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Discussion Starter #121 (Edited)
yes.

Also I'll be posting some data on this within the next day or two, but comparative 2015 stock vs 2015 intake / exhaust.. with intake exhaust it flows so much more.
Stock flow like 135 g/sec
modded flow like 170 g/sec.

huge difference.
The only way we are going to get a valid 87 vs 91+ comparison is when one person does both. All this comparison is going to show is how the tune helps both extremes of vehicle configuration, which is still very interesting and valuable to people, but that is all it will tell.

Anyways, questions OVT:

Are those flows with stock tune or the base tune?
If the latter did you give them both the same intake and exhaust valve timing adjustments?
If so was it the same timing you ended up with for my car?

Changing subjects for last question: Is there anywhere in the RPM band at any loads and any temps where the baseline spark timing advance you specified in the tables is knock limited based on logs for my car? Said another way, is there any condition where you would have liked to specify more spark timing advance but didn't because knock was showing up in my datalogs?

As discussed via email, I, interested in relaxing the spark advance temp correction tables for hotter IATs, and would like a general idea of where the knock susceptability ended up with my tune. I realize some of the power drain is lower air density at hotter temps, but if I'm losing 4-8 degrees of timing advance flaming hot vs freezing (based on the correction table) that makes a big difference too!
 

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On real time logs STOCK I'm seeing knock retard at low-load, steady-state driving. The ecu is from the factory riding knock at low load; that's a certainty.
 

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The only way we are going to get a valid 87 vs 91+ comparison is when one person does both. All this comparison is going to show is how the tune helps both extremes of vehicle configuration, which is still very interesting and valuable to people, but that is all it will tell.

Anyways, questions OVT:

Are those flows with stock tune or the base tune?
If the latter did you give them both the same intake and exhaust valve timing adjustments?
If so was it the same timing you ended up with for my car?

Changing subjects for last question: Is there anywhere in the RPM band at any loads and any temps where the baseline spark timing advance you specified in the tables is knock limited based on logs for my car? Said another way, is there any condition where you would have liked to specify more spark timing advance but didn't because knock was showing up in my datalogs?

As discussed via email, I, interested in relaxing the spark advance temp correction tables for hotter IATs, and would like a general idea of where the knock susceptability ended up with my tune. I realize some of the power drain is lower air density at hotter temps, but if I'm losing 4-8 degrees of timing advance flaming hot vs freezing (based on the correction table) that makes a big difference too!
The flow was on the base file, not stock. Yes they both have starting cam tables the same. Their cars are the same 2015 MT with the same ECU ID so the comparison will be pretty close.

As for ignition timing I would like more across the entire RPM band, but it's knock limited I got the timing up on your car quite a bit, but because these engines are such high compression and th way the cams are, they are knock limited before they can reach MBT.

You have to understand that knock is..dynamic. If you are always chasing knock trying to expel it, you're going to be doing that forever. Every car knocks sometimes. There will always be instances where the car knocks a little, sometimes randomly. That's just how every car is. For instance you could do 2 WOT pulls, first one has a little knock and second one has no knock, it's not uncommon.

I wouldn't focus so heavily on making it never knock, that's practically impossible, but focus on how much knock, how often the occurrence, is it repeatable every single time (which would mean too much ignition).
 

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I suspect the difference is mostly in the exhaust; in any event I'm unwilling to give up the well-known benefits of much better filtration of incoming air that going to a SRI with one of those oiled-gauze things costs me. I back that opinion up with three decades of used oil analysis reports across dozens of engines and the silicate levels found in oil samples with various filtration systems, ranging from "essentially none" (some marine diesels) to oiled gauze and paper filters.

Without exception the paper filter engines have gotten fewer insults due to silicates (dirt that gets past the filter and into the engine) and that is a major contributor to engine wear over time.

I'm VERY interested in the sound profile (in particular what winds up in the cabin!) from the Racing Beat catback.
Totally agree with the oil filters, I will tolerate it for now since it came with one but I will change it out with a dry filter sooner than later. RB definitely improved the sound a ton, but the SRI combined with it really makes it perfect. It does not sound like a 4cylinder engine at all.
 

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The AEM dry flow filter tends to show pretty good filtration, on par with some oems from what I've read.

Also I'm not sure the big flow delta is from the exhaust primarily, because where the max flow rate is occurring int he RPM band (6k) the stock intake is VERY restrictive compared to an SRI (or to a lesser extend CAI) per previous dyno plots seen from corksport injen and K&N.

Not to say at lower rpms where torque is occurring the delta isn't big, and isn't mostly the exhaust, it could be but we don't have the data.
I am on only the second flash and when I hit 6000 RPM today I swear it almost felt like a slight turbo boost kicked in hahaha.
 

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I will be jumping in on this now too since my ecu is supported. Only 500 miles on the car and im modding it already lol. Added sri yesterday.
 

