Dual Pulley DD Reliability.

[chris the man]

Hi all, scoured the forum for this answer.

B8 S4 (2012)
In short, with supporting modifications -
PLM - Heat Exchanger/Expansion Tank
IE - CAI
IE - DP ECU Tune
IE - DSG Tune

(considering gutting or replacing the cats as well).

If I am road tripping the car with DP vs Single, will there be a significant amount of heat soak or additional concerning/damaging issues?

For example, with the larger crank pulley, is the supercharger simply working harder all of the time (all rpms) compared to stock? Or only WOT?

I live in a vegas like climate, VERY HOT here in Saint George, UT. So I am looking to maximize my power, safely. DP is right around the same price as single, which is why I am considering.

THANKS!!!!!

[MSq5]

Hi all, scoured the forum for this answer.

B8 S4 (2012)
In short, with supporting modifications -
PLM - Heat Exchanger/Expansion Tank
IE - CAI
IE - DP ECU Tune
IE - DSG Tune

(considering gutting or replacing the cats as well).

If I am road tripping the car with DP vs Single, will there be a significant amount of heat soak or additional concerning/damaging issues?

For example, with the larger crank pulley, is the supercharger simply working harder all of the time (all rpms) compared to stock? Or only WOT?

I live in a vegas like climate, VERY HOT here in Saint George, UT. So I am looking to maximize my power, safely. DP is right around the same price as single, which is why I am considering.

THANKS!!!!!

With Stage 2 the supercharger spins faster, with DP it spins even faster in relation to engine speed. It might wear the s/c bearings a little faster, but it “works harder” only when on boost and under load. DP is actually about ratio above 3:1 rather than the number of pulleys. A large enough crank pulley alone (194mm and above) can get you over 3:1.

Your HX should prevent heat soak except in slow moving or stalled traffic, but it will recover quickly.

[mercedesinfarct]

I chose to stick with stage 1 for reliability/peace of mind. Plus, for my daily, 400 BHP is more than enough and I never really push it to the limit.

[chris the man]

With Stage 2 the supercharger spins faster, with DP it spins even faster in relation to engine speed. It might wear the s/c bearings a little faster, but it “works harder” only when on boost and under load. DP is actually about ratio above 3:1 rather than the number of pulleys. A large enough crank pulley alone (194mm and above) can get you over 3:1.

Your HX should prevent heat soak except in slow moving or stalled traffic, but it will recover quickly.

Thank you partner that was the exact answer I was looking for. So essentially from there on out, the second pulley will cause the SC to constantly work more then if the pulleys are left alone. This is a concern for me.

The reason why I am so curious is because everyone says the difference between SP and DP is very significant.

I appreciate the fact that the HX should help, I hope by taking the cats off of the car that I will rid of majority of any other problems.

- - - Updated - - -

I chose to stick with stage 1 for reliability/peace of mind. Plus, for my daily, 400 BHP is more than enough and I never really push it to the limit.

Thats kind of where I am at. Im just stuck because the second pulley install is literally right in the same area when we will already have the bumper off of the car.

[01northernS4]

Stage 1 for almost all tuners is just a tune, no pulley (except for I think revo a stage 1+ might include the upper supercharger pulley)

[Morritse]

I chose to stick with stage 1 for reliability/peace of mind. Plus, for my daily, 400 BHP is more than enough and I never really push it to the limit.

Are cars are very close to 400BHP stock, believe it or not!

[doughboy17]

Are cars are very close to 400BHP stock, believe it or not!

That may be a slight exaggeration -- around 360 bhp ish stock.

[cardoboy]

I've put about 12k miles on my car with dual pulley APR. Previously it was stage 2 with the upper pulley only. It's a gigantic difference, with no down side in my experience.

My advice is either stay stage 1 with software only or go straight to dual pulley.

My car ran 141-144mph over 7 runs in a half mile event in 90f heat this past summer. I drove it 2 hours to get there and two hours home.

[Jamen]

30k miles on APr dual pulley with APR Cooling. No issues at all and it’s a daily driver, but I don’t track my car, just occasionally drive Spirited

[JimmyJamesS4]

Dp 179mm with CTS HX daily driven, 145k miles on the clock, smooth as butter

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[onlyaudis]

dual pulley is hell on cats FYI. something to be aware of that often gets left out of the conversation. I am nearly 4 years on EPL stage 1 with dsg tune and I add 4 gallons of ethanol each fill up. zero issues. no cels. no blown cats, car is plenty fast enough. I call that reliability. if you think you can draw more boost in a harsh hot environment and pay no wear and tear penalty for it, probably not being very realistic.

