A turning point in Mercedes tuning...Performance Supercharger Pulley
#1
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From: Santa Barbara & Los Angeles, CA
C32, Cobra, 700hp Vespa
A turning point in Mercedes tuning...Performance Supercharger Pulley
This is the moment everyone has been waiting for. As some have referred to it, a turning point in Mercedes power. Finally, the easiest, and most logical way to make power on our supercharged vehicle. Code3 Performance proudly presents, the C32/SRT6 Performance Supercharger Pulley.
This is not the first prototype with many questions still to be answered. In fact, we have been running this pulley for months. We have 100s of hours of road testing (5000 miles and counting), 25+ dynos, and countless hours of tweaking. The pulley has also been tested on other member cars (testimonials below). The pulley has gone into production already, and will be available within the next 10 days. The basics of the piece.
- 10-15 minute install
- no new belt needed
- no additional pulleys needed
- no ECU tuning needed
- pulley comes with new bearing and snap ring pre-installed, plus extra spacers
- Both written and video instructions by our Master Mercedes Tech
- colors will be available
- Price will be $600
The graphs below are dumped from the dyno CSV data. Blue is the stock run, red is the pulley run. Below that is the A/F from the pulley run. Dynos are performed on a "Superflow 840 Dual Eddy Current & MoTec Wideband AutoDyn Chassis Dyno". Before and After dynos are performed with the car still strapped to the dyno. Dyno run is in 4th gear to 140mph with car in dyno mode. Runs are on 91 octane!
The pulley run also had our new intake mod. It picked up 4-7hp across the entire power band on a stock car. I will post separately about it, as it will be available shortly as well. It will be priced around 1/3 the cost of current intake solutions, and your system still looks stock Plus it sounds awesome! People will definitely know something is lurking under the hood.
Here are two quick testimonials from some pulley beta testers.
##########
TopGun32 says:
"No belt slip, clutch engagement is as stock and boost comes sooner. I have had the Evosport set up on my car, and I can tell you this mod makes as much power and much smoother power delivery from around 3k to 5.5k (s/c power band). We tested last Saturday and made a handful of pulls from 40 to 100 and not once did I experience a lack of power (belt slip) while in the power band) I do suggest adding a FMIC to this set up... more boost, higher IAT's. Ease of install.. pretty much a few screws and need to let the kompressor clutch cool down."
##########
Dan from Crossfire Forums:
"I tested his pulley on my car and as I said to me it felt, power wise, much smoother and I can only compare it to 400 hp V8 feeling since I have had those! I've driven my unmodded SRT6 for 7,000 miles, this is the first time it felt so very smooth as my 6 liter V12 Jag ! The power range came on quicker and with less effort."
##########
As expected, there will be a lot of questions. MB owners have been told for years that the "magical SC pulley" shouldn't be touched, and that it was not possible to modify it without running into many problems... The simple fact is, you would be hard pressed to find another supercharged vehicle that creates power with a crank pulley upgrade versus an sc pulley upgrade. This is the way it should have been done in the first place. I am sure my opinion on why it wasn't will come out during the course of the thread
Here is some quick video footage.
http://www.code3performance.com/C32/c32_pulley.wmv
Peaks - 328.4/328.9
Largest power curve differential - 33.9rwhp and 40.7rwtq
This is not the first prototype with many questions still to be answered. In fact, we have been running this pulley for months. We have 100s of hours of road testing (5000 miles and counting), 25+ dynos, and countless hours of tweaking. The pulley has also been tested on other member cars (testimonials below). The pulley has gone into production already, and will be available within the next 10 days. The basics of the piece.
- 10-15 minute install
- no new belt needed
- no additional pulleys needed
- no ECU tuning needed
- pulley comes with new bearing and snap ring pre-installed, plus extra spacers
- Both written and video instructions by our Master Mercedes Tech
- colors will be available
- Price will be $600
The graphs below are dumped from the dyno CSV data. Blue is the stock run, red is the pulley run. Below that is the A/F from the pulley run. Dynos are performed on a "Superflow 840 Dual Eddy Current & MoTec Wideband AutoDyn Chassis Dyno". Before and After dynos are performed with the car still strapped to the dyno. Dyno run is in 4th gear to 140mph with car in dyno mode. Runs are on 91 octane!
