[Travis Q]

Here's some additional thoughts....

The power is going to be vastly easier to make with a turbocharged powerplant. Also, it will be a bunch easier on parts at this power level than a comparable ProCharger engine. The key to the whole deal is converter and gear ratios....everyone wants to put in a mega-tight converter to throw up a big MPH number, but a looser converter is easier to stage and will be more consistent on average tracks. The turbo combination can indeed be consistent; it's all about consistent boost control, as a small change in boost can equate to a big change in power/ET.

The downside to the turbo option is cost and complexity of the system. The Procharger powerplant is much easier to drive and easier to make consistent, without a doubt.

The Procharger system itself is also a little less expensive up front due to the lack of custom exhaust work.

The downside of the Procharger combination is that it takes a lot better engine components to make the power and have any sort of durability. A billet crank is mandatory, as are top of the line cylinder heads. A very good blower bracket system is necessary (5/8 and 3/4 thick brackets with 1" stands and B7 grade 7/16" studs are a must), as is a built-in crank support if a belt driven system is used (this will need to be incorporated into the blower brackets, as systems compatible with Roots/screw blowers won't work with a Procharger). You're also going to spin the engine a touch higher with a blower to make the combination happy, due to the camshaft profiles and converters used in these combinations.All this translates into more money on the engine side and more overall maintenance cost.

So, the question then becomes one of drivability, ease of tuning, overall cost, and maintenance levels.

The turbocharged combination, overall, is less expensive to build and to maintain.

The Procharged system, overall, is less of a hassle to tune and race.

Also, the cost of both total engine/power adder packages is pretty similar. For 2000 hp, you can expect to spend around $40-45K for the engine and its corresponting blower/turbo components. There will undoubtedly be those who will say "so-and-so did it for a lot less", but I can guarantee you that it's not going to be an apples to apples comparison. 2000 reliable, consistent HP out of a Pontiac with a blower or a turbo isn't going to be cheap. Can you make that power for less money? Sure. Is it going to run sixes at 2700 lb on every hit, on every track and be all-season-long reliable? Nope.

[bryansMtngto]

Originally Posted by Travis Q

Here's some additional thoughts....

The power is going to be vastly easier to make with a turbocharged powerplant. Also, it will be a bunch easier on parts at this power level than a comparable ProCharger engine. The key to the whole deal is converter and gear ratios....everyone wants to put in a mega-tight converter to throw up a big MPH number, but a looser converter is easier to stage and will be more consistent on average tracks. The turbo combination can indeed be consistent; it's all about consistent boost control, as a small change in boost can equate to a big change in power/ET.

The downside to the turbo option is cost and complexity of the system. The Procharger powerplant is much easier to drive and easier to make consistent, without a doubt.

The Procharger system itself is also a little less expensive up front due to the lack of custom exhaust work.

The downside of the Procharger combination is that it takes a lot better engine components to make the power and have any sort of durability. A billet crank is mandatory, as are top of the line cylinder heads. A very good blower bracket system is necessary (5/8 and 3/4 thick brackets with 1" stands and B7 grade 7/16" studs are a must), as is a built-in crank support if a belt driven system is used (this will need to be incorporated into the blower brackets, as systems compatible with Roots/screw blowers won't work with a Procharger). You're also going to spin the engine a touch higher with a blower to make the combination happy, due to the camshaft profiles and converters used in these combinations.All this translates into more money on the engine side and more overall maintenance cost.

So, the question then becomes one of drivability, ease of tuning, overall cost, and maintenance levels.

The turbocharged combination, overall, is less expensive to build and to maintain.

The Procharged system, overall, is less of a hassle to tune and race.

Also, the cost of both total engine/power adder packages is pretty similar. For 2000 hp, you can expect to spend around $40-45K for the engine and its corresponting blower/turbo components. There will undoubtedly be those who will say "so-and-so did it for a lot less", but I can guarantee you that it's not going to be an apples to apples comparison. 2000 reliable, consistent HP out of a Pontiac with a blower or a turbo isn't going to be cheap. Can you make that power for less money? Sure. Is it going to run sixes at 2700 lb on every hit, on every track and be all-season-long reliable? Nope.

I agree with what your saying Travis. Since hes talking about TS racing. Which is still Bracket Racing. I think At this time The blower cars are alittle easier to keep consistant. But either way it takes time and $$$ to get either combo figured out. So its really the persons preferance on which way to go. I like both combinations. WOuld love to be able ot afford 2 cars 1 of each ;-)

[jdw_poncho]

Originally Posted by Travis Q

Here's some additional thoughts....

For 2000 hp, you can expect to spend around $40-45K for the engine and its corresponting blower/turbo components. There will undoubtedly be those who will say "so-and-so did it for a lot less", but I can guarantee you that it's not going to be an apples to apples comparison. 2000 reliable, consistent HP out of a Pontiac with a blower or a turbo isn't going to be cheap. Can you make that power for less money? Sure. Is it going to run sixes at 2700 lb on every hit, on every track and be all-season-long reliable? Nope.

Just to add to Travis' comments, Here's my story...

$34K (includes turbos and fuel system) for the first engine with a home built set of headers, used EFI and the a set of junk e-heads. Rest of the parts are top of the line. Beg for all of the free data I can get, spend lots more money on a dyno, hurt the junk heads and still dont reach 2000hp.

Fast forward to today - Add another 11K for new heads, headers, intake, throttle body and cold side tubing all of which I will build myself.

Add another $2700 for a new EFI system, $4700-$6100 for injectors, and figure $2000 in AN fittings, hoses and various small parts.

Now after thats done add another $7000 for a trans, converter, cooler, and driveshaft.

And I still havent seen it make 2000hp or even know if I can make it reliable..... LOL!! (I'll get there this year...)

If I had any sense 2 years ago or would have listen to people I would have still spend $50K building the engine.

Your car is looking good, good luck with the build.

[Travis Q]

More on backpressure (its time for a coffee break this morning, I'm dragging).....

To boil it down why backpressure is important in a drag racing application, it all has to do with max engine speed. In nearly any drag racing scenario, engine speed allows for a greater window with converter or clutch tuning, and equates to more power strokes per second. If you have two engines that make the SAME peak/average power, but one does so at 1000 higher rpm, and the race car is geared to take advantage of that additional rpm, that will be the faster car, even though the power number is the SAME.

A turbocharged engine with a high backpressure number can make the exact same power number that one with very low backpressure can. It can make the same average power over its operating range that a low backpressure engine can over its operating range. The difference is what that operating range is! High backpressure forces you to run a camshaft with very little overlap. Small overlap numbers means that the engine isn't going to rev. Also, high backpressure applications (like street cars) are not overly sensitive to valve timing events, since the cams are already so small. You can put nearly anything in it, and so long as the overlap isn't too crazy, it will run just fine.

Low overlap engines act a lot more like a NA engine, because there starts to be a small amount of scavenging on the overlap cycle. So these engines can sometimes be a lot more picky about camshafts.

The bottom line is that for the typical drag race engine, it's not worth losing sleep over backpressure, because most guys don't really want to spin their engines over 8000 rpm anyway, or don't have the components to take advantage of it if they did. The gains from reducing backpressure aren't going to come from a huge gain in horsepower; they are going to come from the additional engine speed afforded by a low backpressure combination. And for a typical T/S application, a high backpressure combination may not be all bad....a high backpressure combination is usually one that has a very responsive turbo combination, which means that it will be really easy to get the turbos to follow the boost controller.