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Jetaholic

  • Karma: +3/-0
Re: c and d impellars
« Reply #25 on: January 15, 2008, 02:08:31 PM »
Where did yah copy and paste that from? Hmmm, could you tell me where they get the 5252 oh so knowledgeable

From my understanding 5,252 is the RPM at which torque and horsepower equal each other...why they do at that RPM I have no idea.
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Re: c and d impellars
« Reply #26 on: January 15, 2008, 03:20:55 PM »
that is way to much to read this early but i know what your talking about  but i would  rather build a hi reving big block then a low reving one get on the rs quick and dont look back  alot of people will disagree but when it comes to boats HP is king torque will only get so far you need the HP to do 95% of the rest the harder u can spin that A the faster the boat will go the A is the best cut but it takes both TQ HP to do it  :)

Maybe when it comes to prop boats you would be right. But with Jet boats, you're dead wrong. And dead in the water.
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Ema Non-Performance Marine - BANNED

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Re: c and d impellars
« Reply #27 on: January 15, 2008, 03:57:14 PM »
From my understanding 5,252 is the RPM at which torque and horsepower equal each other...why they do at that RPM I have no idea.

How how much more power do you need to spin 5352 rpms ?
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tofastforu

  • Karma: +4/-1
Re: c and d impellars
« Reply #28 on: January 15, 2008, 04:27:28 PM »
Maybe when it comes to prop boats you would be right. But with Jet boats, you're dead wrong. And dead in the water.
   if you talk to any drag jet boat guy he will tell u that hes probley spinning that motor up around 6500 7000 if not more  and with an AA cut more than likly  true it does take tq to get the boat moving but normally your tq curve falls of around half track and hp takes over thats why i said build for hp rather than tq becouse the tq  comes with the hp theres not a jet boat on here running triple digits thats only turning 5200 it takes the hp to push u to those numbers .  wiht a vdrive u can take a low hp motor and run 100mph and only turn 5200 becouse of the gearing pitch of the prop size of the prop and so on . i have been around this for years thats why i said some will disagree  but im not wrong just a different op  but if its still not enough proof be in blythe this summer and ill show u a 440 ford that spins 6500 with and A cut and runs over 100mph :)
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Re: c and d impellars
« Reply #29 on: January 15, 2008, 05:45:32 PM »
You're mistaken. torque makes HP. You have it backwards. That is a matter of fact, something you cannot argue. You don't have to believe me, I'll scrounge up a list of reputable engine builders for you to call and ask. Hell I'll give you the number for my great uncle Tyler Alexander who was McClaren's Formula 1 race team manager for many years. He was also an engineer for the firm and in fact was the man who invented the "spoiler" along with the air powered "jack" system made to lift cars off the ground for speedy repairs/tire changes. In car racing my family is second to none. In jet boat racing my best friends grandfather owns the most renowned Jet manufacturing company (especially in the Drag boat segment).
I work in a manufacturing shop that is home to over 100 machinists who have all been building engines for years. One of which was a mechanic for a Top Fuel team in the early 80's.
Ever heard the name Dean Moon? As in MoonSpeed equipment? Who was one of the biggest names in offshore racing before his death? His family lives across the street.
Lil' John Lombardo? Held top speed records in the '80s driving funny cars. He's been at my last 21 birthday parties.
All of these people have always told me one thing in common. TORQUE MAKES HORSEPOWER.

This obviously does not mean I know everything, however I do have access to a wealth of information in these particular areas. Need parts? I am only 21 but the life I live has led me to a vast network within the many facets of the racing world.

http://www.grandprix.com/gpe/cref-aletyl.html
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Jetaholic

  • Karma: +3/-0
Re: c and d impellars
« Reply #30 on: January 15, 2008, 05:47:31 PM »
You can do the same with a jet boat. The whole idea behind the 'hi-helix' impellers is to make more thrust at a lower RPM. Of course, you need lots more torque and horsepower to pull that off with a jet boat, but as Jim has said before RPM doesn't always mean MPH. Also the efficiency of the pump comes into play. Some pumps you tighten 'em up and you may lose RPM, but gain MPH. This happens because you have made the pump more efficient by tightening it up.  True, lots of drag boats may be spinning insanely high RPMs, but that doesn't mean that you HAVE to spin that fast to get that kind of speed out of them. It all depends on your pump/motor combo.
« Last Edit: January 15, 2008, 05:53:17 PM by Jetaholic »
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To err is human, to forgive divine...except for running Fords ;D