The pulley run also had our new intake mod. It picked up 4-7hp across the entire power band on a stock car. I will post separately about it, as it will be available shortly as well. It will be priced around 1/3 the cost of current intake solutions, and your system still looks stock Plus it sounds awesome! People will definitely know something is lurking under the hood.
Here are two quick testimonials from some pulley beta testers.
##########
TopGun32 says:
"No belt slip, clutch engagement is as stock and boost comes sooner. I have had the Evosport set up on my car, and I can tell you this mod makes as much power and much smoother power delivery from around 3k to 5.5k (s/c power band). We tested last Saturday and made a handful of pulls from 40 to 100 and not once did I experience a lack of power (belt slip) while in the power band) I do suggest adding a FMIC to this set up... more boost, higher IAT's. Ease of install.. pretty much a few screws and need to let the kompressor clutch cool down."
##########
Dan from Crossfire Forums:
"I tested his pulley on my car and as I said to me it felt, power wise, much smoother and I can only compare it to 400 hp V8 feeling since I have had those! I've driven my unmodded SRT6 for 7,000 miles, this is the first time it felt so very smooth as my 6 liter V12 Jag ! The power range came on quicker and with less effort."
##########
As expected, there will be a lot of questions. MB owners have been told for years that the "magical SC pulley" shouldn't be touched, and that it was not possible to modify it without running into many problems... The simple fact is, you would be hard pressed to find another supercharged vehicle that creates power with a crank pulley upgrade versus an sc pulley upgrade. This is the way it should have been done in the first place. I am sure my opinion on why it wasn't will come out during the course of the thread
Here is some quick video footage.
http://www.code3performance.com/C32/c32_pulley.wmv
Peaks - 328.4/328.9
Largest power curve differential - 33.9rwhp and 40.7rwtq
#2
Great breakthrough!
I ordered the LET 185 which makes the supercharger runs at almost max rpms. I think there is less room for me to order your S/C.
Just one question, replacing a larger crank pulley or a smaller
S/C pulley has the same effect of driving the S/C faster. What are the pros and cons for both solutions???
I am very interested in your intake mod, look forward to it.
The car in the vid sounds like music to me...............
Great work!!
I ordered the LET 185 which makes the supercharger runs at almost max rpms. I think there is less room for me to order your S/C.
Just one question, replacing a larger crank pulley or a smaller
S/C pulley has the same effect of driving the S/C faster. What are the pros and cons for both solutions???
I am very interested in your intake mod, look forward to it.
The car in the vid sounds like music to me...............
Great work!!
#5
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2008 A8L, 2002 996TT X50, 2009 X5
maybe, maybe not my friend... allegedly some SRT-6 guys are running a 192mm crank pulley w/o problems, from what Jerry tells me. Someone'd have to "do the math" to figure out S/C speeds if someone were to add the Code3 part on top of an already crank-pulley-boosted m112k. For example, if someone had an ASP pulley, could they add Code3's S/C pulley without pushing the kompressor too far? It'd be interesting to know, for sure
#7
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Joined: Jun 2007
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From: Philadelphia, PA
2008 A8L, 2002 996TT X50, 2009 X5
As expected, there will be a lot of questions. MB owners have been told for years that the "magical SC pulley" shouldn't be touched, and that it was not possible to modify it without running into many problems... The simple fact is, you would be hard pressed to find another supercharged vehicle that creates power with a crank pulley upgrade versus an sc pulley upgrade. This is the way it should have been done in the first place. I am sure my opinion on why it wasn't will come out during the course of the thread
I'm interested to hear what you think... personally, I doubt it was profit or cost related... I imagine if Renntech had engineered a smaller S/C pulley and ECU tune to go with it, they'd have charged at least $3k for the kit anyway, and people would've paid it.
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#8
This is from Brian at the Crossfire Forum.
