Clean400

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I thought I would share all of the knowledge I acquired searching the Clublexus & Lextreme forums for hours upon end, and condense all that information into one thread. The point of this thread is to make it easier for anyone who wants to go Nitrous with their SC400.

So you want to go Nitrous

There are many reasons to go Nitrous and the main reason of course is to go FAST. The SC400 in it's stock form is a nice luxury cruiser with a reasonably powerful V8 engine, the 1UZ. The 1UZ block in it's stock form is not being pushed to the limit whatsoever. That's why these engines last 400,000 KMs or more with minimal maintenance. The stock engine runs extremely rich from factory, which makes it a great engine to spray nitrous through.

The main question: How much Nitrous can a stock 1UZ handle?

To answer this question we have to look at the different nitrous setups. There are dry kits and wet kits. A dry kit means that you are only spraying Nitrous into your intake. A wet kit means that you are spraying nitrous and fuel into your intake. The reason for a wet kit is to compensate for the added oxygen you are shooting into your engine. The important part to not making your engine go boom is having a proper air/fuel ratio. Since the SC400 runs so rich from factory, running a dry kit is safe up until' a certain shot size.

According to Todd Matsubura the SC400 can take roughly a 100 dry shot without adjusting timing. (Jibby got this information from him. Jibby ran nitrous a few years ago and documented a lot his experience on the Clublexus & Lextreme forums. Todd Matsubura is the owner of TM Engineering and created a 250 direct shot SC400. See here..

Personally, I'm more of a believer in wet kits because they ensure to add a proper amount of fuel to compensate for the extra oxygen you are ramming into your engine. With a wet kit many people have been successful with running up to a 150 wet shot through a single fogger. Anything over a 150 shot I would suggest to run a direct nitrous shot. Todd ran up to a 250 shot, I have no idea how long the 1UZ would be able to handle this much, but that is definitely extreme. I'm sure a 200 shot direct port would be pretty reliable if sprayed with high octane race fuel from a fuel cell (don't quote me on this).

How much power do Nitrous shots add?

When you add a 50 shot, it's technically 50 HP more at the crank. A user on clublexus (AME_VIP) was able to dyno at 300hp at the wheels with a 150 wet kit. A stock SC400 dyno's around 170-180HP at the wheels, so a 120-130 HP increase is actually very good. A user on clublexus said that his friend was able to achieve a flat 13 second 1/4 mile time with a 125 straight shot with slicks and a 2800rpm torque converter. Todd from TM Engineering was able to achieve 11.68 1/4 mile with a 250 shot (the car is basically stock besides slicks, exhaust, race fuel cell).


Nitrous Controllers, safety first!

Window Switches

Nitrous has come along way from the days of push button engagement. With nitrous you want to shoot your nitrous shot within a certain RPM range. Too low and it can blow your engine, too high and you'll be spraying while your car is shifting which is not good for the transmission. To control when your nitrous engages you need a window switch. When you program the window switch you program it to spray nitrous between a certain RPM range. The recommend safe range is usually to start at 3000rpm. You usually want to end the the nitrous a few hundred RPM before the automatic shifts. Right now mine is set at 5600rpm which is very safe. It seems the SC400 shifts at RPM in different gears, for example I noticed in this video I made of the stock SC400 shifting that the car shifts earlier in first gear than it does in second gear. (Link to Thread on Transgo HD-2 Shift Kit and videos). You could play with this RPM range, people have safely run nitrous on a SC400 starting as early as 2500rpm and you could increase the ending RPM range as well. Make sure you know what your doing though.

Throttle Position Sensor

Another safety item you want for your nitrous system is a throttle position sensor. You only want to be shooting nitrous at full throttle. Basically once your system is armed the nitrous will only shoot once your pedal is all the way to the floor.

