Anyone got a good link as to where i can find basic info about supercharging a vehicle? I wanna add a supercharger to my L98 but want to know what other supporting mods are needed. Tuning, fuel injectors ect....


Overall just want to know what im getting into before I start the project...

 

The first thing you want to do is to determine how much horsepower you are shooting for, as well as how much RPM your engine is going to be seeing. This will help you to be able to size up the supercharger in conjunction with the camshaft characteristics needed with your cylinder head flow, and more importantly, the injectors you will need. One thing to note when selecting a camshaft with a supercharger is having too much overlap, you do not want too much overlap because the boost will essentially "leak" right out of the exhaust with both valves slightly opened keeping boost pressure down. Turbo's can get away with that and actually use that to their advantage, but superchargers obviously can't. You will also want a free flowing exhaust so the engine can spin with no restriction. I myself like to wait and get the engine dynoed before selecting a stall speed, which you will definitely want to take advantage of if running an automatic tranny...

There is really nothing special about tuning. Pump gas, E85, Hydrogen, etc, all have a targeted stoichiometric (air/fuel) ratio, and whether naturally aspirated or boosted, we need to keep that ratio where it belongs. As engine RPM rises, the air being taken in is already a given, we cannot control that, we can only compensate for it with additional fuel, maintaining that air/fuel ratio for the perfect burn. We tend to provide a tad more fuel than air at part throttle to keep the engine from leaning out, because less fuel in the combustion chambers will cause more heat, and heat will of course increase the chances of detonation, and detonation causes broken pistons, rods and even cranks. With boosted applications, we will target an even richer air/fuel ratio at full throttle to allow for the fuel to keep combustion temperatures down during quench, because if I told you how hot it gets in there during quench you wouldn't believe me. So, when using pump gas, you will have a target air/fuel ratio of 14.7 (it's a little less now, numerically, due to the ethanol added into the fuel being used) for complete combustion. This is where you will want to be at idle, although some will run a little leaner during idle to save on fuel consumption, because at lower RPM's there is really no threat of running a little hotter. As RPM increases though, more air is entering into the combustion chambers, which will of course raise your air/fuel ratio (numerically) above your air/fuel target, which you then need to compensate for with fuel, otherwise you will be lean. We compensate in a number of ways, we can increase fuel pressure and adjust injector pulse width, or we can run a boost referenced regulator if need be, as the ratio in a boost referenced regulator can be dialed in to stay proportional to the amount of additional air being forced into the engine. At this point we will dial in our spark advance, and just how much will depend on the cylinder heads you are using as well as the type of fuel you are burning, as some burn hotter, and some burn cooler. With the right software, we can dial all of this in, and it takes time to see what the engine likes, because all engine combinations are different, many variables. Hope this helps you get an idea of just some of the things you need to pay attention to...

 

the engine is already built, it uses a crane 2032 cam... has shorty headers and 3" exhaust all the way back

 

What is your desired horsepower number, what is your static compression...?

 

well its a rebuilt stock L98 bottom end, TPIS big mouth intake, crane 2032 cam, ported plenum, ported slp runner, stock throttle body. stock compression should be 9.3:1. Looking to make about 350 hp to the wheels to be a low 12 second car

 

The overlap for the Crane 2032 camshaft is 49º, I would either run another camshaft for the supercharger application, or if you are set on that camshaft, consider a turbo charger instead. Your static compression is actually perfect for a boosted application in my opinion, as your goal of 350 horsepower to the wheels would essentially be accomplished at under 15 pounds of boost pressure...

 

Any idea what the motor is making NA??

 

no idea, i can tell ya it will go 0-60 in 5.8-6.2 seconds pretty consistant.... im sure a tune would help me

 

how about nitrous? how safe is it really?

 

extremely safe. All depends how much you shot for compared to how stock you are. A stock motor can take a 100 shot all day long, for 100k miles.

nitrous is just added air, same as a turbo or SC. It just gets added chemically instead of mechanically. More air, add more fuel and you are safe.

 

yeah those nitrous explosions on you tube make me worried about blowing up the car tho...

 

Good information street lethal.

 

insomniac - Since we are talking online I can't tell if you are seriouse or joking around...

Please be joking. Do you understand that 85% of the public is no smarter than a 5th grader? That is why you see crazy stuff on the internet. If you follow the instructions which is run a little rich on the juice, your car is perfectly safe, if not safer than with a turbo or a blower.

I am not sure what else to say....

 

wish i was but no i wasnt. i have no experience with nos, turbo, and blowers... just looking to get into it


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