GI_Jim

Just as a note guys, be sure that your octane rating does NOT include MTBE or Methanol which are just additives and can reduce the energy value of the fuel. I found this article also and I can relate to the part about how higher octane means less power. I hap a 94 S-10 with a 4.3 V6 CPI and tried running 93 when it called for 87. The 87 definitley gave me more power from the engine. Also as a guess from me couldn't you just take same amounts of both types of gas, burn them in a beaker or some other way and then determine the amounts of carbon and debris produced to see if there really is a quality difference? N E way here is the topic. August 27, 2003 “I only use super/premium/performance/ high octane fuel in my Civic DX. I can feel the power…” This is probably one of the biggest misconceptions in the automotive world, as we know it. Yet, I hear this all the time. For example a close friend of mine who drives a 1996 Pontiac Bonneville tells me that he only uses Chevron 92 octane fuel because “It performs so much better, and my fuel economy is way higher.” This opinion or misconception is not an isolated view to the “gear-heads” that are or think they are car savvy. And the oil companies don’t help the matter by calling their high-octane fuels “Performance” or “Premium,” or whatever they choose. Here is why. The first thing we have to know is obviously, what is octane and why does it matter? Octane can be simply defined in one sentence: Octane is a rating of a fuels resistance to ignite (evaporative qualities). WAIT A MINUTE! Resistance? That’s right, resistance. To put it simply, the higher the octane, the harder it is to get to ignite. Higher-octane fuel resists burning. Lower-octane fuel does not. Lower-octane fuel is actually more explosive, move volatile, and creates a much bigger explosion then its higher-octane counter-part. When you go to the pump to fill your car, you generally have three options. Regular, mid-grade, and super. You also see that there is a rating system. It is a sticker posted to the pump next to the octane rating of the fuel that you choose. It generally says something like this. Regular for example: 87 Octane minimum, measured by using the (R+M)/2 rating. What does this mean? The R in the equation stands for Research Octane Rating, known as RON. This is a test that tries to simulate variables that your car would go through on a given day. It is a test using a single cylinder, four-stroke engine that is idling at 600rpm. The fuel temperature going into the engine is not controlled. It is allowed to vary and fluctuate with the temperature of the conditions at the time. The intake air temperature is varied with barometric pressure to simulate the air being sucked into the car from the outside. The timing is set at 13° BTDC. This is done to covert everything to a SAE standard day, which is 60° F, 0% Humidity, and 29.92 inches barometric pressure. The M in the equation stands for Motor Octane Rating, known as MON. When testing MON, the fuel is heated to 300° F and the intake air is heated to 100° F. The test engine is a single cylinder 4-cycle engine that is run at 900 rpm. Ignition timing is varied with compression ratio. Engine load is varied during test. If you are deciding what fuel to use on a high-compression, high-performance engine, this is the test you would want to use. The RON will always be higher than the MON. So what does this all mean when you go to the pump? It means that to extract the most from the car that you are driving, you have to use the appropriate octane fuel or the car is not going to perform up to its potential. Either the fuel will burn too slowly, and in many cases not burn completely, or it will burn too fast and out of control. The latter is called Detonation. Normal combustion will take place at a pretty steady rate (for a given rpm and load), when a large amount of the charge burns extremely fast and uncontrollably, it is know as detonation. Detonation can destroy an engine in a matter of seconds. There are a few causes of detonation. Usually it is attributed to too much heat, but that is only part of the problem. Pressure and advanced ignition timing both play a role in it too. Usually when detonation takes place, the detonation occurs on the intake side of the chamber, which is the coolest side of the chamber. This happens because detonation did not occur until the pressure got excessive, which was after the spark. By the time that happened, the charge near the exhaust valve has already been burned. Most of the time, detonation will occur after normal combustion has started. Apart from destroying pistons and spark plugs, light detonation can cause all sorts of other problems, like fatiguing cranks and rods quickly and pounding bearings to death, so avoid detonation at all costs. Another problem is Pre-ignition (for cars using octane that is too low). When the charge lights off before the spark, it's called pre-ignition. This can happen with or without detonation, but usually will cause detonation in a high performance engine. Hot spots in the combustion chamber are the usual cause of pre-ignition. This is very unpredictable and can lead to detonation, because it will act just like too much ignition timing, but it won’t be controllable. So this is what happens in cars that use octane ratings that are too low, but what about vise-versa? Generally, the problem with using an octane rating that is too high for your car causes problems that, while not generally as severe as going too low, are still detrimental to the performance and efficiency of your engine. One of the most common problems is lost power. Yes, you read that right, if you use an octane of fuel that is too high for your car, you will lose power. This goes for all the stock or lightly modded Civics out there. Remember when we discussed that octane measures the fuels resistance to burn? Well, this is where that really comes into play in a low compression engine, such as the engines found in 90% of all streetcars. As the fuel is injected into the combustion chamber and the compression stroke begins, cylinder pressure is created. This is vital to combustion as cylinder pressure is what translates into power. When that pressure is not high enough (low-compression), the fuel only partially ignites. This means that there is leftover fuel that has to be expelled through the exhaust valves and expelled through the exhaust. This is bad for several reasons. The first is that this un-burnt fuel leaves deposits and grime all over the cylinder and valves. This robs you of power, fuel economy, and wears engine components pre-maturely. There is also a vital part of any streetcar, the emissions control devices. The catalyst for example often is destroyed by being clogged with carbon and un-burnt fuel resulting from using too high-octane. This results in costly repairs, and guess what? The loss of power and lower fuel economy. Not to mention, you had to pay $.20 more per gallon just to lower your cars potential and performance. So you guys that think that adding 100 octane race gas to your Civic Ex at the track is going to improve your times, you are running in the wrong direction unless you have some kind of forced induction such as Nitrous, Turbo, or Super Chargers. So the next question people ask is, “Why then do high-power, ultra-fast cars use high octane fuel?” Well the answer is simple. Higher-octane fuel contains more POTENTIAL energy but requires the higher heat generated by higher compression ratio engines to properly condition the fuel to RELEASE that higher potential energy. Here is the general rule for choosing octane if you have a question of what it should be. If your compression is 9.5:1 or lower, 87 octane should be plenty. As your compression rises, so should the octane that you choose. Remember that there are variables to everything in life and this is no exception. If you have dramatically advanced ignition timing for example, high-octane may be needed. But for the vast majority of the people on the street, for optimal performance in your streetcar, use the octane best suited for your car, and remember, high-octane does not mean more power! Coby Burns (Writer of above topic not forum poster) Found this at http://www.speedupgrade.com/articles/article/692608/5136.htm

