super or turbo

[Mr. Wyndham]

So the twin-screw type...(Which is basically a much more effecient roots-style) But nobody mentions it...so can I assume that its operation, like recerculation is usually the same deal as roots?

[MerF]

Yup. Essentially a plug-and-play (after tuning the engine of course).

[TFord]

Originally Posted by MerF

The cylinders won't even feel the effects of pinging. The damage is done on the head, piston, and rotating assembly. Of course, when any of these three fail, the effects will be that something goes sideways instead of up and down, and THAT'S when the cylinders get hosed.

well I was trying to keep it short...but MerF I do totally disagree with you on what I got quoted. detonation even on a naturally aspirated vehicle wears down the cylinder wall. I had to pull out the TECH MANUAL on ya!

The fuel/air mixture is normally ignited slightly before the point of maximum compression to allow a small time for the flame-front of the burning fuel to expand throughout the mixture so that maximum pressure occurs at the optimum point. The flame-front moves at roughly 33.5 m/second (110 feet/second) during normal combustion. It is only when the remaining unburned mixture is heated and pressurized by the advancing flame front for a certain length of time that the detonation occurs. It is caused by an instantaneous ignition of the remaining fuel/air mixture in the form of an explosion. The cylinder pressure rises dramatically beyond its design limits and if allowed to persist detonation will damage or destroy engine parts.

A non conventional engine that makes use of detonation to improve efficiency and decrease pollutants is the Bourke engine.

Detonation can be prevented by:

The use of a fuel with higher octane rating
The addition of octane-increasing "lead", methylcyclopentadienyl manganese tricarbonyl (MMT), isooctane, or other antiknock agents.
Increasing the amount of fuel injected/inducted (resulting in lower Air to Fuel Ratio)
Reduction of cylinder pressure by increasing the engine revolutions (lower gear), decreasing the manifold pressure (throttle opening) or reducing the load on the engine, or any combination.
Reduction of charge (in-cylinder) temperatures (such as through cooling, water injection or compression ratio reduction).
Retardation of spark plug ignition.
Improved combustion chamber design that concentrates mixture near the spark plug and generates high turbulence to promote fast even burning.
Use of a spark plug of colder heat range in cases where the spark plug insulator has become a source of pre-ignition leading to detonation.
Correct ignition timing is essential for optimum engine performance and fuel efficiency. Modern automotive and small-boat engines have sensors that can detect knock and retard (delay) the ignition (spark plug firing) to prevent it, allowing engines to safely use petrol of below-design octane rating, with the consequence of reduced power and efficiency.

A knock sensor consists of a small piezoelectric microphone, on the engine block, connected to the engine's ECU. Spectral analysis is used to detect the trademark frequency produced by detonation at various RPM. When detonation is detected the ignition timing is retarded, reducing the knocking and protecting the engine. See also Automatic Performance Control (APC).


Consequences of Knocking
Engine knocking has disastrous consequences for the engine, since it leads to the catastrophical wear of the combustion chamber walls, through particle wear for moderate knocking, to welding for serious knocking. This is due to the contact between those walls and high temperature gases resulting from the unwanted explosion. The processes also lead to a 'knocking' noise for the engine, that give its name to the phenomenon.

[twigg107]

lol right out of the textbooks.

Back on topic.... comparing superchargers and turbos is like comparing apples and oranges. Normal off the shelf superchargers dont past 10-12psi but they put that power to the ground were its needed, low rpms. This is great for v-8's sense they mostly dont rev too high unless the whole engine is built right.

Turbochargers are generally more expensive for pre-fabbed kits but if you know what your doing and build your own kit or already own a vehicle with a turbo from factory, its pretty cheap to go bigger. Also turbos can come in different sizes like different sized exhaust housings, inlet sizes, and turbine wheels. But the bigger you go, the more lag or time to build boost takes longer. Ive worked on some subaru sti's that dont build peek boost until after 5500rpms but are generally dyno queens throwing down 800+hp. Very undrivable on the street.

I personally having tons of fun with turbos cause I own a 05 subaru STi. btw Iam a chevy guy by heart though.... I have a 03 siverado 2500hd, 69 C-10, 67 camaro ss (building from ground up), and a 37 chevy sedan sitting on the side of my shop rusting in the weeds.

[Mr. Wyndham]

Originally Posted by twigg107

lol right out of the textbooks.

