Cliffs on "Dual Pulley"

[Rez90]

What are we talking about.....

kthanks.

[14S4GWM]

Theres a couple extensive threads going on about this.

[mjfloyd1]

Smaller supercharger pulley and larger crank pulley. Both make supercharger spin faster -> take in more air -> more power

[GRUMPY-S4]

What do you want to know?

[Tod]

Is a new crank pulley easily identified by a dealer? Can it be hidden (color etc) like the cts pulley for the Eaton?

Sent from my SAMSUNG-SM-G890A using Tapatalk

[Aim high]

Also how safe is it and I'm sure there's such a thing as "out of its efficiency" In a supercharger, much like a turbo. At what point do we approach that with the stock unit?

[BernanksBeard]

Eaton claims the TVS is capable of running at 24,000 rpm and at a 2.4-2.5 pressure ratio which is 20-22lbs of boost. The dual pulley comes right up to both limits. At 22 psi air starts leaking past the tolerances between the rotor and casting and creating extremely hot air. That 22 psi hard limit is the main reason the Stage 3 supercharger has been a bust, it's not much more efficient than our stock unit, and we have learned that we can get 18-19 psi out of the 1320. They shoulda used the newer eaton TVS2 design, capable of 30 psi or a twin scroll unit.

[Loe]

Cliff Notes:

1) S/C Pulley
2) Overdrive Crank Pulley
3) Software (ecu/tcu if dsg, or ecu if manual) to take advantage of potential boost
4) Octane (though no one has shared logs on a dual-pulley 93 octane yet)

recommended:
- intake or a modified airbox with high-flo filter

required:
-big grin

[Dudemans4]

At this point dual pulley on 93 without tuning actually makes the car run worse. I know first hand my CRANK PULLEY failed and I purchased jhm overdrive pulley. Now I'm running just the CRANK PULLEY on stage 2

[bhvrdr]

At this point dual pulley on 93 without tuning actually makes the car run worse. I know first hand my CRANK PULLEY failed and I purchased jhm overdrive pulley. Now I'm running just the CRANK PULLEY on stage 2

Thanks for that feedback. I'm curious what about the car ran worse with the dual pulleys. When you put a SC pulley on the car with stock software, it just bleeds off boost at mid-higher rpm but you'd still get a bit of a bump in torque down low and the car certainly shouldnt run worse. Any idea what wasnt running right with your car on the dual pulleys? Did you have a chance to log it? I appreciate the feedback as i'm interested in going this route.

Thanks

Mike

[Dudemans4]

Thanks for that feedback. I'm curious what about the car ran worse with the dual pulleys. When you put a SC pulley on the car with stock software, it just bleeds off boost at mid-higher rpm but you'd still get a bit of a bump in torque down low and the car certainly shouldnt run worse. Any idea what wasnt running right with your car on the dual pulleys? Did you have a chance to log it? I appreciate the feedback as i'm interested in going this route.

Thanks

Mike

It was a heat issue and bypass valve was opening 26 percent !!!!!! It was super powerful down low then would fall off hard up top .
A heat exchanger and some timing adjustments would probably help. Everything looked right but I'm no tuner and I can tell you it did not run well from first hand experience.

[bhvrdr]

It was a heat issue and bypass valve was opening 26 percent !!!!!! It was super powerful down low then would fall off hard up top .
A heat exchanger and some timing adjustments would probably help. Everything looked right but I'm no tuner and I can tell you it did not run well from first hand experience.

Hey I appreciate any feedback you have. You didnt happen to do any datalogging did you? Any ideas what your intake air temps got up to and if timing ended up being pulled? You can run 93 octane right? Stock intercooling Im assuming. Thanks for the feedback. Its pretty valuable as we really dont have many people doing this.

Mike

[Ze_Nardo6]

Mike, bottom line is you need to be properly tuned to take advantage of running a dual pulley setup. I wouldn't seek out logs for someones car that ran both pulleys without proper tuning for such.

