Proposal For Comptech S/C'ers
02-12-2002, 03:38 PM
#11
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Are there any clutch-like solutions available on the market for this type of application?? I think it would be awesome to have an S/C boost at really low RPM (below the turbo.)
Chris
Chris
02-12-2002, 08:03 PM
#12
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Nothing is commercially available to modulate boost Chris. Mercedes also uses a clutch to disable the supercharger on their 2.3 liter supercharged I4, but that's only to reduce parasitic losses on the engine when not in boost.
If you truly wanted to control boost this way, you'd need to go with a fluid coupling (or a mini CVT between the drive gear and supercharger).
Frankly, if you want a supercharger to boost at low rpm, you should dump the centrifugal blower and go positive displacement. As far as I'm concerned, in the world of forced induction, centris are a bad compromise. They're good for making big top end numbers, but they don't give you the area under the curve of a well designed turbo or positive displacement unit. Yes, PD SC's can get a little inefficient for all out hp applications, but for streetable cars, they're far more useful (and quicker) than centri apps. The reason centris are so popular with the aftermarket is that they are easy to install since you don't need to craft a new intake manifold.
UL
If you truly wanted to control boost this way, you'd need to go with a fluid coupling (or a mini CVT between the drive gear and supercharger).
Frankly, if you want a supercharger to boost at low rpm, you should dump the centrifugal blower and go positive displacement. As far as I'm concerned, in the world of forced induction, centris are a bad compromise. They're good for making big top end numbers, but they don't give you the area under the curve of a well designed turbo or positive displacement unit. Yes, PD SC's can get a little inefficient for all out hp applications, but for streetable cars, they're far more useful (and quicker) than centri apps. The reason centris are so popular with the aftermarket is that they are easy to install since you don't need to craft a new intake manifold.
UL
02-12-2002, 08:16 PM
#13
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I was told comptech had a whole rack of SC's that they tried but had problems with all but the Paxton.
This could have been about engine mangement issues.
UL, how would one go about building a whipple or eaton based system that is F20C safe. I know about the intake manifold design side. Mainly curious what sort of ecu mods would one need to try to make one work well.
I mean it should be possible right?
This could have been about engine mangement issues.
UL, how would one go about building a whipple or eaton based system that is F20C safe. I know about the intake manifold design side. Mainly curious what sort of ecu mods would one need to try to make one work well.
I mean it should be possible right?
02-13-2002, 05:03 AM
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I guess you guys mean a roots type blower when you are saying "positive displacment"?? I have never heard of that term..
How would you go about using an water/air cooler with a roots type blower??
Chris
How would you go about using an water/air cooler with a roots type blower??
Chris
02-13-2002, 06:24 AM
#18
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Yes, a roots is a PD, like the Eaton M-series.
An air-water intercooler depends on the setup. Most Eaton-based kits replace the intake manifold making an intercooler very difficult to use and custom, since it has to go between the blower and custom housing and the head. It's difficult to design a blower like this to work with one, especially if you want to make the intercooler an option. They are out there, though, as they are available for the Eaton blowers on the 3800 series GM motors.
The alternative is to design the blower to interface with the stock manifold or a custom setup (like the Comptech/Paxton setup). With a setup like that you can use a traditional air-to-air or air-water. I've seen Eaton setups with intercoolers like this, though it requires much more under-hood space than what the S2 has. I would conjecture that to incorporate an intercooler you'd have to do a custom manifold and housing and probably use a sandwich-style air-water unit.
An air-water intercooler depends on the setup. Most Eaton-based kits replace the intake manifold making an intercooler very difficult to use and custom, since it has to go between the blower and custom housing and the head. It's difficult to design a blower like this to work with one, especially if you want to make the intercooler an option. They are out there, though, as they are available for the Eaton blowers on the 3800 series GM motors.
The alternative is to design the blower to interface with the stock manifold or a custom setup (like the Comptech/Paxton setup). With a setup like that you can use a traditional air-to-air or air-water. I've seen Eaton setups with intercoolers like this, though it requires much more under-hood space than what the S2 has. I would conjecture that to incorporate an intercooler you'd have to do a custom manifold and housing and probably use a sandwich-style air-water unit.
02-13-2002, 07:11 AM
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AEM's EMS is not out yet for the S2000. The rumor is that they're still working on the stock ECU settings that will come as software with the kit. I'm not sure if they pre-load the settings, or give you a disk, but that's the piece that they're still working on for the S2000 application. You can buy a universal EMS, that would need a harness made, but it would have NO ECU settings; you'd have to figure them out yourself.
This is the key to increasing the boost, though. I'm not even going to attempt any boost upgrades until I have the EMS.
This is the key to increasing the boost, though. I'm not even going to attempt any boost upgrades until I have the EMS.
