The APR Stage 3 DTR8868 Turbocharger System is Here

[AldermanToffee]

I was comparing these results with the M3/ M4 forums 1/4 mile times as I have to say these numbers are quite impressive.

For the old gen, right? Since the S58 is in the 9’s on stock turbo..

You’re better off comparing 60-130 though, since the previous gen is RWD.

[Arin@APR]

Arin: Any comment on differences between the 93 octane files (pump vs no pump) ?

More fueling headroom means we can keep power full on longer before reducing output for thermal protection situations.

[S4James]

when does this happen typically in a run? Ive heard this response before, and the support guys on the phone have said the opposite. So what exactly does this mean? will the car dyno higher? 1/4 mile? or is under sustained loads at high RPM where this kicks in?

Id like to know the specifics.

[A4 Centaur]

For the old gen, right? Since the S58 is in the 9’s on stock turbo..

You’re better off comparing 60-130 though, since the previous gen is RWD.

Yea, the F80's https://www.m3post.com/forums/showthread.php?t=630463

G80's and the S58 engine are a bit faster for sure: https://g80.bimmerpost.com/forums/sh....php?t=1853637

Wish Audi/Porsche would make an engine as good as the S58. Their response: Ah, aber Sie bekommen unseren herrlichen E839-Motor!

[SQ5onFIRE]

when does this happen typically in a run? Ive heard this response before, and the support guys on the phone have said the opposite. So what exactly does this mean? will the car dyno higher? 1/4 mile? or is under sustained loads at high RPM where this kicks in?

Id like to know the specifics.

If it’s hot out and you’re doing multiple pulls. Your car will slow down without the pump is what he means. Likely why it felt faster to me with the pump. It sustains the same power throughout vs tailoring back power when doing multiple pulls on no pump.

[Jetta03]

Dumping more fuel can be used as a strategy to help reduce timing pull by cooling the air/fuel charge. I'm guessing the APR 'fuel pump' tune is looking for a bit more leeway in terms of injector duty cycle and fuel flow capacity when using such a strategy to get the last bit of boost/horsepower out of the hardware.

[S4James]

Dumping more fuel can be used as a strategy to help reduce timing pull by cooling the air/fuel charge. I'm guessing the APR 'fuel pump' tune is looking for a bit more leeway in terms of injector duty cycle and fuel flow capacity when using such a strategy to get the last bit of boost/horsepower out of the hardware.

Yes but i want specifics, scenarios, scale of HP loss. High gear low gear. etc.

[Arin@APR]

When our modeled (Sensor verified during development) EGT threshold is crossed from running hard it will richen the air fuel ratio to keep EGT down. When that's no longer an option, it reduces power so the engine doesn't melt down.

With the HPFP there's more fueling headroom so you can richen the air fuel ratio more, which doesn't sacrifice much power at all.

If it were my car, I'd probably do it. Simple upgrade for a stage 3 guy.

[S4James]

Im starting to see that... Is it expected to cross that threshold often? And under what conditions?

[Arin@APR]

Depends. Short bursts, maybe not. But driving hard for a while, like multiple back to back pulls, I would expect it.

[oc cc]

Dying for this to be sold to us in CA.

[S4James]

Depends. Short bursts, maybe not. But driving hard for a while, like multiple back to back pulls, I would expect it.

So a full on 30-160 run would probably trigger it.. Theoretically, in mexico. Looks like im making a call.

[AldermanToffee]

Yes but i want specifics, scenarios, scale of HP loss. High gear low gear. etc.

Arin is helpful… eventually ;)

But if you’re wanting specifics like this you’re best off going with a custom tune, not an OTS. They typically aren’t going to give you all of the operating conditions of their tunes.

[Arin@APR]

Specifics aren't something anyone can do because every scenario and condition will be extremely different. In a lunching scenario the first stages of enrichment will happen before the end of the quarter mile - that's easy to tell. I don't specifically know in every scenario if the secondary reduction would trigger - there are too many variables. But adding the HPFP would limit it from activating early, if at all.

And let's be real: A 'custom tuner' is not turning this feature on or using it properly in most scenarios. It's not on by default on many platforms and if it is it's tied to a model that's broken (no longer accurate at all) when changing the turbo. It's even broken when changing simple things like turning up power beyond the OEM levels. To turn this protection on or use it properly you also have to drill and tap the engine and turbo with additional sensors to correct all the factory models within the calibration. They are completely wrong when you upgrade the turbocharger, so the ECU, for example, has no idea what the temps may be. We know because we actually measure it, and then correct the modeled information. This process isn't quick either. This isn't happening with a few logs or a couple dyno pulls. This is part of the reason why our tunes take months to make. So on other setups they'll enrich as much as they can (unnecessarily in many cases, if they enrich at all), and let it get, unknowingly, hotter than is safe for the hardware. We let it enrich as much as it can safely support within our specified bounds, such as injection window, and AFR targets, when a specified corrected EGT limit is crossed. If the available fuel enrichment cannot maintain safe EGT levels the airflow output will begin to reduce, only enough to maintain safe EGT levels, and no more. In doing this it protects the engine and other components from damage.