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Jetaholic

  • Karma: +3/-0
Re: c and d impellars
« Reply #31 on: January 15, 2008, 05:49:41 PM »
You're mistaken. torque makes HP. You have it backwards. That is a matter of fact, something you cannot argue. You don't have to believe me, I'll scrounge up a list of reputable engine builders for you to call and ask. Hell I'll give you the number for my great uncle Tyler Alexander who was McClaren's Formula 1 race team manager for many years. He was also an engineer for the firm and in fact was the man who invented the "spoiler" along with the air powered "jack" system made to lift cars off the ground for speedy repairs/tire changes. In car racing my family is second to none. In jet boat racing my best friends grandfather owns the most renowned Jet manufacturing company (especially in the Drag boat segment).
I work in a manufacturing shop that is home to over 100 machinists who have all been building engines for years. One of which was a mechanic for a Top Fuel team in the early 80's.
Ever heard the name Dean Moon? As in MoonSpeed equipment? Who was one of the biggest names in offshore racing before his death? His family lives across the street.
Lil' John Lombardo? Held top speed records in the '80s driving funny cars. He's been at my last 21 birthday parties.
All of these people have always told me one thing in common. TORQUE MAKES HORSEPOWER.

This obviously does not mean I know everything, however I do have access to a wealth of information in these particular areas. Need parts? I am only 21 but the life I live has led me to a vast network within the many facets of the racing world.

http://www.grandprix.com/gpe/cref-aletyl.html

I don't ever claim to know everything either (although some people would beg to differ with that) but I do know for a fact that you are 100% correct on this. As has been said countless times before...Horsepower is a calculation derived from Torque and RPM.

Engines are built for torque. Horsepower is just an interesting afterthought.
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To err is human, to forgive divine...except for running Fords ;D

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tofastforu

  • Karma: +4/-1
Re: c and d impellars
« Reply #32 on: January 15, 2008, 06:03:19 PM »
thats verry nice my father ran a alcohol funny car in the 70s and 80s then went to TFH thats the one in my pics i used to be fast ass ford my dad and me are also good freinds with Larry Minor who ran top fuel funny cars and top fuel dragsters and my uncle works for Don Phurdome thats why i said this is nothing new also greg shoemaker is a good freind of mine along with jonh west of ultra boats . greg did some test last year on a hallet jet with an A blown 468 nice 800 hp  it ran an honest 112 mph they took the same boat with a single carbed small block making a little more power that would rev to the moon and it ran 3 1/2 mph slower and it was not a tq motor it all depends on real world ap and by the way ray at dogouns  will beg to differ you can build a motor for hp and one for tq he would know he has built many of championship drag boat motors and they  all are built to make hp but im shure the people i have named dont come close to yours but  like i said just my op and would love to show you how fast a NON TQ motor runs  ;D
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UNDONE

Re: c and d impellars
« Reply #33 on: January 15, 2008, 06:08:54 PM »
great your still wrong. call a dyno shop before you make yourself look more like an ass hole.
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Brad @ SCJB

  • Karma: +255/-0
Re: c and d impellars
« Reply #34 on: January 15, 2008, 06:13:20 PM »
great your still wrong. call a dyno shop before you make yourself look more like an ass hole.

Keep this discussion clean, no more name calling.
  • Boat #1: 1978 Liberty
  • Boat #2: 1982 Eliminator Sprint
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tofastforu

  • Karma: +4/-1
Re: c and d impellars
« Reply #35 on: January 15, 2008, 06:16:38 PM »
great your still wrong. call a dyno shop before you make yourself look more like an ass hole.
 i dont c were im wrong i agree that tq and hp work together and are built alike but when u go down to and engine shop and tell them u want to tow your boat at 50 all day they set it up that way cam carb ect. u tell them u want to tow your boat at 50 smoking the tires all the way they change those things thats what i was try ing to say  and by the way its all in good fun so dont get your pantys in a bunch oh sinse were name droping on here i can give u donnys # who is chet herberts mech on his fuel car
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Jetaholic

  • Karma: +3/-0
Re: c and d impellars
« Reply #36 on: January 15, 2008, 06:30:02 PM »
I think all this is is that you're wording what you're trying to say wrong.