[bhvrdr]

Mike, bottom line is you need to be properly tuned to take advantage of running a dual pulley setup. I wouldn't seek out logs for someones car that ran both pulleys without proper tuning for such.

Oh i'm very interested in his logs when only running a stage 2 tune. If he has out of control intake temps on just a stage 2 tune where boost is being bypassed that could actually get worse if he had a "proper" dual pulley tune that was taking advantage of the added boost. So, yeah, id like to see his logs and of course also the logs of people with dual pulley tunes that are making the full boost. If nothing it would be valuable to compare both sets of logs to see what changes were made to things such as afr and timing.

Mike

[Ze_Nardo6]

I understand your point. Would you want to see logs of a car with a stage 2 supercharger pulley running stage 1 software?

[J.S4]

Mike, bottom line is you need to be properly tuned to take advantage of running a dual pulley setup. I wouldn't seek out logs for someones car that ran both pulleys without proper tuning for such.

It's a valid question. Dudeman stated his car ran worse, not that he couldn't feel the difference or that it didn't run better, which I agree doesn't make sense on its face. You would think performance would be on par with stage 2 because you're running the stage 2 file, and when the OD crank pulley spins the blower fast enough to exceed requested boost the excess would be bled off - hence the bpv opening wider. I would be surprised if peak intake manifold pressure was actually lower (which would be my definition of "worse") than stage 2, but logs might indicate why that happened, if it did.

[bhvrdr]

It's a valid question. Dudeman stated his car ran worse, not that he couldn't feel the difference or that it didn't run better, which I agree doesn't make sense on its face. You would think performance would be on par with stage 2 because you're running the stage 2 file, and when the OD crank pulley spins the blower fast enough to exceed requested boost the excess would be bled off - hence the bpv opening wider. I would be surprised if peak intake manifold pressure was actually lower (which would be my definition of "worse") than stage 2, but logs might indicate why that happened, if it did.

^^^^^^ this :)

I understand your point. Would you want to see logs of a car with a stage 2 supercharger pulley running stage 1 software?

I appreciate the question. yes, if we were back in 2010 at the stage where no one had run a smaller supercharger pulley I would absolutely want to see logs of a stage 1 programmed car that was running the smaller supercharger pulley.

If it was showing problems already that would be important to take note of and see if it needed to be addressed when developing a tune for it. As an example, if it was showing out of hand intake temps and pulling timing it may give you an idea how maxed you are with the stock cooling system in place and that if you were going to develop a file you may want to go lower on the timing and richer on the air/fuel in order to try and mitigate the heat issues.

As it turns out, that really hasnt been much of an issue for stage 2 levels and tuners are getting full boost (with no bypass) and also decent timing out of the car without significant detonation. I'm just curious about this at dual pulley levels. I want to make sure the blower isnt just blowing hot air and giving you high IATs and knock. I dont think this is the case but when a poster says their car was running "worse" when it is not even making dual pulley power I want to know whats the thing that is making it run worse. Its great data to have, particularly for a guys like me who only runs 93 octane (no e85 or race gas) and has stock intercooling.

Good discussion.

Mike

[Ze_Nardo6]

Mike, thanks very much for the explanation. Learn something new everyday.

[bhvrdr]

right on man!

[Dudemans4]

^^^^^^ this :)




I appreciate the question. yes, if we were back in 2010 at the stage where no one had run a smaller supercharger pulley I would absolutely want to see logs of a stage 1 programmed car that was running the smaller supercharger pulley.

If it was showing problems already that would be important to take note of and see if it needed to be addressed when developing a tune for it. As an example, if it was showing out of hand intake temps and pulling timing it may give you an idea how maxed you are with the stock cooling system in place and that if you were going to develop a file you may want to go lower on the timing and richer on the air/fuel in order to try and mitigate the heat issues.