[S4James]

likely to trigger by the end of a quarter mile run is specific enough for me. Making that call. Too bad its so expensive in canadabucks. This is why i dont mind "the most power" setup, or the APR premium in this case. My old custom tuned car was worth nothing. I paid 50 grand cash for this one and im not interested in going through three motors like the last time.

[GoCougs1234]

FWIW, I had APR stage 3 installed on my 2021 SQ5 last Friday. I went 91 octane as my region only has 92. APR says there is no aftermarket HFPF file for the 91 octane tune so by that I take it that excess EGTs to the extent that can be experienced on the 91 tune can be handled by the factory fuel pump. I've tested o' plenty the last week, with 1-3 minutes between runs and experienced no derating to the extent that can be measured by acceleration times.

[S4James]

That would kind of make it impossible for you to switch back and forth between e85 and 91 octane tunes if that was the case no? APR needs to get their messaging straightened up with these various configurations.

[Jetta03]

Silly question, are EGT's measured by the O2 sensors?

[ontunerow]

That would kind of make it impossible for you to switch back and forth between e85 and 91 octane tunes if that was the case no? APR needs to get their messaging straightened up with these various configurations.

Their message is whatever fits best at the moment. They told me with their ungraded pump you can only run e85. That fitted the negative when their pump failed with less than 1000 miles in use, and I said I'm running 93.

[Arin@APR]

Silly question, are EGT's measured by the O2 sensors?

There is no measurement. It's modeled. It's a guess based on known variables. But those variables change with tuning and swapping turbos. You have to install a new sensor, and run through many tests to correct them, which is what we do.

[Arin@APR]

The messaging is correct on the website.

E85: Limited power on stock HPFP. More power with HPFP. Files for stock or APR HPFP.
Pump fuel: Full power on stock or upgraded HPFP. Headroom for protection increased. Files for stock or APR HPFP.

[Tom/APR]

That would kind of make it impossible for you to switch back and forth between e85 and 91 octane tunes if that was the case no? APR needs to get their messaging straightened up with these various configurations.

I think what you are asking is this... There are no "flex fuel" files. You are either running 91/93 or E85 (well E60+). No blends. You pump out whatever fuel you are running to put in the one you are changing to and reflash.

[S4James]

The messaging is correct on the website.

E85: Limited power on stock HPFP. More power with HPFP. Files for stock or APR HPFP.
Pump fuel: Full power on stock or upgraded HPFP. Headroom for protection increased. Files for stock or APR HPFP.

That's how i certainly interpreted it. However when i spoke to your reps on the phone and asked if there was any advantage whatsoever to running the HPFP on 93, the answer was an unequivocable no. I have now learned differently, and ill be upgrading to it.

[S4James]

I think what you are asking is this... There are no "flex fuel" files. You are either running 91/93 or E85 (well E60+). No blends. You pump out whatever fuel you are running to put in the one you are changing to and reflash.

No im not. I just thought the scenario of having the hpfp, and no 91 octane file being available seemed unlikely. If the guy is in a place where 91 is all he can get, but he wants to run the FUN e85 file, he would be SOL if that were true.

[davesxx01]

Arin, excellent detailed answer! So much want this turbo but loving my current E85 tune! (And it’s massive low end torque!)

[TunedB9S4]

94 Octane w/~10% ethanol
APR DTR8868 turbo
APR HPFP
Upgraded Injectors
Custom Tune on Deadbeef Flash platform by Logic Street Performance

Just a casual launch. This is *not* the final file revision.

I wanted an upgrade over my previous TTE710. Given the resale value of the TTE, and that the APR turbo happened to be on sale, upgrading made sense - especially here in Canada where prices on everything car related are crazy. Even if I didn't have a turbo with high resale value, the price on the APR turbo alone makes it a logical choice over the TTE810 let alone in consideration of other factors, like more flow on the hot side. Install was not an issue, and the full kit of parts that comes along with it (including a new DV) makes it a real value IMO.

Sadly, LPFP needs replacement so will be able to put up a couple of Dragy when I get the LPFP sorted out in the next couple of business days.