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Discussion Starter #129
I am on only the second flash and when I hit 6000 RPM today I swear it almost felt like a slight turbo boost kicked in hahaha.
Yeah the 1st flash cleans up the valve timing making everything nice and smooth, but the second tune is where the power starts to come in from the spark timing advance. So for many that is where it starts to get fun.

I've finally got my 7th tune. So I'll give it a whirl logging it soon. There will be at least one more after that.

What rev limit did you pick ballsy?
 

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Discussion Starter #130 (Edited)
The flow was on the base file, not stock. Yes they both have starting cam tables the same. Their cars are the same 2015 MT with the same ECU ID so the comparison will be pretty close.

As for ignition timing I would like more across the entire RPM band, but it's knock limited I got the timing up on your car quite a bit, but because these engines are such high compression and th way the cams are, they are knock limited before they can reach MBT.

You have to understand that knock is..dynamic. If you are always chasing knock trying to expel it, you're going to be doing that forever. Every car knocks sometimes. There will always be instances where the car knocks a little, sometimes randomly. That's just how every car is. For instance you could do 2 WOT pulls, first one has a little knock and second one has no knock, it's not uncommon.

I wouldn't focus so heavily on making it never knock, that's practically impossible, but focus on how much knock, how often the occurrence, is it repeatable every single time (which would mean too much ignition).
Thanks for the responses OVT. On the valve timing I would think tha the intake would have a decent impact on the optimal intake valve timing and the exhaust would have a decent impact on the optimal exhaust timing as well.

How much different did my intake and exhaust valve timing end up compared to other 2.5 stock tunes you've completed?

Also thanks for the answers on the spark timing. I would think that high compression ratio engines and turbo charged engines have similar problems as both put up high pressure in the combustion chamber at top dead center, higher pressure means higher temperatures by simple physics, and both of those together are ideal for creating predetonation. So I'm not surprise you can't fully optimize.

and that makes heat a double whammy of lowere air density at a given pressure and higher tendency for knock which makes you also pull back timing. It much more noticeable now with the tune than when I was running 91 octane off the tune. It's pretty similar to how 87 was off the tune.

That is why I was surprised to hear there are temp correction tables, because the 91 octane made them invisible. Maybe it was just at not wot loads, and at wot the impact was there but I didn't really notice.

Do you ever see enough difference between knock with hot and cold data logs to bother editing the temperature spark advance correction table? I'm not interested in backing off timing as much as pushing timing forward at higher temps relative to the factory defaults in the spark advance temp correction table if there is more headroom there.
 

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Thanks for the responses OVT. On the valve timing I would think tha the intake would have a decent impact on the optimal intake valve timing and the exhaust would have a decent impact on the optimal exhaust timing as well.

How much different did my intake and exhaust valve timing end up compared to other 2.5 stock tunes you've completed?

Also thanks for the answers on the spark timing. I would think that high compression ratio engines and turbo charged engines have similar problems as both put up high pressure in the combustion chamber at top dead center, higher pressure means higher temperatures by simple physics, and both of those together are ideal for creating predetonation. So I'm not surprise you can't fully optimize.

and that makes heat a double whammy of lowere air density at a given pressure and higher tendency for knock which makes you also pull back timing. It much more noticeable now with the tune than when I was running 91 octane off the tune. It's pretty similar to how 87 was off the tune.

That is why I was surprised to hear there are temp correction tables, because the 91 octane made them invisible. Maybe it was just at not wot loads, and at wot the impact was there but I didn't really notice.

Do you ever see enough difference between knock with hot and cold data logs to bother editing the temperature spark advance correction table? I'm not interested in backing off timing as much as pushing timing forward at higher temps relative to the factory defaults in the spark advance temp correction table if there is more headroom there.
I use the temp ignition correction tables when needed yes, I have made adjustments to yours quite a bit, that way I can have a "static" timing table with corrections for temp that keeps it from knocking and still get power to the ground with any weather fluctuation (although you will still notice power loss when it's hot, no real way around that unless you can get intake temps below ambient)


your valve timing is tweaked different than the CX5 because of how the CX5 generates more load in lower RPM (AWD / heavier)
 

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I'm on #2 and have seen a quite-material torque lift all the way down to 2k rpm that came right on the base file but no significant hp increase yet.

I haven't tampered with the rev limiter yet though and I am definitely ramming it with the drop coming right at 6k. It's VERY noticeable; if I'm actually going to do an acceleration run I'd shift at 5900 as hitting it is quite dramatic.
 

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I am on only the second flash and when I hit 6000 RPM today I swear it almost felt like a slight turbo boost kicked in hahaha.
Yeah the 1st flash cleans up the valve timing making everything nice and smooth, but the second tune is where the power starts to come in from the spark timing advance. So for many that is where it starts to get fun.

I've finally got my 7th tune. So I'll give it a whirl logging it soon. There will be at least one more after that.