As it turns out, that really hasnt been much of an issue for stage 2 levels and tuners are getting full boost (with no bypass) and also decent timing out of the car without significant detonation. I'm just curious about this at dual pulley levels. I want to make sure the blower isnt just blowing hot air and giving you high IATs and knock. I dont think this is the case but when a poster says their car was running "worse" when it is not even making dual pulley power I want to know whats the thing that is making it run worse. Its great data to have, particularly for a guys like me who only runs 93 octane (no e85 or race gas) and has stock intercooling.

Good discussion.

Mike

I don't want to start a war at all and I will eventually put the pulley back on . iats got up to about 65 Celsius being 32f out. The car just didn't run right up top I had logs but the files corrupted. Maybe there was something wrong with my car I also didn't have a test pipe file and that could've been the problem.I'm just giving you guys my results on a untuned dual pulley setup

[jran76]

I'd like to see the logs too....

At least on my car, there is plenty of headroom to add a dual pulley and get a lot out of it in it current state with the off-the-shelf APR stage 2 tune. Comparing my logs to andthen's when we were both on the dyno is pretty interesting. My APR tune actually has a higher specified pressure (requested boost), so if I can keep everything else in check (IAT's, torque, load, etc.), it should easily be able to use a lot of that extra boost. My specified pressure actually stays above andthen's actual pressure the entire time.

The one interesting thing is his IAT's (with the dual pulley) are actually lower than mine (without the DP) most of the time. We have the exact same Alpha cooling system. The only real difference is he is running E85, and I was on pump 93. I think if I mixed in some E85, or even made the full switch, I'd be OK. Either way, since I added the coolant system, IAT's have not been much of an issue, and seeing the logs from andthen's car with the same system and dual pulleys make it look like a non-issue too.

Actual and Specified MAP (pressure): APR stage 2 in BLACK (dotted line at the top is SPECIFIED) EPL Stage 2+ with E85 in BLUE (dotted line at the top is SPECIFIED)




IAT: APR stage 2 with 93 in BLACK and EPL stage 2+ with E85 in BLUE (both have AMS Alpha coolant system)




Timing: Need a good reason to run E85? APR stage 2 with 93 in BLACK and EPL stage 2+ with E85 in BLUE



Big thanks the B8_Jim for doing the charts too....

[bhvrdr]

I don't want to start a war at all and I will eventually put the pulley back on . iats got up to about 65 Celsius being 32f out. The car just didn't run right up top I had logs but the files corrupted. Maybe there was something wrong with my car I also didn't have a test pipe file and that could've been the problem.I'm just giving you guys my results on a untuned dual pulley setup

hey, no war at all. I think people are just really excited to get any data at all. I wasnt suggesting you were wrong about anything, I was just curious what the data was showing. I appreciate the response.

Mike

[bhvrdr]

I'd like to see the logs too....

Thanks for posting those jran. Neither of those intake temps look bad at all. I'd be very curious to see how it does with the stock heat exchanger. If there are only 5-10 degree differences it may not be a big deal. I guess we'll see soon.

Mike

[Dudemans4]

I'll try to explain a little better when I get off work I'm just super busy

[jran76]

Thanks for posting those jran. Neither of those intake temps look bad at all. I'd be very curious to see how it does with the stock heat exchanger. If there are only 5-10 degree differences it may not be a big deal. I guess we'll see soon.

Mike

Yep, IAT's were fine on both cars, but it was interesting that Tom's were lower (his car did sit for over an hour before getting on the dyno, and mine went on right when I got there). Honestly, since adding the coolant system IAT's have not been an issue in any logging I have done. I know we've discussed this before, but I was regularly seeing 4-6 degrees of timing being pulled, and since adding the coolant system and sticking with "good" gas, it almost never goes over 2-3 degrees being pulled with higher timing to start with.

[PitchS4]

Has anyone done a tune for just a crank pulley? What type of increase in PSI would that show?

[jran76]

Has anyone done a tune for just a crank pulley? What type of increase in PSI would that show?

