Weistec blower efficiency
09-14-2015, 07:26 AM
#26
Super Member
i ran a 10.4@132 mph with a stage 2 clk63 bs full weight which is heavier than a C63 its on you tube http://youtu.be/7gfhEzcAY64
09-14-2015, 07:58 AM
#27
Senior Member
I have personally had several twin-screws on GM platforms, and one of the most lively was a low-compression 6.2 running 16-17psi. However, like others have said... more boost will not necessarily be the best way to add power/efficiency - there is a balance. A nicely matched engine/blower will produce a flat or slightly-rising boost curve. An overspun blower giving a large rising-rate curve will often lead to a less-than-ideal experience.
RNS-11Z: Drop me a note/PM and I can probably help you out with the calcs & the pulleys/belts etc.
09-14-2015, 09:44 AM
#28
Remember fellas, you are boosting a 11.3 compression engine. Heat is the enemy and I think Weistec wants to keep the IAT's down to a certain level to control ping.
Your tune should adapt if you use another pulley. These cars are closed loop24/7.
The timing will probably try to stay the same so you'll need high octane fuel. Your stock injectors on stage 2 will probably be too small. Not sure if you can change injectors and the tune will adapt to that or not.
You can only turn the boost up so much before heat becomes an issue and you will loose power.
Your tune should adapt if you use another pulley. These cars are closed loop24/7.
The timing will probably try to stay the same so you'll need high octane fuel. Your stock injectors on stage 2 will probably be too small. Not sure if you can change injectors and the tune will adapt to that or not.
You can only turn the boost up so much before heat becomes an issue and you will loose power.
Last edited by Merc63; 09-14-2015 at 09:47 AM.
09-15-2015, 09:42 AM
#29
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2012 C63;1971 280SE 3.5(Sold);2023 EQS 450 SUV 4 Matic (Wife's)
I know in my GM truck when you change injectors you need to change the flow rate in the tune. Not sure if the same applies to MB or not, but more than likely. How else would the tune know what the flow was and how to adjust for it through the rev band.
09-15-2015, 11:47 AM
#30
Out Of Control!!
Superchargers are not rated by "max boost". For instance the 2.9L Whipple max efficiency is at 18,000rpm. So the way you figure out what size sc pulley to run to reach that max efficiency is plug your crank pulley diameter and engine max rpm into a formula and see what sc pulley size you need to get 18,000rpm. It's not rocket science guys.
Boost can be greatly affected by many variables. Port the heads or better headers and your boost will drop at the same sc rpm. Boost is just a measure of restriction. I've been able to run over 20psi on my "stage 3" Weistec blower but the 55k ECU goes into limp mode so my tuner bleeds off anything above 17PSI. I should just get a larger sc pulley and retune
Boost can be greatly affected by many variables. Port the heads or better headers and your boost will drop at the same sc rpm. Boost is just a measure of restriction. I've been able to run over 20psi on my "stage 3" Weistec blower but the 55k ECU goes into limp mode so my tuner bleeds off anything above 17PSI. I should just get a larger sc pulley and retune
09-21-2015, 04:13 AM
#31
Former Vendor of MBWorld
Boost Ratings
Our Stage 2 system running our 2.3L twin-screw compressor runs about 7-8 psi. This boost rating is with our high flow air filters, and high flow long tube headers. The exact supercharger pulley size is 57mm and this runs the factory crank damper pulley.
Our Stage 3 system running our 3.0L twin-screw runs about 10-11 psi. This boost rating is with our high flow air filters, and high flow long tube headers. The exact supercharger pulley size is 67mm and this runs a completely different 8-rib drive system with our proprietary crank damper pulley.
We offer a 60mm pulley upgrade for the Stage 3 system which turns the boost to about 14-15 psi but this does require additional modifications to hold the power reliably.
How much power can your C63 (722.9) transmission handle
We recommend upgrading the transmission with our transmission packages when power levels start exceeding our Stage 2 power levels (approximately 570HP at the wheels).
How much power can an M156 engine handle
The M156 engine is very resilient but like everything else, it has its limits. The main issue in terms of power limits is the connecting rods in the engine. It will start to fatigue at around 700HP at the wheels. Keeping a keen eye on detonation, and cylinder temperatures will allow you to make more than that, but the risk isn't worth the reward.
