Anyone else mod other than for econmoy.

[Phantom]

I also mod for power and should be adding 30-40hp after I fix the cracked motor mounts. The reason that I'm adding power is I love working on things and I will be removing a few restrictions when doing it.

My mods for the Bonneville are to be L67 TB (from supercharged version) this will remove the pumping loss from going from a 3" pipe to a 2.5" then to a 2.5x3.2" opening will now be 3" all the way to the intake. This will give me a bit better throttle response so I will not need to press the gas as much.

Then I am going with the revised upper intake that will replace the mating 2.5x3.2" opening that goes back to 3" with a 3" that has a slight taper to increase velocity and even out cylinder filling. I will be cleaning the lower intake runners at this time for smoother flow and reduced fuel pooling this also smooths acceleration.

The last thing I will be doing that adds power is replacing the upper runners this one is where most of the power is coming from but the good thing is the power is mostly added at 2500rpm and up and the lower rpm looses a little power due to a small drop in VE below 1700rpm. So as long as I stay under 80mph highway mpg should stay the same and under 68mph it should go up slightly due to the slower cylinder filling at that rpm.

My Grand Prix has this setup except for the intake runners and shorter gearing and both cars have achieved a best tank at 29.2mpg hw at 75mph in hilly areas and this is with out any aero mods.

[euromodder]

Originally Posted by skyl4rk

Give me efficient power mods so I can downsize my engine and reduce weight.

That's where they work.
And that's where the car manufacturers are applying them.

Make smaller displacement engines, turbo etc. them for high HP output that gets used infrequently, and take care that these measures don't hurt MPG during the more usual low-power driving.

[wdb]

In my book, performance is not all about adding power.

I put a front undertray on my Honda Fit. It provides a substantial improvement in stability at highway speeds, plus the car is more 'planted' in corners. And it gave me 1 or 2 more MPG.

Colin Chapman is famous for saying. "To go faster, add lightness". Another means of improving performance and economy at the same time.

[TheEnemy]

Any time you remove losses/improve efficiency you get more usable power, and better ecconomy when you keep your foot out of it.

I'm one that tries to find a ballance point. Main project right now is Ugly, it currently gets 15/15 and 1.6gph off road. Most of the mods that I am planning will give it both better power (for where I want it) and better ecconomy.

Such as higher compression (power through efficiency)
Friction reduction in the engine and gearboxes
Aerodynamics (for when I have it on the highway)

Lucky for me tuning for off road focuses on torque particularly at low rpm rather than raw power numbers. You would be supprised at the number of 4cyl 2000lb buggies that can go more places than the V8's.

My target for Ugly is 25/20 and 1gph.

[redyaris]

I have instaled an after maket header and a high flow muffler in the anticipation that it would also help fuel economy. My engineer family and friends pointed out that the throatle plate is the biggest restiction in the system and therefore even if the system has lower restiction then the stock setup, it only matters at wot, when using the maximum fuel! I use the exta power about once every month or two for seconds at a time. Not the smartest thing I've ever done.

[Phantom]

Headers can help at lower speed driving but it depends on how bad your stock headers are. On my car the stock header is welded on the inside adding a turbulent restriction as the exhaust leaves the cylinder, from there the inside of the primary is between 10-18% smaller than the one on the rear this makes for slightly uneven power. Opening this up to match the back frees power and balances the performance. Some people that have replaced this report a small increase in MPG but they are driving for performance not economy.

Remember that this will not hold on all cars and each situation needs to be evaluated separately.

[cleanspeed1]

Originally Posted by TheEnemy

Any time you remove losses/improve efficiency you get more usable power, and better ecconomy when you keep your foot out of it.

I'm one that tries to find a ballance point. Main project right now is Ugly, it currently gets 15/15 and 1.6gph off road. Most of the mods that I am planning will give it both better power (for where I want it) and better ecconomy.

Such as higher compression (power through efficiency)
Friction reduction in the engine and gearboxes
Aerodynamics (for when I have it on the highway)

Lucky for me tuning for off road focuses on torque particularly at low rpm rather than raw power numbers. You would be supprised at the number of 4cyl 2000lb buggies that can go more places than the V8's.

My target for Ugly is 25/20 and 1gph.

Can you explain "15/15" and "25/20"? Are you talking about city/hwy mpg?

[TheEnemy]

Originally Posted by cleanspeed1

Can you explain "15/15" and "25/20"? Are you talking about city/hwy mpg?

Highway/city mpg. When I'm on a trail its easier to measure how many gallons an hour I'm burning because the miles traveled will vary wildy depending on how hard the trail is.

[zepplin153]

My father an I are thinking of an engine swap in an older e series BMW he has. An aluminum Chevy V-8 weighs nearly 100lbs less than the factory I-4. The theory Is an over Powered car kind of like the new corvette which at speed gets nearly 30MPG. A 400HP engine turning @ 900RPM. The idea is do this in a smaller car with taller gears.
Which inevitably would possibly lead to better fuel economy....
So, Mod for Power for economy. YES!

[cleanspeed1]

Originally Posted by zepplin153

My father an I are thinking of an engine swap in an older e series BMW he has. An aluminum Chevy V-8 weighs nearly 100lbs less than the factory I-4. The theory Is an over Powered car kind of like the new corvette which at speed gets nearly 30MPG. A 400HP engine turning @ 900RPM. The idea is do this in a smaller car with taller gears.
Which inevitably would possibly lead to better fuel economy....
So, Mod for Power for economy. YES!

An LS swap into a BMW is a beautiful thing. Post pics if you go ahead and do it.