So, you’re thinking about headers?

Headers are probably one of the most debated topics for the IS300 platform. There are lots of reasons to buy them – some of them good, some of them bad. Most likely you’re considering headers because you want to gain power or because you want to increase your exhaust sound… right? Or, maybe your cats are clogged and you just need something to replace them.

Whatever the case may be, you’ll benefit from a better understanding of each style of header and what each style does. There are two main types of headers: long-tubes (often associated with equal length headers) and short-tubes (aka: shorties).

Long-tube headers: Because of their design, long-tube headers are known to produce power in the mid-to-high RPM range. Long-tube headers have lengthy individual runners coming out of each exhaust port, and they typically merge into a common collector (also called a “dump collector”). As a result, the scavenging effect takes place later, which will produce the most power “up top.” This provides for a lot of potential for peak horsepower, but waiting until 4000 rpm and above can be miserable for a street-driven car. Now, for a high-quality set of long-tube headers (such as the original Mazzuri product or the Team Lexus race header) this doesn’t hold true. The Mazzuris made gobs of power of top, but they also improved the entire power-band, though they are quite raspy. Another example of this is the Dezod Development header (either Red or Green), which features their twin 3-1 hand crafted low angle merge collectors and their much-hyped 6-2-1 design. The Megan Racing headers are nowhere near the level of the Dezods or Figs Engineering (or even any of the “OG” headers), for the record. I’ve attached the dyno sheet from Dezod’s website for their Red headers, and as you can clearly see, not only is peak power significantly improved, but also the midrange power is substantially improved. You won’t get this with a cheaper header. Period.

Short-tube headers: If you peek under your hood, you might notice that the factory headers are a form of short-tubes. This is to maximize low-end torque (aka: usable power). As a result of the shorter runners, the scavenging effect occurs earlier and is less drastic. You might find that you’ll make less peak power, but you’ll have most of your power before a car with cheap long-tube headers even starts making any (again, with a high-quality set of long tubes this doesn’t apply). So if you’re racing from a dig, unless you have a very high stall torque converter, the car with the short tube headers is going to pull away from you in a hurry. With a short tube header, you’ll exceed the stock low end power, but you won’t make as much up top. 

Okay, so now that you have an idea of what these two popular header styles do, which one should you buy? Well, frankly, you need to take these characteristics and apply them to what you wish to accomplish.

Megan Racing’s header is probably the most well-known example of the long-tubes, mostly because of its price. Speaking from experience, the Megan header does indeed provide an increase in power, but the power does not come where it’s needed. Due to the low amount of R&D and quality control that is inevitable at its price point, the scavenging effect is not as well utilized as it could be. It makes power, but it leaves a good amount on the table: power you’re not going to find for $200. In addition, waiting until 4000 rpm for the catless header to overcome its lack of backpressure can be quite annoying.

On the other hand, Dezod Development offers a high-quality, American-made long-tube header for our platform. Another American company, Figs Engineering, recently released their own stepped-primary race header. As it is so new, I have not yet come across a dyno sheet for the Figs model, but it’ll compete with the Dezod models, and Mike (Figs) is putting in tons of hours getting them ready. These two headers are the cream of the crop, but many of today’s IS owners say that they’re “too expensive” or “not worth it.” Frankly speaking, if you want to gain power through headers, you’re going to have to open up the wallet a little bit. The saying “pay to play” holds true, and I stand behind it.

OBX headers are something to consider, but even then they’re not ideal. While not a ton of R&D went into their development, they fairly mimic the OEM design, and as such provide a small bump in your usable low end torque production. Realistically, a very high percentage of IS300s on the road today are street cars. Sure, many are track beasts, but for the average IS300 owner, power is needed down low. It’s not often you get above 5k RPM unless you’re really pushing the car. As such, it is more effective to have less peak power, but a large percentage in the low-to-mid range (speaking in terms of a street driven/daily driven car). If you truly want to make good gains, you’ll have to actually spend some decent money on headers.

