Every single day, this question comes up – “what transmission to use when manual swapping my IS300” or something to that effect.  There are quite a few options, which is great.  Unfortunately, there is a lot of confusion and misdirection.  I’m going to clear that up in a single page.

First off, I’m sticking with common manual trans swaps, I’m sure someone will chime in with some crazy manual swap, but again, going by what is commonly available and will bolt up without too much issue.

Here’s the short list: w55 (stock 5 speed IS300 manual), w58 (stock 5 speed mk4 Supra NA), r154 (stock 5 speed mk3 turbo and some jdm cars), ar5 (solstice/sky 5 speed- also in h3’s and colorado’s but lots more work to fit), cd009 (Nissan Z and Infiniti G 6 speed), V160 (stock mk4 Supra turbo), and the t56/magnum (dozens of OEM and aftermarket applications).

There are a few important things to take into consideration when selecting a transmission – fitment, gear ratios, strength and price (I’ll let you research price)

Fitment

• w55/w58 – bolts up with all stock components
• r154 – use 1jz bellhousing, custom driveshaft
• ar5 – use 1jz bellhousing, Verossa shifter housing, custom driveshaft (06 model years is the best option to purchase)
• cd009 – adapter plates, custom shifter and driveshaft
• v160 – custom driveshaft
• t56 – adapter plates, custom driveshaft

Strength/drivability/repair/upgradability (hp and figures are commonly stated, not based on “my brothers cousin made XXX hp on his”)

• w55 – weak but drives well (300-350 whp max)
• w58 – marginal improvement over w55, drives well (350-400 whp max)
• r154 – varied success – older versions drive like a dump truck, newer versions shift better and tend to be stronger – reports of failure range between 500 and 900 whp; almost all internal components are upgradable
• ar5 – essentially a newer r154 that shifts much better – claims of breakage around 500-600 whp are common, though some have pushed over 800; many parts appear to interchange with upgraded r154 parts
• cd009 – drives great, stout transmission, 800-1000 whp handling appears to be relatively common; very expensive upgraded gearsets available
• v160 – used in 1000+ whp Supras very often – drives great, considered one of the best OEM transmissions money can buy; parts are discontinued through Toyota, many parts are being duplicated in the aftermarket
• t56 / tr6060 / magnum – many variants of this transmission lineup with torque ratings anywhere from 350 ft-lbs to 1000 ft lbs, from the factory; many upgrades available enabling sequential shifting and heavier duty gear sets, capable of handling upwards of 2000 whp; shifts great

Gear Ratios

This is where most people go wrong with transmissions.  They see 6 speed as automatically better than 5 speed, but in some cases, shown below, its actually worse.  There’s a lot of math, but I’ll try to explain.

First, a spreadsheet of all of the transmission gear ratios (asterisks are for the 1:1 gear ratio)

For all of the MPH calculations below, I’m going to use a stock 6200 rpm redline with 25″ diameter tires (stock IS300 is 24.6, but many change to slightly larger diameter).  For cruise RPM, it will be top gear at 70 mph.  There are two stock rear differential ratios for the IS300 – 3.91 came in auto cars and 3.73 came in manual cars.  Tacoma 3.55 gear sets can be installed in the OEM diff carrier.  These three gear ratios are what I will use for my tables.  If you want to explore others, I use Apex Garage as it is a very easy to understand calculator.  Lower numerical ratios are available by modifying the subframe for different diff carriers, or installing a heavy duty 8.8″ rear.

Here are all of the 5 speed transmissions:

and the 6 speed transmissions:

So, that’s obviously a LOT of data.  Some things really stick out when you start looking at it closely though.

First off, some common misconceptions – 6 speed transmissions always give better gas mileage because they have 6 gears instead of 5.  The cd009 and V160 are almost identical and commonly talked about.  Notice their cruise rpm in their top gear is actually just a little lower than a w55 but higher than the other 5 speeds listed.

