Choosing a twin turbo SBC kit
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Jpuckett12 (Talk | contribs) (New page: This is my first post so go easy on me, I have a 78 camaro w/355, turbo 350,, it has all forged internals, steel crank, 2.02 heads with roller rockers, 8.5:1 compression ratio. I would rea...) |
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| − | This is my first post so go easy on me, I have a 78 | + | This is my first post so go easy on me, I have a 78 Camaro w/355, turbo 350,, it has all forged internals, steel crank, 2.02 heads with roller rockers, 8.5:1 compression ratio. I would really like to put one of the kits below in the Camaro does anyone know if they are good kits or just a joke, i would also like to know if there is anything that i need but the kits do not have. I have a holley 750 carb mounted on a edelbrock performer rpm intake would those need to be upgraded too. My goal is to have 475+ hp & 430+ ft lbs I believe that it would be easy to achieve with just 6 or 7 psi on each turbo. |
| − | + | 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. 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 careful about high RPMs with a turbo, it is easy to enjoy the power, and not pay attention 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 retard 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 around 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, although 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 venturi, 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. | |
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| + | 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 relocate the carb, air filter, and reconfigure all connections to the carb. | ||
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| + | Using electronic fuel injection, will work much better though, possibly a Mega Squirt unit with a factory type throttle body injector, would be an affordable solution. Considering the modest about of power that you want though, I would consider going with nitrous oxide instead. Regarding the turbos, if you have to ask this question, you do not yet know enough about them to do the installation. It can be done by a do it yourself type person, but you have to know what you are doing. A professional install, will be very costly. Get a good book or two on turbochargers, get to really understand them and everything involved, before undertaking this. One other thing . . . using a turbo with an automatic provides additional challenges. The automatic looks at engine vacuum to determine shift points, and will be confused if it sees pressure instead of vacuum. If you connect the vacuum sense line the the vacuum side of the turbo, it will see high vacuum when the turbo is boosting, causing early up shifts. If you manage to sort all of that out, the next thing you will discover is that the boost to the engine jumps suddenly when the transmission shifts (because the engine slowed down, but the turbo did not. This puts a huge strain on the trans, so it also needs to be modified. | ||
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| + | Turbos are very fun, rewarding, and effective, but if you do not know what you are doing, they can be a very expensive experiment. Ask yourself if you can afford the turbos, all the mods, or, the expense of a destroyed motor or transmission, and the downtime that you will experience in those situations, as well as during what might be a lengthy install process. | ||
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| + | [[Category:Engine]] | ||
| + | [[Category:Undeveloped articles]] | ||
| + | [[Category:GM]] | ||
| + | [[Category:Undeveloped Engine articles]] | ||
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