Supercharger information

I need some information about superchargers. I want to supercharge my 1999 GMC Yukon 5.7L engine. First off, is it true that it is safe for a stock engine to have 6-9 lbs of boost? And second, does a 160 degree thermostat help prevent detonation? Your replies are appreciated.

Go to www.ls1tech.com for info on that kind of stuff.. lots of knowledge there.

Originally posted by fatninja19
Go to www.ls1tech.com for info on that kind of stuff.. lots of knowledge there.


That was a kick in the nuts for everyone here. :rolleyes:

I think this is probably the best site to go to when you want to find out what you need to do for a supercharger. I don't think 6-9 lbs of boost is ok on a stock engine, the website says around 3-4 lbs of boost.

http://www.blowerdriveservice.com/recommend.htm

Tells you everything you need to do and how it will help your engine and supercharger perform.

Originally posted by DeViL
I think this is probably the best site to go to when you want to find out what you need to do for a supercharger.


HAHAHAHAHA oh my shit...

This site has the biggest number of delinquents and idiots I've ever seen. You've no clue how much time I spend laughing at 60% of the posts made on this forum.

I think of AF as more of an Entertainment place than a Automotive Information meca. Seriously now, how often do you read something here that makes you go "hmmm, well gee golly I never knew that..."


This isnt a flame at AF at all, Im just saying... AF in general isnt the most Educated place on the Web. Startin WIF ME!

Well, you're starting with the 350 in your Yukon, right? You engine has 9:1 compression and cast pistons. I would say 3-4 psi boost would be about as much as I would push.

If you get a set of 8:1 forged pistons, 10-15 PSI shouldn't be out of the question. Add a rising rate fuel pressure regulator, and you're in business. Then you have to worry about the strength of your crank and rods. The crank should be good for it, but I wouldn't trust the rods under that level of boost.

Considering the cost of a blower, a set of pistons is not much, a couple hundred. You're basically paying $2000-$3000 for a 4 psi, or an extra $400 for 10 psi.

If you really want to get into this, get a forged crank, rods and pistons. You can get a nice 383 kit with all forged components for a bit over $2000, and coupled with the blower, you'll be making 500+ hp.

That is the direction I would run. My brother had a 94' GT, that was his dream, so live it for him!

If you really want to get into this, get a forged crank, rods and pistons. You can get a nice 383 kit with all forged components for a bit over $2000, and coupled with the blower, you'll be making 500+ hp.

How much do you think it would cost to have those pistons installed in an engine? I wouldn't have a clue how to rip apart the engine and replace the pistons.

What the fuck is your problem redneck?

No problem at all, and I stand by my statement.:)

I give him a website to check out for information and all of a sudden its humorous? I fail to see where it is.

Automotive Information meca. Seriously now, how often do you read something here that makes you go "hmmm, well gee golly I never knew that..."
Ya know there is another forum that is an information section. I would expect repetitive questions in a forum like street racing that probably gets a new person each day.

Well, now re-reading your original post I see that you were refering to the Site that you posted as being a place for information. I thought you were stating AF as the best place for knowledge on Supercharges and such things. My mistake. Whoops... but....

I was refering to AF in general, not just Street Racing. And My original statement still stands... Hope I didnt offend you.:bloated:

Yeah, man you all the sudden snapped! Reading back now it was like holy $hit! What crawled up his a$$!

We still ove ya'!

Originally posted by DeViL


How much do you think it would cost to have those pistons installed in an engine? I wouldn't have a clue how to rip apart the engine and replace the pistons.

What the fuck is your problem redneck?

Depends on what the local shop will charge you... A lot of guys will do it just for a flat of beer. It's not really that hard, you drain everything, take out the distributor, put the engine on a stand and replace the rotating mass. You'll probably have to gently remove the pistons with a 4 lb hammer ;)

This is of course a great time to replace the cam while the engine is upside down on a stand. You can buy everything as a kit and have a local speed shop build it for you.

I agree with Redneck, you get a lot of people passing through here who don't know wtf they're talking about, and I wouldn't want to take advice from them.

Like me for instance. I know about certain cars and such. The rest I leave up to the other guys.

Well, everyone's got the right to have an opinion, and we should all respect that. It's just when some people offer their opinion as fact to others, especially others who are looking for info.

I mean, what if KetteringYukon found someone who said "You can run 15 lbs of boost on that SBC, it's built by Chevy, it can take it! Better use nitrous too!". If he went and did that, and completely destroyed his engine, what then?

It's the same reason I don't recommend cams to people, I just don't know enough about timing!

