Car Enthusiast Club [Now Motorcycle friendly!] - First thread to 150k! ¯\_(ツ)_/¯

[vanished]

I was just reminded of something I've seen/heard of a lot that has never made sense to me and maybe some of you can shed some light on it one way or another:

I've always heard that running AC in the car reduces power or increases fuel consumption.  Of course this is true, it must be by physics, but also by physics, it should be by an insignificant amount.  A powerful AC unit might draw 1800 W, which is only 2.4 HP.  Even if it was really inefficient or a lot more power hungry, what are we talking, like, maybe 5 HP?  On a car with 140+, that shouldn't really be a big deal.

[vanished]

9 minutes ago, vinyldash303 said:

Thats all assuming 100% efficency. The electric window aircon runs at a constant rpm. Your engine doesnt. Automotive ac compressor will use more hp at a higher engine speed on track than it will on highway. That said on a track car they’re more worried about the few hundred pounds of ac equipment than they are the horsepower. 

 

On the freeway its better to use the ac than it is to have windows down. Because areodynamics. In town the opposite is true. 

 

It will be more noticeable on a 140 hp car than it will be on a 325 hp suv. Modern cars will actually decouple the compressor just as if it were turned off above a certain rpm at a certain throttle position. If you look at the tune file for my tahoe you can actually see these settings and fiddle with them

For sure on an actual race car I get why they don't include it, every last HP and lb matters, but I see people talking about this with ordinary sedans and stuff you drive normally in the city.  I guess I'd be curious to know just how inefficient it is then, and what a typical car AC unit would use in terms of power.

[FuzzyYellow]

Got a Topper for the Turdna! it was 5 hours away, but I got it for $100, so it was worth it. got 19 MPG on the way back. That's absolutely nuts for a 1st gen Tundra. they eat fuel like it's going out of style.

[Bitter]

On a ISF it's 10hp

 

 

Now on a 100hp car take 10hp and 10lbft of torque when you're cruising at 50hp holding 60mph.

[Bitter]

Just now, FuzzyYellow said:

Got a Topper for the Turdna! it was 5 hours away, but I got it for $100, so it was worth it. got 19 MPG on the way back. That's absolutely nuts for a 1st gen Tundra. they eat fuel like it's going out of style.

Got some weight reduction too I see! The giant mono-brow surely does not help at highway speeds!?

[FuzzyYellow]

Just now, Bitter said:

Got some weight reduction too I see!

yep. Body is one of the next things on the list, after suspension. I don't know how updated you are on this truck, but Toyota replaced the entire frame, lower control arms, brake lines, etc. back in February.

[vanished]

2 minutes ago, vinyldash303 said:

Sitting in traffic in my s10 it would consume an additional 0.1 gallon per hour. Engine idling in gear would burn 0.44 gph. Ac clicks on and it would bump up to 0.52 ish. Once you were moving you couldnt really tell. In my tahoe i haven’t really looked. You can tell once you’re moving. Like going up a hill in 3rd gear, then hit the button to turn off ac, you can feel the engine pull a little harder.

 

it depends on how much power engine makes and how big of compressor is on it. Tahoe has much larger compressor because the cab is huge vs the s10. Also has front and rear ac so thats two systems on one compressor, has to be even bigger. 

Yeah I seem to remember it being around 0.1 - 0.2 L/h in a TDI Jetta when idling

[Flying Sausages]

[RevoltTrain]

7 hours ago, vinyldash303 said:

Cylinder deactivation kit for my 2007 Tahoe from Texas Speed arrived today. 

So glad you took my recommendation for the TSP bumpstick, thing is gonna be lowkey cool with the cam, and exhaust work you're doing. Honestly if you have extra funds would recommend an open air intake, they just make everything sound better

1 hour ago, FuzzyYellow said:

Got a Topper for the Turdna! it was 5 hours away, but I got it for $100, so it was worth it. got 19 MPG on the way back. That's absolutely nuts for a 1st gen Tundra. they eat fuel like it's going out of style.