The oversized crank pulley creates roughly the same amount of boost and has the same basic effect as the smaller S/C pulley, so any stage 2 tune will work with the oversized crank pulley.

[DGVR6]

This would actually make sense.. Over spinning the charger would create excess heat. I believe the rule of thumb is 1 psi equates to 10f maybe even more on the tvs. If the tune is made to bleed after the threshold is met, then it would be much sooner.

The best thing to do is to find a way to keep iats down..

[colby7]

At this point dual pulley on 93 without tuning actually makes the car run worse. I know first hand my CRANK PULLEY failed and I purchased jhm overdrive pulley. Now I'm running just the CRANK PULLEY on stage 2

Im confused by this post. Did the crank pulley fail while you were running a dual pulley setup? If so, was it the GMG pulley? Or, was a crank pulley failure what caused you to explore going dual pulley in the first place? If it's the latter, does that mean you decided to keep the jhm crank pulley on, and instead removed the aftermarket supercharger pulley?

[cjw]

Thanks for posting those jran. Neither of those intake temps look bad at all. I'd be very curious to see how it does with the stock heat exchanger. If there are only 5-10 degree differences it may not be a big deal. I guess we'll see soon.

Mike

Yeah, if I was ever to add a crank pulley, it would be for 93 octane and stock heat exchanger. I'm sure heat soak would be an issue after a while, but for daily driving in short bursts, it would be nice if it wasn't.

[Hawkpilot6060]

Hey I appreciate any feedback you have. You didnt happen to do any datalogging did you? Any ideas what your intake air temps got up to and if timing ended up being pulled? You can run 93 octane right? Stock intercooling Im assuming. Thanks for the feedback. Its pretty valuable as we really dont have many people doing this.

Mike

Mike,
This is some good info, exactly what we had talked about. I think with my coldfront system, the OD crank pulley may work for me! What do you think? Throw in a bit of E85 from the turnpike and have some fun at PBIR!

Rick

[bhvrdr]

Mike,
This is some good info, exactly what we had talked about. I think with my coldfront system, the OD crank pulley may work for me! What do you think? Throw in a bit of E85 from the turnpike and have some fun at PBIR!

Rick

I think you'll need some programming to be changed Rick. The reason I say that is your actual boost is hitting the requested boost targets. If you add a pulley you're going to be bleeding even more boost since you are already bleeding boost. Thats going to be a calibration change most likely. You could thrown the CW on your tune and it will take the actual boost lower than those boost targets and keep the bypass valve shut but you shouldnt have to do that. Jran? Input?



PS> Btw, rick the weather sucks today but next Wednesday it could be in the upper 50s!!! I'm going to shoot for it.

Mike

[jran76]

I think you'll need some programming to be changed Rick. The reason I say that is your actual boost is hitting the requested boost targets. If you add a pulley you're going to be bleeding even more boost since you are already bleeding boost. Thats going to be a calibration change most likely. You could thrown the CW on your tune and it will take the actual boost lower than those boost targets and keep the bypass valve shut but you shouldnt have to do that. Jran? Input?



PS> Btw, rick the weather sucks today but next Wednesday it could be in the upper 50s!!! I'm going to shoot for it.

Mike

Agreed. The logs from his car show actual and specified really close, and the fact he's already bypassing quite a bit for stage 2 means the overdrive pulley would just exacerbate the bypass even more. It would take either an updated tune with higher specified values (and maybe other things) or something like the CW that would bump up the specified pressure value quite a bit.

[martziniuk]

MRC in the UK make three different sized crank pulleys
http://audisrs.com/about63381.html
It would be interesting if someone could start putting together some measurements on all the available crank pulleys.

[Lamprey]

MRC in the UK make three different sized crank pulleys
http://audisrs.com/about63381.html
It would be interesting if someone could start putting together some measurements on all the available crank pulleys.

http://www.audizine.com/forum/showth...1#post11299321

[schirm]

When you put a SC pulley on the car with stock software, it just bleeds off boost at mid-higher rpm but you'd still get a bit of a bump in torque down low and the car certainly shouldnt run worse.


