase than the modification provided here". Sure having it unequal like the OP here may provide some gain, but is there the possibility to get even more with equal header length.

If I'm spending money to get it fixed, I'd rather spend it right the first time.

[SCOOTA44]

hi daryl, when I did the same mod on my v6 camry, I did not worry about the different length of the header pipes, it did not cause any performance problems and it did free it up. cant see any problem doing the same on the aurion.

I mean more like "does equal header length provide a greater increase than the modification provided here". Sure having it unequal like the OP here may provide some gain, but is there the possibility to get even more with equal header length.

If I'm spending money to get it fixed, I'd rather spend it right the first time.

the only way to equal them up is add length to the rear pipe and somehow bend it around to meet up with the collector, not sure it will go any better than the mod shown. maybe someone will try the longer pipe and compare.

[DJKOR]

the only way to equal them up is add length to the rear pipe and somehow bend it around to meet up with the collector, not sure it will go any better than the mod shown. maybe someone will try the longer pipe and compare.

I've spoken with an exhaust shop or two. It is possible to maintain the length using an appropriate bend and then merging it neatly. The bend shouldn't cause any restrictions so they say. I never inquired about the advantages etc though which was stupid of me. Like I said, I will wait for the dyno results and if the improvement does not seem significant (relatively since it is a dyno test after all), I will choose the equal length option.

[SCOOTA44]

the only way to equal them up is add length to the rear pipe and somehow bend it around to meet up with the collector, not sure it will go any better than the mod shown. maybe someone will try the longer pipe and compare.

I've spoken with an exhaust shop or two. It is possible to maintain the length using an appropriate bend and then merging it neatly. The bend shouldn't cause any restrictions so they say. I never inquired about the advantages etc though which was stupid of me. Like I said, I will wait for the dyno results and if the improvement does not seem significant (relatively since it is a dyno test after all), I will choose the equal length option.

either way as long as its all the same diameter all the way not like the restrictive setup they have now.wouldn't it be interesting if there was room for a full twin system !

Edited December 6, 2009 by scootastaxisx6

[mkay]

thats awsome with the Y pipe, I did the same with my previous camry, now I have seen this I will be seeing my exhaust man this week to do the same, what mufflers are you using ? they seem very small.

The mufflers are actually made by the company I had do the Cat back system, D&T Performance. They have stores in Adelaide and Darwin as far as I'm aware.

[mkay]

Nicely Done Mkay... Anyone from Brisbane trying that??

I'll wait for the dyno results first to gauge some figures. I was thinking more of modifying it but keeping equal header length which means having a bend in the pipe still. Anyone with more knowledge on the subject care to explain if there are any advantages to equal header length?

In my opinion equal length headers are only necessary on a full twin system. With my set up, both pipes merge into one, so you will have equal back pressure on all valves anyway. On the twin system you need to be more pedantic because having different length of pipes overall, will affect back pressure differently of each cylinder bank, affecting the torque curve differently of each cylinder bank.

[Tofuboi]

I am very interested to see the results for this, as the OP states that the drone from the exhaust seems to have disappeared almost entirely from just changing the Y peice. If this is the case, holy cow.

On a side note and regarding twin pipe setups. I have been speaking with the guys at A1 Exhausts in Sunbury here and if I can muster up the courage to do it... We WILL attempt a complete twin pipe setup, this is including a replacement manifold aswell. Twin setup all the way to the back. Not sure on space requirements etc, but we'll see... :P

Good stuff on this though either way! Who knows, I might just do this if it's gonna be a good help.

[mkay]

I am very interested to see the results for this, as the OP states that the drone from the exhaust seems to have disappeared almost entirely from just changing the Y peice. If this is the case, holy cow.

On a side note and regarding twin pipe setups. I have been speaking with the guys at A1 Exhausts in Sunbury here and if I can muster up the courage to do it... We WILL attempt a complete twin pipe setup, this is including a replacement manifold aswell. Twin setup all the way to the back. Not sure on space requirements etc, but we'll see... :P

Good stuff on this though either way! Who knows, I might just do this if it's gonna be a good help.

If you are going to change the stock manifold and do not intend to run the triple cat set-up (two off the manifold, 1 on the main pipe) you will have problems with the check engine light. However I have read a few articles lately on the net about tricking the post cat O2 sensors into thinking they are recieving the correct signal by using diodes on the O2 sensors electrical looms. Just do some google searches for more info.

The post cat O2 sensors on the Toyota only fine tune the fuel mixture by a maixmum of 2% to maximise the catalytic efficiency.

I believe there would be sufficient room for a full twin system but would recommend using the standard Manifolds with the Cats incorporated and running two high flow cats further down the line to gaurentee you will not have the check engine light issue.

Good luck.

Edited December 7, 2009 by mkay

[mkay]

Car is booked in for a dyno run Wednesday morning. I will video the run and post the results wednesday evening. The video may take me a few days to post.

[Tofuboi]

I am very interested to see the results for this, as the OP states that the drone from the exhaust seems to have disappeared almost entirely from just changing the Y peice. If this is the case, holy cow.

On a side note and regarding twin pipe setups. I have been speaking with the guys at A1 Exhausts in Sunbury here and if I can muster up the courage to do it... We WILL attempt a complete twin pipe setup, this is including a replacement manifold aswell. Twin setup all the way to the back. Not sure on space requirements etc, but we'll see... :P

Good stuff on this though either way! Who knows, I might just do this if it's gonna be a good help.

If you are going to change the stock manifold and do not intend to run the triple cat set-up (two off the manifold, 1 on the main pipe) you will have problems with the check engine light. However I have read a few articles lately on the net about tricking the post cat O2 sensors into thinking they are recieving the correct signal by using diodes on the O2 sensors electrical looms. Just do some google searches for more info.

The post cat O2 sensors on the Toyota only fine tune the fuel mixture by a maixmum of 2% to maximise the catalytic efficiency.

I believe there would be sufficient room for a full twin system but would recommend using the standard Manifolds with the Cats incorporated and running two high flow cats further down the line to gaurentee you will not have the check engine light issue.

Good luck.

Yeah I've been tossing up that idea aswell. The only reason why I wanted to go off stock manifolds is the pipe distance issue that was talked about earlier. If I can somehow get it to the same pipe length for both peices and not have any drastic bending in the pipe, I should be ok. Another thing I was concerned about was fitting two cats side by side on the twin pipes down the middle of the car. If room there is ok then i should be fine to go ahead.

Who knows...

[the_random_hero]

Daryl - they won't be strictly 'tuned' length from factory, have you actually done any measuring? As soon as you hit the cat, that's the end of the tuned bit.

I definitely wouldn't recommend a full twin setup, from experience you're a lot better with a good single setup then splitting at the rear.

Edited December 7, 2009 by the_random_hero