By my calculations: (based on the stock 74mm S/C Pulley)
Stock Crank Pulley : 74mm S/C - - Ratio = 2.0270
Engine RPM @ 6,000 - - S/C RPM = 12,405
Engine RPM @ 6,200 - - S/C RPM = 12,819 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 14,473
178mm Crank Pulley : 74mm S/C - - Ratio = 2.4054
Engine RPM @ 6,000 - - S/C RPM = 14,432
Engine RPM @ 6,200 - - S/C RPM = 14,914 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 16,838
181mm Crank Pulley : 74mm S/C - - Ratio = 2.4459
Engine RPM @ 6,000 - - S/C RPM = 14,676
Engine RPM @ 6,200 - - S/C RPM = 15,165 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 17,122
185 Crank Pulley : 74mm S/C - - Ratio = 2.5000
Engine RPM @ 6,000 - - S/C RPM = 15,000
Engine RPM @ 6,200 - - S/C RPM = 15,500 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 17,500
Using a Stock Crank Pulley, the S/C pulley would need to be reduced to:
63.6mm to equal the boost of 178mm Crank Pulley running @ 6,200 Engine RPM
62.5mm to equal the boost of 181mm Crank Pulley running @ 6,200 Engine RPM
61.2mm to equal the boost of 185mm Crank Pulley running @ 6,200 Engine RPM
If 20,700 is the max S/C RPM; and to be safe we decide to stay 10% under max - that's a target of 18,630 S/C RPM - - (when at 6,200 engine RPM)
Stock Crank Pulley would need a 50.9mm S/C Pulley
178mm Crank Pulley would need a 59.2mm S/C Pulley
181mm Crank Pulley would need a 60.2mm S/C Pulley
185mm Crank Pulley would need a 61.6mm S/C Pulley
By my calculations: (based on the stock 74mm S/C Pulley)
Stock Crank Pulley : 74mm S/C - - Ratio = 2.0270
Engine RPM @ 6,000 - - S/C RPM = 12,405
Engine RPM @ 6,200 - - S/C RPM = 12,819 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 14,473
178mm Crank Pulley : 74mm S/C - - Ratio = 2.4054
Engine RPM @ 6,000 - - S/C RPM = 14,432
Engine RPM @ 6,200 - - S/C RPM = 14,914 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 16,838
181mm Crank Pulley : 74mm S/C - - Ratio = 2.4459
Engine RPM @ 6,000 - - S/C RPM = 14,676
Engine RPM @ 6,200 - - S/C RPM = 15,165 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 17,122
185 Crank Pulley : 74mm S/C - - Ratio = 2.5000
Engine RPM @ 6,000 - - S/C RPM = 15,000
Engine RPM @ 6,200 - - S/C RPM = 15,500 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 17,500
Using a Stock Crank Pulley, the S/C pulley would need to be reduced to:
63.6mm to equal the boost of 178mm Crank Pulley running @ 6,200 Engine RPM
62.5mm to equal the boost of 181mm Crank Pulley running @ 6,200 Engine RPM
61.2mm to equal the boost of 185mm Crank Pulley running @ 6,200 Engine RPM
If 20,700 is the max S/C RPM; and to be safe we decide to stay 10% under max - that's a target of 18,630 S/C RPM - - (when at 6,200 engine RPM)
Stock Crank Pulley would need a 50.9mm S/C Pulley
178mm Crank Pulley would need a 59.2mm S/C Pulley
181mm Crank Pulley would need a 60.2mm S/C Pulley
185mm Crank Pulley would need a 61.6mm S/C Pulley
#9
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From: Santa Barbara & Los Angeles, CA
C32, Cobra, 700hp Vespa
Thanks for the math Jerry. The good news is, it looks like it will work with both. We will get on the dyno with a car this week that already has a crank pulley. This could very well be the combination we have all been looking for to keep those pesky 335i's at bay
#12
This is from Brian at the Crossfire Forum.
