Engine technology thread.

[Allch Chcar]

Originally Posted by Exage

With that being said I'm surprised they (the environmentalists) haven't tried making their own custom eco headers! Or have they and I just haven't bothered researching it?

Stock is usually fine, there's not much money in the eco parts except for trash like tornadoes... Eco can mean economical or ecological and they are not always mutually inclusive. An ecomentalist might pay $100 for an off the shelf eco header but they don't exist. It'd be custom work just like everything else. And there is far more lower hanging fruit than engine mods. Aerodynamics is easier/cheaper and pays off much quicker than the smallest of engine mods. And you'd have to be of stout heart to make your car as ugly as I've seen . Two words, boat tails.

[serialk11r]

Originally Posted by Allch Chcar

Wow, way to go guys, you turned this into a fuel efficiency thread .

lolol sorry I do apologize, I don't know much about cars as in like history, tuning, blah, so all I can talk about is thermodynamics and that sort of crap :P

I'm a huge nerd, so the engineering stuff is what makes me interested. Actually that's not exactly true, I find it kinda dull but for some reason I get a strange sense of satisfaction from thinking about certain real life applications. For example trying to squeeze the most fuel efficiency out of my mom's 4 speed auto 4WD 2.1 ton Honda Pilot is really really fun Getting the stupid torque converter to lock up and stay there is pretty tricky. Thankfully I play piano so my feet have pretty fine control, but that auto transmission has a mind of its own. Within a few days of learning to drive I swore I would never buy a car that didn't let me pick the gears myself (although I can justify CVT).

[Dimman]

Thread is just about Engine Tech. Fuel economy, and the deep details are valuable info too.

Edit:

Originally Posted by Allch Chcar

Two words, boat tails.

Just... wow...

[Zorro]

Originally Posted by Allch Chcar

Now who wants to discuss spark advance and air:fuel ratios! :P

keep going, I'm learning.

[Allch Chcar]

Originally Posted by Dimman

Thread is just about Engine Tech. Fuel economy, and the deep details are valuable info too.

Edit:



Just... wow...

[IMG]boat-tail-geo-metro.jpg[/IMG]

Bwahahaha Something like that does make a big difference, near 15% better MPG on the highway for the tiny geo metro for 50-60mph speeds. And some of the forumites I hang out with are crazy enough to do it too. But I hear the rubberneckers really get dangerously distracted by stuff like this so I wouldn't even consider it just for that reason . Even at the "low speeds" that cars travel with the heavy weights and poor rolling tires that are common, aero drag is the biggest drag force from 20-35mph on up.

Somebody can continue this anytime .

[Exage]

I'm surprised there isn't a big pole mark in the back of that tail! The rear window is covered and the passengers side mirror is removed. So all you have for backing up is that dinky drivers side mirror...

[Exage]

Xantonin you asked about Toyota Red vs Toyota Pink coolant in the other thread.

Toyota Red Coolant is a "Long Life" coolant. It is considered a Organic Acid Technology (or OAT).

Toyota Pink Coolant is a "Super Long Life" coolant. Hybrid Organic Acid Technology (aka HOAT). It offers longer service intervals then the regular Toyota Red. I believe it was introduced it 2002 and made it's way to the full Toyota line up around 2006.

In my owners manual it stated:

Coolant type selection

Use of improper coolants may damage your engine cooling system.

Only use "Toyota Super Long Life Coolant" or similar high quality ethylene glycol based non-silicate, non-amine, non-nitrite, and non-borate coolant with long-life hybrid organic acid technology. (Coolant with long-life hybrid organic acid technology is a combination of low phosphates and organic acids.)

Mixtures for USA and Canada (I won't bother)

Toyota recommends "Toyota Super Long Life Coolant", which has been tested to ensure that it will not cause corrosion nor result in malfunction of your engine coolant system with proper usage. "Toyota Super Long Life Coolant" is formulated with long-life hybrid organic acid technology and has been specifically designed to avoid engine cooling system malfunction on Toyota vehicles.

Please contact your Toyota dealer for further details.