[01northernS4]

So... seems like the general consensus is DP ratio is safe for daily driving if you have sufficient cooling done and you don't racecar 24/7... daily spirited drives, redlines, launches and the occasional track shouldn't be a problem.

People have had problems with cats on these cars at stock, stage 1 and 2... probably mostly dependent on driving style and if cooling upgrades are done or not.

As far as I see when I'm out of warranty Merc cooler and DP ratio here I come... and of course watch the EGT's… when too hot stay out of the kitchen...

A bunch of members on here have had DP at not crazy ratios (3.2 or less) for many, many km on daily driven vehicles with no cat failures or problems whatsoever.

Sounds about right?

If so, I'm sold.

[Morritse]

So... seems like the general consensus is DP ratio is safe for daily driving if you have sufficient cooling done and you don't racecar 24/7... daily spirited drives, redlines, launches and the occasional track shouldn't be a problem.

People have had problems with cats on these cars at stock, stage 1 and 2... probably mostly dependent on driving style and if cooling upgrades are done or not.

As far as I see when I'm out of warranty Merc cooler and DP ratio here I come... and of course watch the EGT's… when too hot stay out of the kitchen...

A bunch of members on here have had DP at not crazy ratios (3.2 or less) for many, many km on daily driven vehicles with no cat failures or problems whatsoever.

Sounds about right?

If so, I'm sold.

DP just raises the potential of max EGTs, it's not inherently worse for cats, it just allows you to be harder on them.

Anything which causes high EGTs will be hard on your cats. Driving hard all the time on stock will. Driving without hitting more boost than stage 2 levels on dp will be no harder on them than stage 2 would be.

You have to remember though that people don't go dual pulley to never drive their car hard, so this factor is somewhat of a confounding variable.

[01northernS4]

DP just raises the potential of max EGTs, it's not inherently worse for cats, it just allows you to be harder on them.

Anything which causes high EGTs will be hard on your cats. Driving hard all the time on stock will. Driving without hitting more boost than stage 2 levels on dp will be no harder on them than stage 2 would be.

That's what I figured by reading everyone's experiences on here at DP ratios... nothing to be afraid of if you have the right cooling, maintenance and don't torture test your vehicle every single second of the day... sounds and looks like a daily DP ratio should be as reliable as any other stage all else being equal (primarily driving style)... but I defer to the experts here until I go DP myself.



If one were to daily a dp ratio what is generally considered max safe EGT? Are there safeties built into the tunes for this or would one simply lay off the fun pedal when they are seeing these numbers on the gauge?

And how much different are the max EGT's for stock, stage 1, stage 2 single pulley and stage 2 dp ratio?

[01northernS4]

DP just raises the potential of max EGTs, it's not inherently worse for cats, it just allows you to be harder on them.

Anything which causes high EGTs will be hard on your cats. Driving hard all the time on stock will. Driving without hitting more boost than stage 2 levels on dp will be no harder on them than stage 2 would be.

You have to remember though that people don't go dual pulley to never drive their car hard, so this factor is somewhat of a confounding variable.

Completely appreciate and agree people go dual pulley to drive their car hard but I think the question here is about daily driven vehicle at dp ratio... you can daily drive a vehicle hard but at some point if you're smashing the throttle at every light redlining and tracking every week... is it really a daily driven vehicle at that point? I mean you can but you also can't be surprised when the cats go pop... as everyone says, pay to play... but normal daily driven dp ratio, with occasional hard driving and track visits should not have problems with cats from what I read here... strictly from what I've read here... I guess I'll know myself as soon as I'm out of warranty!

[MSq5]

Completely appreciate and agree people go dual pulley to drive their car hard but I think the question here is about daily driven vehicle at dp ratio... you can daily drive a vehicle hard but at some point if you're smashing the throttle at every light redlining and tracking every week... is it really a daily driven vehicle at that point? I mean you can but you also can't be surprised when the cats go pop... as everyone says, pay to play... but normal daily driven dp ratio, with occasional hard driving and track visits should not have problems with cats from what I read here... strictly from what I've read here... I guess I'll know myself as soon as I'm out of warranty!