By my calculations: (based on the stock 74mm S/C Pulley)
Stock Crank Pulley : 74mm S/C - - Ratio = 2.0270
Engine RPM @ 6,000 - - S/C RPM = 12,405
Engine RPM @ 6,200 - - S/C RPM = 12,819 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 14,473
178mm Crank Pulley : 74mm S/C - - Ratio = 2.4054
Engine RPM @ 6,000 - - S/C RPM = 14,432
Engine RPM @ 6,200 - - S/C RPM = 14,914 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 16,838
181mm Crank Pulley : 74mm S/C - - Ratio = 2.4459
Engine RPM @ 6,000 - - S/C RPM = 14,676
Engine RPM @ 6,200 - - S/C RPM = 15,165 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 17,122
185 Crank Pulley : 74mm S/C - - Ratio = 2.5000
Engine RPM @ 6,000 - - S/C RPM = 15,000
Engine RPM @ 6,200 - - S/C RPM = 15,500 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 17,500
Using a Stock Crank Pulley, the S/C pulley would need to be reduced to:
63.6mm to equal the boost of 178mm Crank Pulley running @ 6,200 Engine RPM
62.5mm to equal the boost of 181mm Crank Pulley running @ 6,200 Engine RPM
61.2mm to equal the boost of 185mm Crank Pulley running @ 6,200 Engine RPM
If 20,700 is the max S/C RPM; and to be safe we decide to stay 10% under max - that's a target of 18,630 S/C RPM - - (when at 6,200 engine RPM)
Stock Crank Pulley would need a 50.9mm S/C Pulley
178mm Crank Pulley would need a 59.2mm S/C Pulley
181mm Crank Pulley would need a 60.2mm S/C Pulley
185mm Crank Pulley would need a 61.6mm S/C Pulley
By my calculations: (based on the stock 74mm S/C Pulley)
Stock Crank Pulley : 74mm S/C - - Ratio = 2.0270
Engine RPM @ 6,000 - - S/C RPM = 12,405
Engine RPM @ 6,200 - - S/C RPM = 12,819 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 14,473
178mm Crank Pulley : 74mm S/C - - Ratio = 2.4054
Engine RPM @ 6,000 - - S/C RPM = 14,432
Engine RPM @ 6,200 - - S/C RPM = 14,914 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 16,838
181mm Crank Pulley : 74mm S/C - - Ratio = 2.4459
Engine RPM @ 6,000 - - S/C RPM = 14,676
Engine RPM @ 6,200 - - S/C RPM = 15,165 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 17,122
185 Crank Pulley : 74mm S/C - - Ratio = 2.5000
Engine RPM @ 6,000 - - S/C RPM = 15,000
Engine RPM @ 6,200 - - S/C RPM = 15,500 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 17,500
Using a Stock Crank Pulley, the S/C pulley would need to be reduced to:
63.6mm to equal the boost of 178mm Crank Pulley running @ 6,200 Engine RPM
62.5mm to equal the boost of 181mm Crank Pulley running @ 6,200 Engine RPM
61.2mm to equal the boost of 185mm Crank Pulley running @ 6,200 Engine RPM
If 20,700 is the max S/C RPM; and to be safe we decide to stay 10% under max - that's a target of 18,630 S/C RPM - - (when at 6,200 engine RPM)
Stock Crank Pulley would need a 50.9mm S/C Pulley
178mm Crank Pulley would need a 59.2mm S/C Pulley
181mm Crank Pulley would need a 60.2mm S/C Pulley
185mm Crank Pulley would need a 61.6mm S/C Pulley
#13
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Joined: Nov 2003
Posts: 1,067
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From: MILFORD,CT
E36M3 race car/Ferrari F355 GTS/1973 Mini 1275GT/Fiat Abarth/ML63/SLK55
This is from Brian at the Crossfire Forum.
By my calculations: (based on the stock 74mm S/C Pulley)
Stock Crank Pulley : 74mm S/C - - Ratio = 2.0270
Engine RPM @ 6,000 - - S/C RPM = 12,405
Engine RPM @ 6,200 - - S/C RPM = 12,819 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 14,473
178mm Crank Pulley : 74mm S/C - - Ratio = 2.4054
Engine RPM @ 6,000 - - S/C RPM = 14,432
Engine RPM @ 6,200 - - S/C RPM = 14,914 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 16,838
181mm Crank Pulley : 74mm S/C - - Ratio = 2.4459
Engine RPM @ 6,000 - - S/C RPM = 14,676
Engine RPM @ 6,200 - - S/C RPM = 15,165 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 17,122
185 Crank Pulley : 74mm S/C - - Ratio = 2.5000
Engine RPM @ 6,000 - - S/C RPM = 15,000
Engine RPM @ 6,200 - - S/C RPM = 15,500 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 17,500
Using a Stock Crank Pulley, the S/C pulley would need to be reduced to:
