LEXUSA

Well I finally joined the elite and now own a '97 Coach edition LS400 with 119,000 miles. She is a beauty, dark green, chrome wheelz. New Firestone FR710 tires aren't supposed to be the greatest but will do for now. I think she needs an alignment but maybe new shocks too. I'd like to alleviate some of the floatyness even though this is part of what the car is all about. I'd like to replace the shocks before any alignment if I replace them at all. I've searched here some and found Bilstein mentioned some but no real review or comparison. Lowering the car a touch is something I'd like to accomplish but definitely not slammed or HerraFrush. So what say you those who have Bilstein on their 2nd gen LS400? Is there a thread that has covered this already somewhere? What about alignment specs? I also have a '96 Miata and spend quite a bit of time on Miata.net. The suspension section is actually too full of information, information overload and the myriad of combinations folks have tried. Most any other site I visit for just about any other car is really lacking the indepthness so it's feast or famine. Do you all just get aligned to factory spec and call it a day? Alignment on a Miata is crucial to turn in, stability, twitchyness and tire life. Factory spec is terrible.

How much heavier are the 20's vs. your stockers ? Heavier wheels have the greatest negative effect on performance than adding weight anywhere else, unsprung and rotational. Brakes are also unsprung but don't rotate.

It's OK to load a cold engine a little bit. Keep the rpm down as much as possible. If you live right next to the on-ramp you take to get to work I'd give it a minute or two if its cold out. Normally a leisurely drive from your neighborhood to the highway is enough to get it warm. Just take'er easy until some temp starts to show.

Wow, is $6k typical, I thought they brought more. Is there anything wrong with either? On a scale from 1 to 10 how would you conservatively rate the '98? 10 being that it looks new, very little wear.

At this juncture I will conceed my faulty reasoning. I assumed the compression would be around 10:1. With the compression at 10.5:1 the factory timing is probably rather mild and for it to !Removed! even further to compensate for 87 octane may put it into the loss of efficiency area. Retarding timing in crisis situations with turbo set-ups is only for moments at which power and efficiency are way down. This is ok since it saves the engine but if it runs for extended periods it is not good.

Is it that obvious I am smarter than the Lexus engineers? I'll have to tone it down a bit, I get crazy on public forums which encourage discussion and thoughts not mainstream. It has been my experience that most folks don't understand "American Pump Gas". I too used to think there was some benefit to running higher octane other than to preventing knock, but there isn't. But enough of that, seems like most that have tried it in an LS400 have not experienced any improvement. I believe the rear gear ratio is 4.09 or so. Does the rear ring and pinion in an LS400 also fit other Lexus or Toyota vehicles?

Taller gearing if its available. Something around a 3.90 rear gear would take about 200rpm off of top gear highway cruise.

Damn, thats up there. This is a motorcycle engine after all. The first generation Hayabusa only had 10.5:1 compression, ran best on 87 octane "pump" gas.

"Premium" is usually recommended by manufacturers as a safety cushion if the engine has any possibility of detonation in the worst of conditions. The only OEM car engines I've ever seen that were "designed" to run on premium are older American designs. Terrible combustion chamber/piston top, poor ignition control, they were designed to detonate. Please note: I now realize the 1UZFE isn't a motorcycle engine, thanks for pointing that out. I used to run premium in everthing I owned because I thought it was better fuel. What is the compression for this engine?

You are suggesting that higher octane with more ignition advance is better than using lower octane with less advance. There is a limit to how much advance/!Removed! can be used with good results but I doubt it would take much to run 87 octane. Does an LS400 for sure have a knock sensor? I'm not advocating the use of 87 octane as a means to saving money. 87 octane is better fuel than 93 and runs more cleanly because it has less additives in it to prevent knock/ping/detonation. I'd love to see what the LS400 combustion chamber looks like. I bet it is very "motorcycle" looking, shallow pentroof design that does not promote knock/ping/detonation with 10:1 compression or a bit more. If so, I can't for the life of me understand why this motor won't run better on 87 octane. I have a Suzuki sportbike with the same displacement per cylinder, 11something:1 compression and loves 87 unless it is really hot outside. It doesn't have a knock sensor, the ECU runs a set advance curve.

Was that thread about those not happy with the 25mpg highway or those getting in the mid teens? If the Temp Sensor is bad and reading low then the engine will stay in warm up mode and run richer. I have a motorcycle that had a problem like this from the factory. Using the correct thermostat and sensor is crucial for an engine to run correctly with fuel injection. FI relies on sensors to adjust it so if they are off, it will be off.