I think you summarized it well. I just went DP and Merc HX about three weeks ago or so. Almost out of warranty (49,500 miles).

I progressed up the power ladder. Stock to intake filter and Chipwerke, then to real Stage 1 with tube and airbox mod, then Stage 2 179 crank pulley, then added to HX and Stage 2 DP 187/57. I was cautious given that I was still in warranty and looking for possible issues that never materialized. I’m done with power mods for the foreseeable future. I might get a race gas/100 octane tune just to play with. That’s it. No ethanol here.

We will probably find out together if cats fail or supercharger leaks. If cats fail I’ll likely go with a catless setup with extra resos or x-pipe, as we have no emission testing here.

[Vogz]

That may be a slight exaggeration -- around 360 bhp ish stock.

My car put down 320awhp stock. That's 380hp with a super conservative 15% drivetrain loss correction.

It also ran 12.8@107mph stock at a curb weight of just under 4000lbs. HP calculators based on 1/4 mile put it between 380 and 400hp.

Saying these cars are very close to 400hp stock isn't an exaggeration at all.

[chris the man]

Everyone thank you so much for the input.

Im not worried whatsoever about the cats. I’ll most likely do them as preventative.

However. I am not going to lie. I am very disheartened here.

A few of us went cruising today. Was lucky to be able to meet up with a guy from Salt Lake running a DP setup. There was a bunch of us in the pack and he was kind enough to let me roll with him. Almost identical setup to my plan but with the better AMS cooler pump setup.

I can’t be anything but upset as, no matter how fast the car felt. The Subaru we were running with would just keep getting away from us.

I have a Subaru currently. Purchased the Audi to have as a faster and nicer car. I’m about to spend $5grand and the last thing I want is the get beat by a blue 16year old kid car.

[Morritse]

Everyone thank you so much for the input.

Im not worried whatsoever about the cats. I’ll most likely do them as preventative.

However. I am not going to lie. I am very disheartened here.

A few of us went cruising today. Was lucky to be able to meet up with a guy from Salt Lake running a DP setup. There was a bunch of us in the pack and he was kind enough to let me roll with him. Almost identical setup to my plan but with the better AMS cooler pump setup.

I can’t be anything but upset as, no matter how fast the car felt. The Subaru we were running with would just keep getting away from us.

I have a Subaru currently. Purchased the Audi to have as a faster and nicer car. I’m about to spend $5grand and the last thing I want is the get beat by a blue 16year old kid car.

Well. Unless the subie was heavily heavily modified, or his car was Uber fucked up, this won't happen.

I don't think it's easy to have STIs run mid 11s

AFAIK, an FBO STI runs low 12s at best, we run low 11s pretty easily

[rand0mher0]

395awhp on my DP set up (mustang dyno), logged almost 5k miles on it so far and hasn't missed a beat. The car isn't my daily but I wouldn't hesitate to daily it if needed.

[chris the man]

Well. Unless the subie was heavily heavily modified, or his car was Uber fucked up, this won't happen.

I don't think it's easy to have STIs run mid 11s

AFAIK, an FBO STI runs low 12s at best, we run low 11s pretty easily

Thank you sir, and yes. Just like mine the car has had a complete over haul, fully built, larger turbo and multiple fuel tunes.

My current STI is the same to that, but whats so funny to me is that the DP S4 feels SO MUCH FASTER. I am not sure if its the shifts, holding boost through gears etc. But its a VERY different experience.

[Morritse]

Thank you sir, and yes. Just like mine the car has had a complete over haul, fully built, larger turbo and multiple fuel tunes.

My current STI is the same to that, but whats so funny to me is that the DP S4 feels SO MUCH FASTER. I am not sure if its the shifts, holding boost through gears etc. But its a VERY different experience.

Ok so you bought the s4 without first researching if it would be faster than your Subaru and now you're disappointed?

What is your car's 60-130?

[chris the man]

Ok so you bought the s4 without first researching if it would be faster than your Subaru and now you're disappointed?

What is your car's 60-130?

It’s funny that you ask this exact question, I feel like you must have been in my same position as it seems like you speak with experience.

Correct, I expect the strong suit of the S4 to significantly hold much more power in the upper 60+ mph range.

Not that I’m irritated or upset. The Subaru had spent well over $13k to get the speed it had.

And I believe I’ll be able to achieve close to that at a fraction with a significantly nicer car.

