Easy way to 400 RW HP?

So that brings me to my next question: What combinations have brought the highest torque curves in the dyno pulls and still be a reliable, streetable engine? N/A of course.
 
Bluesman73 said:
So that brings me to my next question: What combinations have brought the highest torque curves in the dyno pulls and still be a reliable, streetable engine? N/A of course.
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Strokers... Other can get more specific than that, but I will keep it short and sweet.
 
Bluesman73 said:
So that brings me to my next question: What combinations have brought the highest torque curves in the dyno pulls and still be a reliable, streetable engine? N/A of course.
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Simply put, torque is a function of stroke, compression, and displacement. Making an uber-torquey naturally aspirated 4V motor isn't going to be easy either, since it lacks all three of those.

IMHO, put a blower on it. If Kenne-Bell style blowers are available for this motor, then that would be your best bet.

Paul.
 
Engine technical-babble aside, you'll actually get a bunch of "free" rear wheel horsepower by using the proper transmission.... i.e. a stick shift.

I think a manual trans absorbs something like 10-15 percent of the flywheel horsepower that reaches the axle.

An automatic gobbles up as much as 30% of that energy due to all the slipping, and fluids sloshing around in the case.

So, you'll actually waste a ton of money by sticking with the automatic.

Example: You'd need 460 flywheel horsepower running through a manual transmission to get 400 horses to the wheels.

400hp times 1.15 (115%) = 460 hp at the crank.

You'd need 520hp going through an automatic for the same 400 rear wheel hp.

400hp times 1.30 (130%) = 520hp at the crank.

I'm not saying that getting 460hp out of a 4.6L engine is easier, but certainly it's more attainable than 520hp! Plus, you don't have to "beef up" a Tremec or TKO and hope it's going to hold up to that kind of punishment.

My 2 cents.
 
Dr. Paul said:
A car that has only maybe 350 rwhp, but a real nice long, flat torque curve is going to be absolute blast to drive, and will annhilate 99.9% of what you're going to encounter on the street - from Mustangs to Camaro, and vettes and maybe even the occasional Viper since he will probably spin the tires into next week.
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Bingo. 350 HP on the ground with a 3800 lb IRS air ride chassis will annihilate most other high-powered, bone-jarring, wheel-spinning, street vehicle, NASCAR driver wannabes on the street or the track.
 
Sounds good. Looks like my goals will be changing. Most of my research is with tradtional 2v pushrod engines. Having fun the the 4v DOHC is my next research goal. But it it also apparent there is no replacement for displacement, so I need to keep that in mind considereing I really don't want to swap engine sizes.
 
I have to say that i've done my research on this 400RWHP, and everyone is right. It's gonna take alot of money to make that much power. It all depends on how deep your pockets are. As for me, I am going to make at least 400 at the rear wheels, but it's my ambition that drives me to do it. Not the money. And yes i do have a job that accompanies that kind of money, just not right away because i just recently got into the mark 8's. I do however, found all the right people to do the work on the car(some work done by me). My advice, shop around! Good luck!
 
EconomySpeedNStyle said:
Engine technical-babble aside, you'll actually get a bunch of "free" rear wheel horsepower by using the proper transmission.... i.e. a stick shift.

I think a manual trans absorbs something like 10-15 percent of the flywheel horsepower that reaches the axle.

An automatic gobbles up as much as 30% of that energy due to all the slipping, and fluids sloshing around in the case.

So, you'll actually waste a ton of money by sticking with the automatic.

Example: You'd need 460 flywheel horsepower running through a manual transmission to get 400 horses to the wheels.

400hp times 1.15 (115%) = 460 hp at the crank.

You'd need 520hp going through an automatic for the same 400 rear wheel hp.

400hp times 1.30 (130%) = 520hp at the crank.

I'm not saying that getting 460hp out of a 4.6L engine is easier, but certainly it's more attainable than 520hp! Plus, you don't have to "beef up" a Tremec or TKO and hope it's going to hold up to that kind of punishment.

