Performance Myths...

[GlassWolf]

DUDE - are you thinking INTAKE? No throttle body I've EVER seen has coolant run thru.
You MUST be thinking intake.....

I was thinking intake manifold, too.

A heated TB. Okkkkkkkk......
Let me explain. On Turbo-diesel, all the normal "bolt-ons" make MAJOR gains due to the fact that they increase the BOOST of the turbo.
Not so on normally aspirated vehicles....

just for the record, a lot of them also monkey more importantly with the fuel/air mixture, which also allows for more boost.
This also often leads to upgrades in fuel injectors, fuel rails, and intake/exhaust, as well as transmission upgrades just to handle the added torque and HP gains.

I've seen trucks done with "bolt ons" mostly that put out over 600HP and 1000lb-ft of torque from big diesels. Those things are insane for moving things.. like the random house or building.

I just want to explain a little further......
To be exact: I have a Dodge Ram 5.9 (360ci) V8.
Glasswolf - stick to things you know (maybe car audio?) but definitely not new car/truck performance.
I'm not trying to be a jerk, but ALLLLLLLLL new transmissions have OVERDRIVE, or 5 speed, which negates your gas mileage because of overgearing theory.
Check out 4.56 gear reviews on dodgetalk.com.
Ok, now I understand, you have a diesel. diff animal. planning on one myself shortly.....
and ceramic coating not even relevent! My JBA titanium ceramic only controls under hood temps. (they claim!)

overdrive is just a sub -1:1 gear ratio. usually about .69 to .78 to one.
If you change the gearing in the rear diff, it will alter gas mileage with or without overdrive. The extent it affects mileage will vary based on that ratio.

I don't have a diesel. I used them as examples. I have a 66 Charger (3 actually) with a stroked 440 (496) the entire car I built from the ground up. I have an A727 trans with a GV OD unit. 4.11 gears, 3.23 with OD. If I went to a 3.91 or 3.55 rear end and engaged the OD, the top OD gear would drop correspondingly.

Ceramic coating serves two purposes if it's done right actually. Aside from reducing heat in the engine compartment, thereby increasing efficiency, it also prevents the headers from rusting out from the inside within a matter of a few years, as non coated stel ones are prone to do. I recommended ceramics so they'd last. Not to improve performance, aside from reducing temperatures in the engine bay which helps. I prefer tuned, full length headers. Not shorties, block huggers, or cheap ones with crappy poorly engineered collectors. Not everyone wants to blow $700 on a set of headers though.

In regards to gearing, it's also not just about the final gear ratio. It's also a matter of how closely the car is geared. Some cars have a very steep first gear so the car leaps off the line, then it hits second and lurches out of it's powerband. Others are close-ratio and do better at longer runs, but aren't as quick off the line. It's a matter of deciding what you want the car to do. There are always trade-offs to everything. Including gear ratios and acceleration versus top end.

I run 10.20s in the quarter. I'm fairly confident I have a fair knowledge of what I'm doing, but by no means do I know everything there is to know about anything. I think my 0-60 is probably in the twos somewhere but never timed it. 60' is 1.6s.

hotter plugs are only used for high comp engines or Forced Induction engines. if any gas is left in the cylinder after combustion, detenation has a higher chance of occuring. 'hot' plugs burns off as much gas possible.

mm hotter plugs aren't always better in every engine. I've seen just as many cases of poorer outcomes by running the wrong plugs for an engine based on compression, fuel octane, etc.. as I have of improving anything by doing so.
Know what you're doing before taking the more is better approach to any situation. That's general advice. Not directed to anyone specifically.

forgot underdrive pulleys. Didn't see a much gain. don't recommend, especially if you have a hi-power audio system!!

an underdrive pulley on an alternator will hurt for output of current, but for performance you can gain around 10-15HP on a typical 4.6L mustang GT with a simple pulley swap.
an underdrive pulley on a supercharger makes a huge difference :)

[Jonathan]

You use a colder plug with higher compression/Forced induction, not a hotter one

Heat range refers to how much heat the plug removes from the chamber, not how hot the spark is. Colder plugs have shorter insulators, meaning a shorter path for heat to travel to the water journals in the head and more heat dissipated from the chamber. This makes the plug itself operate at a lower internal temperature, which is why it's called a "cold" plug.

Hot plugs are made to have a higher internal temperature in order to burn off oil and carbon deposits, it has nothing to do with spark quality or intensity

Too hot and the center electrode blisters and you melt the electrodes, and the overheating of the plug will cause detonation/pre-ignition. Too cold and the plugs will foul and the engine will likely misfire. There is an optimum heat range to keep a plug in (tip temp should be between 450C and 850C), and that range will be determined by the specific application. Advance the timing, up the compression, add boost, things along those lines will mean going to a colder plug down the road. But general rule of thumb-if the plugs are fouled, you need a hotter plug. If they've been overheating, you need a colder plug. Of course that's assuming that everything else is in proper tune.

[GlassWolf]

note if you really want a full, clean burn, use an MSD style ignition box. 2 or 3 firings per power stroke as opposed to the conventional single fire per stroke guarantees a better burn of anything in the cylinder.

If the car is older, going to an MSD ignition system and a stronger coil with electronic distribution is a major improvement as well over the older style magnetic distributors.

[brent]

the belief that higher octane fuel automatically makes any car run better.
octanes are supposed to match compression ratios. more isn't always better.

Whoa, this is a biggy. You know how many idoits are out there right now running 93 octane in a completely stock vehicle. It is amazing. They can't even here the fuel pings. IMO this all goes back to the small block and big block days of the past. Newer vehicles are not made to burn off the carbon deposits from higher octanes. I dunno, this is why I drive a chevy truck with an old school 400 small block that will smoke pretty much any import on the road.

[GlassWolf]

I can run premium pump gas, but my engine is happy with 100 octane rocket ruel, too. I mainly keep the toluene mix for the strip, though.