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2011 Audi S5 B8 Sportback
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I think someone on Audizine already tried fitting a fixed supercharger snout from a previous gen, although it did fit, it didn't work:
"We tried retrofitting a CTUB snout and rotor pack in the blower with the goal of reliability, but while it fit, we couldn't get the ecu happy and it kept making boost at idle."

By the way, I also had contact with Powerhouse Automotive regarding the supercharger porting, but I didn't go with them as I am from mainland Europe which makes the import/export process cumbersome and expensive (although I would go for them if I would live in the UK).

In the end I got my spare supercharger ported by Startline Motors, they removed quite a bit of material from the supercharger and also checked the state of the supercharger bearings (said they were fine). I will get it installed in the spring, to combine it with some regular maintenance.
View attachment 182330
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Why is there a hole in the bottom of your intake?
 

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Do you have any power runs before to see the affect of your porting? Then power runs when you have fitted it. :)
Yes, I will provide some info on the numbers before/after (already have some Dragy runs). However, I am also moving down to a 177mm crank pulley at the same time (to stay within the specified ~2.8 pulley ratio to prevent future supercharger clutch issues) so these numbers will not be really comparable.
Why is there a hole in the bottom of your intake?
This was a picture that was taken during the porting process, they welded it up afterwards. The pre-CREC supercharger does not have the blockage that CREC superchargers have (first picture), the guys that did the porting made the inside of the supercharger similar to a ported pre-CREC supercharger.
 

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Yes, I will provide some info on the numbers before/after (already have some Dragy runs). However, I am also moving down to a 177mm crank pulley at the same time (to stay within the specified ~2.8 pulley ratio to prevent future supercharger clutch issues) so these numbers will not be really comparable.
Do you have a smaller SC pulley, so DP? If so, the smaller SC pulley can be associated with the clutch issues, so put your std SC pulley back on and put a 189mm crank pulley on. I have a CTS 187mm crank pulley only and Dippy has a 189mm pulley with no problems! I have 2.98 ratio. Only issue I have had is on the dyno in the summer, IATs get too high at 80 C. But now I have upgraded my heat exchanger. Now in the winter with temps around 6 C the IATs hover around 15 degrees under normal driving, too busy control the power and watching the road to see the IATs under full boost! I have FIS so can just look at the dash screen to see IATs.

This was a picture that was taken during the porting process, they welded it up afterwards. The pre-CREC supercharger does not have the blockage that CREC superchargers have (first picture), the guys that did the porting made the inside of the supercharger similar to a ported pre-CREC supercharger.
The only thing with porting is you can actually remove too much and make the flow worse. Not saying yours will be like that if the company you are using is tried tested and proven, but machining our material to create more volume can affect pressure and airflow. Some have found the larger throttle body needs to be matched with other mods/parts to get the full benefit. It's all about the airflow and velocity. I'd do it if I was seeking more power, but I'm happy with my Stage 2 :)
 

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There are plenty of stage 2 CREC engined cars in the UK with larger crank pulleys, mine is 187 and Dippy's is 189mm with no issues. We do have the std SC pulley though.

I can't get my head round why they fail though as no more power or torque goes through the SC, just an increased speed, but maybe if the increased speed demands more load on the clutch? But the increase in speed is only 3-5krpm.

When I put my larger crank pulley on, I did this a week before my remap and as you say Gid, any more that 1/4 throttle and the EPC and limp mode comes on. This was because the SC speed sensor was picking up 'extra' speed. After the remap, that speed sensor was either recalculated with the new pulley ratio or turned off, I don't know, I didn't ask my mapper. So I think there maybe an issue with your tune? The clutch is separate and I think you should be able to run the pulleys and tune.

I'm sure the SC clutch could be 'gutted' and a solid fixed drive input inserted, created? :)
I've inspected my clutch post removal and it definitely was burned up. Shavings were all throughout the snout and there wasn't much remaining on the clutch itself. This was commonly found on all of the ones that were replaced witih the bolted or welded clutches.
 

