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Discussion Starter #41
I agree that we are in unknown territory...

There are actually a slew of things to consider about getting a full 3" turbo back on an unknown platform but here are a couple things related to OP.

1: In my experience, it's not hard at all to get over 20HP without upgrading anything in the exhaust at all as long as you're tuning a forced induction car. Depends on the car though.
2: Depending on the size of the wastegate on the OEM turbo, a full turboback system can introduce boost creep problems where the ECU is unable to bypass enough exhaust through the wastegate to keep the turbo from continuing to build more and more boost out of control as the RPMs rise. More flow is great as long as you can maintain control of the boost.

Frankly, not enough stuff done to these 2.5T engines for us to know these answers yet
 

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Discussion Starter #42
So I drove about 20 miles so far today in various conditions. From previous experience I know that OVT sends you a VERY conservative tune for your first so that they can see from the logs how the engine will react to tweaks, so I wasn't expecting much. Here is what I can say: better idle, smoother and better throttle response, can feel extra torque under the curve with no spikes, seems to pull much more smoothly to redline without feeling like it's going to fall off of a cliff...

I'll datalog as soon as I can and send it back to OVT for tune #2 which will be more aggressive.
 

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There are actually a slew of things to consider about getting a full 3" turbo back on an unknown platform but here are a couple things related to OP.

1: In my experience, it's not hard at all to get over 20HP without upgrading anything in the exhaust at all as long as you're tuning a forced induction car. Depends on the car though.
2: Depending on the size of the wastegate on the OEM turbo, a full turboback system can introduce boost creep problems where the ECU is unable to bypass enough exhaust through the wastegate to keep the turbo from continuing to build more and more boost out of control as the RPMs rise. More flow is great as long as you can maintain control of the boost.

Frankly, not enough stuff done to these 2.5T engines for us to know these answers yet

No, the turbo isnt big enough to make creep. You did notice my user name, right? LOL


Definitely do NOT want back pressure. I agree this platform needs a good 3" system (minimum) from the turbo back to make any real power, but there are no downpipes available yet and I will be damned if I pay $1000 for a Corksport exhaust no matter how "pretty" it is.

Sorry to disappoint you. You won't hear "needs backpressure" from me...😉

Ha, then youre smarter than the average bear. Yea, anything CS sells is fucking way overpriced.
 

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No, the turbo isnt big enough to make creep. You did notice my user name, right? LOL
A user selected name is just a user selected name. *shrug*

Any turbo can be over-spun. Can it generate enough boost to damage the engine? Maybe so or maybe not in this case...but it can damage itself and hurt power output by driving the turbo well beyond it's usable limits turning it into nothing but a very inefficient blow dryer. You can't just spin a turbo to the moon for the hell of it.

I'll add that even if the turbo would not damage the engine at full tilt and wouldn't damage itself at full tilt, it's still an absolutely idiotic idea to find the idea of a turbo that can no longer be slowed down is acceptable in any condition. If the wastegate duty cycle is maxed and you're still building boost beyond what is called for by the ECU, fix that shit.
 

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A user selected name is just a user selected name. *shrug*

Any turbo can be over-spun. Can it generate enough boost to damage the engine? Maybe so or maybe not in this case...but it can damage itself and hurt power output by driving the turbo well beyond it's usable limits turning it into nothing but a very inefficient blow dryer. You can't just spin a turbo to the moon for the hell of it.

I'll add that even if the turbo would not damage the engine at full tilt and wouldn't damage itself at full tilt, it's still an absolutely idiotic idea to find the idea of a turbo that can no longer be slowed down is acceptable in any condition. If the wastegate duty cycle is maxed and you're still building boost beyond what is called for by the ECU, fix that shit.

You really dont understand turbos man. Putting a larger exhaust on wont cause boost creep, if you have the same (or larger) diameter all the way. In other words, dont use a large DP and small CB. However, the turbo we are talking about here would cease to create useable boost before it would boost creep just looking at the exhaust side.


