I have a 1994 Chevy Silverado shortbox with a 350 5.7L V8. I have a power pulley, K&N cold air intake and headers with dual exhaust. I have been contemplating putting in an Extreme Energy Computer Controlled camshaft, XR258HR from CompCam. Do the pros of doing this outweigh any cons. My vehicle never leaves the pavement and it is half freeway driven/half street driven. I don't know if the cost($500 parts and then add for labor) warrant it as the tech at comp cam had no dyno record for this cam and said I could expect 10-20 HP but he did not know for sure. Is it worth it for that tiny of a gain? Is there something better that I can have that will not alter my trucks computer and setup? What else can I do to squeeze out more horse?
for the money i would look at a more aggresive cam. 10-20hp isn't really that much to justify it in my opinion
You didn't mention what state you're in, but if it is a smog-state, you may want to double-check with Comp to ensure it is legal. This is going to sound like a stretch, but it's been my experience that a cam on a non-Vortec 5.7L isn't going to make a huge (noticeable) difference.You'll get into the powerband faster, but as far as seat-of-the-pants, not really. Think about this... for $500 + labor ($225est), you could probably track down a used supercharger. The only down side to this is the premium fuel requirement, but the power gains will be a legitimate 50-65 Rear Wheel HP. I had a barely-used centrifugal blower kit and sold it for $1,200. If premium fuel scares you, think about a stroker build or used crate engine swap. A 383 build will gain similar power to a blower and the total cost would be under a grand. As far as a used crate engine, they're out there, you just have to look for them. Smoke some tires!!!-DAN
Dan, Thanks for your reply. The more I have thought about it, the more I have decided on just goimng with an entirely different motor. I was under the impression that my motor came stock with 250 horsepower but I have read that the 5.7 may have only had as little as 210HP back in 94. I live inLas Vegas, Nevada and yes they smog so there are legal limitatations that I am facing(seriously, what is wrong with this state?)I do have a mechanic with a smog who can "help" me in the smog area but even at that I don't think my motor can achieve the horsepower I was looking for. Someone mentioned that I may be able to bore this out to 400 but what would my horsepower be then? My brother also has a racing motor in his 84 shorty that he is considering selling as he wants to be more competitive against cars. He has a 396 with 450 Horsepower. A little excessive for the every other day driving I was looking for but it is fun. I will defenitely have to have my mechanics help on that one too as Nevada classifies that as a hotrod, special plate required, age restriction of vehicle and 2500 miles per year. The last one is the biggest joke. I would be limited to pretty much a sunday drive around town with that mileage restriction and I want to drive it more than that. Chevy had the 350 vortech and now the 325 vortech. Will the supercharger fit both of these models? There was a feature in truckin that had a charger on the chevy that took the horse to 510 and was decent for every day driving as well. I have heard some not so good things about the 325 vortech, cold knock being one of them. So if anyone out there has any ideas on what motor I should go with please send your thoughts. My motor right now is strong and runs great, just won't be able to achieve what I am looking for.
If you're talking about small-block Chevy engines, another option is higher-ratio rocker arms. It essentially multiplies the valve lift of the cam lobe without having to switch out the cam. I agree with Dan, in terms of a truly noticeable performance difference, a supercharger is probably the way to go. You can get the same amount of power with an all-motor build, but by the time you're done, you will have probably spent quite a bit more than you would have with a supercharger. I would try to find one with less than 60,000 miles on it, if possible.
Are those superchargers pretty rare? They aren't going to reduce the life of the motor are they? I am not familiar all that much with them other than I know that they are a load of instant horsepower and a huge gain in horsepower at that. I was wondering what you guys recommend for a motor should I decide to purchase a new crate motor. I would like to achieve in the area of 325-350 horsepower to have the edge on all those new stock models out there.
IN regard to superchargers affecting engine life...it's all how you drive them. If you're driving foot-to-the-floor 24/7, then yeah, it'll probably affect your engine life. But if you drive mellow most of the time and put your foot in it only 10-20 percent of the time, you'll probably be fine. Most modern supercharger systems have some sort of bypass mechanism for off-throttle driving or cruising, which means the engine is essentially operating like a normally-aspirated engine. Most bolt-on kits have relatively modest boost levels, usually between 5-7 psi. Even with a compression ratio of around 10:1, you should be OK. Once you start monkeying around with the pulley size and other things, you're kind of opening up a can of worms.
You can gain a true 5-7 horsepower by removing the stock Fan and adding an Electric fan.
Good tip. Actually, on our Diesel Power forums, I got a guy asking how to permanently engage his fan clutch, and I asked why. He seemed to think it would cool his engine off better. I recommended that he get an electric fan setup.
Thanks to both of you for responding. I have been researching alot about the intercooled supercharger and there is good information on procharger.com. I have a power pulley on my motor so I am not sure how much that would affect the charger. I will find out next week as I plan to run down to there shop and check out what would work best on my motor. It may not be worth adding it due to the mileage. I have 217,000 km on it which is approxiamte 140,000 miles. I don't want to put alot into it if all those parts are not able to work on a rebuilt or bored out motor.I don't know why they wouldn't, but I am sure you have read or know someone who has gone through the trouble of spending only to find out it was the wrong way to go about it. I am fine if I need to go with a new motor right from the get go.Do things right the first time. I have heard about the electric fan and my brother mentioned that to me should I purchase his 450 hp 396 as it will run too hot here in Vegas without it. Thanks again for shatring your knowledge. Now if only someone knew what color that blue was on that chevy in the 09 spring fling on the web exclusive photo...
The only major issue you run into with adding forced induction on a high-mileage motor is more blow-by, which can either potentially contaminate your oil, or increase oil consumption, or both. All things being equal, it's probably better to install a supercharger if the engine has under 60,000 miles, but I've seen it done on higher-mileage engines. As long as you're not constantly on the throttle with it, you should be OK, but the average lifespan on forced-induction gas engines from the factory is about 150,000 miles anyway. Just a few things to think about.
Hi there, could you give some more info on electric fan swap. I have the 4.8l gm engine in my 2003 sierra.Is it a easy job, etc. Does it alter anything for the computer?Thanks,