No the LS does also at least my 93 does. It is behind the lining in the back.

Just to let everyone know a lexus will outrun a chevy impala with a police interceptor package. I occasioally drive one on duty and it has no where near the power of my lexus. But just remember no matter how fast your CAR is our RADIOS are much faster. B)

ayan, For the subs and amp I had Circuit City install them and will also have them install the new alpine dvd unit in there with a couple of screens in the back (the dash kit isn't shipping for 3 more weeks and the other stuff will be done a little later), also a lot more things but to get back to your question. Yes they did a really good job on the install. Along with being in the military I work at CC. They warranty all the work they do for the life of the car and if you ever sell the car or get a new one and want to transfer the system it is free. Don't let them tell you that they can't do an install on the car if you want one. ( they will sometimes do that. ) If you decide to and there is any trouble or questions just contact me at james.hilderbrand@us.army.mil and I will take care of it.

I understand what you mean. This was a while back and in retrospect a stupid trick. I have definitley slowed down since just because I want to take care of my car and I'm not in the business of injuring others or putting them in danger. I am now an army mp so I more or less do just the opposite. I don't reccommend what I was talking about just thought i would answer the question. So now any stock 93 LS 400 owner knows what the car will do and so no need to test it out.

The only problem that you would have with that is that right under that deck sits your gas tank so there is really no room for that. The only solution would be to have a custom box molded directly in front of the gas tank to fit the shape of your trunk and curve a port to that hole. In the same topic you would have a hard time calculating the volume and length necessary to produce the correct resonance for that port.

Well then I since someone else did I'll tell it I did 147 in my 93 LS400 with 126000+ miles (no one can tell me that doesn't show great workmanship on a car) with the added weight of three people in the rear seat and a front passenger but we all started to freak so I let off but i did log the top speed with my gps. It is kind of neat to see the needle on that end of the speedometer too.

Will that company ship a body kit for a 93 LS400 to the U.S. and at what price. And also can they match the original paint or will I need to get the kit and or my car painted?

Has anyone been that fast in one, if not how fast did you get up to.

I recently read where another person asked the question about what the top speed was on a stock LS400 somewhere in the postings but everyone that replied made it seem as if it was a no no to answer. If it is not a problem I do have an answer to the question.

I have a slow leak in my coolant resivoir and a mechanic told me that it would be around $250 to get a new one because the whole assembly (resivoir, cap, low coolant sensor) has to be replaced and that wasn't including labor. I know I can replace it myself, I was just wondering if anyone knew where I could get the unit cheaper. Also a power steering pressure line. The mechanic said that these could only be ordered through lexus but I'm sure there has to be someone out there that builds these.

Thanks UCF3 But they said that because the LS uses cathode (shorter life) instead of LED that they don't even mess with them.

Thanks VMF just trying to keep mine running great as long as possible.

Not belts, just had serpentine, timing, water pump, pulley and tensioner for timing, tensioner for serpentine, fan bracket and a couple other small upkeep things replaced ($1500 bucks worth). Sound is definitley coming from top of valve cover. Just want to make sure it's nothing serious. Oh yeah just in case someone was else was wondering the plug wires are not arcing either (same noise created by that problem on another vehicle so I definitley checked that first) by the way my car has 126000 miles on it and in the manual I read that valve spacing adjustments are recommended like every 90K.

I have the apparently infamous blinking dash problem. When it is real cold the dash lights are on and as it warms up they start to blink and then go off. About 15 mins later as they apparently warm up more they do the disco effect and then come on for good until they cool down again. Having done electrician work in the past it reminds me of a bad ballast ( power source ) on a flourecent lighting system. Is that the problem? If not does anyone know? And what is the fix. I saw another fix for a similar problem but on a foreign version of my LS 400 with an all digital readout. Will that same fix work? If not could someone tell me the exact part to look for to fix it. I know this question must get old to some of you veterans to the website but I would really like to just fix this myself rather than pay for a diagnostic and some mechanic to work on it, unless that is what someone recommends. Thanks.