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Discussion Starter #1 (Edited)
Since we have been having so much fun as of lately, I thought I might as well bring this subject back to the top.:D
I found a link I would like you guys to check out. It makes some of the "pro's" on the #1 thread look kinda silly.
Cams for Turbocharged Engines - Hot Rod Magazine

heres a copy & paste from the link that I really enjoyed-

"Another factor influencing cam design for a turbocharger is charge density. Because turbo applications make such dramatic power, the common misconception is that the intake and exhaust port velocities need to be quite high, in turn mandating very large-duration camshafts to make a given amount of power. Actually, the exact opposite is true. Because of the increased pressure along with a corresponding increase in oxygen and fuel density, more fuel and air are moving into the chamber, but the velocity is actually lower. The combustion chamber pressure therefore rises more quickly, and filling occurs earlier in the stroke compared with a similar NA application."

I have my flame/BS resistant suit on, so fire away. :stir:
 

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Sounds reasonable to me. My cam is tiny.
 

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you sure you want to do this???

here's a "copy/paste" from your same article.

On the other hand, Roots blowers make boost immediately off idle, so they don't need exhaust help to pull the charge out of the cylinder. A cam optimized for a Roots supercharger can have higher intake duration (at 0.050) than equivalent-duration-operating-range cams for other applications. For example, a beltdriven centrifugal blower or a turbo would have a smaller intake to trap cylinder pressure during the intake stroke because they take longer to get up to peak boost

I guess the "discussion" is now over... :sleeping:
 

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Discussion Starter #4
you sure you want to do this???

here's a "copy/paste" from your same article.

On the other hand, Roots blowers make boost immediately off idle, so they don't need exhaust help to pull the charge out of the cylinder. A cam optimized for a Roots supercharger can have higher intake duration (at 0.050) than equivalent-duration-operating-range cams for other applications. For example, a beltdriven centrifugal blower or a turbo would have a smaller intake to trap cylinder pressure during the intake stroke because they take longer to get up to peak boost

I guess the "discussion" is now over... :sleeping:
You two Boobs are very much the same. I have never one time insinuated that a turbo makes boost as quickly as a blower. As a matter of fact, if the turbo deal has a fault at all, it is the SLIGHT hesitation at the hit. And things can be done to help with that. And I will state once again that it isn't an issue at all with boat drags. You have have posted before about how Bob Fry's boat, or how Info's boat leaves. So is it an issue?
Seems to me I have heard that the blower guys have much more of an issue trying to deal with getting the hit softened up enough that they don't blow the pump away. Sometimes that advantage you guys keep wanting to claim is actually a disadvantage.
 

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steelcomp was here
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you sure you want to do this???

here's a "copy/paste" from your same article.

On the other hand, Roots blowers make boost immediately off idle, so they don't need exhaust help to pull the charge out of the cylinder. A cam optimized for a Roots supercharger can have higher intake duration (at 0.050) than equivalent-duration-operating-range cams for other applications. For example, a beltdriven centrifugal blower or a turbo would have a smaller intake to trap cylinder pressure during the intake stroke because they take longer to get up to peak boost

I guess the "discussion" is now over... :sleeping:
...next...
 

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steelcomp was here
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You two Boobs are very much the same. I have never one time insinuated that a turbo makes boost as quickly as a blower. As a matter of fact, if the turbo deal has a fault at all, it is the SLIGHT hesitation at the hit. And things can be done to help with that. And I will state once again that it isn't an issue at all with boat drags. You have have posted before about how Bob Fry's boat, or how Info's boat leaves. So is it an issue?
Seems to me I have heard that the blower guys have much more of an issue trying to deal with getting the hit softened up enough that they don't blow the pump away. Sometimes that advantage you guys keep wanting to claim is actually a disadvantage.
So are we back to you making the rules for the discussion by limiting this to jet boats only?:yes:
 

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Discussion Starter #7
This thread and that link was actually more about cylinder head flow. I have said before that "its not how much the head is flowing but WHAT is flowing through the head". That extra dense, compressed charge will make a very mediocre set of stock style heads perform , and do it with a very mild camshaft.
I believe that there are many-many boaters out there that have a good stout forged bottom end with low compression and mild heads that would like to increase their performance. I would like to point out that they would get way more for their money to consider turbocharging what they currently have instead of trying to change/port heads, camshaft, compression, ect. you know, the usual routine.
Then they would have a variable power output that can still burn the same pump gas they are used to. And if they decide to poor some good fuel and boost to it once in a while will make more power than most other more expensive routes.
 