The next limit of the engine, is the piston ring land. Now it is worth mentioning that there are 2 different pistons that came equipped with the M156 engine. One is the standard piston and the other is the P31 piston. Although the P31 is a much nicer and stronger piston, the engine consistently runs a very tight ring gap from the factory, which can be catastrophic to a forced induction engine running high cylinder pressures. A P31 piston is more resilient than a standard piston, but enough heat and time will damage the ring land due to a tight ring gaps.
How fast did customers go with off the shelf parts
Stage 2 customers have gone as fast as 10.4 as discussed in an earlier post. Many have gone 10.5's, and there are many more than this that have been in the 10's. You can purchase everything needed straight off of our website to do this. Those that have gone 10.4-10.5's have a better wheel and tire combo, and that is the only thing we don't sell, but we can easily help with.
Stage 3 customers have gone even lower in the 10's. We have Australian customers who have gone 10.3's very easily with our off the shelf system and tuning.
Stage 3 60mm customers have gone 9's and have MPH records with this system.
Boost and the M156 engine
The M156 engine has an extremely efficient cylinder head design, along with great valve shrouding in the cylinder, great oiling, high revs, and high compression. It is very hard to compare this engine to anything out there. Some things do however stay constant. Calculating cylinder pressures, supercharger RPM's against compressor efficiency, intercooler efficiency, etc. will give you an idea of how boost you can safely get away with before having diminishing returns as others said.
Without boring you with actual calculations, we have found that the boost pressures we offer with each system is at its best efficiency for the given combination.
To add, there is no way you can anywhere near 20 psi with our 3.0L system on this engine. The supercharger can't create enough pressure to keep that boost to redline. Not to mention, the air box design is at capacity and will not suffice past the 60mm combo.
Let us know how we can help from here, and always feel free to call us or email us at tech@weistec.com
Thanks again!
Weistec Engineering
09-22-2015, 01:17 AM
#32
Super Member
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c63 coupe p31weistec stg3 SOLD,2013 C63 BLACK SERIES.
RNS-11Z, thanks for posting this up. It gives a good chance to speak more in technical terms in regards to our products.
Boost Ratings
Our Stage 2 system running our 2.3L twin-screw compressor runs about 7-8 psi. This boost rating is with our high flow air filters, and high flow long tube headers. The exact supercharger pulley size is 57mm and this runs the factory crank damper pulley.
Our Stage 3 system running our 3.0L twin-screw runs about 10-11 psi. This boost rating is with our high flow air filters, and high flow long tube headers. The exact supercharger pulley size is 67mm and this runs a completely different 8-rib drive system with our proprietary crank damper pulley.
We offer a 60mm pulley upgrade for the Stage 3 system which turns the boost to about 14-15 psi but this does require additional modifications to hold the power reliably.
How much power can your C63 (722.9) transmission handle
We recommend upgrading the transmission with our transmission packages when power levels start exceeding our Stage 2 power levels (approximately 570HP at the wheels).
How much power can an M156 engine handle
The M156 engine is very resilient but like everything else, it has its limits. The main issue in terms of power limits is the connecting rods in the engine. It will start to fatigue at around 700HP at the wheels. Keeping a keen eye on detonation, and cylinder temperatures will allow you to make more than that, but the risk isn't worth the reward.
The next limit of the engine, is the piston ring land. Now it is worth mentioning that there are 2 different pistons that came equipped with the M156 engine. One is the standard piston and the other is the P31 piston. Although the P31 is a much nicer and stronger piston, the engine consistently runs a very tight ring gap from the factory, which can be catastrophic to a forced induction engine running high cylinder pressures. A P31 piston is more resilient than a standard piston, but enough heat and time will damage the ring land due to a tight ring gaps.
How fast did customers go with off the shelf parts
Stage 2 customers have gone as fast as 10.4 as discussed in an earlier post. Many have gone 10.5's, and there are many more than this that have been in the 10's. You can purchase everything needed straight off of our website to do this. Those that have gone 10.4-10.5's have a better wheel and tire combo, and that is the only thing we don't sell, but we can easily help with.
Stage 3 customers have gone even lower in the 10's. We have Australian customers who have gone 10.3's very easily with our off the shelf system and tuning.