63.6mm to equal the boost of 178mm Crank Pulley running @ 6,200 Engine RPM
62.5mm to equal the boost of 181mm Crank Pulley running @ 6,200 Engine RPM
61.2mm to equal the boost of 185mm Crank Pulley running @ 6,200 Engine RPM
If 20,700 is the max S/C RPM; and to be safe we decide to stay 10% under max - that's a target of 18,630 S/C RPM - - (when at 6,200 engine RPM)
Stock Crank Pulley would need a 50.9mm S/C Pulley
178mm Crank Pulley would need a 59.2mm S/C Pulley
181mm Crank Pulley would need a 60.2mm S/C Pulley
185mm Crank Pulley would need a 61.6mm S/C Pulley
By my calculations: (based on the stock 74mm S/C Pulley)
Stock Crank Pulley : 74mm S/C - - Ratio = 2.0270
Engine RPM @ 6,000 - - S/C RPM = 12,405
Engine RPM @ 6,200 - - S/C RPM = 12,819 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 14,473
178mm Crank Pulley : 74mm S/C - - Ratio = 2.4054
Engine RPM @ 6,000 - - S/C RPM = 14,432
Engine RPM @ 6,200 - - S/C RPM = 14,914 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 16,838
181mm Crank Pulley : 74mm S/C - - Ratio = 2.4459
Engine RPM @ 6,000 - - S/C RPM = 14,676
Engine RPM @ 6,200 - - S/C RPM = 15,165 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 17,122
185 Crank Pulley : 74mm S/C - - Ratio = 2.5000
Engine RPM @ 6,000 - - S/C RPM = 15,000
Engine RPM @ 6,200 - - S/C RPM = 15,500 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 17,500
Using a Stock Crank Pulley, the S/C pulley would need to be reduced to:
63.6mm to equal the boost of 178mm Crank Pulley running @ 6,200 Engine RPM
62.5mm to equal the boost of 181mm Crank Pulley running @ 6,200 Engine RPM
61.2mm to equal the boost of 185mm Crank Pulley running @ 6,200 Engine RPM
If 20,700 is the max S/C RPM; and to be safe we decide to stay 10% under max - that's a target of 18,630 S/C RPM - - (when at 6,200 engine RPM)
Stock Crank Pulley would need a 50.9mm S/C Pulley
178mm Crank Pulley would need a 59.2mm S/C Pulley
181mm Crank Pulley would need a 60.2mm S/C Pulley
185mm Crank Pulley would need a 61.6mm S/C Pulley
I assume a larger HE and johnson 030 would be a must to keep high IATs at bay for folks wishing to try the double whammy.
what about fuel? will my evosport ecu adapt?
lawd have mercy........
#14
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From: Santa Barbara & Los Angeles, CA
C32, Cobra, 700hp Vespa
As far as tuning, this is one of those instances when software might actually be worth doing. I am headed to the dyno tomorrow night with a crank pullied car to do some testing. A/F and MAP are the two big concerns right now. We already have a MAP solution ready to go that will extend the range, if its needed. Plus it has a built in port for running a boost gauge, so no need to tap anything
#15
Brandon
So from around 2600 RPM to about 4000 the car is running from the mid 14's to 13's A/F Ratio? What are the stock A/F ratio from 2600 to 4000? Sorry if I am reading this incorrectly.
Basically I am just making sure the car at any RPM is no where near a dangerous A/F ratio.
If there is no tune needed and easy to install I think I may in. How many will you have and how long to get them.
What are the negative affects of this upgrade compared to a crank pulley upgrade.
This looks like a very good product I think people will be all over when all questions are asked and answered.
So from around 2600 RPM to about 4000 the car is running from the mid 14's to 13's A/F Ratio? What are the stock A/F ratio from 2600 to 4000? Sorry if I am reading this incorrectly.
Basically I am just making sure the car at any RPM is no where near a dangerous A/F ratio.
If there is no tune needed and easy to install I think I may in. How many will you have and how long to get them.
What are the negative affects of this upgrade compared to a crank pulley upgrade.
This looks like a very good product I think people will be all over when all questions are asked and answered.
#17
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Joined: Dec 2007
Posts: 5,034
Likes: 6
From: Corona, CA
03 g35 coupe...........02 c32 Sold
This is from Brian at the Crossfire Forum.
