1 3/4 or 1 7/8 headers??
Team Owner
Joined: Mar 2005
Posts: 20,933
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From: salem OR
Seriously, you are not arguing with me, you are arguing with basic science. Boost is the resultant pressure you can not push through your engine, it is NOT an indication of power . If you do something to the exhaust and boost goes up, you have increased exhaust restriction. You CAN argue with that, but you will be just proving that you don't understand how forced induction works by doing so 
Edit: And because you LOVE to argue, even when you are completely wrong, I am going to offer you someone else to argue with.
Meet A. Graham Bell. He wrote the book "Forced Induction Performance Tuning", arguably the best book on forced induction out there right now.
Chapter 14, page 217:
"Many enthusiasts, and even some tuners, have got the idea that the basis for improved performance from a forced induction engine is more boost pressure. However, this is false reasoning. Consider for a moment the CART champ cars in the USA. The purpose built 8-cylinder race engines are restricted to a capacity of 2.65 litres and a single turbo pushing a maximum of about 3 1/2 psi boost [...] Obviously, it is not as a result of massive boost pressures, but rather because the inlet and exhaust systems and cylinder heads flow efficiently, consequently encouraging good flow into and out of the cylinders...
Don't ever think that you can beat flow restrictions simply by upping the boost, and likewise don't ever think that increased boost pressures are the key to improved performance. Just take a look at your garden hose for proof of what I am saying. With the tap opened right up and the nozzle on the garden hose closed down, pressure in the hose is high, but water flow from the nozzle is dismal, or even non existent. Opening the nozzle will drop pressure in the hose right down, but flow from the nozzle improves. Getting rid of flow restrictions will have a similar effect on any engine"
Corky Bell, author of "Maximum Boost" and "Supercharged!" agrees. As does Earl Davis, from "Supercharging, Turbocharging & Nitrous Oxide".
From Davis' book intro, page 15:
"Improving the efficiency of the engine will cause the residual pressure (boost) to decrease. Remember, the output of a blower is somewhat fixed. The blower still pumps the same volume of air, even though the amount of residual pressure (boost) went down. It is worth remembering: Boost is residual pressure, not an indication of results"
Google their names so you can e-mail them and request changes to any upcoming editions of their books if you STILL think I am wrong. I am not arguing over this any more, it is getting ridiculous. Do I need to quote more books? Would you like me to dyno my car with a plug on 3exhaust tips and show you a before and after where the plugged up tips show more boost and less power? How about a dyno of a supercharged car before and after headers being installed, showing a drop in boost and an increase in pressure? The ONLY time an increase in boost translates into extra horsepower, is if your boost is going up because you are driving the supercharger harder. Since you never replaced pulleys, that is not the case.
Or how about you just realize that we are talking about some REALLY SIMPLE, REALLY BASIC concept here that can be argued with as sucessfully as you could argue against newton's first and second laws of motion?
Edit: And because you LOVE to argue, even when you are completely wrong, I am going to offer you someone else to argue with.
Meet A. Graham Bell. He wrote the book "Forced Induction Performance Tuning", arguably the best book on forced induction out there right now.
Chapter 14, page 217:
"Many enthusiasts, and even some tuners, have got the idea that the basis for improved performance from a forced induction engine is more boost pressure. However, this is false reasoning. Consider for a moment the CART champ cars in the USA. The purpose built 8-cylinder race engines are restricted to a capacity of 2.65 litres and a single turbo pushing a maximum of about 3 1/2 psi boost [...] Obviously, it is not as a result of massive boost pressures, but rather because the inlet and exhaust systems and cylinder heads flow efficiently, consequently encouraging good flow into and out of the cylinders...
Don't ever think that you can beat flow restrictions simply by upping the boost, and likewise don't ever think that increased boost pressures are the key to improved performance. Just take a look at your garden hose for proof of what I am saying. With the tap opened right up and the nozzle on the garden hose closed down, pressure in the hose is high, but water flow from the nozzle is dismal, or even non existent. Opening the nozzle will drop pressure in the hose right down, but flow from the nozzle improves. Getting rid of flow restrictions will have a similar effect on any engine"
Corky Bell, author of "Maximum Boost" and "Supercharged!" agrees. As does Earl Davis, from "Supercharging, Turbocharging & Nitrous Oxide".