Back on topic.... comparing superchargers and turbos is like comparing apples and oranges. Normal off the shelf superchargers dont past 10-12psi but they put that power to the ground were its needed, low rpms. This is great for v-8's sense they mostly dont rev too high unless the whole engine is built right.

I kinda began to guess this, after reading all of everbody's posts... I'm sold on a supercharger - that's what I'll be getting, however, I want to install it on my own. and I'll probably go roots, but from what I've read so far in this thread, their not good in the high 5000+ rpm range, is this true?

Which is why I won't get a centrifugal supercharger: too many negatives, but I just want to make sure I don't desroy my car - that's why I keep asking these questions.
I've learned a lot so far. but untill I get under the hood and start doing stuff, it's all speculation, and textbook readings bouncing around in my head right now.

[TFord]

roots blowers give you a significant increase throughout the whole power curve...which is what I like about them, the blower for the 350Z makes that little car feel like a freakin vette off of the line.

oh yeah... welcome twigg107. wow Its nice to see how many gearheads we got here. we need to open up a shop or something...lol

[twigg107]

What kind of car do you plan on doing this too. root style chargers are a simple in design and more cost efficient. Generally most off the shelf kits generate peek tq and around 2k rpm give or take. :/

any stock motor will have a shorter life span with boost. So if you want to get the most life out of your motor.... no boost it. This is kind of subjective though.... I mean, if its properly built motor and good tune. There shouldnt be any problems. Really, you should be preping the motor to handle the boost first.

[Mr. Wyndham]

That would be awsome...

"So, how did you decide you wanted to open your own shop?"

"A Camaro forum..."



Oh, so the roots-style isn't bad at all then. Okay - made my decision a little easier. Now I want to learn about boost. What's the general rule with roots-style boost - i think I heard for every pound of boost add 20 hp...is that right?

[twigg107]

Originally Posted by TFord

roots blowers give you a significant increase throughout the whole power curve...which is what I like about them, the blower for the 350Z makes that little car feel like a freakin vette off of the line.

oh yeah... welcome twigg107. wow Its nice to see how many gearheads we got here. we need to open up a shop or something...lol

Thanks for the welcome. Those 350z's are nuts with a blower!! I have a VQ35 motor sitting in my shop with a bent rod because it was boosted. :eek:

I have a shop that builds highend import motors..... our buisness partner has been building race engines for 35 years and wanted to get into the import market. Its amazing to have someone around to show you all the little tricks to build crazy motors!!!

BTW we cant wait for the new camaro to come out...... can we say turbocharger!!!!

[TFord]

hell yeah...twigg send me some pics of that build up. Ive been patienty waiting on the camaro too. Ill be getting all the parts to build up and blow my camaro after that warranty expires. Dragoneye I wish I could open a shop, but being active duty I spend half the year underwater. Believe it or not I knew very little about cars 3 years ago. got tired of the mechanics down here overpricing everything so I decided that I was gonna learn to do it myself. hell I work on missiles for a living couldent be that much different right...lol

[Mr. Wyndham]

I'm right with you on the 3 years thing, more like 5 for me though. But It's amazing how simple some of this stuff is once you get to understanding it!

missiles, huh. strap a few to the sides of the Camaro...lol, then you'll beat EVERYTHING on the 1/4 mile

[twigg107]

Originally Posted by TFord

hell yeah...twigg send me some pics of that build up. Ive been patienty waiting on the camaro too. Ill be getting all the parts to build up and blow my camaro after that warranty expires. Dragoneye I wish I could open a shop, but being active duty I spend half the year underwater. Believe it or not I knew very little about cars 3 years ago. got tired of the mechanics down here overpricing everything so I decided that I was gonna learn to do it myself. hell I work on missiles for a living couldent be that much different right...lol

Warranty.... whats that!!!! navy Iam guessing.... did several years as a army infantryman aka bulletstopper.

Its all about wanting and appling yourself to learn, Iam the first one to admit that I dont know everything about cars. Iam very very lucking being 26 years old and having people around me that knows sooooo much about cars.

[Mr. Wyndham]

Its all about wanting and appling yourself to learn, Iam the first one to admit that I dont know everything about cars. Iam very very lucking being 26 years old and having people around me that knows sooooo much about cars.

Right Amen to That!

[Mr. Wyndham]

Originally Posted by MerF

Yup. Essentially a plug-and-play (after tuning the engine of course).

I just saw this statement...what do you mean by "engine tuning"? i assume it's not just bolt 'n drive, huh?