Common rule of thumb with manual transmissions is that if you are competing in some sort of straight line racing, you want to go through the traps in whatever gear is 1:1 as the overdrives (less than .99 ratio) tend to be smaller gears and are weaker.  Lets look at a car that should trap around 110 mph, typical of a low boost turbo kit’d IS300.  At stock redline, all of the 5 speeds will get it done with any of the available gear ratios and require three shifts to get there.  Same goes for both t56 variants.  The CD009 and V160, however, require getting into 5th gear for  110 mph, so one extra shift.  When starting to make the sort of power to trap 110, 120, 130 and more, in a manual transmission, getting off the line can be the hardest part.  A longer first gear actually makes it easier to launch a higher powered car.

Looking at the charts above, gear ratio wise, the cd009 and V160 are actually pretty poor choices for a stock rear end IS300, as they gain strength but gear ratio wise are really only good for low powered cars.  Medium to high powered cars will have difficulty putting the power down in low gears and excessive shifting will be annoying.

Lets look real close at the cars they came in.  The V160 in the Supra was paired with a 3.13 gear ratio.  This is a very good gear ratio combo.  Our 110 trap example above lets you cross the traps in 4th and cruise in 6th is 2350 rpm.  The cd009 in the Z cars was paired with a 3.55 gear ratio, which works ok with their 300ish hp engines.  Many in the Z groups complain about the short gearing when making more power than stock.  In a Supra, the cd009 would be a much better candidate to swap, where the gear ratios are well suited to stock Supra rear diff gearing.

Differential considerations:

• W55 – works ok at stock power levels with stock 3.73 rear, 3.55 would be a nice upgrade though, especially if making 300-350 whp
• W58 – nice gear ratios, usable with all three above listed diffs with moderate power levels
• R154 – if you need medium power handling levels, this is a good option gear ratio wise, would be real nice paired with the 3.55 rear end, 3.73 works ok
• ar5 – 1st through 3rd are on the short side, 4th is standard 1:1 and 5th is a nice overdrive – pair with 3.55, or, if available 3.43
• cd009 – if you’re going with this transmission, hopefully you’re making some power to warrant it, but you’ll want to change rear diffs to low 3.xx’s to make it really good.  3.55 is really just barely livable given you should be making over 600 whp to actually want to go this route as the R154/AR5 are much better options for the medium power levels with respect to gear ratios and fitment.  One other note – the Z cars have a larger diameter stock tire, so that changes effective gear ratio a little as well
• v160 – same as cd009 but substitute fitment issues for cost – this is by far the most costly transmission
• t56/magnum – works well with high 3.xx gear ratios, so no need to change your rear diff until you start breaking it – if I was going manual in my IS300, it would be the t56

I hope this clears up some widespread confusion regarding the different transmission options for the IS300.

These are LSU 4.9 sensors and their respective details.

0 258 017 020 (1.26meter)
0 258 017 025 (1.00meter)
0 258 017 036 (0.38meter)
0 258 017 038 (0.34meter) Grey sheath?
0 258 017 049 (0.55meter)
0 258 017 051 (0.62meter) Extra Heat protection to lead?
0 258 017 098 (1.4meter) Extra long lead
0 258 017 099 (0.91meter) Grey sheath?
0 258 017 130 (0.72meter)

0 281 004 018 (0.38meter)
0 281 004 019 (0.47meter)
0 281 004 028 (0.54meter)
0 281 004 029 (0.65meter)
0 281 004 106 (0.33meter)
0 281 004 186 (0.45meter)
0 281 004 187 (0.37meter)

Automatic

3.909 (3.91). 43 teeth on ring gear

M98 limited slip

M96 open diff

Manual

3.727 (3.73), 41 teeth on ring gear

M85 limited slip

M96 open diff

The tundra 4.7L has a 130/150 Amp alternator and it ALMOST bolts right up to your 2JZ.

Simple grind down the top ear by about 5MM and she will bolt right up.

Wiring goes as follows:

The 2JZ 3 pin connector the pins are as follows:
1-L-terminal for charging light
2-IG-terminal for ignition power
3-S-terminal for Alternator sense

The Tundra 4 pin connector the pins are as follows:
1-S-terminal
2-IG-terminal
4-L-terminal
So pin 1 goes to 4, pin 2 goes to 2 and pin 3 goes to 1. The pin 3 is left vacant so use silicone sealant to fill it.
S = White
IG = Yellow Or Black-Yellow
L = Yellow-Green

This page will serve as a reference for buying sensors directly from part suppliers like digikey/mouser.