Straight Shot vs Progressive

With nitrous you can shoot the full nitrous shot right away or you can bring on the nitrous shot progressively. The advantage to having a progressive nitrous shot is that you can set your 150 shot to start as a 75 shot. This way you won't be spinning your tires from launch. There are simple and advanced progressive controllers. Some progressive controllers are time based, some are RPM based and some are very advanced and take a multitude of factors into consideration. Basically a progressive controller is meant so that you can safely spray less nitrous for traction reasons and then ramp it up to a larger amount. Progressive nitrous controllers do have their downside though as it is harder on the solenoids. The fuel and nitrous solenoids will have to be rebuilt more often with a progressive kit. With a straight nitrous shot the fuel and nitrous solenoids will last much longer without a rebuild. Generally from what I've read people with a progressive nitrous system tend to rebuild their solenoids after about 25-30 1/4 mile drag uses or a full season of racing.

*Some controllers combine Progressive, Window Switch and TPS all into one unit*

Nitrous Filter

Another safety item that is recommended is a Nitrous filter. This is placed before the nitrous solenoid and captures any debris before it is run through the solenoid. Debris can clog up your nitrous solenoid. The dangerous of clogging up the nitrous solenoid is that it can remain stuck open and you will continue shooting nitrous even after you want it to stop. This is rare but can happen and is obviously not fun. A nitrous filter is safe insurance for this not to happen. Nitrous filters can be reused.

Purge

A nitrous purge is the cloud of nitrous that you see shot up in the air in fast and the furious. This is not just done for show even though it looks cool. What this does is that it clears the nitrous lines of any old nitrous. It also gets the nitrous ready right at the solenoids ready to shoot. The reason you want to do this, especially with a wet kit is that you want your nitrous and fuel to shoot at the same time. If your nitrous is coming from your trunk all the way to your engine, the extra fuel will reach your engine before the nitrous. You can run without it, but it is recommended, and is friggen sweet.

Nitrous Jets

Nitrous jets are what controls the size of your nitrous shot. This is how you control the power of your nitrous system. The jets are inexpensive and only cost about $3-5 a piece. For a dry kit you only need to change the nitrous jet to change the power. WIth a wet system you need to change both the nitrous and fuel jet to change the power. To change jets it only takes about 5 minutes, so in 5 minutes you can change your power from 50 to 150hp. There are charts available online that help you choose your jet sizes for the power you want.

Bottle Size & How long it Lasts

The nitrous bottles come in all sizes. A 10lb tank fits nicely where the spare tire would be. Obviously a 15lb or 20lb tank will last longer but the larger the bottle the more space it takes up in the trunk.

There are a lot of variables in how long a Nitrous tank lasts. The larger the shot size the more nitrous is going to be used per nitrous run. The follwing is a calculation taken from the NX nitrous website.

How long will a bottle of nitrous last?
A. That depends on the level of power being produced. The formula for calculating your nitrous usage is: 0.8 lbs N2O X 10 seconds = 100 horsepower. I.E. If your system is jetted for 100 horsepower it will use 0.8 lbs of nitrous for every 10 seconds of usage.

So with a 100 shot you will get 125 seconds out of a 10 pound tank. Or 2 minutes and 5 seconds of boost. Now that might not sound like a long time, but try to count to 2 minutes and 5 seconds. Then try to imagine how long you will be under full throttle.

Bottle Pressure & Why it's important.

"To get peak performance from your nitrous system it's a well known fact that nitrous bottle pressure plays an important role. If your bottle pressure is too low, your nitrous system tune up will be pig fat and have less than desired results. Too much bottle pressure and you may be getting into a lean tune up, unable to activate the nitrous solenoids, or in a worst case situation run into safety issues with the bottle itself. Most nitrous companies recommend a nitrous bottle pressure around 900-950 PSI, and many racers run upwards of 1000 PSI depending on the volume they are using and other factors . The tricky part is getting that bottle up to the correct pressure and maintaining it there for during the run. Ideally you want to avoid your nitrous pressure droppping below 750-800psi during a pass to avoid the liquid nitrous turning to a gas." Source

To get your bottle pressure up to the recommend range you need a bottle heater. This is a heater that wraps around your nitrous tank. When shopping for a bottle heater make sure to buy one with a safety shut off. Heating your bottle up too high is dangerous. With bottle heaters there is a downside though, they take roughly 20-30 minutes to heat up the bottle to the required temperature. Also after a nitrous run, your PSI drops and you have to wait for it to get back up in PSI if you want your system to be running at it's optimal level.

