B8 Ko4 owners follow up thread

[bhvrdr]

I haven’t noticed any loss around 3000 RPM. The Wagner FMIC is the biggest intercooler available for this platform and it took a little bit of time for the K03 to fill it with compressed air. The bigger K04 seems to do a better job there.

At 3000 RPM I have similar boost (~20 PSI) but more air flow (higher MAF values). Below are a couple more logs from the Base file (v1.0). It holds 24 PSI to 6200 RPM. I’ll log some more data tomorrow.



MAF values are 290 m/s up top.

You are still overboosting significantly. I suspect the original file was fine with boost request it's just that you are overioosting so much he had to turn it down. You want to address the issue though. Check n75 and Westgate.

Mike

[Perry01]

You are still overboosting significantly. I suspect the original file was fine with boost request it's just that you are overioosting so much he had to turn it down. You want to address the issue though. Check n75 and Westgate.

Mike

My tuner has made some adjustments, I just haven’t had time to log data yet. He said there is a complex pre-control / pre-prediction computer model of the turbocharger, turbine housing and wastegate and also a closed loop controller on top which obscures what you're doing underneath so it takes some time to get it right. He also stuck in a hard limiter on N75 duty to calm things down until he gets it all sorted out. Unlike other tuners, he responds to emails within hours not days or weeks. Revisions are usually sent the same day I email him datalogs. It runs great on the current file but he wants to make sure the tune is producing safe power with good drivability.

I’ll post more datalogs later.

[A4x]

That's the tricky part of tuning for a K04. The boost is low then spikes so hard it is tough to control with the N75. Hency why APR is on v3 of their software.

[bhvrdr]

That's the tricky part of tuning for a K04. The boost is low then spikes so hard it is tough to control with the N75. Hency why APR is on v3 of their software.

The stock turbo technically "spikes" worse than a K04. The K04 is a larger turbo so it ramps up slightly slower than the stock turbo and holds boost to redline slightly better (its not THAT much bigger). The stocker spikes low in the rev band hard then drops off a cliff by redline.

Mike

[Spawne32]

lol my boost request is higher then my actual boost on the K03 throughout the entire power band

[Perry01]

The K04 is a larger turbo so it ramps up slightly slower than the stock turbo and holds boost to redline slightly better (its not THAT much bigger).

Mike

The K04 holds boost slightly better at redline?

My K03 couldn’t produce more than 15 PSI at redline but my K04 can hold 24 PSI to redline. I know it’s not ideal to have that much boost up top but it just shows how much more capable a genuine Borg Warner K04 is compared to the stock turbo.

[bhvrdr]

The K04 holds boost slightly better at redline?

My K03 couldn’t produce more than 15 PSI at redline but my K04 can hold 24 PSI to redline. I know it’s not ideal to have that much boost up top but it just shows how much more capable a genuine Borg Warner K04 is compared to the stock turbo.

Lol, not for long it wont.

But yeah, the K04 does better in the upper rpm band. I guess the point I was trying to make, and you are supporting it, is that the stock turbo is a "little turbo" that spikes low and then drops off. The K04 is not as much of a little spikey turbo. It ramps up slightly more progressively and holds. Folks seeing spikes and overboost on the k04 have either a hardware problem, SW problem, or both. Folks seeing no spikes on the stocker likely have a junk wastegate. The stocker is not supposed to ramp up slowly and have trouble keeping up with boost requests. They do that when they are on their way out though.

Mike

[Perry01]

Yeah, the stock turbo spiked early and then dropped off a cliff after 5000 RPM. My base K04 file produced a nice boost curve (no spike) but it was overboosting. Keep in mind this was the base K04 file and the new revision doesn’t seem to have nearly as much PSI. A software adjustment is all that was needed.

[bhvrdr]

IE has great experience so I'm looking forward to seeing your final product.

Mike

[A4x]

The stock turbo technically "spikes" worse than a K04. The K04 is a larger turbo so it ramps up slightly slower than the stock turbo and holds boost to redline slightly better (its not THAT much bigger). The stocker spikes low in the rev band hard then drops off a cliff by redline.

Mike

Not necessarily true. The K04 comes on a bit later in the RPM range when the exhaust pressure from the engine is much higher, causing a huge spike in boost.