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Has there been any movement on the IE fixed / welded clutch on the CREC? I'm in the US with a 3.0T A6 and I've just burnt up my 3rd clutch in 2 years, running APR Stage 2+ with DP. When it fails I get the EPC light and no boost. I've done some experimenting with welding the previously worn out clutches (and they really are worn out, burnt up, pitted and FUBAR), and I'll fit one of them to the car this week without the silly shroud on the back so I can put it on and take it off without removing the supercharger. I take it I'll need to get the codes tuned out by APR, otherwise the car's going to complain about the clutch being closed when it expects it to be open, etc., but I'll suck it and see, and then report back.
What kind of movement are you referring to? I know that IE now offers to code out the CEL. Other than that, they are not supporting a DP stage 2 tune yet. Only Stage 1 E85 or stage 1 single pully. I'm currently on EPL Stage 2 DP with the bolted clutch.
 

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I really don't see the point in dual pulley anymore. There are plenty of options available to max out the pulley ratio via crank pulley alone. From what I have seen, the SC clutch issues do seem to be on DP cars?

Is the extra power, which is isn't that much worth breaking the SC clutch? A stage 2 using just a 189mm pulley (no porting) should get you around 480bhp. If you are a number chaser, then you're going to have to move away and replace the standard parts, but is it worth it for 20bhp?
 

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[/QUOTE]
I really don't see the point in dual pulley anymore. There are plenty of options available to max out the pulley ratio via crank pulley alone. From what I have seen, the SC clutch issues do seem to be on DP cars?

Is the extra power, which is isn't that much worth breaking the SC clutch? A stage 2 using just a 189mm pulley (no porting) should get you around 480bhp. If you are a number chaser, then you're going to have to move away and replace the standard parts, but is it worth it for 20bhp?
I wouldn't say I'm chasing numbers. To each their own I suppose. I agree that the ROI after a certain point gets smaller and smaller, which is always the case when modding cars. FWIW, the difference from a 2.9x PR and a 3.2X PR is significant. Similar to going from stage 1 to stage 2. The bolted clutch has been working out great, aside from the CEL for the supercharge speed not meeting the requested parameters. When it gets a little warmer, I'll be swapping out the HPFP for an autotech that's sitting in my garage.
 

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My ported supercharger got installed today. There were some hiccups along the way. The intercooler bricks from the ported supercharger got damaged in shipping so while installing they swapped those over from the ‘old’ supercharger. So, if anyone goes the same route, ensure your supercharger is well protected when shipping (some plastic bubbles in a cartboard box are not enough protection).

At the same time they installed a smaller 177mm pulley I ordered. They called me again because swapping a smaller pulley for a larger pulley was a weird request (“This will lower the boost pressure, are you sure?”). Yes, I am sure, lowering the pulley ratio ensures the magnetic clutch will not slip anymore (just below a 2.8 pulley ratio or PR).

After installation I have to say the car overall feels lighter, strangely enough there is a lot more torque below 2500 rpm despite moving down in pulley ratio. Also there are no more signs of slipping. I suppose my magnetic supercharger clutch was really on its way out, now the car really feels OEM only with more power. Shift quality, which is also described in the Audi workshop manual as symptoms of a failing supercharger clutch, has also increased significantly.

My maximum boost pressure (as per MAP-sensor through VCDS) is now 1.21 (with the 177mm + Conti belt), while with the 189mm (+ Gates RPM belt) my boost pressure was 1.3. Online I am reading conflicting statements about whether a ported supercharger results in more, less or equal boost pressure. I haven’t measured times yet. Most important to me is that the car is now driving smooth (better than stock) and faultless.

Additionally, I had no signs of coolant consumption, but I choose to order a thermostat and waterpump anyway because these are known to fail and easy to access while the supercharger is off. The thermostat was indeed leaking, so the forums made a good call on that. I was somewhat suprised, as the car has less than 30k miles. The PCV was still in good condition, I did not replace the PCV.
 

