OOOOOHHHHH!!!!! I'm starting to get a stiffy just thinking about that little bottle in my trunk!!!

Edogg, there's always a chance something can $h!t the bed with or without mod's. Nitrous Oxide CAN do serious damage but most of those stories come from guys at the drag strip pushing a 150HP shot :eek: Even the most popular performance mod's on this site (torque converter) can have their downfalls but for $600 + install for 55-75HP..sign me up!!! Plus you're not putting the constant strain on the motor...just at needed moments...like when that dropped LS flies by you again!!!

BTW, JBrady, thanks for all the research.

 

Bottle won't fit in the trunk!

 

to run nitrous at the track you need a release valve with a hose (well some tracks requires it). You dont need to build your LS motor if your running a 75 shot. Go with the ZEX, it comes with a processor. It chages your sparks, air fuel, when it is activated, it's happends on from second gear and on. A good saftey for most people. Venom is the best because it is a PC base, you can change how your system works with your PC. it comes with a mini computer that changes all your setting, and you can program your jet of NOS. Venom is the best then ZEX, basically because it has a processor.

 

I do not know you guys,i am quite reary about still blowing the enigne or damaging something,it would cost a fortune to fix lexus parts,plus i do not know how much extra hp the tranny or engine can handle.

 

EDOGG.
Don't worry your engine is bullet proff. Your tranny is designe to handle up to 400hp. Don't worry talk to your lexus repair guy, he'll tell you its safe up to 300+. make sure you tell him its a Japanese Lexus part, he'll be bias against anyting non lexus like NOS.

 

Hey LS400in520,how about if your engine has about 135,000 miles on it,i am still concerned about the internals of the engine.

 

EVERYONE concerned about engine damage....

The MAIN concern regarding engine damage is DETONATION. This is HIGHLY unlikely with this system for several reasons. The other is excess RPMs. Of course if your engine is damaged due to overheating, lack of proper maintenance or other malady you have bigger problems. Mileage is not a major concern. I ran 20psi of boost in my 4 cylinder 250hp Ford right up until I pulled the (still running strong) engine at 210,000 miles. I have MANY stories like that.

DO NOT worry about your engine handling 70-100hp more. This is NOT a problem. Without detonation and without excess RPMs most ANY engine can handle at least 50% more power than its factory output. YES, that means the Lexus 4.0 stock internals can handle 450hp (probably 600hp). BUT, if you detonate you can ruin it with no mods whatsoever. Ditto for over-reving (although the rev limiter won't let a non-modified engine over-rev). I do not know if Lexus drops fuel or spark for its rev limiter. Dropping spark is not a problem with nitrous, dropping fuel IS a problem. Someone please check this out. I thought I read it on the GS or SC forum some time back. Lextec? Mean Gene? Mo?

 

I've done a couple of nitrous installs,no Lexus ones yet. Let me see if I can help some of the misinformed

You can buy the same ZEX nitrous system for almost $100 less than ZEX direct from mail order sources like Jegs www.jegs.com or Summit Racing www.summitracing.com I've ordered parts from both places and never had problems.

There's no rigging of an extra throttle switch,you tap the factory TPS (throttle position sensor) signal wire and run it to ZEX unit. When it senses wide open throttle (approx 4.5 volts) the system starts injecting nitrous. Letting off the throttle lowers signal voltage,shutting off the nitrous flow. NOS brand systems do require fabricating a bracket for their throttle microswitch.

The ZEX kit does not alter ignition timing and it's not gear-based as LS400in520 thought.

You can't use this system on a 98-on LS,GS,ES,RX,or IS (LX450 and LX470s will be able to use it). This system and some of NOS' kits are called dry systems. Dry because fuel is not injected at the nozzle,just nitrous. The extra fueling is done through the fuel injectors by increasing fuel pressure to the regulator. If you look at a dry system install,you'll see a line from the nitrous solenoids teed into the vacuum line on the fuel pressure regulator. The 98-on models I've mentioned do not use a vacuum-referenced fuel pressure regulator,they are now mounted in the fuel tank.

A 55hp shot should work fine in a bone stock application. Jetting to 75hp may require a fuel pump,and I'd recommend a colder range spark plug,and absolutely NO platinum spark plugs (the platinum coating gets shot off by the nitrous charge).

Doublewhoosh what are your recommendations,since you've done Lexus nitrous installs.

Years ago there was a magazine called Street Power,put out by the same guys who write Sport Compact Car. They had an SC400 with an NOS dry nitrous system installed by St. Andres in CA

 

LexusTech, thanks for the imput. Do you know for sure that the 97 and older Lexus cars have a TPS sensor that reads 4.5 volts? Do you know how the rev limiter works, fuel cut or spark cut?

Good tip on the Summit and Jegs sources. $500+- is a great price.

 

I also thank you for the great information, and also as JBrady, I am curious about the TPS sensor and how the rev limiter works on the pre-97 models, especially the 93. The info sheet says it's a "breeze" to install, however, I don't think this is a project to take on myself. What should I be looking for in a mechanic to do the install, besides previous experience with nitrous??

 

DoubleWhoosh,we still need your take on the NOS for the 90-94 LS,how safe and the dangers.

Since you have do NOS for the LS before,If i buy a NOS kit would you consider installing it in my LS for me?

 

I went and checked ZEX's site,the trigger voltage signal can actually be as low as 4.2 volts.

TPS
As far as I remember,even the older units are linear type sensors. Late 80's Toyotas should've been the last ones with simple on-off sensors. I'll try to remember for next week and look it up in the manuals @ work to verify.

Rev Limiter
The rev limiter cuts fuel,so does the speed cut. Maybe I should have added this to my previous post...if your car has a manual transmission get an RPM window switch (allows you to set the on and off RPM values).

zushwa,visit the local drag strip and look around the pits. Check out cars running nitrous and see if the owners can recommend an installer. I'd also try locating an old domestic car speed shop and ask them. The local "import performance shop" aka former stereo/rims/tint place would be the last ones to ask.

 

hey i was wondering how all the wires would run through the trunk if i could hardly run amp wire back there...and wont it be bad because the gas tank is right there?