The K03 is better able to 'ride' the exhaust pressure ramp up of the engine and doesn't necessarily spike as much.

[bhvrdr]

Not necessarily true. The K04 comes on a bit later in the RPM range when the exhaust pressure from the engine is much higher, causing a huge spike in boost.

The K03 is better able to 'ride' the exhaust pressure ramp up of the engine and doesn't necessarily spike as much.

But the ihi has a smaller turbine wheel and comes on bam immediately spiking no?

[A4x]

I bet if you let both turbos run without any boost controller, the K04 would spike much higher PSI (a few hundred RPM later).

[Perry01]

Besides the initial spool-up, you shouldnt have any spikes if your ECU is tuned properly. Here is V2. The boost curve looks pretty flat. I emailed the logs and he is going to adjust the N75 duty cycle so I’m not bleeding of as much boost between 2000-4000 RPM. That should give me a better lower end. I’m pretty close to requested boost on V2 with 20.2 PSI at 6200 RPM.

[A4x]

Looking better!

Yea we were talking about how the K04 is tough to tune for because of the boost spike. Agreed there should be no spike if you're tuned correctly.

10psi @ 2500 rpm is pretty much the exact same as me. I can usually cross 20psi a little before 3000 rpm. I hit 293 g/s airflow.

Are you logging any timing pull/retard at each cylinder to see if the timing advance is too aggressive or not?

[Perry01]

Looking better!

Yea we were talking about how the K04 is tough to tune for because of the boost spike. Agreed there should be no spike if you're tuned correctly.

10psi @ 2500 rpm is pretty much the exact same as me. I can usually cross 20psi a little before 3000 rpm. I hit 293 g/s airflow.

Are you logging any timing pull/retard at each cylinder to see if the timing advance is too aggressive or not?

He wants to dial in the boost before he tackles timing advance. The V2 file has zero timing pull on any cylinder but only 9° advance up top.

V3 will have more boost between 2000-4000 RPM and more timing advance throughout the powerband.

Current MAF values are 302 g/s at 6200 RPM.

[A4x]

You're not going to get more boost at 2000-2800 rpm when the N75 is already pegged at 96%.

I never hit 6200 rpm in my logs lol. Too fast. My 292 g/s was at like 5500 rpm. Also I'm sure your Hawaiian air is very different than Michigan lol.

[Perry01]

The N75 value is 95.7% from 1500-2000 RPM then tapers to 67% at 3100 RPM before climbing back up.

If he adjusts the tune to hold the N75 value at 95.7% a little longer it should enable the turbo to spool up a bit faster and give me more boost down low.

[A4x]

Oh I missed that room to play in the N75. Looks great!

[bhvrdr]

Cool to see the progression guys. Hopefully they are planning a production k04 file for several box codes?

Mike

[Perry01]

Cool to see the progression guys. Hopefully they are planning a production k04 file for several box codes?

Mike

He is doing a B8 K04 tune on their shop dyno today. I wonder if it’s a member here?

[A4x]

How do you flash these onto your ECU?

[Perry01]

How do you flash these onto your ECU?

With their flash tool. They already provide off-the-shelf Stage 1 and Stage 2 tunes for the B8/8.5 platform so I’m sure they have lots of box codes already in their system.

[Perry01]

Full disclosure, I have JHM hardware on my 4.2 V8 with Malone software and Burger Motorsports software on my GTI.

It is good to have lots of options out there.

[shaunm82]

Did you have to pay to move up to the K04 tune? Since you had their software beforehand?

[Perry01]

Since I already had their software it was just an upgrade fee

[shaunm82]

Nice. I did notice that they only charge the difference in software to move up from 1-2, which is nice. I assumed it was the same to go K04, but didn't see pricing on a K04 tune only.

I'd love to drop in there the next time I'm in Utah.. still have family there, but I moved away years ago.

[A4x]

Hey Perry, any updates? Anxiously awaiting your updates to see if they got some additional low end This is all great info to see with such a lack of logging in this thread.

Btw the CTS turbo kit is on sale at ECS (and probably other vendors) for $2000 and change right now.

[Perry01]

The CTS K04 seems to really perform well. $2,000 is a good price.