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Discussion Starter · #110 ·
My ported supercharger got installed today. There were some hiccups along the way. The intercooler bricks from the ported supercharger got damaged in shipping so while installing they swapped those over from the ‘old’ supercharger. So, if anyone goes the same route, ensure your supercharger is well protected when shipping (some plastic bubbles in a cartboard box are not enough protection).

At the same time they installed a smaller 177mm pulley I ordered. They called me again because swapping a smaller pulley for a larger pulley was a weird request (“This will lower the boost pressure, are you sure?”). Yes, I am sure, lowering the pulley ratio ensures the magnetic clutch will not slip anymore (just below a 2.8 pulley ratio or PR).

After installation I have to say the car overall feels lighter, strangely enough there is a lot more torque below 2500 rpm despite moving down in pulley ratio. Also there are no more signs of slipping. I suppose my magnetic supercharger clutch was really on its way out, now the car really feels OEM only with more power. Shift quality, which is also described in the Audi workshop manual as symptoms of a failing supercharger clutch, has also increased significantly.

My maximum boost pressure (as per MAP-sensor through VCDS) is now 1.21 (with the 177mm + Conti belt), while with the 189mm (+ Gates RPM belt) my boost pressure was 1.3. Online I am reading conflicting statements about whether a ported supercharger results in more, less or equal boost pressure. I haven’t measured times yet. Most important to me is that the car is now driving smooth (better than stock) and faultless.

Additionally, I had no signs of coolant consumption, but I choose to order a thermostat and waterpump anyway because these are known to fail and easy to access while the supercharger is off. The thermostat was indeed leaking, so the forums made a good call on that. I was somewhat suprised, as the car has less than 30k miles. The PCV was still in good condition, I did not replace the PCV.
Glad it's going good for you.

Did you increase throttle body size and port match the SC inlet to suit? I got mine ported match to a 82mm TB but have not yet installed.

Who done your mapping?
 

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My maximum boost pressure (as per MAP-sensor through VCDS) is now 1.21 (with the 177mm + Conti belt), while with the 189mm (+ Gates RPM belt) my boost pressure was 1.3. Online I am reading conflicting statements about whether a ported supercharger results in more, less or equal boost pressure. I haven’t measured times yet. Most important to me is that the car is now driving smooth (better than stock) and faultless.
As long as the porting increases airflow (i.e. you are porting to a bigger TB) then it has the potential to increase boost across the curve, but there are dependencies. The obvious one is the ECU map since the bypass valve acts to limit boost. The other is the pulley ratio because the rpm of the rotors governs airflow - and if the intake allows less airflow than that rpm demands then the porting will increase it. I have no idea what is needed to support this and I believe that APR invested significant time and money in their ultracharger development to find out. If their figures are correct then their ultracharger (without porting) increases peak boost as well as top end boost. In theory porting would increase these a bit more.

FYI I used to see around 1.25 peak with my 189mm pulley. But I just had a major service done with new air filter and now the peak is 1.3. That shows how airflow makes a difference even before the top end.
 

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Did you increase throttle body size and port match the SC inlet to suit? I got mine ported match to a 82mm TB but have not yet installed.

Who done your mapping?
I did not purchase a larger throttle body. Of course there will be more gains with a larger port-matched throttle body and supercharger.

I have not yet contacted my tuner (MRC Belgium), as I am still within bounds of my previous tune. I will ask for their opinion on the logs later.

Summarised, lower PR + ported supercharger compared to a higher PR + stock supercharger:
  • A lot smoother and snappier in day-to-day driving, strangely enough more torque down low
  • No supercharger clutch slipping noise (especially noticeable with the top down)
  • Significantly lower IATs (difference ~30 degrees Celsius lower in a 60 - 120 mph run, also taking ambient temperature into account)
  • Almost no timing corrections (also depends on your tune)

Note: despite my supercharger clutch making a slipping noise and poor shifts on WOT, I never actually got a check engine light with the 189mm.
 
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