Got that good old fashioned midwest weight reduction

 

Rust is lighter than carbon fiber

[dcgreen2k]

38 minutes ago, RevoltTrain said:

Got that good old fashioned midwest weight reduction

Rust is lighter than carbon fiber

Don't have to worry about weight reduction if there's nothing there in the first place

[iDeFecZx]

8 hours ago, TVwazhere said:

Your Type R doesnt have air conditioning or good speakers? Sounds like a race car to me

 

If you think that's firm, you'll hate the Koni spring's lowering springs I got. Definitely a lot firmer (but for me not unbearable) I tend to avoid pot holes, though occasionally I do hit one and the car hits so hard I fell my soul leaving my body

The speakers in the civic are that bad that anything over 10 volume gets badly distorted and its still not even loud lmao.

The rides by no means awful I just forgot how stiff it was compared to both its older contemporaries

[Ordinarily_Greater]

Hello car enthusiasts

 

As someone who's always interested in stock cars and live in the JDM area, I couldn't help myself to want a Civic FD as a daily street car.

The looks and performance seemed perfect to me. Also i am new to the car modding community.

 

So if i ever bought one, i will prepare for the mods that i will do:

1. a real exhaust design that works and looks like the one in the picture i put, and i have been said that for a stock engine (yes imma leave it stock), you dont put dual rear exit so... i guess single rear exit with a branch to 2 holes?
2. Tires, Brakes, lighter Rims, any recommendations for street use?

Thats pretty much it, thanks everyone

 

P.S. anyone have a civic fd as well? have u tried this bodykit?

downloadfile.bin

[iDeFecZx]

53 minutes ago, Ordinarily_Greater said:

Hello car enthusiasts

 

As someone who's always interested in stock cars and live in the JDM area, I couldn't help myself to want a Civic FD as a daily street car.

The looks and performance seemed perfect to me. Also i am new to the car modding community.

 

So if i ever bought one, i will prepare for the mods that i will do:

1. a real exhaust design that works and looks like the one in the picture i put, and i have been said that for a stock engine (yes imma leave it stock), you dont put dual rear exit so... i guess single rear exit with a branch to 2 holes?
2. Tires, Brakes, lighter Rims, any recommendations for street use?

Thats pretty much it, thanks everyone

 

P.S. anyone have a civic fd as well? have u tried this bodykit?

downloadfile.bin 39.76 kB · 3 downloads

Is this an FD2 Type R or a regular one?

If its a Type R then Mugen are the goto place for a good sounding exhaust system. 

[Euchre]

That 'Triumph Acclaim' some posts back is really a Honda for sure, just manufactured by BL in the UK with their own badges on it. Straight up the same car as the early 80s Honda Civic sedan in the US otherwise.

 

As for the AC thing, in a vehicle with '140hp', that's peak output, at high RPM. The lower the RPM, the greater the impact of a 5hp load vs the output of the motor. If you make 50hp at 900rpm, you're losing 10% of power - that's a seriously noticeable difference. When you are accelerating from a dead stop, you want to turn off AC if you want max power to get up to speed quickly. This is why most vehicles disengage the AC clutch when you go full throttle at low RPM. I have the totally separate AC switch on my car, so when I do come to a full stop on rural roads that have high speed limits (45mph+), I kick it off until I'm back up to speed again. With recirculation turned on (also a discreet control on my car), I barely feel a drop in the temp of the air being blown out, before I re-engage the AC compressor.

[3 Lions]

1 minute ago, Euchre said:

That 'Triumph Acclaim' some posts back is really a Honda for sure, just manufactured by BL in the UK with their own badges on it.

Yep I did actually say that in my post. 

[Ordinarily_Greater]

1 hour ago, iDeFecZx said:

Is this an FD2 Type R or a regular one?

If its a Type R then Mugen are the goto place for a good sounding exhaust system. 

its gonna be a regular 2006 manual or matic (paddle shifts FTW) FD, and im planning to bodykit with the one in the image. A silver mugen RR concept i guess

 

my plan is im gonna find a centered single pipe then route it to those fake "tips" so they actually do something.