V3 revision had a quick spool up (20 PSI @ 2500 RPM) but was followed by a dip in boost immediately afterward. The next revision will address initial spool up to generate good boost down low without the spike and dip. The end goal is a nice boost curve with around 15 PSI at 2500 RPM, a peak of 25 PSI between 3500-5000 RPM tapering to 20 PSI at redline. It may take several more revisions but it will be worth the time and trouble to get it right.

[A4x]

So today I threw on my stock intercooler for fun. Ran some logs. Here is a comparison of the boost build up in 2nd gear, TR8 vs stock intercooler. Driving around in D mode, the car is a bit less laggy, it really was noticeable but I only drove for like 25 minutes. I need a few more days to determine if it is worth it or not to give up the cooling power of the TR8.



Here is the N75% which shows that the turbo has to work less with the stock intercooler. It means the TR8 has a higher pressure drop across the intercooler than the stock unit does. The stock unit actually flows pretty good with low restriction. It's just piss poor at cooling lol.

[Coldcarnival]

So today I threw on my stock intercooler for fun. Ran some logs. Here is a comparison of the boost build up in 2nd gear, TR8 vs stock intercooler. Driving around in D mode, the car is a bit less laggy, it really was noticeable but I only drove for like 25 minutes. I need a few more days to determine if it is worth it or not to give up the cooling power of the TR8.



Here is the N75% which shows that the turbo has to work less with the stock intercooler. It means the TR8 has a higher pressure drop across the intercooler than the stock unit does. The stock unit actually flows pretty good with low restriction. It's just piss poor at cooling lol.

Dam that's huge, not to mention how much the bigger intercooler weights compared to the stock

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[AllroadCorbin]

The CTS K04 seems to really perform well. $2,000 is a good price.

V3 revision had a quick spool up (20 PSI @ 2500 RPM) but was followed by a dip in boost immediately afterward. The next revision will address initial spool up to generate good boost down low without the spike and dip. The end goal is a nice boost curve with around 15 PSI at 2500 RPM, a peak of 25 PSI between 3500-5000 RPM tapering to 20 PSI at redline. It may take several more revisions but it will be worth the time and trouble to get it right.

I still don’t have this dip in boost some people talk about with CTS and APR


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[A4 Centaur]

I guess you can't fake the data, but the bar and plate does allow air to move more easily, try sucking air on the stock IC and then with the TR8. Not sure why it would show that kind of value though?

Heat mean loss of power, so I guess you will need to find the balance of both worlds.

Here at altitude there is so much heat soak, it's a no brainer. Ripping up and down from 5280 MSL to over 7000 MSL really plays hell with heat soak, especially in summer.

I'll take a little more lag or whatever over heat. That APR IC let's her breath, flows great, and when you look at Wagner, AWE and APR, and TR8 are quite similar in volume.

Perhaps you should make a 6 Liter FMIC or add NOS to cool it since it sheds heat so poorly and really is a POS design with plastic end caps and cobby build.

[Spawne32]

I don't want to shit on A4x's thing here with promoting how much faster the turbo spools on the stock intercooler compared to the TR8, but the TR8 intercooler, along with all the other treadstone intercoolers are budget intercoolers, and i cannot emphasize the word budget enough. Are they good, well made intercoolers for the price? Yes? But there are far superior products that will give you better IAT's without compromising performance. Those intercoolers are just far more expensive. So take that under consideration.

[A4x]

I don't want to shit on A4x's thing here with promoting how much faster the turbo spools on the stock intercooler compared to the TR8, but the TR8 intercooler, along with all the other treadstone intercoolers are budget intercoolers, and i cannot emphasize the word budget enough. Are they good, well made intercoolers for the price? Yes? But there are far superior products that will give you better IAT's without compromising performance. Those intercoolers are just far more expensive. So take that under consideration.

I'm not promoting how much faster it is. I was just giving logs for facts and letting others decide. Actually I was surprised to see it was such a little difference, which speaks volumes for the value you get with a TR8. But maybe it is a big difference? I need to go drive some more.

Also I would love to see anyone with a $1000 intercooler do the same comparison.

ECS posted a similar loss of power below 2700 RPM for their intercooler, on a stock turbo car. I would think a bigger turbo makes it even worse.

[Spawne32]

I'm not promoting how much faster it is. I was just giving logs for facts and letting others decide. Actually I was surprised to see it was such a little difference, which speaks volumes for the value you get with a TR8. But maybe it is a big difference? I need to go drive some more.