So it is still quiet at cruising speeds, mpg has improved as well as WOT topend power. Has the off idle accelleration gotten better or worse? Sometimes a free flowing exhaust can kill some bottom-end. Are you still running the catalytic converters? What does the stock exhaust look like?

I know you were just kiddin', I was just being the good cop. You can't tease us like this Blayd and not expect some harassment, this is just the beginning.

Give the man a chance. He may not have all the details of the car committed to memory yet or pics but I'm sure he will. Don't criticize him for being well funded. Cubic dollars always help accellerate any build.

Cool. A turbo LS400 with a tube chassis or at least the front half. Take some pics of the rearend too. Does it still use the LS400 automatic transmission? This is a street car with tags and a title? Do you remember what your trap speed was at the end of the 1/4mile?

Drag racing times come down to boring math. Power to weight. So many things can be figured out from ET, trap speed, 60' times etc. Kinda takes some of the fun out of it but is accurate. Independent Rear Suspension don't usually care much for high hp drag strip starts. Going to a custom 9" Ford would really help, lotsa gear ratios and uber-strong. Figure out some kinda 4 link rear suspension, might could even use some of the existing set-up.

Those inline ventilation-type fans look to be way too small to provide enough volume or pressure but I've wondered if another set-up could work. A turbo or procharger is probably the most efficient type of airpump. I suppose its just a question of how much hp an electric motor would need to be and how to overdrive the turbine. A much steeper pitch impeller would help to keep the rpm/overdrive down. Maybe a modified Pro-Charger type set up but with an electric motor. It wouldn't run all the time, just when you hit it, like nitrous.

Some cars come with a factory style tubular header. I checked eBay and found an LS manifold, don't look too performance oriented but maybe it flows well for OEM. Its amazing how some automobile manufacturers are realizing that a good flowing exhaust system helps across the board. Emissions, economy, power, sound, longevity etc. I'm kinda surprised Lexus doesn't do this. Do you know yet what the inside of the OEM manifolds look like? Post some pics or at least your impression of their design.

If its just sound you are after then start with the mufflers in the back and replace them with FloMasters or Turbo Mufflers or whatever you like the sound of. If that doesn't give you the sound or volume you are looking for then move forward and replace whatever is next. The catalytic converter kills some sound but not much so keep those intact. Some manufacturers have sound bites of what their mufflers sound like. Check out FloMaster, Thrush or any of the ricer brands that I don't know the names of.

Is there another thread to the details of your build? 10second 1/4 mile times with no turbo is ambitious. Is this engine in a full bodied LS400? You sure you ain't runnin' the 1/8th mile? Just kidding. Can't wait for pics.

I did this on a Nissan truck and all it blew was the Main Fuse. The truck is quite a bit simpler and has alot less electrical gadgetry I know but that is what a Main Fuse is for, to protect the wire going to the other fuse boxes. You may have more than one individual fuse to replace but the Main for sure.

Do you have a link to these headers? How much bigger than OEM are they? Material? Do they claim a horsepower/torque increase?

I've been involved in many "discussions" like this one on various motorcycle forums. I know what I know from a couple of discussions with a VP RacingFuels rep years ago and personal experience. American "pump" gas and race gas should be not be considered even remotely similar. The additives in 89, 91 and 93 kill power and performance in the process of preventing knock. Race fuel continues to make power as octane increases however more octane than needed will hurt performance and efficiency. Lower octane "pump" gas should give better mpg and make more power. Sometimes this isn't the case for unknown reasons. Maybe the ECU over-compensates to control knock and retards the timing too much. I would not think the ECU in a Lexus would be so sloppy and deliver such poor spark control as that is usually reserved for American automotive engineering. Regular 87 octane should run the cleanest as it burns the hottest. Higher octane fuel will leave more deposits due to incomplete burn if too much octane is run. Saving 10 to 20 cents per gallon should never be a reason to run lower octane. Does anyone know what temperature the various Lexus engines run at, what temp the thermostat opens at?

What year did Lexus start using knock sensors on the LS series?

These are just suggestions based on my experience over the years, what I've found that works and what doesn't. A buddy of mine had an Acura MDX SUV. It got terrible mileage, around 15mpg or so. 3.0L engine I believe but it revved high at highway speeds, mid 2K area as I remember. I know something as simple as a taller gear might sound too easy to be true but the proof is in the results.