 

hopefully this car (manual, silver) is what im getting, hopefully in 2 years someone will sell a fd like this again

[Ordinarily_Greater]

1 hour ago, iDeFecZx said:

Is this an FD2 Type R or a regular one?

If its a Type R then Mugen are the goto place for a good sounding exhaust system. 

its gonna be a regular 2006 manual or matic (paddle shifts FTW) FD, and im planning to bodykit with the one in the image. A silver mugen RR concept i guess

 

my plan is im gonna find a centered single pipe then route it to those fake "tips" so they actually do something.

 

hopefully this car (manual, silver) is what im getting, hopefully in 2 years someone will sell a fd like this again

[AlwaysFSX]

17 hours ago, Euchre said:

That 'Triumph Acclaim' some posts back is really a Honda for sure, just manufactured by BL in the UK with their own badges on it. Straight up the same car as the early 80s Honda Civic sedan in the US otherwise.

 

As for the AC thing, in a vehicle with '140hp', that's peak output, at high RPM. The lower the RPM, the greater the impact of a 5hp load vs the output of the motor. If you make 50hp at 900rpm, you're losing 10% of power - that's a seriously noticeable difference. When you are accelerating from a dead stop, you want to turn off AC if you want max power to get up to speed quickly. This is why most vehicles disengage the AC clutch when you go full throttle at low RPM. I have the totally separate AC switch on my car, so when I do come to a full stop on rural roads that have high speed limits (45mph+), I kick it off until I'm back up to speed again. With recirculation turned on (also a discreet control on my car), I barely feel a drop in the temp of the air being blown out, before I re-engage the AC compressor.

Sounds like a problem for torqueless engines only.

[Automobili3XF]

Got myself a Renault again, this time a Megane Grand Tour, 2L engine and 6 speed manual.

Its also my first wagon ever, in fact the first wagon i've ever driven.

[Euchre]

6 hours ago, vinyldash303 said:

One of the other students in my high school autos class had a Tercel stickshift. Not sure if it was the 3 cyl or 4 cyl. Thing was so... idk. We’ll say ‘rough around the edges’ that if you had the AC on and came up to the stopsign with AC on the engine would stall. Also on steeper dirt roads you had to ride the clutch because it didnt make enough torque to keep the vehicle moving. 10/10.

I've never seen a Tercel with a 3 cyl engine, but it sounds like the one you refer to may have been lacking any function of one of the 4 cylinders it had. The ones I drove were no sports cars, but they could certainly handle driving without riding the clutch and the AC wouldn't stall them.

 

8 hours ago, AlwaysFSX said:

Sounds like a problem for torqueless engines only.

I said 900rpm, not 9000rpm. That's close to idle speed for most engines, and even some large V8s don't make over 100hp below 2000rpm, because they don't start making much torque before then. In the real world of driving, people don't usually launch off of stoplights at 2k rpm, dumping the clutch or power braking, even when driving relatively aggressively.

[iDeFecZx]

2 hours ago, 1984_C10 said:

Got myself a Renault again, this time a Megane Grand Tour, 2L engine and 6 speed manual.

Its also my first wagon ever, in fact the first wagon i've ever driven.

@Mr.Dingle Megane friends

[bcredeur97]

2 hours ago, Euchre said:

I've never seen a Tercel with a 3 cyl engine, but it sounds like the one you refer to may have been lacking any function of one of the 4 cylinders it had. The ones I drove were no sports cars, but they could certainly handle driving without riding the clutch and the AC wouldn't stall them.

if a mitsubishi mirage with a 1.3L 3 cylinder can work fine then I'm sure there was something wrong with that Tercel too...

[chaozbandit]

 

[bcredeur97]

Since it was related to recent conversations...

 

[Energycore]

11 hours ago, 1984_C10 said:

Got myself a Renault again, this time a Megane Grand Tour, 2L engine and 6 speed manual.

 

 

Its also my first wagon ever, in fact the first wagon i've ever driven.

How do you like the ride?