Also I would love to see anyone with a $1000 intercooler do the same comparison.

ECS posted a similar loss of power below 2700 RPM for their intercooler, on a stock turbo car. I would think a bigger turbo makes it even worse.

Well I mean you did prove your point that it does spool faster, but the real question here is how much does that outweigh the lack of cooling a smaller intercooler provides. There really is no practical way to make up the difference there. You need a bigger core to cool the charge better but you must sacrifice something. I think ideally the best options have proven to be larger but thinner, well designed cores, using the stock size charge piping, and hard piping at that, but I think they are also the most costly of all the options. IE has one of the best designs ive seen thus far overall, but far as I am aware any of the larger intercoolers are designed for 2.5" charge piping.

[Perry01]

I still don’t have this dip in boost some people talk about with CTS and APR.

My tuner is still working on the custom K04 tune. After I get back from vacation I’ll upload the newest revision and hopefully the boost control issue will be resolved.

[Perry01]

So today I threw on my stock intercooler for fun. Ran some logs. Here is a comparison of the boost build up in 2nd gear, TR8 vs stock intercooler. Driving around in D mode, the car is a bit less laggy, it really was noticeable but I only drove for like 25 minutes. I need a few more days to determine if it is worth it or not to give up the cooling power of the TR8.



Here is the N75% which shows that the turbo has to work less with the stock intercooler. It means the TR8 has a higher pressure drop across the intercooler than the stock unit does. The stock unit actually flows pretty good with low restriction. It's just piss poor at cooling lol.

Maybe it’s your turbo or tune. You should be able to generate 15 PSI of boost at 2500 RPM with any aftermarket intercooler.

This is a log from my 2nd or 3rd revision, still with boost spike and dip but it generates almost 15 PSI of boost at 2500 RPM and 20 PSI at 3000 RPM with a gigantic Wagner FMIC

[A4x]

Maybe it’s your turbo or tune. You should be able to generate 15 PSI of boost at 2500 RPM with any aftermarket intercooler.

This is a log from my 2nd or 3rd revision, still with boost spike and dip but it generates almost 15 PSI of boost at 2500 RPM and 20 PSI at 3000 RPM with a gigantic Wagner FMIC

I get 20 psi at 3000 rpm consistently, so you've got nothing there. Sometimes I'm at 15 psi at 2500 rpm. It all depends what I am doing with the engine and RPMs before I start logging. My K03 logs were similarly laggy so maybe I need a carbon cleaning? My only K03 logs were with the TR8, so I figured I would do this experiment with the stock IC.

I have had logs come out looking like this when I cheat a bit. Beat this LOL.



I overlayed my K03 boost, so you can see it is not the K04 turbo or tune that is unusually laggy. Maybe my cat is fried, or I need a carbon cleaning OR THIS IS COMPLETELY NORMAL?!

[Perry01]

I get 20 psi at 3000 rpm consistently, so you've got nothing there. Sometimes I'm at 15 psi at 2500 rpm. It all depends what I am doing with the engine and RPMs before I start logging. My K03 logs were similarly laggy so maybe I need a carbon cleaning? My only K03 logs were with the TR8, so I figured I would do this experiment with the stock IC.

I have had logs come out looking like this when I cheat a bit. Beat this LOL.

I overlayed my K03 boost, so you can see it is not the K04 turbo or tune that is unusually laggy. Maybe my cat is fried, or I need a carbon cleaning OR THIS IS COMPLETELY NORMAL?!

I didn’t intend to turn this into a pissing match. My point is that I think you are approaching your turbo lag issue the wrong way. A properly tuned K04 should have plenty of boost down low. Switching to stock intercooler it is just counterproductive.

Here is a K04 R log provided by Jake at JHM with APR tune. It produces over 24 PSI of boost at 2500 RPM.



My point was maybe your turbo lag issue is due to something other than your intercooler.

[A4x]

Maybe, especially since my K03 was also laggy. So where else should I look? Carbon clean? Switch cat for a test pipe?

I'm very familiar with that log from Jake. I've had it for a long time. That car is 6 speed manual (vs my 8 speed) and it looks eerily similar to my log when I cheat a bit.

I've privately talked with many members on here that tell me their boost and torque don't kick in until 3000 rpm with the K04.

Let's see what you can get in a few weeks.