For a "grunt" motor or "building for torque" as you call it, the motor makes all its power in the lower range of RPM and not much in the mid-range.

On a motor "built for horsepower" as you call it, the motor is making its power in the mid-high RPM range.

This is not the correct way to word what you're trying to say.

A motor that is "built for horsepower" in your terms is nothing more than a motor that is built with a much more steady torque curve. In other words, the torque curve does not drop off as quickly and because of this, horsepower continues to rise even though torque is dropping off. It's just dropping off at a much slower rate than a "built for torque" motor. It is because of the fact that there is still much torque to be had that your horsepower at higher RPMs continues to rise.

On a "built for torque" motor as you call it...actually nothing could be further from the truth. Yes there is plenty of torque at the lower range of RPMs, however the torque curve on these motors drops off a lot faster, causing your peak horsepower to happen at a lower RPM. And due to the fact that peak HP is at a lower RPM, the amount of peak HP is also less.
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To err is human, to forgive divine...except for running Fords ;D

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tofastforu

  • Karma: +4/-1
Re: c and d impellars
« Reply #37 on: January 15, 2008, 06:36:15 PM »
exactly thats what happens after a few drinks.with a jet you want it to keep climing to go faster and faster im not at the river boating all day i sit on a sand bar with my freinds and familly and look for races it fun for me  thanks for clarifying?  ;)
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Jetaholic

  • Karma: +3/-0
Re: c and d impellars
« Reply #38 on: January 15, 2008, 06:49:39 PM »
Right. This is what we've been trying to tell you. The less the torque curve drops off, the more the horsepower will keep climbing after peak torque. The torque curve controls everything related to horsepower.

However, how much horsepower and at what RPM you want it at is governed by what impeller cut you run. You want the horsepower curve of the engine to match the horsepower demand of the impeller. As far as MPH, not just pump RPM control that. The weight of the boat and the amount of thrust produced @ what RPM (which is controlled by the efficiency of the pump) will control MPH. You may have two pumps running the same impeller spinning the same RPM yet one pump makes less thrust than the other. This would mean that that pump is less efficient than the other. The other pump is getting more work done with the same impeller spinning the same RPM.
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To err is human, to forgive divine...except for running Fords ;D

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Ema Non-Performance Marine - BANNED

  • Karma: +18/-1
Re: c and d impellars
« Reply #39 on: January 15, 2008, 06:52:33 PM »
I think all this is is that you're wording what you're trying to say wrong.

For a "grunt" motor or "building for torque" as you call it, the motor makes all its power in the lower range of RPM and not much in the mid-range.

On a motor "built for horsepower" as you call it, the motor is making its power in the mid-high RPM range.

This is not the correct way to word what you're trying to say.

A motor that is "built for horsepower" in your terms is nothing more than a motor that is built with a much more steady torque curve. In other words, the torque curve does not drop off as quickly and because of this, horsepower continues to rise even though torque is dropping off. It's just dropping off at a much slower rate than a "built for torque" motor. It is because of the fact that there is still much torque to be had that your horsepower at higher RPMs continues to rise.

On a "built for torque" motor as you call it...actually nothing could be further from the truth. Yes there is plenty of torque at the lower range of RPMs, however the torque curve on these motors drops off a lot faster, causing your peak horsepower to happen at a lower RPM. And due to the fact that peak HP is at a lower RPM, the amount of peak HP is also less.