By my calculations: (based on the stock 74mm S/C Pulley)
Stock Crank Pulley : 74mm S/C - - Ratio = 2.0270
Engine RPM @ 6,000 - - S/C RPM = 12,405
Engine RPM @ 6,200 - - S/C RPM = 12,819 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 14,473
178mm Crank Pulley : 74mm S/C - - Ratio = 2.4054
Engine RPM @ 6,000 - - S/C RPM = 14,432
Engine RPM @ 6,200 - - S/C RPM = 14,914 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 16,838
181mm Crank Pulley : 74mm S/C - - Ratio = 2.4459
Engine RPM @ 6,000 - - S/C RPM = 14,676
Engine RPM @ 6,200 - - S/C RPM = 15,165 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 17,122
185 Crank Pulley : 74mm S/C - - Ratio = 2.5000
Engine RPM @ 6,000 - - S/C RPM = 15,000
Engine RPM @ 6,200 - - S/C RPM = 15,500 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 17,500
Using a Stock Crank Pulley, the S/C pulley would need to be reduced to:
63.6mm to equal the boost of 178mm Crank Pulley running @ 6,200 Engine RPM
62.5mm to equal the boost of 181mm Crank Pulley running @ 6,200 Engine RPM
61.2mm to equal the boost of 185mm Crank Pulley running @ 6,200 Engine RPM
If 20,700 is the max S/C RPM; and to be safe we decide to stay 10% under max - that's a target of 18,630 S/C RPM - - (when at 6,200 engine RPM)
Stock Crank Pulley would need a 50.9mm S/C Pulley
178mm Crank Pulley would need a 59.2mm S/C Pulley
181mm Crank Pulley would need a 60.2mm S/C Pulley
185mm Crank Pulley would need a 61.6mm S/C Pulley
By my calculations: (based on the stock 74mm S/C Pulley)
Stock Crank Pulley : 74mm S/C - - Ratio = 2.0270
Engine RPM @ 6,000 - - S/C RPM = 12,405
Engine RPM @ 6,200 - - S/C RPM = 12,819 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 14,473
178mm Crank Pulley : 74mm S/C - - Ratio = 2.4054
Engine RPM @ 6,000 - - S/C RPM = 14,432
Engine RPM @ 6,200 - - S/C RPM = 14,914 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 16,838
181mm Crank Pulley : 74mm S/C - - Ratio = 2.4459
Engine RPM @ 6,000 - - S/C RPM = 14,676
Engine RPM @ 6,200 - - S/C RPM = 15,165 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 17,122
185 Crank Pulley : 74mm S/C - - Ratio = 2.5000
Engine RPM @ 6,000 - - S/C RPM = 15,000
Engine RPM @ 6,200 - - S/C RPM = 15,500 - Rev Limiter W/Tune
Engine RPM @ 7,000 - - S/C RPM = 17,500
Using a Stock Crank Pulley, the S/C pulley would need to be reduced to:
63.6mm to equal the boost of 178mm Crank Pulley running @ 6,200 Engine RPM
62.5mm to equal the boost of 181mm Crank Pulley running @ 6,200 Engine RPM
61.2mm to equal the boost of 185mm Crank Pulley running @ 6,200 Engine RPM
If 20,700 is the max S/C RPM; and to be safe we decide to stay 10% under max - that's a target of 18,630 S/C RPM - - (when at 6,200 engine RPM)
Stock Crank Pulley would need a 50.9mm S/C Pulley
178mm Crank Pulley would need a 59.2mm S/C Pulley
181mm Crank Pulley would need a 60.2mm S/C Pulley
185mm Crank Pulley would need a 61.6mm S/C Pulley
#20
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Posts: 1,067
Likes: 4
From: MILFORD,CT
E36M3 race car/Ferrari F355 GTS/1973 Mini 1275GT/Fiat Abarth/ML63/SLK55
A larger HE us a must, whether used by itself, or in conjunction with a crank pulley.
As far as tuning, this is one of those instances when software might actually be worth doing. I am headed to the dyno tomorrow night with a crank pullied car to do some testing. A/F and MAP are the two big concerns right now. We already have a MAP solution ready to go that will extend the range, if its needed. Plus it has a built in port for running a boost gauge, so no need to tap anything
As far as tuning, this is one of those instances when software might actually be worth doing. I am headed to the dyno tomorrow night with a crank pullied car to do some testing. A/F and MAP are the two big concerns right now. We already have a MAP solution ready to go that will extend the range, if its needed. Plus it has a built in port for running a boost gauge, so no need to tap anything
OK pl keep us posted. save the fuel issue my car may be a prime candidate for a double whammy. assuming IATs are controlled, no clutch slip, ok fuel....I would be 390 rwhp
one more important thing..........will the s/c engagement point be unaffected in terms of rpm or load? i don't want to give up my 24 mpg hiway.
#21
MBWorld Fanatic!
Joined: Jun 2007
Posts: 2,949
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From: Philadelphia, PA
2008 A8L, 2002 996TT X50, 2009 X5
Thanks for the math Jerry. The good news is, it looks like it will work with both. We will get on the dyno with a car this week that already has a crank pulley. This could very well be the combination we have all been looking for to keep those pesky 335i's at bay
TIA!