Stage 3 60mm customers have gone 9's and have MPH records with this system.
Boost and the M156 engine
The M156 engine has an extremely efficient cylinder head design, along with great valve shrouding in the cylinder, great oiling, high revs, and high compression. It is very hard to compare this engine to anything out there. Some things do however stay constant. Calculating cylinder pressures, supercharger RPM's against compressor efficiency, intercooler efficiency, etc. will give you an idea of how boost you can safely get away with before having diminishing returns as others said.
Without boring you with actual calculations, we have found that the boost pressures we offer with each system is at its best efficiency for the given combination.
To add, there is no way you can anywhere near 20 psi with our 3.0L system on this engine. The supercharger can't create enough pressure to keep that boost to redline. Not to mention, the air box design is at capacity and will not suffice past the 60mm combo.
Let us know how we can help from here, and always feel free to call us or email us at tech@weistec.com
Thanks again!
Weistec Engineering
Boost Ratings
Our Stage 2 system running our 2.3L twin-screw compressor runs about 7-8 psi. This boost rating is with our high flow air filters, and high flow long tube headers. The exact supercharger pulley size is 57mm and this runs the factory crank damper pulley.
Our Stage 3 system running our 3.0L twin-screw runs about 10-11 psi. This boost rating is with our high flow air filters, and high flow long tube headers. The exact supercharger pulley size is 67mm and this runs a completely different 8-rib drive system with our proprietary crank damper pulley.
We offer a 60mm pulley upgrade for the Stage 3 system which turns the boost to about 14-15 psi but this does require additional modifications to hold the power reliably.
How much power can your C63 (722.9) transmission handle
We recommend upgrading the transmission with our transmission packages when power levels start exceeding our Stage 2 power levels (approximately 570HP at the wheels).
How much power can an M156 engine handle
The M156 engine is very resilient but like everything else, it has its limits. The main issue in terms of power limits is the connecting rods in the engine. It will start to fatigue at around 700HP at the wheels. Keeping a keen eye on detonation, and cylinder temperatures will allow you to make more than that, but the risk isn't worth the reward.
The next limit of the engine, is the piston ring land. Now it is worth mentioning that there are 2 different pistons that came equipped with the M156 engine. One is the standard piston and the other is the P31 piston. Although the P31 is a much nicer and stronger piston, the engine consistently runs a very tight ring gap from the factory, which can be catastrophic to a forced induction engine running high cylinder pressures. A P31 piston is more resilient than a standard piston, but enough heat and time will damage the ring land due to a tight ring gaps.
How fast did customers go with off the shelf parts
Stage 2 customers have gone as fast as 10.4 as discussed in an earlier post. Many have gone 10.5's, and there are many more than this that have been in the 10's. You can purchase everything needed straight off of our website to do this. Those that have gone 10.4-10.5's have a better wheel and tire combo, and that is the only thing we don't sell, but we can easily help with.
Stage 3 customers have gone even lower in the 10's. We have Australian customers who have gone 10.3's very easily with our off the shelf system and tuning.
Stage 3 60mm customers have gone 9's and have MPH records with this system.
Boost and the M156 engine
The M156 engine has an extremely efficient cylinder head design, along with great valve shrouding in the cylinder, great oiling, high revs, and high compression. It is very hard to compare this engine to anything out there. Some things do however stay constant. Calculating cylinder pressures, supercharger RPM's against compressor efficiency, intercooler efficiency, etc. will give you an idea of how boost you can safely get away with before having diminishing returns as others said.
Without boring you with actual calculations, we have found that the boost pressures we offer with each system is at its best efficiency for the given combination.
To add, there is no way you can anywhere near 20 psi with our 3.0L system on this engine. The supercharger can't create enough pressure to keep that boost to redline. Not to mention, the air box design is at capacity and will not suffice past the 60mm combo.
Let us know how we can help from here, and always feel free to call us or email us at tech@weistec.com
Thanks again!
Weistec Engineering
09-22-2015, 08:14 AM
#33
Out Of Control!!
According to Weistec they did testing and the max efficiency is 7-8PSI with a 57mm sc pulley. So if you wanted to run 10PSI you would have to get a larger crank pulley. And according to Weistec pushing it past it's efficiency which means even more heat. Raising boost doesn't always mean more power
