997.2 Turbo Updates from Cobb Tuning
#17
08-23-2014, 12:25 AM
Can you rise the boost to 26psi? And there will be no knocks!
On 26psi it must go much quicker
#18
08-23-2014, 08:08 AM
The Turbos are maximized around 23psi, the exact theory of why the meth doesn't produce power is unknown to me, I just know that is good to lower the AIT (can go down to 80 degrees) but do not produce power...
#19
08-23-2014, 10:00 AM
Former Vendor
Methanol injection works on the principle of, if you're into physics, latent heat of vaporization. By spraying a fine myst of methanol (alcohol) into the charge air stream you're effectively removing heat from it that turbos inherently cause. Think of turbos as hairdryers 
Even with the turbos operating well within their efficiency they will heat up air. As you raise boost you make the turbos work harder, spin faster, pushing them further and further outside of their efficiency. Intercoolers will help the situation by performing heat exchange and lowering/controlling those charge air temps, but only to a point until they heatsoak and the higher the boost, the lower the efficiency, the higher the heat, the faster the intercoolers heatsoak and become virtually ineffective. When the DME sees high intake temps it is calibrated to start pulling ignition timing, and sometimes boost (i.e. lowering load), to do its best at preventing pre-ignition/knock making the car lose power and get slower and slower from one run to the next. Even with the most efficient map set up perfectly within turbo efficiency you will cross into this high IAT area and you will start to lose power.
This is where methanol injection comes to the rescue helping remarkably in thermal management of the overall system. It ensures the intake temperatures stay near or even below ambient temps at times. This has many benefits including suppressing pre-ignition/knock due to high intake temps, incurring power losses in back to back runs and high speed WOT runs recovering your lost power.
It doesn't stop there though. With the additional octane that alcohol (methanol) provides a tune can be pushed more aggressively on both the load (boost) and ignition timing fronts. To do this safely though you must have the appropriate failsafe in place that detects any issues with flow and reacts as quickly and effectively as possible to prevent any engine damage in the case of low flow, overflow, running out of methanol in the tank. The best and the only kit we'll run and recommend on our shop/customer cars is the Aquamist HFS-4 (for direct injection motors such as the 997.2) and HFS-3 (for port injection motors such as the 997.1).
We have done a LOT of tuning with methanol injection on the BMW's direct injection platform which is basically the same as what you have on the 997.2s. Direct injection in itself raises effective octane due to superior atomization of fuel and in cylinder cooling effects that you can think of it as removing heat from the cylinder/combustion but that is a topic in itself and I'd be happy to discuss that with you guys as well if anyone's interested.
Adding methanol on top of gasoline (non-race gas high octane) will effectively raise octane levels on pump gas allowing for more ignition timing and boost, always, allowing for additional power gains to be had everywhere in the power curve over what is typically available on just a pump gas tune. We have the the Aquamist HFS-4 sitting on the shelf ready to be installed on our 997.2 once the next update from Cobb is released and we can keep pushing on.
As a final comment, nothing really comes close to properly fueling a motor like spraying from injectors. This is especially true on the direct injection setups such as the 997.2. Direct injection has some disadvantages when compared to port injection but the advantages IMHO far outweigh its disadvantages. Its main disadvantages are in that it is hard to upgrade the hardware at this time, although it has been done on a few platforms we support in various ways. However, fuel atomization is vastly superior over port injection and, if you're lucky to have E85 in your area at the pumps, it is around 105 octane on its own BUT, when direct injected at high pressures such as what the 997.2 injectors and the high pressure pump provide, effective octane raises to over 160 points! The issue is with E85 is that ethanol burns faster than gasoline and it requires 30% more volume out of the fuel system to be supplied at the same power levels. Now this is again another topic in itself but certainly worth investigating on this platform as its been on the BMW N54 and other platforms we've been involved on over the years.
Even with the turbos operating well within their efficiency they will heat up air. As you raise boost you make the turbos work harder, spin faster, pushing them further and further outside of their efficiency. Intercoolers will help the situation by performing heat exchange and lowering/controlling those charge air temps, but only to a point until they heatsoak and the higher the boost, the lower the efficiency, the higher the heat, the faster the intercoolers heatsoak and become virtually ineffective. When the DME sees high intake temps it is calibrated to start pulling ignition timing, and sometimes boost (i.e. lowering load), to do its best at preventing pre-ignition/knock making the car lose power and get slower and slower from one run to the next. Even with the most efficient map set up perfectly within turbo efficiency you will cross into this high IAT area and you will start to lose power.This is where methanol injection comes to the rescue helping remarkably in thermal management of the overall system. It ensures the intake temperatures stay near or even below ambient temps at times. This has many benefits including suppressing pre-ignition/knock due to high intake temps, incurring power losses in back to back runs and high speed WOT runs recovering your lost power.