Mike

I have the APR pulley on with no tune currently for 2,000 miles no issues. Definitely some extra torque down low.

I don't want to start a war at all and I will eventually put the pulley back on . iats got up to about 65 Celsius being 32f out. The car just didn't run right up top I had logs but the files corrupted. Maybe there was something wrong with my car I also didn't have a test pipe file and that could've been the problem.I'm just giving you guys my results on a untuned dual pulley setup

Test pipe file just gives a green light to the 02 sensors so you dont throw a CEL I thought.

[Loe]

I'm pretty new to this platform, so bare with me...

If *KR can cause the BPV to open, does the same apply vice versa? I'm asking because if the DP set-up on a tune not specifically made to request a higher target, will the opening of the BPV after reaching the target boost to maintain boost cause ignition timing to drop into a lower table as well?

[jran76]

I'm pretty new to this platform, so bare with me...

If *KR can cause the BPV to open, does the same apply vice versa? I'm asking because if the DP set-up on a tune not specifically made to request a higher target, will the opening of the BPV after reaching the target boost to maintain boost cause ignition timing to drop into a lower table as well?

What is *KR?

I think the answer to your question would completely depend on the tune as every tuner seems to handle the relationship between IAT, manifold pressure, timing, knock correction, torque values, load, bypass, etc. differently.

[bhvrdr]

I'm pretty new to this platform, so bare with me...

If *KR can cause the BPV to open, does the same apply vice versa? I'm asking because if the DP set-up on a tune not specifically made to request a higher target, will the opening of the BPV after reaching the target boost to maintain boost cause ignition timing to drop into a lower table as well?

Jran answers this question really well. Each calibration table/map usually interdepends on multiple other maps...or more importantly a set of "orders." The OEM Audi tuning strategy is crazy into doing this.

Lets give an example on just air fuel ratios.

Audi apparently targets about .90 AFR literally from zero rpm to redline under load. Thats 13.2:1 all the way to redline. Now the thing is, you will almost NEVER see an actual AFR on the stock car at 13.2:1 at redline. Even in 40 degree weather at sea level i've never seen that air fuel ratio. Thats because Audi has a bunch of different commands for a given situations that tells the car to enrich. So if it sees intake air temps, as an example, hit certain temp thresholds it will tell the car to enrich. This strategy likely allows them to claim certain fuel economy benefits if the situations were to allow it.

The same interrelatedness goes for load, timing, engine coolant temps, even battery voltage if you can believe it.


Your question about whether opening the bpv will cause the ECU to revert to lower timing values is an interesting one then. If you could control all other variables, i'd say the answer is no. Just running a smaller pulley that opens the BPV should not cause a different timing table to be used...meaning the timing tables likely do not have a command in them to reduce timing as the BPV opens. BUT keep in mind this is not an A and B relationship. Running the pulley is allowing more boost down low which theoretically could impact intake air temps, knock, etc so it could have an indirect affect.

Ok, i'm going to stop blabbering now. Fun topic though.

EDIT...

Here I found a screenshot I made of my ECT and IAT compensation tables for a calibration for my other car...





Mike

[Hawkpilot6060]

[QUOTE=bhvrdr;11376212]I think you'll need some programming to be changed Rick. The reason I say that is your actual boost is hitting the requested boost targets. If you add a pulley you're going to be bleeding even more boost since you are already bleeding boost. Thats going to be a calibration change most likely. You could thrown the CW on your tune and it will take the actual boost lower than those boost targets and keep the bypass valve shut but you shouldnt have to do that. Jran? Input?



Mike, thanks for the info! I thought it was just bleeding it up top, but you know more than I. Yes, next Wednesday looks killer cold, still hoping for an 11 before summer! This looks like a great chance! Tire pressure is going down, and the damn mats are coming out! Lol. See you Wednesday at PBIR.