Oil Pressure:

• Honeywell (0-150PSI) PX2AN2XX150PSAAX

This example assumes you have a 3 wire solid state relay, such as the holley fuel pump controller one.

A popular question in the car world is one regarding braking power: How do I get my car to stop faster? Simply put, a moving object – in our case, a car – is stopped by friction. When you lock up your brakes and stop your wheels from rotating, you are transferring the stopping requirement to your tires. It is then up to your tires to create sufficient friction to bring your car to a halt. If your wheels are locked up, there is nothing that a big brake kit can do that isn’t already being done. On that same note, you can have the biggest brakes possible for your car, but if you have low-quality tires, it won’t matter.

Sure, bigger brakes can allow you to stop with less pedal pressure, as they create more friction sooner than the OEM setup. But, speaking purely about a situation where already you have your OEM brakes completely locked up, tires are the only thing remaining to bring your car to a halt.

If your car isn’t stopping well or quickly enough, it’s likely that you need better tires. If you install good tires and now your problem is brake fade, you need better pads. If you install better pads but now parts are overheating, you need bigger brakes or better airflow for cooling & heat dispersion. I’m not saying that big brakes are useless; rather, I’m saying that people often make the incorrect assumption that brakes are the primary (and, to some people, only) thing responsible for stopping your car.

Now that we’re on the same page, I’d like to make three quick points on the relationship between your tires and your brakes.

1. After you’ve applied the brakes, your tires stop the car. If you’ve installed low-quality or undersized tires (for instance: stretching a small tire onto a wide wheel, which seems to be all the rage with some IS owners…), your brakes are powerless, no matter how big they are. If you’ve engaged the ABS, the only thing that will stop the car is stickier or larger tires. If, for some reason, you can’t engage the ABS, it’s likely that your brakes are worn out or your current pads aren’t up to the task.
2. Your pad choice affects brake fade. A better pad can sustain higher temperatures longer before it will fade. This is true to a point – if you keep upgrading pads, you’ll eventually reach a point where the rotors can get hot enough to melt parts and ruin wheel bearings.
3. If your pedal goes all the way to the floor when you brake, you likely need better brake fluid and better cooling because you boiled the fluid.

Now, with all that said, I want to make something clear: I’m not saying that bigger brakes are useless or that you will not thoroughly enjoy them. I could name offhand five or ten IS owners who have upgraded to either the Supra TT or the LS400 calipers and they’ll rave about their setup. My only goal with this write up is to make clear that your brakes and tires have an intricate relationship, and you cannot expect to stop well without both being of good quality.

Upgrading to bigger brakes is definitely helpful for people who plan on exceeding the stock/bolt-on power rating (ie: boost), but even the naturally aspirated folk out there can appreciate the improved “bite” that a BBK will provide. Just make sure you have proper quality tires to match!

I see questions on this topic all the time: installing an aftermarket head unit in the IS300. There are many options, but it seems that many questions still remain. I plan to give an overview of some of the options available to you and hopefully clear up any lingering confusion. This won’t be a step-by-step guide as much as comprehensive information about the methods available to you. My advice is to pick the one that you feel most comfortable with and best suits your goals. 

1. Probably the most well-known solution is the Metra Tyto-01 harness, which connects your new headunit to the stock amp, allowing you to keep all 4 OEM speakers in place (though you can upgrade the speakers at the same time, if you wish). Many people opt for this method because it doesn’t require a new amp, it doesn’t require 2 new rear speakers, and it can be done fairly quickly. In summary: the RCAs come out of the headunit, plug into the Tyto box, and then a harness comes off of that and plugs into the stock harness feeding in from behind the glove box. You have to take the blue (in most cases it’s blue, but I can’t speak for every single stereo system) illumination wire off the new headunit and splice it into the illumination wire on the IS harness. Don’t forget the ground, or else your stereo won’t work properly and you’ll have to pull it all apart again.

Personally, I don’t quite understand the hype about this option because most have the intention of keeping the OEM system. If you plan on adding a real amp and new speakers, my opinion is that option #2 (which I will get to in just a sec) is easier, but we all have our preferences. The main reason I don’t like the Tyto option is because it involves keeping your stock amp (and in many cases, the OEM speakers), which to me is the weakest link of the OEM system. Most people go through all this and come out with really no improvement to sound quality, which seems to be more work than it’s worth. But, it makes for a simple install of your new and modernized headunit, which for some people is enough. For those of you going this route: don’t overthink it. It’s designed to be simple and quick.