It doesn't stop there though. With the additional octane that alcohol (methanol) provides a tune can be pushed more aggressively on both the load (boost) and ignition timing fronts. To do this safely though you must have the appropriate failsafe in place that detects any issues with flow and reacts as quickly and effectively as possible to prevent any engine damage in the case of low flow, overflow, running out of methanol in the tank. The best and the only kit we'll run and recommend on our shop/customer cars is the Aquamist HFS-4 (for direct injection motors such as the 997.2) and HFS-3 (for port injection motors such as the 997.1).
We have done a LOT of tuning with methanol injection on the BMW's direct injection platform which is basically the same as what you have on the 997.2s. Direct injection in itself raises effective octane due to superior atomization of fuel and in cylinder cooling effects that you can think of it as removing heat from the cylinder/combustion but that is a topic in itself and I'd be happy to discuss that with you guys as well if anyone's interested.
Adding methanol on top of gasoline (non-race gas high octane) will effectively raise octane levels on pump gas allowing for more ignition timing and boost, always, allowing for additional power gains to be had everywhere in the power curve over what is typically available on just a pump gas tune. We have the the Aquamist HFS-4 sitting on the shelf ready to be installed on our 997.2 once the next update from Cobb is released and we can keep pushing on.
As a final comment, nothing really comes close to properly fueling a motor like spraying from injectors. This is especially true on the direct injection setups such as the 997.2. Direct injection has some disadvantages when compared to port injection but the advantages IMHO far outweigh its disadvantages. Its main disadvantages are in that it is hard to upgrade the hardware at this time, although it has been done on a few platforms we support in various ways. However, fuel atomization is vastly superior over port injection and, if you're lucky to have E85 in your area at the pumps, it is around 105 octane on its own BUT, when direct injected at high pressures such as what the 997.2 injectors and the high pressure pump provide, effective octane raises to over 160 points!
The issue is with E85 is that ethanol burns faster than gasoline and it requires 30% more volume out of the fuel system to be supplied at the same power levels. Now this is again another topic in itself but certainly worth investigating on this platform as its been on the BMW N54 and other platforms we've been involved on over the years.
#22
08-23-2014, 04:22 PM
Methanol injection works on the principle of, if you're into physics, latent heat of vaporization. By spraying a fine myst of methanol (alcohol) into the charge air stream you're effectively removing heat from it that turbos inherently cause. Think of turbos as hairdryers Even with the turbos operating well within their efficiency they will heat up air. As you raise boost you make the turbos work harder, spin faster, pushing them further and further outside of their efficiency. Intercoolers will help the situation by performing heat exchange and lowering/controlling those charge air temps, but only to a point until they heatsoak and the higher the boost, the lower the efficiency, the higher the heat, the faster the intercoolers heatsoak and become virtually ineffective. When the DME sees high intake temps it is calibrated to start pulling ignition timing, and sometimes boost (i.e. lowering load), to do its best at preventing pre-ignition/knock making the car lose power and get slower and slower from one run to the next. Even with the most efficient map set up perfectly within turbo efficiency you will cross into this high IAT area and you will start to lose power.
This is where methanol injection comes to the rescue helping remarkably in thermal management of the overall system. It ensures the intake temperatures stay near or even below ambient temps at times. This has many benefits including suppressing pre-ignition/knock due to high intake temps, incurring power losses in back to back runs and high speed WOT runs recovering your lost power.
It doesn't stop there though. With the additional octane that alcohol (methanol) provides a tune can be pushed more aggressively on both the load (boost) and ignition timing fronts. To do this safely though you must have the appropriate failsafe in place that detects any issues with flow and reacts as quickly and effectively as possible to prevent any engine damage in the case of low flow, overflow, running out of methanol in the tank. The best and the only kit we'll run and recommend on our shop/customer cars is the Aquamist HFS-4 (for direct injection motors such as the 997.2) and HFS-3 (for port injection motors such as the 997.1).
We have done a LOT of tuning with methanol injection on the BMW's direct injection platform which is basically the same as what you have on the 997.2s. Direct injection in itself raises effective octane due to superior atomization of fuel and in cylinder cooling effects that you can think of it as removing heat from the cylinder/combustion but that is a topic in itself and I'd be happy to discuss that with you guys as well if anyone's interested.
Adding methanol on top of gasoline (non-race gas high octane) will effectively raise octane levels on pump gas allowing for more ignition timing and boost, always, allowing for additional power gains to be had everywhere in the power curve over what is typically available on just a pump gas tune. We have the the Aquamist HFS-4 sitting on the shelf ready to be installed on our 997.2 once the next update from Cobb is released and we can keep pushing on.