Another way get your nitrous system up to pressure is with a push system. Personally I use a system called Nano Nitrous. This system is used as a second compressed air tank that attaches to your Nitrous tank. What this does it that the compressed air keeps your main Nitrous tank always up to pressure. The beauty of this is that your always ready to go and race whenever you want. Also it has performance advantages, as with a normal nitrous tank your bottle pressure tapers off by the end of a run. With a Nano System the nitrous stays at full pressure throughout the entire run, resulting in a faster 1/4 mile time. A compressed air tank can be filled up at your local scuba shop or paintball shop.

How much does a Bottle cost to fill up?

This varies depending on region. Some regions are only $30 and others are $100 to fill up a 10lb bottle. Where I live in Montreal Canada it's $100 to fill up a bottle! Ouch! In the US it is generally much cheaper than Canada, enjoy your low nitrous prices!

What you need for a setup

Generally it's good to start off with a basic kit that includes the tank, lines and fuel solenoids. From here you can add your nitrous controller, switch, bottle heater, etc.

Basic Kit

• Tank
• Nitrous Lines
• Fuel & Nitrous Solenoids (This is for Wet Kit. You only need one nitrous solenoid if you are running a dry kit)
• Basic switch

Recommended Accesories

• Nitrous Filter
• Window Switch & Throttle Position Sensor
• Bottle Heater
• Purge
• PSI gauge

High End Accesories

• Nano Nitrous System (you won't need a heater if you get this)
• Progressive Nitrous controller (It usually includes a window switch and TPS built in)
• Wideband Sensor (this connects to modern progressive controllers and shuts off your nitrous when your A/F ratio goes off the map)
• Bottle Opener

Supporting Mods for Nitrous

This obviously depends on how much nitrous your shooting. And whether you run a dry or wet kit. These are all best case scenario, the more safety items the better.

Up to 100 SHOT

One step colder copper plugs. Personally I use NGK BK7RE.
Good Tires

*Anything over 100 shot you will want to start pulling timing with a dry kit*

Up to 150 Shot

Shift kit. The SC400 automatic transmission will not be able to shift fast enough in it's stock form around the 100-125 shot range. Personally I just installed the Transgo HD-2 Shift Kit and could not be happier. See thread.

Fuel Pump. I'm almost sure with the stock SC400 pump you could get by with a 150 shot. Just to be safe though change your fuel pump to something better. You can put a Supra TT fuel pump or a Walbro Unit. Personally I have a knock off Kyosan unit which is a replica of the Denso Fuel TT Pump, it's cheap and works great. Make sure to do the 12v Fuel Pump ECU Mod bypass mod Link

At this point you probably want to consider an LSD as well if your planning on using it to launch. If you're just doing highway runs you could get away with the open diff.

Progressive controller would be wise if you plan on doing a 125-150 shot.

*Personally I would start pulling timing with anything over a 100-125 shot just to be safe. But people have run up to 150 shot with no timing pulled with a wet kit*

Up to 200 Shot

If you're one of the crazy few who feels that a 150 shot is not enough than there are a few things you can do. First of all make sure general maintenance is done on your engine because anything over 150 shot is pretty extreme.

I would personally recommend that anything over a 150 shot, that you use a direct fogger kit. What a direct fogger system does is that you are shooting the nitrous and fuel directly into each intake port of the engine. So with a V8 you would have 8 separate dual nozzles for fuel and nitrous. Direct port is actually safer than single fogger through the intake, so if you have the money a direct fogger system is best.