What rev limit did you pick ballsy?
I want OVT to get me at 6500-6700. Hasn't been changed yet, just sent him data log #2 and reminded him. I feel 6200 is extremely premature but don't want to strain the components too much too often so figure around 65 to 6700 shoud be optimal. I still want to feel more pull though, WOT in 2nd still seems to not give me much though the consistency/smoothness through the RPM band is impressive with only 2 flashes logged.
 

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Discussion Starter #134
I use the temp ignition correction tables when needed yes, I have made adjustments to yours quite a bit, that way I can have a "static" timing table with corrections for temp that keeps it from knocking and still get power to the ground with any weather fluctuation (although you will still notice power loss when it's hot, no real way around that unless you can get intake temps below ambient.
I had the same thought on the temp correction tables. It really is all you need to fine tune ignition timing once you get in the ballpark with the static table.
 

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Discussion Starter #136
Sorry I don't have a go pro or anything to record with.

I did manage to almost kill my battery with the dome light AGAIN. So I figured if I'm going to drive around for longtime, I might as well hit some mountain roads.

Oh my gosh. The right foot pedal is in control of a true sports car's soul and the rest of the chassis isn't far behind. It's some pretty realistic rally racing. I can point and stomp to pull the car through corners rather than just handling the corners, what a blast. The engine sounds the throttle response, the control with the mtx, it's as good as it gets. My brakes felt like they needed to be a bit stronger. I think stickier pads will be enough, but I've definitely got to watch my speed. Stomp on the gas on a snaky downhill section and 30-60 in second is about two seconds. Really really fun.
 

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whip out the phone plant your thumb on the bottom of it and hold it sideways using the steering wheel like you`re mounting it on top! lol

On a more serious note if anyone can, please post a before and after video. I will do one as well, but they lost my intake and waiting to receive an e-mail from them on Monday confirming if they had found it. So without the intake I will not tune my car.
 

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Discussion Starter #138 (Edited)
your valve timing is tweaked different than the CX5 because of how the CX5 generates more load in lower RPM (AWD / heavier)
Okay but you've tuned Mazda 3s 2.5g skyactivs per your website and what do you plan on doing for the stock Mazda 6?

I would think the dramatically shorter intake with an Sri would mean that a fair amount of intake timing advance would be optimal relative to stock intake optimal intake valve timing, at almost every speed and load. The Optimal intake valve closure timing is at least somewhat determined by the intake air column momentum which is much less with an Sri vs stock.

As far as the exhaust goes, well significant changes in exhaust velocity and back pressure will affect how quickly the combustion chamber is evacuated, so again, it would seem a change in exhaust valve timing to optimize vs stock exhaust would be a reality. Certainly the tweaks you made for me with my aftermarket exhaust helped.
 

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Hey OVT, I shot you an email, did you get it?
 

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Okay but you've tuned Mazda 3s 2.5g skyactivs per your website and what do you plan on doing for the stock Mazda 6?

I would think the dramatically shorter intake with an Sri would mean that a fair amount of intake timing advance would be optimal relative to stock intake optimal intake valve timing, at almost every speed and load. The Optimal intake valve closure timing is at least somewhat determined by the intake air column momentum which is much less with an Sri vs stock.

As far as the exhaust goes, well significant changes in exhaust velocity and back pressure will affect how quickly the combustion chamber is evacuated, so again, it would seem a change in exhaust valve timing to optimize vs stock exhaust would be a reality. Certainly the tweaks you made for me with my aftermarket exhaust helped.
How do you know that the intake air momentum differs stock vs SRI? The way intake advance on these cars works isn't what I think you think advancing does. The cam profile, angle, lift, and degree all play a factor, especially considering where "base" or 0 is on the cam. You dont simply just keep advancing and advancing until you've reached peak advance, There are limitations that are too deep to get into, secondly over-advance hinders flow and stability in high RPM and over advance in certain areas, paired with the exhaust can cause knock and reversion of the exhaust back into the clinder..

To put it simply you have to tune both cams to work in tandem, not doing so causes problems.
There are many load points and RPM points on these maps where you want to do the exact opposite and run practically 0 intake cam advance, but this is getting really deep into how and why the skyactiv does what it does which i'd rather not go into explaining.

Exhaust side the header itself is designed for scavenging, and you need to pair the exhaust cam with the intake for overlap where there is a point both intake and exhaust valves are open at the same time.

You're going deep into tuning philosophy but a skyactiv is not something you want to learn on. because what works for some (like advancing cam down low, retarding up high, etc) does not work for these like you think.

Also the mazda 6 , CX5, Mazda 3 2.5L Sky all has different tunes, depending on US market, Euro, Asian , etc. There are certain parts of these tunes that are necessary and specific to the are these vehicles are sold in like weather, gas quality, etc, each and every car is hand developed based on good known tables + the stock rom. For example the Asian market cx5 Sky 2.5L mapping is quite different than the US, due in part to fuel quality. If I just Copy/pasted my tuned settings in whole to those roms there would be some dead skyactivs right now..
 
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