2. Another option you have to renovate your sound system, though it requires a bit more hands-on work, is a separate Metra harness, the 70-8116. This harness will allow you to eliminate the stock amp (and preferably add one of your own, one that can actually push some decent power) while still retaining the stock speaker harness. I recommend installing a new headunit as well; I don’t see the point in going through all the work only to keep the OEM unit. This is important: it requires new rear speakers or you could fry your new headunit/amp. There are probably multiple ways to carry this out, but I opted to run power from the battery (with inline fuse) to the headunit & a switched power wire to the illumination wire on the headunit (you will need this or it won’t turn on); dual RCA cables, activation signal, & single power cable to my amp (grounded the amp in the trunk); and the Metra harness from the amp back into the stock speaker harness location (behind the glove box where the amp used to be). Since the stock rear speakers have four wires feeding into them, you’ll either have to slightly repin the Metra harness or pay attention to what wires are “hot” in the rear and which are not. Wire in the speakers accordingly.

I chose this method for two reasons: 1) I have a 2001, so the Tyto harness is not quite plug-and-play, plus I didn’t feel the Tyto setup was sufficient for what I wanted; 2) The stock amp does not allow the speakers to come anywhere near their potential, and once you put actual power to them you’ll see that they are indeed decent speakers. Even if you run your front speakers straight off the new headunit (without a new amp), you’ll notice that they will sound much much better than they ever have. I installed new 6x9s in the rear, and I will eventually upgrade the two fronts, but for now I’m pretty satisfied.

3. Your last option, which is the most labor-intensive and will turn some people away, is to run your own wires from headunit to amp to speakers and subwoofer (if applicable). For the audiophiles out there, this is the best option to achieve optimum sound quality, as you’ll be able to upgrade to a thicker gauge wire. While it might require the most elbow grease, it’s theoretically the simplest way. You’ll need power and ground coming off the battery (with an inline fuse) to your new headunit; you’ll likely have to run the activation signal from HU to amp; you’ll have to route the RCAs to your amp (presumably located in the trunk; amp will need its own power and ground as well), and lastly you’ll run wires from the amp to your speakers and subwoofer. No Metra harnesses, no nothing. You have a blank canvas to do and create as you please. FYI: Crutchfield has a great chart to help you guys determine what gauge wire you’ll need for your power goals right here.

So there you have it. If you’re looking to install a new headunit (and more) into your IS300, here are your options. Hopefully, I’ve eliminated some of the lingering confusion and misinformation that litters the interwebs. Have fun and go nuts.

Note: the first two options do not include directions on adding a subwoofer; if you are wiring everything yourself, this doesn’t matter.

So, you’ve got yourself $2000 and you want to make your IS300 faster. Let me guess – you’re thinking about the CXRacing turbo kit. You’ve read great reviews and you’re ready to “pull the trigger,” eh? Sound about right? Or maybe you think you’re smarter than the average joe – you’ll buy the kit and upgrade the most important parts. Pretty clever, huh?

Take it from me, that’s $2000 that could — and should — be put elsewhere. If you’re serious about putting down power, then you need to build a good foundation. In stock form, the IS300 is a respectably sporty car. It goes without saying that the 2jz-GE motor is a great platform to start with. However, there are certain areas of the car that you really should look to improve before you dump money into forced induction (not to mention, it’s my opinion that the CXRacing turbo kit is an example of being pennywise and pound foolish).

If forced induction is really what you want, don’t go into it with a fixed number like $2000 in your head. Yes, the IS300 can be boosted for less money than other cars (though not as cheaply as Civics and the like), but your build should not be limited by your budget. I understand that not everyone has super deep pockets, but here is an example: let’s say you picked up an almost-finished turbo setup for a steal of a deal, but it comes with an outdated management system like the Unichip. You take it over to a friend’s house for him to look it over, and he says that you should invest in a quality management unit. If your reply is, “I don’t have the money for that right now,” that’s a red flag. You don’t need every single goodie available for the car, but your budget should not limit the reliability and safety if your build. If you want forced induction, wait until you can truly afford it.