From Davis' book intro, page 15:
"Improving the efficiency of the engine will cause the residual pressure (boost) to decrease. Remember, the output of a blower is somewhat fixed. The blower still pumps the same volume of air, even though the amount of residual pressure (boost) went down. It is worth remembering: Boost is residual pressure, not an indication of results"
Google their names so you can e-mail them and request changes to any upcoming editions of their books if you STILL think I am wrong. I am not arguing over this any more, it is getting ridiculous. Do I need to quote more books? Would you like me to dyno my car with a plug on 3exhaust tips and show you a before and after where the plugged up tips show more boost and less power? How about a dyno of a supercharged car before and after headers being installed, showing a drop in boost and an increase in pressure? The ONLY time an increase in boost translates into extra horsepower, is if your boost is going up because you are driving the supercharger harder. Since you never replaced pulleys, that is not the case.
Or how about you just realize that we are talking about some REALLY SIMPLE, REALLY BASIC concept here that can be argued with as sucessfully as you could argue against newton's first and second laws of motion?
reducing tubing size to all 3 inch. Not even reading your post!
The rubber 90's in Andy's kit are hurting your boost! Having all
3 inch EVEN turns and the same size. Those rubber elbows are 3 and and 1/8 inch turns. Reducing size on all turns. Your front turn right now to your intercooler is about half open.
Through the whole tract
I have Lamiar flow. Something that make my intake charge fill
alot better. Than your yours Something you must not know about! Thats why instead of losing a pound with the larger
exhaust. I gained 2 psi making the one back from from the larger exhaust! You can argue all day! I have the proof with the results!
Don't insult me either! I don't do that to you and we are friends! I have found more hp and could make a 620 rwhp550 rwtq on any dyno! With no tuning!
There are posts from Turbo guys running hard pipe instead of corragated flex tube and gaining boost.
Thats for dam sure! So if it wasn't my changes, where I had My big gains I suppose you think it was all tune by the way you act?
Last edited by 3 Z06ZR1; Apr 20, 2009 at 03:01 AM.
Pro
Joined: Sep 2008
Posts: 510
Likes: 0
From: San Antonio TX
Rick
Pro
Joined: Sep 2008
Posts: 510
Likes: 0
From: San Antonio TX
Riiight... So if 2 1/2" primaries are the correct primary size for an 8THOUSAND horsepower top fuel drag car with an 8.5L engine pushing 50PSI on Nitromethane, it logically follows that it too must be the correct primary size for the OP's 500WHP V8?
I guess my side by side dyno comparison really wasn't needed when we can take some relevant real world examples like that and extrapolate to our cars... Wish someone would have told me that before I spent money doing a scientific comparison
I guess my side by side dyno comparison really wasn't needed when we can take some relevant real world examples like that and extrapolate to our cars... Wish someone would have told me that before I spent money doing a scientific comparison
You say Rockin' Blue like to argue, but so do you. I'm too old for the smart remarks. I don't want them or need them. I made an extreme example....not a comparison.
I would much rather listen to ARH suggestion than yours.
Safety Car
Joined: Jan 2006
Posts: 4,598
Likes: 78
From: Miami FL
2020 C6 of the Year Finalist - Unmodified
St. Jude Donor '08-'09-'10-'11-'12-'13-'14-'15-'16,'17,'18-'19-'20-'21-'22
In most supercharged street cars, the exhaust valve closes oh, about 180 degrees, give or take a couple of dozen, BEFORE the intake valve closes. So if I keep cramming air into the cylinder through the open intake valve, with no way out, the pressure will keep going up. PV = nRT and all that thermodynamical stuff, including PV to the gamma = constant.
Powerlabs is right in that pressure is the result of resistance, but a closed exhaust valve is sort of the ultimate in resistance. More air in the cylinder means more pressure, which is reflected in intake manifold pressure (i.e. "boost"), and more ability to combust fuel, hence more power.
This is even better shown in a diesel engine. 100+ psig intake manifold pressures are not unknown in some of the tractor pull events . . .
Shove in more air, burn more fuel, make more power.
Powerlabs is right in that pressure is the result of resistance, but a closed exhaust valve is sort of the ultimate in resistance. More air in the cylinder means more pressure, which is reflected in intake manifold pressure (i.e. "boost"), and more ability to combust fuel, hence more power.
This is even better shown in a diesel engine. 100+ psig intake manifold pressures are not unknown in some of the tractor pull events . . .
Shove in more air, burn more fuel, make more power.
Melting Slicks
Joined: Aug 2006
Posts: 2,167
Likes: 11
From: Powell TN
Cruise-In VIII Veteran
Safety Car
Joined: Aug 2006
Posts: 4,206
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From: Makena, Maui & NM
Safety Car
Joined: Sep 2007
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From: Los Alamitos California
St. Jude Donor '09
I saw this in someone's signature. "Never argue with an idiot. They drag you down to their level and beat you with experience." Not that it's relevant.
San
San
Last edited by oldmansan; Apr 21, 2009 at 01:08 AM.
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