A little confusion here, doesn't a toque engine have a flat curve and keep climbing and a HP engine drop the torque when the HP takes over and pulls it all the way to the moon ?
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pw_Tony

  • Karma: +12/-0
Re: c and d impellars
« Reply #40 on: January 15, 2008, 07:09:45 PM »
Not exactly. You guys are all talking too vague. Shit a 1200 Gsxr makes 40lbs of torque, but it holds it all the way to 12,000rpm that's why it makes so much horsepower, because of it's flat torque curve.
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jimbo

  • Karma: +1/-0
Re: c and d impellars
« Reply #41 on: January 15, 2008, 07:20:35 PM »
You guys are getting a little worked up over this ain't ya? BTW the formula for HP is torque times RPM so you can't have HP with out having good torque numbers . But from my seat you both are some what correct . I,m just an old mech and I don't know anybody important ,but I did stay in a Holiday Inn Express last nite if that counts . Peace  Jimbo.
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Brad @ SCJB

  • Karma: +255/-0
Re: c and d impellars
« Reply #42 on: January 15, 2008, 07:23:24 PM »
You guys are getting a little worked up over this ain't ya? BTW the formula for HP is torque times RPM so you can't have HP with out having good torque numbers . But from my seat you both are some what correct . I,m just an old mech and I don't know anybody important ,but I did stay in a Holiday Inn Express last nite if that counts . Peace  Jimbo.

....and i saved a ton on my car insurance by switching to gieco.
  • Boat #1: 1978 Liberty
  • Boat #2: 1982 Eliminator Sprint
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tofastforu

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Re: c and d impellars
« Reply #43 on: January 15, 2008, 07:36:32 PM »
that sh t is funny but watch out he might call u and a$$ H  :oLE
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crewchief22

  • Karma: +66/-0
Re: c and d impellars
« Reply #44 on: January 15, 2008, 08:14:40 PM »
So, let me see if i'm understanding things right..... 

I need to multiply horsepower x torque x $1000.00 to get my overloaded Hondo to run over 60 mph  >:D


OK, I think I got it know  ;D
  • Boat #1: '77 Hondo Pantera GT Jet
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"Racing is life!  Anything that happens before or after, is just waiting"    Steve McQueen

The problem with America is stupidity. I'm not saying there should be a capital punishment for stupidity, but why don't we just take the safety labels off of everything and let the problem solve itself?

flytime

  • Karma: +21/-0
Re: c and d impellars
« Reply #45 on: January 15, 2008, 08:28:41 PM »
So, let me see if i'm understanding things right..... 

I need to multiply horsepower x torque x $1000.00 to get my overloaded Hondo to run over 60 mph  >:D


OK, I think I got it know  ;D

Dont wory about your Hondo Keith. Your boat runs GREAT!. It was fast enough for me anyways!

Bob
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the jet boat never did this to you bob ::)
Can I get next in line behind The Beav

crewchief22

  • Karma: +66/-0
Re: c and d impellars
« Reply #46 on: January 15, 2008, 08:33:39 PM »
Thanks Bob.

Maybe I can convince the wife I need nitrous  :o





Not likely  :'(
  • Boat #1: '77 Hondo Pantera GT Jet
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"Racing is life!  Anything that happens before or after, is just waiting"    Steve McQueen

The problem with America is stupidity. I'm not saying there should be a capital punishment for stupidity, but why don't we just take the safety labels off of everything and let the problem solve itself?

Ema Non-Performance Marine - BANNED

  • Karma: +18/-1
Re: c and d impellars
« Reply #47 on: January 15, 2008, 11:13:23 PM »
Thanks Bob.

Maybe I can convince the wife I need nitrous  :o





Not likely  :'(

Take her to a show and let her see those big shinny things on top of the engine. If she likes you might end up with a 6-71 GMC Blower.
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Ema Non-Performance Marine - BANNED

  • Karma: +18/-1
Re: c and d impellars
« Reply #48 on: January 16, 2008, 02:54:01 AM »
Jetboy here is what I was trying to remember;
Quote
With RPM reduced to 70% of maximum, fuel needed is reduced to only 32% of maximum, while speed is maintained at 66% of maximum.
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crewchief22

  • Karma: +66/-0
Re: c and d impellars
« Reply #49 on: January 16, 2008, 06:50:46 AM »
Take her to a show and let her see those big shinny things on top of the engine. If she likes you might end up with a 6-71 GMC Blower.

Doesn't work, her dad use to be a crew member on a top fuel dragster.
  • Boat #1: '77 Hondo Pantera GT Jet
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"Racing is life!  Anything that happens before or after, is just waiting"    Steve McQueen

The problem with America is stupidity. I'm not saying there should be a capital punishment for stupidity, but why don't we just take the safety labels off of everything and let the problem solve itself?

 


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