Now, just because you don’t have the money for forced induction doesn’t mean you can’t improve your car. Like I said earlier, you can and should take that $2000 you have and invest it into building a solid platform. Before you do anything, you should be sure that your maintenance is taken care of. With the mileage and years on our cars nowadays, chances are there is an area or two (if not more) that needs your attention. When you have confirmed that your car’s maintenance is up to snuff, proceed reading this article.

Without further adieu, I present to you – the four (technically five) best modifications you can do to your IS300 with a limited budget. Not only will these additions improve your smile-per-gallon ratio, but they’ll also provide you a car that is far more reliable and enjoyable once boosted.

1. Quality tires. I cannot stress enough how important these are. Having quality tires will not only increase your car’s performance abilities, but it also will make your car safer. Many people have debated how important big brake kits are to a car’s stopping ability, but what is often forgotten is the grippiness of the car’s tires. Simple physics will tell you that friction is the force that stops a car. If you lock up your OEM brakes when attempting to stop, there is nothing more that a big brake kit will do to help. When your brakes are locked, it’s up to your tires to do the rest. Having poor quality tires will greatly hamper your ability to stop, possibly putting you in a dangerous situation. Again, I cannot stress that enough. 
2. Sway bars. Some call them anti-roll bars, but the point of them is to influence your car’s handling characteristics. Simply and generally put, the stiffer the sway bars, the more easily they will induce oversteer. What specifically does each sway bar do?
   1. Softer front bar: will increase front chassis roll; will increase front grip/traction, while decreasing rear grip/traction; will provide slower steering response; increases off-power steering in corner entry.
   2. Stiffer front bar will: decrease front chassis roll; decrease front traction while increasing the rear (aka, understeer); provide faster steering response; decrease off-power steering in corner entry.
   3. Softer rear bar will: increase rear chassis roll; increase rear grip, while decreasing front; decrease on-power steering.
   4. Stiffer rear bar will: decrease rear chassis roll; decrease rear traction, while increasing front traction (aka, oversteer); increase on-power steering.

Even a stiffer rear sway bar will noticeably increase your car’s sportiness. It might not add gobs of power, but sway bars make a huge difference on this car’s driving characteristics. Your car will feel flatter and more confident in each turn, thus allowing you to hit them harder and faster than you ever imagined (assuming, of course, you’ve taken modification 1 to heart).

3.  Whether you prefer coilovers or a shock/spring combo, you’ll find yourself reaping the benefits time and time again. Upgrading to adjustable suspension will allow you to fine tune your car’s driving characteristics to suit your exact needs. Track day? Switch over to a stiffer setting to maximize traction. Daily driver? Even if you set it back a bit softer, you’ll still have better handling than stock. While this upgrade isn’t exactly necessary, it’s definitely not something you’ll regret. Upgraded suspension coupled with upgraded sway bars will give you lots of flexibility for adjustments.

4.   Valve body upgrade. The “Toyomoto” style valve body rods were the first attempt at this upgrade, and they essentially remove any dampening between shifts. They do slam into each gear, and going into reverse can be rough. Since no company ever sold a stiffer spring to replace the OEM version, shimming the valve body is the best available budget-friendly option. Depending on what materials you use, the shims themselves could be free or very close to it (however, you will need to buy new transmission fluid). The shims make each shift noticeably more firm, but they preserve some of the stock dampening, so you won’t be jolted going into reverse or chirp your tires going into 3rd gear. Be sure to add a cooler when you do this mod, and you’ll have a stronger, much more capable transmission on your hands. We go into more detail of this upgrade here.

4a. For the manual guys – Figs Clutch Damper Device Delete. Essentially, it will improve the engagement of the clutch by removing the fluid restriction to the clutch slave cylinder. They go into more detail on this mod on their website, but at only $32, it’s certainly a budget-friendly mod with a lot of upside. Low risk, high reward as they say. This “mod” might not be as immediately noticeable as the valve body shims, but for the price it’s hard to beat it.

So, there you have it. Let’s say you spend $800 on a shock/spring combination, $500 on grippy summer tires, $400 on sway bars, and $40 on either the valve body upgrade or the CDD delete, and you’ve now spent less than you were going to spend on a suspect turbo kit and substantially improved your IS300.