SleeperX

What is the best way to lower/manage the temperature in the engine?

1) Higher octane fuel
2) Meth injection
3) Lower the compression in the cylinder
4) etc.

V12Godspeed

I am doing this by 2 ways...

1. I have a meth injection which seems to be working pretty good right baout now. I only use it on hot days. When I ran the 11.9 I ran it with the meth in that heat!!!

2. I am running straight 100 Octane, since I only use my cars on weekend I could afford to run it for now until my pocket gets dry...at 7.49 a gallon I don't know how long I could keep this up. lol!!!! Talk about a boost, the car feels like it's on steroids.....

3. Thinking about it stil...l, my tech says to shave the heads to bump up compression to 10.5 and run C16....

BrianS

Larger capacity radiator with thermal coating?
One heat range colder plugs?
Better ventilation through the engine bay?

SleeperX

Thanks.. Does the Meth lower your engine temerparture or your IATs?

SleeperX

Thanks..

SLK55R

I use all 100 octane but its only 5.30 a gallon here

SleeperX

Does anyone have the link for gasoline stations that sell 100 octane by state.

Zod

hmm you see I was always wondering how your car coupes with heat. You see allot of people mention that the heat is the killer, yet in your vids you showed us high speed runs vs no need to mention (x car name) and your car was fine.

Now I know you have a bigger pulley now, which means more heat, but my question is this:

How much more heat is it generating compared to before?

Did suffer from heat sock before, but not as much?

Am just curious

As for what cooling mods:

• Bigger heat exchanger (a lot of members now going custom, many examples available with proven gains)
• Or the evo / renntech cooling kits
• -10c fan (think its done through ECU)
• Pte thermostat (heard about it, but do not know how it works)
• Evo / VRP spacers
• Headers which you have (coated) to help with heat
• Some exhaust work (race cat or cat removal)
• And the biggest of them all SLR top mounted intercoolers

but with the prices of 65s and 600.... one must rase the question. I know i am as i saw 3 sl65 for the same price i paid for my car

SleeperX

I think you are confusing heat soak which is caused by higher IATs with higher engine temperatures. My car used to heat soak... I don't think it does anymore ...

Zod

Oh! then forgive me and do please explain .
I know AIT is air intake temp, which means outside air coming into the car, yes?

so how does engin heat differ? if outside air is hoter then engin will be hoter no? and vis versa?

also please tell how you solved heat soak? As i live in extramly hot environment!

SleeperX

Larger heat exchanger and seperate the cooling system.
The engine temperature that I am referring to is the temperature in the cylinder...

JAYCL600

When you say cylinder I think you are referring to combustion chamber, please correct me if not. If so why do you want to lower the temp there?

edit: i believe you want a certain temp but obviously not too hot or u run the risk of detonation, higher octane fuel helps with this, as well i think there are certain thermal coatings u can put on the internals to assist with the transfer of heat.

J

SleeperX

Jason,
How is it going? Pm (can't be) sent.... Your in box is full.

chiromikey

i'm not sure you want to lower engine temps. higher engine temps (to a point) are more efficient and create more power. the only reason people should try to cool engine temps is as a bandaid to cool iat's because they haven't seperated their i/c coolant from their engine coolant.

imho and at the most, run pte's 160* thermostat and the -10* fan mod. if for some reason you are experiencing high enough engine temps for the ecu to control knock then rule out a cooling system problem and then suppliment with a few gallons of 100 octane because we all know how crappy gas blends are nowadays.

is there a specific problem you're trying to cure?

JAYCL600

+1

my PM box is cleared just for you Frank

BrianS

Try here...

http://www.sunocoinc.com/site/Consum...T100Locations/

SleeperX

Thanks.....

phatmitzu

Good stuff! Theres one by my work in Los Angeles!

V12Godspeed

my IAT's. but since I have gotten the monstrous HE don't seem the need to use it...unless under a very hot day and hard driving.

phatmitzu

I wonder why not many interests in doing this?

SleeperX

http://www.superchargersonline.com/content.asp?ID=104
FEATURES :: ENGINE TUNING & MAINTENANCE
Detonation, Knock, and Pre-Ignition 101
8/4/2003 1:59:00 PM



As you probably have already figured out, detonation (aka "knock") is a big issue in the world of forced induction. You probably know that detonation is a bad thing, and that by adding a supercharger (or any forced induction power adder), you must take additional measures to avoid detonation, especially if your engine has other modifications. Normally the simple solution to stop detonation is to run higher octane fuel... but before we get ahead of ourselves, let's start from the beginning.

What is detonation / knock?

Under normal conditions, the combusting air and fuel mixture inside the combustion chamber ignites in a controlled manner. The mixture is ignited by the spark, normally in the center of the cylinder, and a flame front moves from the spark towards the outside of the cylinder in a contolled burn. Detonation occurs when air and fuel that is ahead of the flame front ignites before the flame front arrives because it becomes overheated. Under these conditions, the combustion becomes uncontrolled and sporadic and often produces a pinging noise, or a "knock" noise when the conditions become worse.

So far, detonation sounds cool... why is it bad?

Detonation is definitely not cool. Detonation causes sudden pressure changes in the cylinder, and extreme temperature spikes that can be very damaging on engine pistons, rings, rods, gaskets, bearings, and even the cylinder heads. Even the best engine components cannot withstand severe detonation for more than a few seconds at a time. More severe detonation obviously leads to more severe forms of engine damage. If there is enough heat and pressure in the combustion chamber, detonation can begin to occur before the spark plug even fires, which would normally initiate the combustion. Under these circumstances, known as "pre-ignition", the piston may be travelling up towards a wave of compressed, exploding gas. These are the worst kinds of detonation conditions, and can bend con-rods and destroy pistons.

