boost questions for boost experts...
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Originally Posted by Bryan Wilkinson
Why would you make a statement like that when you know it is not true? Boost and What gas you run have absolutely nothing to do with each other.
I like how you pick apart my statement then add other vairables to strengthen yours.
Her never said anything about a cam, or any other motor work. He simply said dropping compression with 6.0L heads which should actually put him closer to 8.6-8.7:1 depending on the gaskets used and running 16psi (on an otherwise stock motor with it's normal efficiency). In that instance how am I wrong saying that unless he has the tune spot on that he isn't going to break something? Everyone knows that the tune is key and with crappy gas like 91 octane you don't have much of a cushion.
Yes, it can be done, Parish did it, I've done it for awhile on my VERY similar set up to what this guy wants to run. But rather than lead him to believe it's all peaches and he'll suffer no pitfalls I'd rather err on the side of caution and tell it like it is... On a stock 5.3L with only dropped compression you could very easily break something with that much boost (if all things are done right and he is making the power he should be for that amount of boost) and low octane.. Period.
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Originally Posted by Bryan Wilkinson
What he should have said is static compression ratio. If the static compression ratio never gets to a detonation point, then the amount of boost has no reference to his statement. My CR Ratio is 10:1. I am running 16 psi on pump gas. No knock, no detonation, no retard. Boost has nothing to do with it.
Next.........
Next.........
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Originally Posted by Bryan Wilkinson
There are two different approaches to your goal.
Option 1 lower the compression, add more boost. Not very efficient
Option 2 find a happy medium, 9.5:1, 10-16 psi, get great gas milege, awesome throttle response, great low rpm drivability is dependent on the cam, and valve timing. 99% of the time an off the shelf cam will not work for what you are doing. I have access to a program that can help you with that when you get there. Head and cam design are key to the whole thing, lowering your compression and throwing boost at it, is the 50-60's approach to making HP. And it does, but at the stress of everything under the intake. The key to making reliable power and lots of it that can be driven on the street, is do not overdrive any one part, but get each part to work 50-60% of its capability. That is where I am,
Option 1 lower the compression, add more boost. Not very efficient
Option 2 find a happy medium, 9.5:1, 10-16 psi, get great gas milege, awesome throttle response, great low rpm drivability is dependent on the cam, and valve timing. 99% of the time an off the shelf cam will not work for what you are doing. I have access to a program that can help you with that when you get there. Head and cam design are key to the whole thing, lowering your compression and throwing boost at it, is the 50-60's approach to making HP. And it does, but at the stress of everything under the intake. The key to making reliable power and lots of it that can be driven on the street, is do not overdrive any one part, but get each part to work 50-60% of its capability. That is where I am,
the 5.3L motor is already at 9.5:1 compression so im starting to like what youre saying...heh.
i think im beginning to understand what youre saying about how you can leave the intake valve open longer (i think), but wouldnt that kill throttle response, because at idle, when its not under boost, it should kill the volumetric efficiency of the engine as the piston is coming up, it will push some of the charge out of the intake valve back into the intake. now when its under boost or at higher rpms, where there will be boost anyways, i can see where it would help.
i guess i dont understand the dynamics of cams and timing that well...but id like to hear more of your suggestions.
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Originally Posted by jerrad
so your motor will make the same power at 16#s as it would at 30#s? and would make the same power on 93 octane as 110? if so why not run 0 boost on 87 octane?
the octane of a fuel basically means how fast it burns as it is a measure of the amount of unbranched alkanes to branched alkanes in the fuel. 87 burns quickest, 116 burns slowest, having the most complicated chemical structure (more branches). so i think hes saying that you could make the same power using low octane as high octane if you controlled the timing right. i.e. less advance for low octane and more advance for higher octane....i think.
what hes saying about the boost is this:
imagine blowing a gallon of air through a 2" diameter straw in 1 second, then
imagine blowing a gallon of air through a 1" diameter straw in 1 second.
the pressure in the small straw will be higher than the large straw, but they will both move the same amount of air.
i think the 0 lbs of boost thing was the wrong way to put it though because youll never have 0 lbs of boost if you expect to have more than 0 lbs of boost in the chamber. it will at least have to equal the pressure in the chamber, and if there are restrictions before the chamber (heads, intake, throttle body etc..) then your boost guage will read higher than the pressure in the cylinder.