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Discussion Starter #8
So are we back to you making the rules for the discussion by limiting this to jet boats only?:yes:
Why , have you come up with an application where physics don't apply? What is it this time? Airplanes? Tractor puller? Snowmobile? Land speed racer? Top fuel car?

I'm aware that there are some applications that turbos may not be the perfect fit for. For jet boats I think they are a great fit. And I'm still not convinced that they wouldn't work for the V-drive crowd, but don't care if they give it a try or not.
 

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I will never forget the words that came out of my grandfather's mouth over 30 years ago... I keep going back to this every time I hear someone compare a roots blower with a turbo.

"Turbos are great, except, the bigger the instantaneous demand on the engine, the more time you have to wait to have your ass pulled into the seat."

Keep in mind he raced buggies at Baja, drag raced in Pomona in the '60's and flew gyro copters in WWII with the Screaming Eagles in the 101st Airborne and built/flew his own planes until he passed at the age of 89 years old. RIP pops...

They definitely have a place in the performance world, there is no arguing that, in fact, they're awesome, but that was never really the argument, the argument always was, there are less tricky ways of getting the same result power wise, but having it at your fingertips.

You just cannot deny the fact that a roots blower just is far superior and making the stump pulling grunt from standstill to scary much quicker.

I really do believe a jet is quite literally the only real good place for turbos, basically because they have a stall converter built into them that lets them spin 3000 plus RPM from the opening of an anemic bottom end of a turbo deal.

I have no dog in this fight (can't afford either) but I can tell you what I would install in either the I/O or the jet if I had the opportunity... It wont say Vidal Sassoon on the side... :stir:

Carry on...
 

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This thread and that link was actually more about cylinder head flow. I have said before that "its not how much the head is flowing but WHAT is flowing through the head". That extra dense, compressed charge will make a very mediocre set of stock style heads perform , and do it with a very mild camshaft.
I believe that there are many-many boaters out there that have a good stout forged bottom end with low compression and mild heads that would like to increase their performance. I would like to point out that they would get way more for their money to consider turbocharging what they currently have instead of trying to change/port heads, camshaft, compression, ect. you know, the usual routine.
Then they would have a variable power output that can still burn the same pump gas they are used to. And if they decide to poor some good fuel and boost to it once in a while will make more power than most other more expensive routes.
Dollar for dollar, supercharging is one of the best deals around, regardless of how it's done.
For those going low budget, the old draw through Rajays are still hard to beat.
For more money, the blow through injected deals are hard to beat.
For looks, nothing beats a polished roots blower for the wow factor.
 

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Discussion Starter #11 (Edited)
Dollar for dollar, supercharging is one of the best deals around, regardless of how it's done.
A pair of turbos capable of 2000hp when put on any common flat top 540+-~cid engine, can be had for $1300 brand new and will last for hundreds of hrs of abuse. How much would a supercharger capable of same cost$ and how long would it last before needing restripped?
 

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A pair of turbos capable of 2000hp on a flat top 540cid can be had for $1300 brand new and will last for hundreds of hrs of abuse. How much would a supercharger capable of same cost$ and how long would it last before needing restripped?

So all you need is two turbos and no ducting, exhaust work, special tuning tools... Hmmmm...

I always heard that the costs for each were comparable. The turbos being more involved and more odds and ends.
 

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Discussion Starter #13
So all you need is two turbos and no ducting, exhaust work, special tuning tools... Hmmmm...

I always heard that the costs for each were comparable. The turbos being more involved and more odds and ends.
Turbo needs headers, supercharger needs headers, turbo needs intercooler, supercharger needs intercooler, either one needs some form of fueler(carb-efi), The aluminum ducting is cheap, the additional expense will be the wastegates and BOV, but its a wash when compared to the blower intake and drive hardware, not to mention a good intercooler for a supercharger is much more expensive than one can be had for a blowthrough.
How much did you say that 2000hp capable blower costs? And how long between rebuilds?
 

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Dollar for dollar, supercharging is one of the best deals around, regardless of how it's done.
For those going low budget, the old draw through Rajays are still hard to beat.
For more money, the blow through injected deals are hard to beat.
For looks, nothing beats a polished roots blower for the wow factor.
I beg to differ...
 

