Choosing a twin turbo SBC kit
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New Contibution. I do not think that there are any poorly made turbochargers, though some obviously are better that others by design features. Variable exhaust housing vanes, water cooled center sections, ball bearings etc, are all features that you will pay more for. I did not look at the kits in question, but I have seen a lot of them on ebay. Some are great values, in terms of what you get for the money, but that has little to do with suitability for your application. | New Contibution. I do not think that there are any poorly made turbochargers, though some obviously are better that others by design features. Variable exhaust housing vanes, water cooled center sections, ball bearings etc, are all features that you will pay more for. I did not look at the kits in question, but I have seen a lot of them on ebay. Some are great values, in terms of what you get for the money, but that has little to do with suitability for your application. | ||
| − | The most important thing will be matching the turbo size on both the compressor and exhaust turbine sections, as well as the exhaust housing. Your goal of 475/430 are easily within reach, even with a single turbo. The advantage of a dual turbo arrangement is primarily one of getting to use smaller turbos, which will spool up quicker, less lag until boost. | + | The most important thing will be matching the turbo size on both the compressor and exhaust turbine sections, as well as the exhaust housing. Your goal of 475/430 are easily within reach, even with a single turbo. However, you won't likely get that with 6 or 7 pounds of boost, unless your engine as it sits now, is producing over 320 H.P. The advantage of a dual turbo arrangement is primarily one of getting to use smaller turbos, which will spool up quicker, less lag until boost. Be very carefull about high RPMs with a turbo, it is easy to enjoy the power, and not pay attentio to the tachometer. RPMS are way more destructive to an engine than boost is usually, so design for more torque at lower rpm to get your power, that is what turbos are great at. However, be aware that as boost goes up, so does you octane requirement and or need for intercooling, timing retart control, water injection, or some other way to suppress detonation. These items probably are not included in the kits you are looking at. At boosts aroung 7 PSI, don't waste you time and money on intercoolers, control detonation some other way. |
| − | You do not need to change your intake manifold. The carburetor will work as well. However, if you leave the carburetor on the intake manifold, you will need to make some modifications to it. Blowing pressurized air into the venturis, fights the flow of fuel into them. A way around this, is to put the carburetor inside a box, and pressurize the box, that way, the fuel in the fuel bowl is also pressurized, and balance is restored. However, you should then also, install foam floats, if you do not already have them, or the hollow brass floats may collapse under the pressure. Obviously, you need to figure out how to keep the throttle linkage and fuel line entrances from leaking air. | + | You do not need to change your intake manifold. The carburetor will work as well, allthough it would probably work a bit better if it were smaller. Unless you are running this engine at 10,000 RPM, this carb size is overkill, and hurts your low end performance without improving your high end performance. However, if you leave the carburetor on the intake manifold, you will need to make some modifications to it. Blowing pressurized air into the venturis, fights the flow of fuel into them. A way around this, is to put the carburetor inside a box, and pressurize the box, that way, the fuel in the fuel bowl is also pressurized, and balance is restored. However, you should then also, install foam floats, if you do not already have them, or the hollow brass floats may collapse under the pressure. Obviously, you need to figure out how to keep the throttle linkage and fuel line entrances from leaking air. |
Alternatively, you can mount the carburetor upstream, and have the turbo(s) suck air through it. This way, you can leave the carb relatively unmodified (rejetting would be a good idea) but you will have to reloacate the carb, airfilter, and reconfigure all connections to the carb. | Alternatively, you can mount the carburetor upstream, and have the turbo(s) suck air through it. This way, you can leave the carb relatively unmodified (rejetting would be a good idea) but you will have to reloacate the carb, airfilter, and reconfigure all connections to the carb. | ||
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