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"what hes saying about the boost is this:
imagine blowing a gallon of air through a 2" diameter straw in 1 second, then
imagine blowing a gallon of air through a 1" diameter straw in 1 second.
the pressure in the small straw will be higher than the large straw, but they will both move the same amount of air."
ok but im saying if you have the same turbo (not a little stock vs. a huge race turbo) at 16 pounds then up the boost to 30 the one with 30 is going to be alot more powerful.
imagine blowing a gallon of air through a 2" diameter straw in 1 second, then
imagine blowing a gallon of air through a 1" diameter straw in 1 second.
the pressure in the small straw will be higher than the large straw, but they will both move the same amount of air."
ok but im saying if you have the same turbo (not a little stock vs. a huge race turbo) at 16 pounds then up the boost to 30 the one with 30 is going to be alot more powerful.
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What he is saying is perfectly correct in the ways that i understand boost. What I don't like is the way he comes across when saying it.
The problem is that you didn't mention changing anything else about the natural efficiency of your motor via cam swaps or head design so I gave my opinion on the info you gave since I was running a similar setup.
My new motor is all about getting the air in and out as efficiently as possible using much the same ways Bryan described and some of it is almost exactly how my engine builder described it which makes me even angrier that I can't agrue anything with Bryan... LOL
I don't even talk about PSI on my new setup because I honestly don't care what it is. We are going to build the motor for a turbo and just add boost.
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The problem is that you didn't mention changing anything else about the natural efficiency of your motor via cam swaps or head design so I gave my opinion on the info you gave since I was running a similar setup.
My new motor is all about getting the air in and out as efficiently as possible using much the same ways Bryan described and some of it is almost exactly how my engine builder described it which makes me even angrier that I can't agrue anything with Bryan... LOL
I don't even talk about PSI on my new setup because I honestly don't care what it is. We are going to build the motor for a turbo and just add boost.
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Originally Posted by jerrad
"what hes saying about the boost is this:
imagine blowing a gallon of air through a 2" diameter straw in 1 second, then
imagine blowing a gallon of air through a 1" diameter straw in 1 second.
the pressure in the small straw will be higher than the large straw, but they will both move the same amount of air."
ok but im saying if you have the same turbo (not a little stock vs. a huge race turbo) at 16 pounds then up the boost to 30 the one with 30 is going to be alot more powerful.
imagine blowing a gallon of air through a 2" diameter straw in 1 second, then
imagine blowing a gallon of air through a 1" diameter straw in 1 second.
the pressure in the small straw will be higher than the large straw, but they will both move the same amount of air."
ok but im saying if you have the same turbo (not a little stock vs. a huge race turbo) at 16 pounds then up the boost to 30 the one with 30 is going to be alot more powerful.
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i am curious though...why do stock turbo motors (grand nationals, turbo supras) come from the factory with low compression, like 8:1. why didnt they just adjust for this with tuning? do you know something that the car manufacturers dont know?
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Originally Posted by Bryan Wilkinson
If you have to generate 30psi of boost to make 800RWHP on a LS motor, then you went about it the wrong way, and you have a lot of work to do.
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Get off your high horse, your talking to people like a pompus *** as usual
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Originally Posted by Bryan Wilkinson
Will do, it just gets so irritating when people start throwing out information that they have no understanding of. The forum is suppose to be where people can go and get useful information and as usual what we have here is people that have absolutely no clue what they are talking about. The difference with me, is I am just blunt about it. I do not make post looking to be popular. I made the response to help shed some light on the misinformation.
I dont know how to tell someone that they continue to give bad information in a nice way. Perhaps we should set some guidelines on the forum that you cannot respond to questions, unless you have proven by fact that you understand the theories behind the question. Building an engine is not guess work.
Sorry for coming across so rude.
I dont know how to tell someone that they continue to give bad information in a nice way. Perhaps we should set some guidelines on the forum that you cannot respond to questions, unless you have proven by fact that you understand the theories behind the question. Building an engine is not guess work.
Sorry for coming across so rude.
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Originally Posted by Bryan Wilkinson
The people on this forum making stupid power, could care one rats butt about driving there car on the street or getting good gas milage, or using the stock computer or passing emissions and still making better than 800RWHP. That however was my goal.
Your very right Brian, people who come to me with wanting to make power, would also like to be able to drive their cars without hassle. I know I like my car that way also. I also care about gas milage and smog because my shop is in the good old california with crap *** 91 octane.
I can also say I follow alot of the same theory that you do as well. One of our cars I am proud of is a little 370 CID iron block I builts, heads/cam, D1SC blower seeing about 12-13 psi on the gauge right now, long tubes, high flow cats, fuel system, ect.... Puts down almost 700RWHP and just under 600TQ. It passed smog the following weekend as well on the same tune. 9.1 static CR inthe motor, about 22-20* of timing in certain areas. So at this point we are pushing the limits of the stock MAF, or we could be making more if we awere not. 91 octane, no booster added. So not too shabby.