[Morritse]

It’s funny that you ask this exact question, I feel like you must have been in my same position as it seems like you speak with experience.

Correct, I expect the strong suit of the S4 to significantly hold much more power in the upper 60+ mph range.

Not that I’m irritated or upset. The Subaru had spent well over $13k to get the speed it had.

And I believe I’ll be able to achieve close to that at a fraction with a significantly nicer car.

I was just trying to get a better idea of how fast your car is to see what you'd need to do to build your S4 faster.

You have any sort of benchmarks? Traps? Times?

[KLX]

30k miles on APr dual pulley with APR Cooling. No issues at all and it’s a daily driver, but I don’t track my car, just occasionally drive Spirited

+1

[Allan691]

I've put about 12k miles on my car with dual pulley APR. Previously it was stage 2 with the upper pulley only. It's a gigantic difference, with no down side in my experience.


My car ran 141-144mph over 7 runs in a half mile event in 90f heat this past summer. I drove it 2 hours to get there and two hours home.

With or without cooling upgrade?

I am basically in your shoes (12K miles ago).. Currently I am APR Single Pulley Stage 2, and about to add a JHM 179 crank.. with no cooling upgrades. Can you elaborate for me the "gigantic difference"? What ratio are you now with DP? Thanks.

[MSq5]

With or without cooling upgrade?

I am basically in your shoes (12K miles ago).. Currently I am APR Single Pulley Stage 2, and about to add a JHM 179 crank.. with no cooling upgrades. Can you elaborate for me the "gigantic difference"? What ratio are you now with DP? Thanks.

You will need to upgrade cooling.

[Allan691]

You will need to upgrade cooling.

lol thx. Saw this today on IG.. Thought it was a bit telling...

IMG_8567.jpg

[DatPandaJPEG]

Old thread but trying to get some input without starting a new thread, hopefully some of y’all see this.

Just went APR stage 2 dual pulley, upgraded cooling to ECS heat exchanger, already had APR TCU tune and APR open intake. Loving the car right now, it’s insane the difference from stage 1 to this. Only thing I’ve noticed is how quickly the oil gauge indicates the car is getting to the middle or operating temps. Before the pulleys on stage 1 it would take 5-10 minutes of driving, now it’s like 2 minutes. My car is garage kept, temp inside there today was around 63F, as soon as I left to go to the store and got to the end of my street, maybe 3/4 a mile oil temps on the gauge were already almost at operating temp. It hasn’t gone past the middle on the gauge, not sure if this is just normal based on the pulley ratio and ~30% faster SC speed. Wondering if others noticed this, anything to worry about or check etc. Going to get some sort of logger now that my car is at this stage to help me keep up with some things but as of now I’m just having to pay attention to how the car feels.

Sorry long post but TIA!

[MSq5]

Old thread but trying to get some input without starting a new thread, hopefully some of y’all see this.

Just went APR stage 2 dual pulley, upgraded cooling to ECS heat exchanger, already had APR TCU tune and APR open intake. Loving the car right now, it’s insane the difference from stage 1 to this. Only thing I’ve noticed is how quickly the oil gauge indicates the car is getting to the middle or operating temps. Before the pulleys on stage 1 it would take 5-10 minutes of driving, now it’s like 2 minutes. My car is garage kept, temp inside there today was around 63F, as soon as I left to go to the store and got to the end of my street, maybe 3/4 a mile oil temps on the gauge were already almost at operating temp. It hasn’t gone past the middle on the gauge, not sure if this is just normal based on the pulley ratio and ~30% faster SC speed. Wondering if others noticed this, anything to worry about or check etc. Going to get some sort of logger now that my car is at this stage to help me keep up with some things but as of now I’m just having to pay attention to how the car feels.

Sorry long post but TIA!

Do we have an oil temperature gauge? I don't see one on my cluster. Could you mean water temperature gauge? Maybe I'm misding something.

[DatPandaJPEG]

Sorry yup misspoke, meant water temp gauge. Assuming just with the new ratio it’s causing the faster temp increase?

[MSq5]

Sorry yup misspoke, meant water temp gauge. Assuming just with the new ratio it’s causing the faster temp increase?

Yeah, I thought so. Maybe just coincidence as the supercharger, even spinning faster with higher ratio pulley(s), will not be making enough power to raise engine temperatures sooner unless you are going wide open throttle. That is something that ought not be done, anyway, until the engine is already up to operating temperature.