Anything over 150 shot you will need to start pulling timing with a wet kit. As a safety measure it's always good to pull timing when shooting nitrous but people have safely run up to 150 shot with wet kits without pulling timing. The SC400 runs rich that's why your able to get away with such a high shot without pulling timing. To pull timing you will need a stand alone ECU or you could use a timing retard module. Stand Alone ECU's are fun because a lot of them have nitrous controls built in now, and the bonus is that off the bottle you can run advanced timing and get the most out of your engine.

Fuel Cell for Race Fuel. This is a separate small fuel tank that your fuel solenoid would connect to. You would fill this up with race fuel. Race fuel has higher octane and would make it safer to spray higher shots.

Exhaust. The stock SC exhaust has catalytic converters that actually flow pretty well. There are some minor bottlenecks but the stock system can take up to a 150 shot no problem. Anything over this a new exhaust would probably be necessary.

LSD. Preferably the TRD clutch style LSD or something similar. The Torsen is good but can't hold the same amount of power as a clutch style LSD. Also the clutch LSD will keep you in a straight line better. I personally have a Torsen LSD from a JDM Supra N/A. With the Torsen you have to have a progressive controller to not shock the diff too much to break it. With a TRD clutch LSD you would be able to do a much more aggressive launch.

Progressive Controller. Any shot this high you would want the shot to come in progressively. Also advanced progressive controllers offer Gear by Gear profiles. This way you can make nitrous come in differently in different gears.

Other recommended upgrades regardless of shot size: 4th Solenoid Mod, Transmission Cooler (I use the B&M Transmission Cooler 70264).

Where to tap your fuel for a wet kit.

Attachment 501310
Attachment 501311
More photos here.

What a Nitrous System looks like under the hood.
Attachment 501312

What it looks like in the trunk.
Attachment 501313

How much does it all cost?

This really depends on your kit.

A basic kit example ($500)

With this kit you have everything you need to get started. I highly recommend that you also purchase a window switch and TPS. This will run you about $100-200. You can even find progressive units for as low as $200. See here

Bottle Heater $100-200 (or $400 for a Nano System).

Nitrous Filter $50

So for as little as $800-1000 you can piece together a nitrous system. Install cost ranges from place to place. It's not very hard to install. Expept at minimum $300-700 depending on your kit and region.

I would highly recommend a bottle opener as well. It is so convenient to have. It's about $200 for an opener but it's well worth it. This way you can open or close your nitrous bottle without going in your trunk. It's not good to have the bottle open when not in use, it puts extra pressure on the solenoids. Open the nitrous before you use the system, then after you use it close it. Never just leave the bottle open for extended periods of time.

A neat little nitrous switch panel for the SC400 is this one. It fits perfectly in the SC400's cup holder compartment. My installer used the top of a black spray paint can to mount the nitrous switch in. It looks really sweet. The switches are hidden by the cup holder flap. You have a nice switch to control your purge, arm the system and to open the bottle. The bottle heater switch on my setup is not being used since I have a Nano System.




What to do when shooting nitrous.

• Turn off Overdrive (You don't want to be shooting nitrous in overdrive).
• Turn on PWR mode.
• Turn off Traction Control (If traction control engages while shooting, this could be bad)
• Open Bottle
• Arm Nitrous
• Purge (only a short burst. Don't waste Nitrous it's expensive! Unless your a show off lol)
• FLOOR IT (Once done your run, it's best to take your foot off the pedal slowly to disengage the nitrous. Don't slam on the brakes by any means. Do the nitrous in a safe area where you have a lot of room ahead of you).
• Close Bottle
• Purge the remaining nitrous in the line.
• Disarm nitrous.