02-13-2002, 08:42 AM
#20
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Its called vaporware Harry :-)
Marcucci, MB used to use Eaton blowers and now uses IHI. Both systems use the clutch so I don't know if that's a Mercedes designed component.
In terms of intercooled Eaton systems, most OEM apps use them. Jaguar XKR, Ford Lightning, GM 3800 all use intercoolers (water to air). The problem is that the aftermarket, for whatever reason, doesn't go to the trouble to diesgn them in. Additional cost would be about $500-$750 per kit. You'd need additional space to do it, but not as much as you think. A 2"x2" core running the length of the plenum would do wonders to reduce temperatures (my CRX using an Eaton kit sees a deltaT of 150-160 F between intake air temp and discharge temp at 8 psi without any cooling system).
To effectively do a PD kit for an F20C, you'd need to go to an oversize blower. While Lysolm/whipple types are more efficient (65-70 vs. 60-65 for an Eaton), I only have specs on the Eatons so here goes (all assuming of course you have engine management taken care of).
Currently, the F20C displaces 1.0 liter per revolution. At peak volumetric efficiency (torque peak) the motor probably ingests 115-120% of that (or 1.15-1.2 liters).
To generate 6 psi of boost, you'll need approximately 40% more air by volume. That would mean 1.4-1.6 liters per revolution. In reality, because of inefficiencies, you'll need to have the blower displace a little more. Call it 1.5-1.7 liters.
If we were to select an M90 blower from Eaton, we'd get a blower that displaces 1.5 liter per rev. So, to get it to produce the boost we wanted, we'd only have to drive it at 1.1 times engine speed. This keeps peak revs on teh blower below 10k rpm. This is good, as the thermal efficiency of Eaton blowers is pretty consistent/linear below 12k rpm. Typically, between 5k and 10k rpm you'll see an additional 2-3 degrees of intake charge temp heating for each additional 1k rpm. Above 12k, that goes to 4-6 degrees or mroe per 1k rpm. At only 6 psi with an M90 you could expect to see deltaTs in the 65-75 F range. That relatively small temp gain means you wouldn't need a really big intercooler core. So, for a 1 psi pressure drop (which you'd need to compensate for in your drive ratio) you could expect a 35-45 F drop in intake temps (with ice in the reservoir it would be better of course).
Of course, since Jackson Racing has exclusive aftermarket rights to Eatons for the Honda market, you'd have to choose a different blower type, but that's not so bad. Designing a drive belt system isn't too tough, but developing a manifold isn't easy.
UL
Marcucci, MB used to use Eaton blowers and now uses IHI. Both systems use the clutch so I don't know if that's a Mercedes designed component.
In terms of intercooled Eaton systems, most OEM apps use them. Jaguar XKR, Ford Lightning, GM 3800 all use intercoolers (water to air). The problem is that the aftermarket, for whatever reason, doesn't go to the trouble to diesgn them in. Additional cost would be about $500-$750 per kit. You'd need additional space to do it, but not as much as you think. A 2"x2" core running the length of the plenum would do wonders to reduce temperatures (my CRX using an Eaton kit sees a deltaT of 150-160 F between intake air temp and discharge temp at 8 psi without any cooling system).
To effectively do a PD kit for an F20C, you'd need to go to an oversize blower. While Lysolm/whipple types are more efficient (65-70 vs. 60-65 for an Eaton), I only have specs on the Eatons so here goes (all assuming of course you have engine management taken care of).
Currently, the F20C displaces 1.0 liter per revolution. At peak volumetric efficiency (torque peak) the motor probably ingests 115-120% of that (or 1.15-1.2 liters).
To generate 6 psi of boost, you'll need approximately 40% more air by volume. That would mean 1.4-1.6 liters per revolution. In reality, because of inefficiencies, you'll need to have the blower displace a little more. Call it 1.5-1.7 liters.
If we were to select an M90 blower from Eaton, we'd get a blower that displaces 1.5 liter per rev. So, to get it to produce the boost we wanted, we'd only have to drive it at 1.1 times engine speed. This keeps peak revs on teh blower below 10k rpm. This is good, as the thermal efficiency of Eaton blowers is pretty consistent/linear below 12k rpm. Typically, between 5k and 10k rpm you'll see an additional 2-3 degrees of intake charge temp heating for each additional 1k rpm. Above 12k, that goes to 4-6 degrees or mroe per 1k rpm. At only 6 psi with an M90 you could expect to see deltaTs in the 65-75 F range. That relatively small temp gain means you wouldn't need a really big intercooler core. So, for a 1 psi pressure drop (which you'd need to compensate for in your drive ratio) you could expect a 35-45 F drop in intake temps (with ice in the reservoir it would be better of course).
Of course, since Jackson Racing has exclusive aftermarket rights to Eatons for the Honda market, you'd have to choose a different blower type, but that's not so bad. Designing a drive belt system isn't too tough, but developing a manifold isn't easy.
UL