Its all in the heads and the cam. I think I could get more out of the cam though, it was my first cam choice to start on thie setup, 224/232 116LSA, .558/.568. Heads are almost at 90% intake to exhaust ratio. I had them hog the crap out of the exhaust, I didnt care about intake.
And the guy daily drives it every single day for the past year so far.
I would say though at 800 plus, ditching the maf is a good choice with boost because it just becomes a pain to work around.
Rick
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Originally Posted by Bryan Wilkinson
Rick,
91 Octane..........You da man. proving the point once again. My MAF quits working at 4200RPM. So the HPTuners 2 Bar setup was the one route to go. For now I am just going to stick with it. Today I am two lbs over the 2 bar limit, but I am hoping with the new heads coming out, that the boost will drop, and power will go up. We will see.
Thank you for your comments it is refreshing to see that other people can step out of the box.
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Thank you for your comments it is refreshing to see that other people can step out of the box.
Rick
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Originally Posted by Bryan Wilkinson
Power is all about controlling heat in the combustion chamber. 110 is used to reduce that heat. You can do the same by adding fuel through the pcm, and adjusting the timing.
Originally Posted by Bryan Wilkinson
Race gas is a crutch for those who do not understand how to tune a car.
Remember Marko's Supra that put down 1500whp? They disabled the WG and maxed out the 6-bar MAP sensor in the process. Not effecient at all, but hey it worked for 2 dyno pulls (the 2nd pull cracked the block).
Cars with tough motors that operate on their knock limit on pump gas can see large gains with just a few points more octane. Supras, Evos, etc. on 93 octane generally gain 2-4 mph just by mixing in a few gallons of good gas, and letting the ECU figure out the timing. Is running sub-optimal timing at 19 psi as effecient as running full timing at 16 psi? No. Does it make more power? Yes. Unfortunately 2JZ and 4G63 pistons are crap, and don't really work with the quench on the head. So your car with flattop pistons and tons of quenc might be different. I am also told its easier to get swirl with a 2-valve head, but I don't have any experience with head design.
Power is about cylinder pressure at the right time in the compression and power strokes. To get more cylinder pressure, you need more air/fuel flow. You can get this with a poor flowing head/cam with more boost or a better flowing head and less boost. I agree the better flowing head is going to have more det resistance at the same power level, since there will be less heat (boost) in the intake charge, and less residual exhaust left over in the chamber (as it will probably have a better intake/exhaust presure ratio). But I don't think the difference is going to be dramatic. I am speaking from experience with my and my friends' Supras. Mine went from stock turbos with a horrible pressure ratio to a T66 with a pressure ratio of ~1:1 at most RPMs and 19 psi.
Sorry to be rude, but I think your completely incorrect.
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Sadly, the Pump Gas Drags is not to me LS1 friendly. Any guy with a 540ci BBC and a turbo setup will put us on the trailer. John Cunningham (I have met him) went low 9's on just HP with a 540ci with I think Big Chief heads.
Going for 900rwhp with an F1R, 93 pump gas, 22 degrees of timing, with a 10:1 block and 75 lb injectors sounds like it's going to break at some point.
Going for 900rwhp with an F1R, 93 pump gas, 22 degrees of timing, with a 10:1 block and 75 lb injectors sounds like it's going to break at some point.
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Originally Posted by Bryan Wilkinson
As I promised PurEvl, Grant, every one is entitled to an opinion. even you. Sorry PurEvl, I cant resist.....Grant, When you make the power that I do, then you can challenge me on theroy...Sorry about that comment, I am working on my delivery.
Dont come into this GM forum and start throwing around tuner crap, WE DONT CARE. Sorry again PurEvl....I love you man!!!!!
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Originally Posted by Bryan Wilkinson
As I promised PurEvl, Grant, every one is entitled to an opinion. even you. Sorry PurEvl, I cant resist.....Grant, When you make the power that I do, then you can challenge me on theroy...Sorry about that comment, I am working on my delivery.
Dont come into this GM forum and start throwing around tuner crap, WE DONT CARE. Sorry again PurEvl....I love you man!!!!!
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Originally Posted by Grant B
This isn't true. Look up the combustion energy of different octane gasolines, they are virtually the same. Octane is a measure of detonation resistance, and THATS ALL. It does not necissarly mean the gas burns slower, or burns cooler (although it can, like ethanol and methanol).
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While I know that my statements regarding MY OPINION of PUREVL and Brian W may instigate, I want them to know that I respect them because they are two of the few that are trying to advance the LS1 sport. Please don't take it personally that I don't share most of your views, I still respect the effort. Thanks!
SC-