I used to own the car the name is based on. There was only one time that i experienced boost creep. I had to put a dead stock turbine housing on for a reason i dont remember. Since it wasnt ported and the ex-man and O2 housing were, it created a crimp in the flow. I knew this would happen and just took the boost controller out of the loop running 7psi. It would creep up to 18psi and stay there no matter how long i accelerated.



I also used to professionally port the exhaust side pieces with repeatable results of 2-3mph and .3.-.4 seconds gained in the 1/4, with no other changes to the car or boost level.


On the 4G63, putting a cat less 3" turbo back was good for up to 50hp gain alone, depending the other mods in the mix. So if you were running 16 psi on the stock exhaust and put a full 3" without a cat on, youd get around 25-30hp if you changed nothing else.
 

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You really dont understand turbos man.
Yup, not going to sit here and argue with your Appeal to Authority. A simple search immediately confirmed exactly what I was saying...and seeing as I've experienced exactly what I was saying on a Mazdaspeed 3, yeah. So I'll leave this discussion with this.

https://innovativetuning.com/boost-creep-definition-causes-solutions/

"Boost creep is caused by a fully opened wastegate not being able to flow enough exhaust bypassing the turbine wheel."

"Factory intake and exhaust systems are generally more restrictive than aftermarket performance parts. Upgrading intake and exhaust components may induce boost creep where it was not present before. An increase in flow into and out of the turbo requires an increase in wastegate flow to maintain target boost pressure at each RPM. If wastegate flow is near capacity prior to installing intake/exhaust upgrades, or those upgrades cause a large increase in flow, freeing the system up can put the wastegate flow requirement beyond capacity at which point the boost level becomes out of control."
 

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Discussion Starter #47
Mat contacted me today and is working on my second tune file. He said the log from tune 1 looked good and that he is working on the boost tables for this second round.
 

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Mat contacted me today and is working on my second tune file. He said the log from tune 1 looked good and that he is working on the boost tables for this second round.
I'm looking forward to hearing your updates. I want to get this tune for my car once it's been dialed in. Thanks!
 

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Discussion Starter #49
Second tune file loaded. I'll drive it to and from work the next couple of days and then do some logs. I'll report back either tomorrow or the day after.
 

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Cant wait to see the results, by the way, whats your opinion on the cork sport boost tube and short ram intake? thanks.
 

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Discussion Starter #51
The second tune feels real good. VERY smooth power delivery and a nice bump in torque in the midrange. Because of traffic this morning I could not get more than 1/2 throttle anywhere, but it is a definite improvement. Can't wait to open it up.

As for the Corksport parts, they are worth the money IMHO. Definite improvement by themselves.
 

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The second tune feels real good. VERY smooth power delivery and a nice bump in torque in the midrange. Because of traffic this morning I could not get more than 1/2 throttle anywhere, but it is a definite improvement. Can't wait to open it up.

As for the Corksport parts, they are worth the money IMHO. Definite improvement by themselves.
This is something I missed but I insisted on using a dynamometer so I wasn't able to "get the feel" of each tune.
 

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Discussion Starter #54
Tune is doing great. Sent in logs and waiting for #3. It has more torque everywhere and revs much better. It can easily spin the tires from a pretty decent roll. I am impressed how little if any torque steer this car has compared to my Mazdaspeed 3's. Of course they had more power, the second one a lot more, but they also had better motor mounts and much better tires.
 

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Discussion Starter #55

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Tune is doing great. Sent in logs and waiting for #3. It has more torque everywhere and revs much better. It can easily spin the tires from a pretty decent roll. I am impressed how little if any torque steer this car has compared to my Mazdaspeed 3's. Of course they had more power, the second one a lot more, but they also had better motor mounts and much better tires.
Do you know how many more files until "you're good to go"?
 

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Discussion Starter #58
Do you know how many more files until "you're good to go"?
No way to tell really. It took about 4 for my CX-3 if I remember correctly. Since this is new territory, and the engine is turbocharged, I am sure he will take his time. Most people are done at about 6 or so.
 

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Hey torque, should I get the pedal commander or no. I heard that OV changes the throttle sensitivity when you get the tune, would that be good enough or would you suggest I get the pedal commander too.
 
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