[S4James]

94 Octane w/~10% ethanol
APR DTR8868 turbo
APR HPFP
Upgraded Injectors
Custom Tune on Deadbeef Flash platform by Logic Street Performance

Just a casual launch. This is *not* the final file revision.

I wanted an upgrade over my previous TTE710. Given the resale value of the TTE, and that the APR turbo happened to be on sale, upgrading made sense - especially here in Canada where prices on everything car related are crazy. Even if I didn't have a turbo with high resale value, the price on the APR turbo alone makes it a logical choice over the TTE810 let alone in consideration of other factors, like more flow on the hot side. Install was not an issue, and the full kit of parts that comes along with it (including a new DV) makes it a real value IMO.

Sadly, LPFP needs replacement so will be able to put up a couple of Dragy when I get the LPFP sorted out in the next couple of business days.

Ill put money on this turbo performing very well.

[handspin]

wow custom, APR did mention leaving room for such projects since the OTS stays very much in the range of safety

why is a new diverter valve necessary with the APR b9turbo? was stated that the turbo came with a new DV


"Additional HPFP software is available for max output on ethanol and increased protection headroom on pump fuel. Lastly, for dedicated race cars the turbocharger is designed with headroom to go even further on your own!"

https://www.goapr.com/products/engin...parts/T4100001

[TunedB9S4]

wow custom, APR did mention leaving room for such projects since the OTS stays very much in the range of safety

why is a new diverter valve necessary with the APR b9turbo? was stated that the turbo came with a new DV


"Additional HPFP software is available for max output on ethanol and increased protection headroom on pump fuel. Lastly, for dedicated race cars the turbocharger is designed with headroom to go even further on your own!"

https://www.goapr.com/products/engin...parts/T4100001

Yes. I called APR before making the purchase and they very kindly confirmed there is room beyond what their tunes achieve.

The tuner has commented that compared to the TTE810, the APR turbo seems to spool more quickly and run with less back pressure.

[Arin@APR]

Awesome results! Glad we could be a part of your build!

[TunedB9S4]

I feel quite confident (as does the tuner) that there is a 10.7 run yet to be had. Couple of more optimizations but, so far so good.

94 Octane
APR DTR8868 turbo
APR HPFP
Upgraded Injectors
Custom Tune on Deadbeef Flash platform by Logic Street Performance

[handspin]

Sub 10 E85? Any plans to convert

[TunedB9S4]

Sub 10 E85? Any plans to convert

I've got an LPFP on order (good for around 1000HP) to pair up with a similar HPFP (also good for around 1000HP) and then will put in some runs with something spicier than 94

and, yes, I'll never come close to utilizing them at 100% capacity but I won't be fuel starved, either....Injectors still have plenty of room to play.

[TunedB9S4]

refinements ongoing with 94 octane pump gas.

[GoCougs1234]

Just curious - how are you launching? I have found it exceptionally tricky - far more so than stage APR stage 1. On APR stage 1, with my setup, launching on the upswing at ~3,500 RPM produced the best results and was relatively easy to replicate once I figured out what worked best for my setup.

I have an SQ5 on the 91 octane tune, and 99% of the time I either launch flat with no boost or launch hot and hit a torque limit and get a 60' time barely better than stock at 1.90 s. I've only ever had two good launches and that was also on the upswing at ~3,500 RPM (and even then, these two launches only matched my stage 1 60 ft at 1.76 s).

[TunedB9S4]

I can't speak to your tune, but I launch in a fairly straightforward way...

Rear tires (ExtremeContact DWS06 Plus) at around 35 PSI. Front tires closer to 40 PSI. Traction off. Automatic (or manual).

The right road (some around me provide grip, others provide more slip)

And yeah... aiming for 3400 on the upswing in case I overshoot 3500.

I've got 2nd gear launch, but haven't played around with it enough. It does, however, seem to completely eliminate any wheel spin at launch.

[S4James]

Can anyone tell me what the cracking pressure of the wastegate is set to? I want to check mine.

[TunedB9S4]

I know one of the dragy "slips" is invalid, but, I was connected when I began the run. Sometimes dragy seems to do that. So, in theory, with a custom tune, 93/94 octane, and the APR turbo, you can hit a very respectable 1/4 mile.

Oh - these runs are with the PCV 'fix' that was posted on FB a few months back. I can now consistently hit the 0-60 and 1/4 miles and 1/8th times with far less variation.

Can't wait to see what ethanol does for this turbo. Nice job APR.

[macspring]

Hi, can I ask what the DV ‘fix’ you mentioned.
I’m not on Facebook. 🫣
Thanks.

( Great thread by the way )

[handspin]

stated something about APR sending a new DV with the turbo.. this is the diverter valve?