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Turbo needs headers, supercharger needs headers, turbo needs intercooler, supercharger needs intercooler, either one needs some form of fueler(carb-efi), The aluminum ducting is cheap, the additional expense will be the wastegates and BOV, but its a wash when compared to the blower intake and drive hardware, not to mention a good intercooler for a supercharger is much more expensive than one can be had for a blowthrough.
How much did you say that 2000hp capable blower costs? And how long between rebuilds?

Well to put into perspective (just because I think you are being somewhat bias and one sided) let's just say I have a low compression 454 in a jet that has headers and a fuel system that can support the 1050 Dominator on it.

I could put a blower on it for quite a bit of dough less than twin turbo. To add to that, in about 1/4 of the time.

Nice try, but I don't think so.

If I had the time and money to take off enough where I could actually wear out the blower strips in say an 8-71 on a lake boat, damn the costs, I'm obviously loaded.... LMAO

Besides, I could have the blower rebuilt and stripped for around $300 including the gaskets. Sort of a weak argument to be honest.

I see where you are going, but gonna call it a tie.
 

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This thread repeats the same bullshit the other one did, Same shit, different thread.
Some how thru voodoo black magic, the boost of a turbo is a different chemical make up than that of a roots. The 20 lbs in the manifold cannot flow as well thru the ports, or mix with as much fuel as the turbo-ized air. Its been changed at the molecular level.

It this thinking that makes turbo folk look down right foolish. That, and the fact that virtually every acceleration record in the world is held by roots/screw, and yet they continue the debate based on internet racing.

Not unlike the LS freaks. No real dent in the racing world, but they are the most superior engine ever built, of any size.
No wonder LS and turbos are so meant for each other.

turbo ls.jpg



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mo balls than $cents$
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The price difference isnt much i know for a fact.example:

Got interested in turbos after seeing hass's banks deal run hard.uncle was runnin a nice bds 8-71 atop a nice 540. Tx20 ran pretty hard but even with a shot of nitrous under the 1050's it never performed as we wanted.over the winter he decided ti build a fresh shortblock 496 and after alot of research on bt carbs i was convinced it was da shit for jets.i started working on him to let me change his blown to turbo'd.finally agreed and i started selling all his blown stuff off and got decent price for it all.bought headers from mark/turbos from guy in dallas 1100 shipped 2200hp capabld s475's/950 c&s bt carb/used ev pro hat/used belt drive aeromotive pump n 13202 regulator/60mm gates/2 air to water intercoolers(260 shipped), plumbing and tubing and he was out less than 600 from pocket.the tt496 killed the blown540 and we were outrunning boats we cldnt touch before.on pumpgas at that.its not as expensive as most think.u can buy up and forward nice ss turbo headers for bbc's now for under 700 shipped thatd work great in a boat.

700 for ss turbo headers
1200 for turbs
250ish pair of 60mm wastegates
100 for blowoff valve
100-350 for air to water intercooler depending on whats needed
Ev pro hat 200ish used
Aeromotive 13202 regulator used 150
Belt drive pump setup 400 used in good shape
carb 800-1700 depending on hp and range from 800-2200hp capable
plumbing coldside 300ish
afr meter 150-400

I cld add in all the fuel plumbing but thatd be on a blown deal too & when comparing to blown dont leave out header costs.for what rewarder cost new i can build a bbc hotside in ss with already made headers.so if we re adding up costs leave headers and hotside out.nice blower thatll make 2khp or more 4500 or so for it and drive setup along with intake. havent even gotten to its fuel system and at 4500 id be done buyin parts for a turbo deal, its just the truth.
 

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mo balls than $cents$
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After all that, you should do a public service, and hide that mess under a hatch.
Beauty is in the eye of the beholder bob ;) i think a blown deal is badass not because of the blower, but what it does is beautiful.turbos are no different.if ya know what youre looking at with a turbo setup, it becomes appearent the owner didnt just call up good vibrations and order bolt on power adder. some of the turbo setup i see are pure art to my eyes and alot of others.someone with no engine knowledge will look at either setup and just appreciate the one thats shiney lol you get the point..
 

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You mean turbos look like ass? LOL

I had blowers for years. Small blocks big blocks cars boats. One pair of turbos and I'll never have a blower again. For any reason. :yes:

Why ?? Must be a reason. It's indescribeable.

How about this: A boat to compete in TAF. The roots deal gets bearings every 3 or 4ish hits. Some sooner. A turbo would go for many races. The crew throwing back beers instead of pulling the engine and rolling in bearings.
 
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