My 2 cents.
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I am sorry but an auto tranny is NOT going to eat up THAT much horsepower. Most auto trannies when built properly will yield less than 20% drivetrain loss. If you tune to lock the converter sooner you will also have more power too being that the TC is taken out of the picture after that.

Also, to convert from RWHP to Crank horsepower you divide the rwhp number by the percentage of what hp is remaining after loss, in decimal form.

An example will be at while putting down 400 to the wheels. For example a 15% loss converting from rwhp to fwhp would look like:

400 / .85 = 470.58 flywheel horsepower

400 x 1.15 = 460 flywheel horsepower is an inaccurate conversion
 
You're right...

I don't know why I did the math that way... but the theme of my post is correct.

No matter how you say it, an automatic transmission will soak up a bunch of existing horsepower.

According to Superstang.com , the numbers are 10-15% for a manual and 20-25% for an automatic.

The same can be said for AWD platforms, which soak up even more power... maybe 40% or more!?

I've also read that chassis dynos give weird numbers when the test vehicle is an auto.

And even with early lockup (which wears out the converter clutch if raced heavily), on the drag strip the horsepower loss is going to be even more pronounced than a converter-locked 3rd gear dyno run.

So, regardless of my crappy math skills, the key is that there is "free" rear-wheel horsepower when running a stick shift. I'd say about 10% of the flywheel horses to be had.

Remember, the poster was asking about 400hp to the wheels. It's just a suggestion. I'd imagine a stick would also hold up better behind a 470hp engine than a 4R70W behind a 530hp engine (exaggerated for effect)....and be cheaper to boot.

Towards the end of the Superstang article is also postulates that stick shift cars lose a STATIC amount of horsepower in most cases!
 
EconomySpeedNStyle said:
You're right...

I don't know why I did the math that way... but the theme of my post is correct.

No matter how you say it, an automatic transmission will soak up a bunch of existing horsepower.

According to Superstang.com , the numbers are 10-15% for a manual and 20-25% for an automatic.

The same can be said for AWD platforms, which soak up even more power... maybe 40% or more!?

I've also read that chassis dynos give weird numbers when the test vehicle is an auto.

And even with early lockup (which wears out the converter clutch if raced heavily), on the drag strip the horsepower loss is going to be even more pronounced than a converter-locked 3rd gear dyno run.

So, regardless of my crappy math skills, the key is that there is "free" rear-wheel horsepower when running a stick shift. I'd say about 10% of the flywheel horses to be had.

Remember, the poster was asking about 400hp to the wheels. It's just a suggestion. I'd imagine a stick would also hold up better behind a 470hp engine than a 4R70W behind a 530hp engine....and be cheaper to boot.
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I am telling you dude, those loss % numbers that superstang.com gave are inflated. Yes, there will be a difference when comparing loss through a manual and loss through an auto tranny. The thing you gain in an auto tranny is consistency and never missing a gear. That can count for A LOT in a race, especially the brackets! A stock 4R70W tranny with a shift kit and an aux. trans cooler will be able to withstand a pretty decent amount of power. Putting 400 to the tires with one in that form would be no big issue. Being that this dude already is running a 4R70W tranny it would most likely be more expensive to swap to a manual versus refreshing his 4R, if needed, and installing the kit and cooler too. 400rwhp isn't a heck of a lot for a 4R tranny to need to hold. The 4R70W in mildly modded form is more than up to the task, and will surely not lose anything more than 20% through the slushbox if that.
 
rocket5979 said:
OH THE BLASPHEMY!!! :D hehehhhehehehe.
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How's this for blasphemy?

My machinist said he received the rotating assembly going into my Mark... along with the HONDA bearings that are going in there?

HONDA? He said they are used in a lot of HP cars, but since I don't know jack about it, I'll take his word for it, since he does have a few High HP cars.
 
Frogman said:
How's this for blasphemy?

My machinist said he received the rotating assembly going into my Mark... along with the HONDA bearings that are going in there?