[DatPandaJPEG]

I usually always stay in comfort mode for a while before any pulls. Have you noticed any difference in water temp times since going DP?

[djn876]

Do we have an oil temperature gauge? I don't see one on my cluster. Could you mean water temperature gauge? Maybe I'm misding something.

You can activate the lap timer which I think gives you a display of oil temp as well, but yeah i don't think that's what he was referring to either as stated below.

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[djn876]

I usually always stay in comfort mode for a while before any pulls. Have you noticed any difference in water temp times since going DP?

The water temp gauge on the car is a dummy indicator. It'll be in the middle well before the car is fully warm, and won't go above middle until the car is already overheating. Don't rely on that for j for information. The car warms up very fast if you go drive it and I never noticed any change in how quickly it warms up or coolant temps at dual pulley or any other stage. Plus, normal driving doesn't care whether you are dual pulley, or no tune at all since you aren't in boost all of the time you aren't putting any significant additional heat load on the system. If you get out there and beat on it right away, sure it's going to warm up faster, but that's not great for the engine.

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[DatPandaJPEG]

The water temp gauge on the car is a dummy indicator. It'll be in the middle well before the car is fully warm, and won't go above middle until the car is already overheating. Don't rely on that for j for information. The car warms up very fast if you go drive it and I never noticed any change in how quickly it warms up or coolant temps at dual pulley or any other stage. Plus, normal driving doesn't care whether you are dual pulley, or no tune at all since you aren't in boost all of the time you aren't putting any significant additional heat load on the system. If you get out there and beat on it right away, sure it's going to warm up faster, but that's not great for the engine.

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Even at stage 1 I would drive a while before really going hard on the car, since getting the DP, tune and HX installed I’ve taken it relatively easy. Might just be noticing things after the fact now I was not noticing before. But I do know for sure that the week before everything was installed it, that gauge was not reading warm temps this fast (even if it’s not super reliable). Granted I was up in Asheville NC where it was pretty cold, morning ambient temps around 33-40. Biggest worry for me currently with it showing how warm the water temps are getting in 45 seconds of driving was if I actually did go push the car WOT and not know something wasn’t right. A need to get a logging system now at this stage without a doubt.

[MSq5]

I usually always stay in comfort mode for a while before any pulls. Have you noticed any difference in water temp times since going DP?

No difference that I can notice. As djn876 observed, its not a true calibrated temp gauge, anyway. Not sure its useless, but at least let it get to the middle before any hard pulls.

[DatPandaJPEG]

No difference that I can notice. As djn876 observed, its not a true calibrated temp gauge, anyway. Not sure its useless, but at least let it get to the middle before any hard pulls.

Might ge tot checked out for peace of mind. It’s 34 degrees out this morning in Bham, just did cold start and went around my neighborhood, maybe 2 miles and never got over 24mph and by the time I was back in my garage gauge was reading middle. Seems quick for these temps and off a cold start.

[djn876]

Might ge tot checked out for peace of mind. It’s 34 degrees out this morning in Bham, just did cold start and went around my neighborhood, maybe 2 miles and never got over 24mph and by the time I was back in my garage gauge was reading middle. Seems quick for these temps and off a cold start.

Mine is usually almost in the middle by the time I get to a main road even below freezing which is maybe 5 minutes of driving usually at 40 or under so doesn't sound unusual at least to me, but logging will help. Usually by 65 or 70 deg C it's pretty close to mid line on the temp gauge, which is well below the operating range of 90 to 102ish deg C. Thermostat doesn't even start to open until 87C so it'll warm up pretty quick.

If you see temps of over 105 during normal driving or higher and the fans run all the time, then I'd be concerned about the thermostat or maybe water pump.

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[sepheroth86]

Mine is usually almost in the middle by the time I get to a main road even below freezing which is maybe 5 minutes of driving usually at 40 or under so doesn't sound unusual at least to me, but logging will help. Usually by 65 or 70 deg C it's pretty close to mid line on the temp gauge, which is well below the operating range of 90 to 102ish deg C. Thermostat doesn't even start to open until 87C so it'll warm up pretty quick.

If you see temps of over 105 during normal driving or higher and the fans run all the time, then I'd be concerned about the thermostat or maybe water pump.

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Dang. My thermostat must be sticking open. My car takes 15 or so minutes for the temp gauge to reach the middle. Several miles before it starts blowing heat.