I hope this helps some people, a lot of this information comes from the trials and experiences of forum members using nitrous with the SC400. Before I put nitrous in my car I knew next to nothing about it. With a lot of reading and research I pieced together a kit for my car and I am very satisfied with the results. I only a used one full 10lb tank of nitrous with only 50 shot jets so far and I'm satisfied with the results. Even a 50 shot you notice the difference. I was going to up the jet size from my starter jet size this summer but didn't have the time as my car was getting other mods done to it. Now my car is in storage so I will have to wait until' next year. I plan to run a 150 shot progressive. With a torque converter, shift kit, good tires & 150 progressive shot, I'm sure the SC400 can run high 12's. I'm probably going to be installing a Megasquirt MS3x stand alone which has progressive nitrous controls built in. Right now I have a simple straight shot controller, part of me wishes I had went progressive. If anyone wants to add anything feel free! Obviously this guide does not include everything, so read up on nitrous and learn about it. The more you understand the more comfortable you will feel with it. Enjoy the spray

dengman

wow. Thank you for the time put into this. I've been wanting to go nitrous on my LS but havent had the time to look into it. Back when I was in Kansas City when Nano first came out it was highly spoken of. Being at work I wasn't able to read everything. Skimming through.. I'm glad and thankful for this post.

rcchris7

iTrader: (1)

Great write up, bookmarked this for some reading material later once I have time

Clean400

iTrader: (2)

No problem! I just wish there was something like this when I started researching on the forums. If you were planning on putting a shift kit, too bad the Transgo shift kit does not work for your A650e 5 speed auto. I think Toyomoto makes one but I'm not sure on the price. If not a more expensive option would be IPT. Or you could just put shims yourself in the autobox. There's a guy who modifies shift kits on the supramania forums, I know he specializes in the 4 speed auto but maybe he could do something for the 5 speed Link

I'm sick so I had a whole morning to write this up. Enjoy the read!

andrew7

Great write up! Props for taking your time to do this! So much good info!

willhickey

iTrader: (1)

great thread man

1JZPWRD

iTrader: (59)

It is a great write up.

I wonder what a stock 1JZ can handle on NOS?

Clean400

iTrader: (2)

Things get a bit more complicated when you add in another forced induction method. The general rule of thumb with forced induction that I heard is that a 50 shot will become a 100 shot. Forced induction has a multiplier effect on nitrous power. Even a small 35 shot will make a huge difference on a turbo car.

You could even just use the nitrous to help spool up the turbo then cut off the nitrous right when the turbo powerband starts to kick in. This way you have good power off the nitrous and crazy power on the nitrous. Plus this way you won't have to use much nitrous and your bottles will last a long time. You'll eliminate any turbo lag you had and it's probably safer to cut off your nitrous once your turbo starts kicking in, unless you really know what you're doing. Turbo systems run hot and the nitrous system has the added bonus of cooling everything down.

Thanks guys! Had to give back to the community after all the useful info I've learned from here.

Kris9884

iTrader: (7)

Bump

Surely there has been numerous changes and new info in the last 2 years. I actually found this thread off Lextreme. Could we add to it whatever we have learned in the meantime?

oldManTan

this sounds extremely easy to do. i'm hoping someday i'll get this installed. don't mind dropping 1000 bucks for double the power almost.

ISFFUN

iTrader: (4)

Just for old time's sake - Todd's SC didn't have a stock motor. The bottom end was from a Tundra.

Rdockery25

Great write up! I'm in the process of installing a dry zex kit on my 97 sc400. I am trying to get a solid answer as to where to run the intake/regulator hose combination. Please include a picture if possible.

Ali SC3

iTrader: (10)

I could never give up my cupholder, everything else seems to be well on point. nice writeup.

Kris9884

iTrader: (7)

Same, I'd give up my power windows before my cup holder but it can be put almost anywhere.

Supra1uz1

I'm putting a 1uz I'm my mk3 Supra my plan is to put shots of nitrous and see how much it takes to blow up only thing I'm worried about is trans