... strangely enough I almost said that exact same thing... "15lbs of boost all the way... the motor will love it i swear.":D

Cams.. oh my goodness one of the easiest way to gain power is allow in more air/fuel into the combustion chamber. The wilder the cam... the more Peak HP you'll gain at the loss of low end Torque... I could explain but i'd most likely forget something important... so I'll just steal the article on Camshafts from Musclecarclub.com

Camshafts

For an engine to make more power, it has to take in more air. In most four stroke engines, the air must enter the combustion chamber through the valves. The camshaft controls the opening and closing of the valves by regulating the time that the valve is opened and closed, and how much the valve is opened by. An easy solution to have more power, would be to alter the characteristcs of the camshaft so that it either keeps the valves open for a longer period of time, or lift the valve higher off it's seat so that more air can pass into the combustion chamber. It all sounds very easy, but once again, there's more to it than meets the eye. Like most engine mods, this one is also a compromise.

In the perfect engine, the inlet valve will open when the piston is at TDC (top dead center), and as it travels down the bore, it will suck in a full charge equal to it's displacement. The exhaust valve would open at BDC (bottom dead center), and the full displacement of spent gasses would be pumped out of the engine - the perfect engine running at 100% volumetric efficiency. In practice, the stresses on the valvetrain would just be too much for the materials to handle. To lift a valve of say 50g some 10mm off it's seat in less than a millisecond (at 6000rpm) without it bouncing or doing anything untoward in the next 100,000 miles of it's life, simply doesn't work with the materials in use today. So, the manufacturers used their multi-million dollar research budgets to come up with a simple solution.

The piston travels rather slowly at TDC compared to the middle of the stroke - there's not much of the pumping action being done in the 10 or 20 degrees around TDC. So, they start to open the valve gently while the piston is still on it's way up on the exhaust stroke. Although this creates valve "overlap" (time in which both the intake and the exhaust valves are open), it does allow the engine to breathe better and create more power.

When the time that the inlet valve stays open is made longer, the overlap starts to become a problem at low engine speed. The exhaust gasses get pumped into the inlet tracts, substantially diluting the incoming charge and causing the engine to run very poor. That's why an engine with a wild camshaft runs uneven at idle - it's choking in it's own exhaust gasses. However, when the engine speed goes up, the exhaust gasses pick up momentum, and during the overlap period, the departing exhaust charge creates a partial vacuum behind it, sucking in more of the fresh intake charge.

This leads us to two important conclusions:

Firstly, the wilder the camshaft, the less power the engine will make at low rpm. Such wild engines will normally not have enough power at regular "civilized" driving speeds to pull the skin off a rotten banana. To pull away from a stop, you will have to rev it up to come "on the cam", or stall the engine at every attempt at a civilized getaway. Secondly, the engine will only produce more power at the very top of it's rev range. These are important points to consider when choosing a racy camshaft for your engine. Are you willing to sacrifice low speed drivability in exchange for more top end power? It's up to you to decide.

No, we are not against performance camshafts. We have owned several "hairy" cammed cars, and want to point out the facts to you so you won't end up wit a car you hate. Driving such a car to work every day soon starts to get on one's nerves. And if you transport passengers in your vehicle, be warned : they are usually not very sympathetic towards the neck-wrenching style of driving that such a vehicle demands to keep it "on the boil". If you do decide to go with a hairy cam, there are a few things you can do to slightly alleviate the associated low speed problems.

1. A good free-flow extractor exhaust with long primary pipes tuned to low engine speed optimisation can make the engine come on the cam a little sooner. The long 4-into-1 systems seem to be able to "pull the engine on the cam" a little sooner than the regular banana style 4-into-2-into-1 systems.

2. Long ramstacks on the intake. A ram stack are those shiny flared tubes you often see on the carburettors of high-performance engines. These artificially create a longer intake path for the air, allowing it to build up some momentum. They also have an added benefit that they can allow up to 8% more flow into the carb when compared to the usually blunt ending of the carb mouth.

3. Proper gas-flowing of the cylinder head. A lot of cylinder heads out there flow more air in the wrong direction than they can flow in the right direction. Most people who gasflow cylinder heads don't even realize that they are making it easier for the gasses to also flow well in the wrong direction! Remember that the main problem is that the exhaust gasses flow into the intake port during the increased overlap period. We can put you in touch with people who can do special things to a cylinder head so that it is difficult for the exhaust gasses to pop out through the intake port in the camshafts' overlap period. There's a whole science behind optimising the head to make it "cam-friendly", and usually there is a substantial improvement in the low speed range if the cylinder head is flowed properly, by a person who knows what directional flowing is about. Note that it is easy - even for experienced "port grinders" - to completely ruin the reverse-flow characteristics of your cylinder head.

4. Match the engine controls to the camshaft. The different profile of the camshaft plays havoc with the fuel injection's standard factory mapping. The ignition timing and mixture requirements of the engine is vastly different to that of a standard engine. The way we would recommend to do this, is to fit a UNICHIP. The engine can be run on a loading type dynamometer, and the engine management system can be reprofiled to match the specific engine's state of tune. The unichip is perfect for modified engines, because of it's ability to be reprogrammed whenever needed, i.e. if you decide to make more mod's, you simply have the unichip reprogrammed to match your new requirements. You don't have to throw it away like a conventional, old style "chip".