400RWHP + 20MPG... How to do it??

kck6894 · Jul 25, 2005

NUTCASE said:
I don't think the whole % thing on drivetrains is all that accurate. it might work out if you have say, 300hp. but lets say you put a 800hp motor on the same drivetrain. I just don't see how the same trans is now going to soak up like 70 more hp just becouse you got a bigger motor. same thing with the drive shaft. how is a ds that soaks up lets say 25hp on a 100hp car now all of a sudden going to soak up 100hp just becouse you went to a 400hp motor

I don't remember where I saw it but someone was doing a study on that not too long ago. They dynoed a bunch of combo's and when they were done the % was the most acurate way to determine power loss at any power level. I will look around and see if I can find it and post a link.

FiveOfastback · Jul 25, 2005

Build a 300-325 RWHP motor and use a 100 shot of N2O
My 67 has 308 dynod RWHP and 410RWHP with a 100 shot on a plate system. Car gets 16-17 MPG on the highway
Motor is as follows
GT40X crate engine B cam
Long tube headers
650 Holley
MSD dizzy
Edelbrock rpm air gap port matched
1,7 roller rockers
Electric fuel pump set at 6 psi
jets in carb 71 front 70 rear
Gears 3.89 could probably get better MPG with 3.55's
WC T-5 trans
Non Aero 67 fastback body
225/5016 tires front 255/50 rear

Build a 300-350RWHP small block Car will run 12 all day and run high 11's with Nitrous. Simple as that!

MeanMussy · Jul 25, 2005

NUTCASE said:
I don't think the whole % thing on drivetrains is all that accurate. it might work out if you have say, 300hp. but lets say you put a 800hp motor on the same drivetrain. I just don't see how the same trans is now going to soak up like 70 more hp just becouse you got a bigger motor. same thing with the drive shaft. how is a ds that soaks up lets say 25hp on a 100hp car now all of a sudden going to soak up 100hp just becouse you went to a 400hp motor

It actually is modeled well as a linear relationship (i.e. a percentage).

Think of it this way. A bigger motor has more HP. There for it has the ability to spin things up quicker.
This means that the trans, driveshaft, axle, wheels, and all other rotating components are going to accelerate at a greater rate. Inertia doesn't change for these components, just angular acceleration. Whch means TQ required to spin them at the higher ramp rate will increase. Thus the losses due to spinning them will increase. Same goes for engergy lost (I use the term energy here, but power is just change in energy over a given amount of time...) due to heating, noise, and other losses.

So, drive train loss is essentially a percentage of engine HP.

MeanMussy · Jul 25, 2005

kck6894 said:
347CI 11.25:1 COMP
PORTED TW heads
AFM N-111 CAM
VICTOR 5.0 INTAKE
42LB INJECTORS
90MM THB
POWER PIPE
80 MM PRO-M AIR FLOW METER
1 3/4 LNG TUBE HEADERS
3" X-PIPE AND CAT BACK
92 OCTANE PUMP GAS
4.56 GEARS

Thanks man!!

That's A LOT of gear! And you still get those MPG numbers! Very nice! Very promising!!

Dbeck002 · Jul 25, 2005

kck6894 said:
347CI 11.25:1 COMP
PORTED TW heads
AFM N-111 CAM
VICTOR 5.0 INTAKE
42LB INJECTORS
90MM THB
POWER PIPE
80 MM PRO-M AIR FLOW METER
1 3/4 LNG TUBE HEADERS
3" X-PIPE AND CAT BACK
92 OCTANE PUMP GAS
4.56 GEARS

20 mpg with 4.56 gears? are you running a T56 with .52 overedrive? lol

kck6894 · Jul 25, 2005

I run a Tremec TKO. It turns about 3000 rpm at 70 MPH.

NUTCASE · Jul 26, 2005

MeanMussy said:
Thanks man!!

That's A LOT of gear! And you still get those MPG numbers! Very nice! Very promising!!

becouse he is spinning higher when he is crusing he is putting his motor in an RPM where it operates more efficiently.

if you have a h/c/i setup that doesn't kick in until 3000 rpm what makes you think lugging it at 1200 rpm is going to help you. force a motor into an rpm range for which it is inefficient is going to force it to consume more feul.

why do you think all these little *** cars and v-dubs that spin like 3500 rpm on the hyway still get like 40mpg

NUTCASE · Jul 26, 2005

wow, it even bleeps out j a p

grey5.0beast · Jul 26, 2005

a 7.3l turbo deisel! lol jk. maybe a good turbo setup and a good tune

vristang · Jul 26, 2005

NUTCASE said:
wow, it even bleeps out j a p

And *** should be bleeped. I find that offensive.

RICER is much more PC.

NUTCASE · Jul 26, 2005

vristang said:
And *** should be bleeped. I find that offensive.

RICER is much more PC.

ok....sorry

vristang · Jul 27, 2005

NUTCASE said:
ok....sorry

I hope you realized I was kidding.

It sounded sarcastic when I thought it in my brain. Sarcasm just doesn't type well.

Ranchero5.0 · Jul 27, 2005

With what's in my my sig running 75+ I average in town and highway around 18mpg per tank. Used to get 20mpg running 60-65. As said above, build it for torque and put a little boost on top for the bonzai runs.

FYI, at 2500rpm cruise speed boost is just a blip of the throttle away. The blower is helping even that low on the rpm.

If gas prices get really miserable I'll swap the 3.27's back in and pick up 2-3mpg with this combo, but lose a good bit of performance.

Jamie

olymaster · Jul 27, 2005

next thing youll see a geo metro with 50mpg and 500 hp

kck6894 · Jul 27, 2005

olymaster said:
next thing youll see a geo metro with 50mpg and 500 hp

How much nitros do you think a metro could handle?

QDRHRSE · Jul 27, 2005

kck6894 said:
347CI 11.25:1 COMP
PORTED TW heads
AFM N-111 CAM
VICTOR 5.0 INTAKE
42LB INJECTORS
90MM THB
POWER PIPE
80 MM PRO-M AIR FLOW METER
1 3/4 LNG TUBE HEADERS
3" X-PIPE AND CAT BACK
92 OCTANE PUMP GAS
4.56 GEARS[/QUOT

I'm not knocking this combo one bit but that 20mpg must have been going really slow.

cleanLX · Jul 27, 2005

stock motor, good exhaust, good meter, e-brock intake = 240+rwhp, 200 shot, done.
that's going to make darn handy 400hp a tthe wheels, and upwards of 450tq.
3.55-3.73 rear gears, 17-20 around town, 24-26 highway...
Doesn't get any easier than that.

kck6894 · Jul 27, 2005

QDRHRSE said:
kck6894 said:

347CI 11.25:1 COMP
PORTED TW heads
AFM N-111 CAM
VICTOR 5.0 INTAKE
42LB INJECTORS
90MM THB
POWER PIPE
80 MM PRO-M AIR FLOW METER
1 3/4 LNG TUBE HEADERS
3" X-PIPE AND CAT BACK
92 OCTANE PUMP GAS
4.56 GEARS[/QUOT

I'm not knocking this combo one bit but that 20mpg must have been going really slow.

Click to expand...

Well, actually I think it gets about 5 MPG in town (sometimes I have a hard time keeping my foot out of it ), but on the highway at 70 I get 20mpg. Almost all of my highway driving is on a 2 lane highway. Since it's a 60mph zone that also includes an occasional pass

400RWHP + 20MPG... How to do it??

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