HONDA? He said they are used in a lot of HP cars, but since I don't know jack about it, I'll take his word for it, since he does have a few High HP cars.
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HONDA???!?!!!!??? HOOOOOOONDDDAAAAAAAA!!!!!??? He should be shot. lol. :D
 
rocket5979 said:
I am telling you dude, those loss % numbers that superstang.com gave are inflated. Yes, there will be a difference when comparing loss through a manual and loss through an auto tranny. The thing you gain in an auto tranny is consistency and never missing a gear. That can count for A LOT in a race, especially the brackets! A stock 4R70W tranny with a shift kit and an aux. trans cooler will be able to withstand a pretty decent amount of power. Putting 400 to the tires with one in that form would be no big issue. Being that this dude already is running a 4R70W tranny it would most likely be more expensive to swap to a manual versus refreshing his 4R, if needed, and installing the kit and cooler too. 400rwhp isn't a heck of a lot for a 4R tranny to need to hold. The 4R70W in mildly modded form is more than up to the task, and will surely not lose anything more than 20% through the slushbox if that.
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My point is, you have to spend more on the engine to get the same results you'd get from a manual....

At the end of the article, he states that many manual trans'ed cars lost 35hp at the transmission REGARDLESS of how much power was being generated...

SO.... 435 flywheel hp to get 400 rear wheel hp? Or 500 flywheel hp to get 400 rear wheel hp? Which would YOU choose in a NA 4.6? In fact, how much of a difference in cost are you looking at??
 
I would run from any engine builder who is still falling for that "Honda bearing" bullsh*t. That garbage is so mid-90s, and so full of crap that I'd horse whip him for even suggesting it.

Clevite Tri-Metals should be more than enough for your engine. People make over 1000 HP using Clevite Tri-Metals, so why would you go with anything else? I've made over 800 HP on them and never paid the price.

I swear, some engine builders try to be so revolutionary that what gets put together doesn't even make sense to the bastard who put it together. :rolleyes:
 
EconomySpeedNStyle said:
My point is, you have to spend more on the engine to get the same results you'd get from a manual....

At the end of the article, he states that many manual trans'ed cars lost 35hp at the transmission REGARDLESS of how much power was being generated...

SO.... 435 flywheel hp to get 400 rear wheel hp? Or 500 flywheel hp to get 400 rear wheel hp? Which would YOU choose in a NA 4.6? In fact, how much of a difference in cost are you looking at??
Click to expand...



Don't believe every article you read, no matter who it comes from. That 35 hp constant loss is total horsesh1t.

Having something such as drag be a constant number such as 35 is friggin stupid! It is a parabolic curve. The faster you go the more wind resistance you have. The same concept applies to drag within a transmission or anything else for that matter. It is simple physics. The more power you get the more power the transmission or other accessories will rob, which is why drivetrain loss is measured in percentages and not constant numbers. That 35 hp constant loss figure paired along with the 30% auto tranny drivetrain loss quote tells me that the person who wrote that either was a total moron, or they had an agenda. I am willing to bet the second one versus the first option; or maybe a mix of both. That is rampid in the racing world.

I trust those figures about as far as I trust a car magazine's 1/4 mile quote on a stock vehicle! ;)
 
I think that the reference to the Honda bearing is not necessarily the bearing material, it is a reference to the new size bearing he will be using as the crank was probably damaged and needed turning and the new rods share the same size as the honda on the big end.
 
Frogman, if you have custom shi!t in that motor, I wouldn't be suprised at all if you're running all manner of wierd bearing sizes (i.e. Honda sized bearings).

Often times, people will have billet cranks machined with smaller rod journals to shave weight, additionally, you may be running Honda size wristpins and such (also to save weight).

My 422 SBF uses standard Oliver billet 6.200" SBC connecting rods and bearings. Since my pistons were also custom made, I told them what pins and such to cut them for.

Oh, and I support Clevite Tri-Metals as well. :D King Alecular also makes nice bearings.

Paul.
 
Dr. Paul, that's what I'm eluding to, but he should get that from his builder's mouth.
 
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