What causes detonation?

Detonation occurs when several conditions / factors inside the combustion chamber exist at the same time. Increased compression, high temperatures, lean fuel/air mixture, advanced ignition timing, and lower octane fuels are all factors that PROMOTE detonation conditions. The good news is that, because there are so many factors in play, you can always find a way to eliminate detonation if it exists.

So, where do superchargers fit in?

A supercharger increases the amount of air inside the combustion chamber (see "Bye Bye 14.7 psi"), which in turn increases the compression inside the combustion chamber. Along with increased compression comes higher temperatures and higher pressures, which as we know, tend to increase the chances that some form of detonation will occur. In order to compensate for the increased compression and heat, we must change one or more of the other factors / conditions to move us away from our detonation threshhold. Tuning the supercharger system to the engine in this way for maximum performance without detonation is something that supercharger manufactuers do so, chances are, you won't have to worry about it unless you do other modifications to your engine that place you closer to your detonation threshhold.

How do I get rid of it?

The two most common tricks used by supercharger manufactuers and engine tuners looking to obtain maximum performance without detonation is 1. use higher octane fuel, and 2. retard the ignition timing.

Higher octane fuel burns more controllably and is not as likely to combust before the flame front. This is why racing engines use 100+ octane gasoline. The ONLY benefit of racing gasoline is that it moves you away from the detonation threshhold, which allows you to be more aggressive with power producing factors - i.e. raise compression, advance timing, etc. This is why you'll be disappointed if you put racing gasoline in your mom's bone-stock '82 Toyota Cressida thinking you'll turn it into a race car. If you don't have detonation, the increased octane will do you no good. For cars designed for daily street driving, you obviously won't want to fill up with 100+ octane fuel every week at the tune of 5 bucks a gallon. This is why supercharger manufactuers tune their supercharger systems to run properly without detonation on 91 octane fuel - aka "premium" at your local gas station (in some states premium gasoline is around 93 octane).

Retarding the ignition timing will delay the timing of the spark, which also moves you away from your detonation threshhold. Most popular "power programmers" or "chips" increase engine power by advancing the ignition timing, and requiring you to run a higher octane fuel to avoid detonation. These work great, except the advanced ignition timing is NOT compatible with most superchargers, unless you're happy to run 100 octane fuel. In fact, many supercharger systems include an "ignition boost retard" that retards the ignition timing when it senses boost from the supercharger. This allows you to maintain stock performance while not under boost, yet still remain safe while the supercharger is making its boost (and power).

Another way to avoid detonation is to cool the incoming air charge to lower the temperature inside the combustion chamber. On a supercharged application, this task can be handled by an intercooler (see "Let's Talk Intercoolers") or by a water injection system (less common). The intercooler takes the incoming air charge and passes it over a series of air-cooled or water-cooled fins and ducts, thus cooling the air in the same way that a radiator cools your engine's coolant. Intercoolers are thus very popular in higher output supercharger systems, where detonation becomes more of a problem. Often times, the intercooler allows you to run more boost and also allows you to eliminate the ignition boost retard, meaning you'll notice increased performance, and still experience no detonation. Another way to lower the temperature of the combusting air and fuel is to run cooler heat range spark plugs. Many supercharger manufacturers will recommend cooler plugs for you supercharged engine.

Because lean condition (fuel starvation) also contributes to detonation, it is important to make sure that the fuel system (pump, injectors, etc.) is capable of delivering the increased fuel requirements of the supercharged engine. Often times, an otherwise perfectly tuned engine will experience detonation just because the fuel pump can't deliver enough fuel to the engine. Upgrading certain fuel components is almost always necessary when supercharging an engine. Most supercharger systems normally include the upgraded fuel components if they are necessary. If you are installing a supercharger on an engine with other modifications, make sure you consider the additional fuel requirements and compensate with larger injectors and / or a bigger fuel pump.

Some modern vehicles come with "knock sensors" that listen for detonation, and automatically retard the ignition timing to eliminate detonation. Although these devices are effective in preventing engine damage, they are not tuned for performance, so you should not rely on the knock sensors and expect your engine to run its best.

Conclusion

Altough detonation can be potentially damaging to an engine, a simple understanding of what it is, and what causes it, will help you stay away from your detonation threshhold. Pay attention to "knock" and pinging noises that come from your engine becuase they could indicate detonation inside the combustion chamber and should be dealt with immediately. If you're looking for a new supercharger system, don't worry too much about detonation - the manufacturers have designed the system for use on your stock engine, and if you follow the manufactuer's fuel recommendations, you will not have a detonation problem. If you ever do notice detonation, perhaps from bad (low octane) gasoline or extremely high air temperatures, just drive with a light foot until you are able to resolve the cause of the problem.

Sunny55

That is great to know. Good find!

mclarenm8d

I've wondered about colder plugs myself ... basic laziness as to why I haven't done it. I did a quick scan of the engine comparment and decided it's not something I want to tackle on my own and I didn't want to explain why I wanted to do it to the technician that works on my car. I know it would make my car run rougher in the winter, but I would take that.

SLK55R

Forgot to add that I am running one range colder plugs. For me its just getting the V12 plugs.

V12Godspeed

WHat does this do? Some one please explain....