And from Toyota: http://www.toyota.com/owners/parts-s...chemicals.html

Normal Green Coolant vs. Long and Super Long Life Coolants:

With the advanced metallurgy in todays engines and engine systems. What used to suffice 20-30 years a ago as green coolant that contained silicates, amines, nitrites, and borates etc.. would react with the materials in the new engines and cooling systems (particularly seals) and cause leaks. It doesn't happen instantly but over time the the coolant system would develop leaks. I don't recommended that you mix or replace Pink with Red if it is avoidable and I extremely do not recommend mixing or replacing Pink or Red with/to Green for the reasons stated above.

[xantonin]

Ah I see, thanks.

I flushed out my red fluid for some Amsoil coolant. 8)

[Matador]

You guys actually use OEM fluids?

[Exage]

Originally Posted by MatadorRacing_F1

You guys actually use OEM fluids?

I'm running 94 (PON) Octane gas (no ethanol), Amsoil 5W-30 for oil (but OEM filter), Redline MT-90 for transmission. Going to switch my brake and clutch fluid over to Castrol GT-LMA when I get the chance. And I might change the power-steering eventually (undecided on the brand).

For coolant top ups I do use the OEM coolant. And there is a very good chance I'll just keep it the same when I change it. As you can see I'm happy to "waste" money on fluids. The car would run just fine on less expensive stuff, but then again I'm not your average dopey driver/owner and I want to service this car for more than a couple years.

[xantonin]

Originally Posted by Exage

I'm running 94 (PON) Octane gas (no ethanol), Amsoil 5W-30 for oil (but OEM filter), Redline MT-90 for transmission. Going to switch my brake and clutch fluid over to Castrol GT-LMA when I get the chance. And I might change the power-steering eventually (undecided on the brand).

For coolant top ups I do use the OEM coolant. And there is a very good chance I'll just keep it the same when I change it. As you can see I'm happy to "waste" money on fluids. The car would run just fine on less expensive stuff, but then again I'm not your average dopey driver/owner and I want to service this car for more than a couple years.

x2

For a while I was using Royal Purple at 2,500 oil change intervals.

If the only thing changing fluids often hurts is my wallet then I don't really give a shit.

I am, however, experimenting with longer intervals but getting my oil tested at normal interval points.

[Exage]

Dimman Please take a look at this article. It's on the effects of the length of connecting rods and there respective ratios and hopefully it can explain it better than I can and help you! It's base is on engines producing peak power above 6000rpm.

http://www.stahlheaders.com/Lit_Rod%20Length.htm

It mainly effects the pistons acceleration, dwell, cylinder pressures, and ultimate force on the crankshaft. It also influences piston side loads and cylinder and bearing wear.

As you can see the simple change of connecting rod length can change the engines characteristics and wear on components regardless of stroke and bore size (though typically you'll have to change the stroke and/or revised pistons). As a result have to re-tune and optimize your ignition timing and fuel map, possibly even valve events (opening and closing) through different cams. Head work, intake manifolds, exhaust manifolds...

It's not impossible to do, but it requires a lot of thought, more then a couple of advice phone calls, time, and a ton of money for custom parts. Planning questions should go to a racing engine builder or the like for obvious reasons.

I really hope this helped you!

[NESW20]

that's the ONE thing i don't like about the stroker in my 3SGTE: my rod:stroke ratio is worse than stock. my engine is VERY picky about how much timing advance i can run, especially on pump gas.

pretty sure there's someone out there who has built a long-rod stroker in an MR2, but IIRC, it was pricey. *sigh*

[Dimman]

Thanks, Exage. I'll probably have to go over that a few times before it sinks in.

I wasn't particularly thinking of fiddling with my own rod/stroke ratio. My car's stroke is a tiny 71.5mm, which affects the piston speed when it revs right? Can you explain the forces on a piston/pin/rod when you rev (like 9-10k rpm range), or point me to a suitable site. I've seen some calculations for mean (average?) piston speed, but isn't it the peak speeds or how that relates to acceleration/direction change that is what kills rods?

Basically the Supra crowd is more about just adding boost. But my 1JZ seems more suitable for adding revs (with appropriate head work to flow enough air to take advantage of it) and I want to take a less common route to power.