As a final comment, nothing really comes close to properly fueling a motor like spraying from injectors. This is especially true on the direct injection setups such as the 997.2. Direct injection has some disadvantages when compared to port injection but the advantages IMHO far outweigh its disadvantages. Its main disadvantages are in that it is hard to upgrade the hardware at this time, although it has been done on a few platforms we support in various ways. However, fuel atomization is vastly superior over port injection and, if you're lucky to have E85 in your area at the pumps, it is around 105 octane on its own BUT, when direct injected at high pressures such as what the 997.2 injectors and the high pressure pump provide, effective octane raises to over 160 points! The issue is with E85 is that ethanol burns faster than gasoline and it requires 30% more volume out of the fuel system to be supplied at the same power levels. Now this is again another topic in itself but certainly worth investigating on this platform as its been on the BMW N54 and other platforms we've been involved on over the years.
Even with the turbos operating well within their efficiency they will heat up air. As you raise boost you make the turbos work harder, spin faster, pushing them further and further outside of their efficiency. Intercoolers will help the situation by performing heat exchange and lowering/controlling those charge air temps, but only to a point until they heatsoak and the higher the boost, the lower the efficiency, the higher the heat, the faster the intercoolers heatsoak and become virtually ineffective. When the DME sees high intake temps it is calibrated to start pulling ignition timing, and sometimes boost (i.e. lowering load), to do its best at preventing pre-ignition/knock making the car lose power and get slower and slower from one run to the next. Even with the most efficient map set up perfectly within turbo efficiency you will cross into this high IAT area and you will start to lose power.This is where methanol injection comes to the rescue helping remarkably in thermal management of the overall system. It ensures the intake temperatures stay near or even below ambient temps at times. This has many benefits including suppressing pre-ignition/knock due to high intake temps, incurring power losses in back to back runs and high speed WOT runs recovering your lost power.
It doesn't stop there though. With the additional octane that alcohol (methanol) provides a tune can be pushed more aggressively on both the load (boost) and ignition timing fronts. To do this safely though you must have the appropriate failsafe in place that detects any issues with flow and reacts as quickly and effectively as possible to prevent any engine damage in the case of low flow, overflow, running out of methanol in the tank. The best and the only kit we'll run and recommend on our shop/customer cars is the Aquamist HFS-4 (for direct injection motors such as the 997.2) and HFS-3 (for port injection motors such as the 997.1).
We have done a LOT of tuning with methanol injection on the BMW's direct injection platform which is basically the same as what you have on the 997.2s. Direct injection in itself raises effective octane due to superior atomization of fuel and in cylinder cooling effects that you can think of it as removing heat from the cylinder/combustion but that is a topic in itself and I'd be happy to discuss that with you guys as well if anyone's interested.
Adding methanol on top of gasoline (non-race gas high octane) will effectively raise octane levels on pump gas allowing for more ignition timing and boost, always, allowing for additional power gains to be had everywhere in the power curve over what is typically available on just a pump gas tune. We have the the Aquamist HFS-4 sitting on the shelf ready to be installed on our 997.2 once the next update from Cobb is released and we can keep pushing on.
As a final comment, nothing really comes close to properly fueling a motor like spraying from injectors. This is especially true on the direct injection setups such as the 997.2. Direct injection has some disadvantages when compared to port injection but the advantages IMHO far outweigh its disadvantages. Its main disadvantages are in that it is hard to upgrade the hardware at this time, although it has been done on a few platforms we support in various ways. However, fuel atomization is vastly superior over port injection and, if you're lucky to have E85 in your area at the pumps, it is around 105 octane on its own BUT, when direct injected at high pressures such as what the 997.2 injectors and the high pressure pump provide, effective octane raises to over 160 points!
The issue is with E85 is that ethanol burns faster than gasoline and it requires 30% more volume out of the fuel system to be supplied at the same power levels. Now this is again another topic in itself but certainly worth investigating on this platform as its been on the BMW N54 and other platforms we've been involved on over the years.So now we know that
Meth does not simply add power like NOS, but allows to rise boost and pull angles
Without knocks
#23
08-23-2014, 05:16 PM
my setup on alpha 28 and gt2rs IC's i boost 1.8-1.9bar(95%duty) timing set at 11-18 deg max with a single M15 jet 100% meth no knock!! without meth and 94 oct i boost 1.45 bar timing 9-17 deg max !
meth definitely work!!!
meth definitely work!!!
Last edited by mtlsp; 08-23-2014 at 05:25 PM.
#26
08-24-2014, 09:31 AM
Registered User
Join Date: Feb 2004
Location: Laurel Hollow NY
Age: 52
Posts: 133
Rep Power: 33 
I got my A&P license in 1989. I worked in school on ww2 or vietnam era warcraft in school. A lot of the Late ww2 or vietname planes had Alky injection for max power take off to lower knock counts and maximize power. This is a very old technology. Nothing new.