Now, as I said, both styles of headers will gain some power. Their style (short or long) will determine where that power is gained. Neither will gain something crazy like 50 horsepower, which raises the question: are headers truly worth it?

I can say from personal experience that Megan headers are not worth it. The power band is so much better on stock headers (unless you only plan on running the expressways, in which case Megans might suit you better), especially when tuned. OBX headers will provide a small bump in low end umph, but if you’re looking for true gains with headers, then you need to either source a used set of Mazzuris or Xerds (as they’re both discontinued), or you need to purchase a new set of Dezods or Figs headers. The fact of the matter is that you’re not going to get high-quality power with a low-quality product.

Both Figs and Dezods are impressively high-quality, and offer the best overall power increase. Yes, they are indeed more expensive, but you’re paying for hours upon hours of R&D, in addition to build materials and rather impressive performance gains. For most people, paying real money for headers is out of the question, except for the naturally-aspirated purists. If you’re serious about making good old naturally-aspirated power in your IS300, then you’re going to have to look beyond the price. Megan Racing and OBX headers just won’t cut it.

Note: If you plan on installing catless headers, you will need an o2 simulator or delete. Spacers and foulers are the cheap way to solve the issue, and they are hit-or-miss. If you’ve been listening long enough and you understand that cheap headers won’t cut it, why even bother trying the cheap route to resolve your Check Engine Light?


Checking your Steering and Suspension Components – Lexus IS and GS specific

First off, the terminology I will use.  Some of these parts have different names, depending on who you ask or where you go.  I’ll try to be as generic as possible.

Ball Joint – a ball and stud joint that usually has a wide range of motion.  Usually used to connect control arms to steering knuckles

Control Arm – hinged link that connects the hub or knuckle to the chassis.  (Some parts have other names but also fall under the control arm definition)

Tie Rod – a ball and socket joint like a ball joint, co nnects the steering gearbox or rack and pinion to the steering knuckle for directional control.

Bushing – rubber, polyurethane or metal that is the interface between a control arm and the chassis – allows for flex and rotation


In the above picture, we have in blue the lower control arm, some refer to as LCA #1.  In Red, another lower control arm, LCA #2, also known as a caster arm or radius arm.  Orange is the lower ball joint, green is the upper control arm with integral ball joint, and in purple, the steering knuckle.  If they were pictured, the outer tie rod end attaches to the lower ball joint.

How to check it all.  All we need to check this stuff is a pry bar or similar substitute about 2-3′ long and a jack.  A friend to help is nice but not required, but most importantly, we’re going to need some common sense.

Ball Joints:  With the car flat on the ground, place a jack underneath the forward lower control arm, LCA 1.  Raise the jack until the tire is approximately 3-4″ off of the ground.  Now, using your pry bar, situate it underneath the tire and try to pry the wheel and tire straight up.  Here is where having a friend helps.  You need to see if there is any up or down movement in the lower ball joint as you are prying up.  Any movement at all calls for immediate replacement.  You can visually see movement, or, I like to put my hand on the joint to feel for movement.  While we have it jacked up this way, grab the wheel and tire at the 12 and 6 o’clock positions and shake it back and forth.  Look and feel for movement in the upper and lower ball joints.  Same goes here as earlier, any movement, replace it now.

Tie Rod Ends:  With the car jacked up as before, or from the frame, either way, grab the tire and wheel at 3 and 9 and rock it back and forth.  Feel the inner and outer tie rod ends for a light clunk.  An extremely small amount of play is acceptable, but if in doubt, change it out.  Movement here, any at all, will cause the vehicle to be out of alignment.  Even if the alignment machine says it is aligned, as soon as you drive the vehicle, the numbers mean nothing.

Control Arm Bushings:  The forward lower control arm is pretty reliable, but shake the wheel/tire at 12 and 6 with the car jacked up from the chassis (not the control arm as before) and look for movement.  The rear lower control arm is more difficult to test and you should just be looking for visually worn or torn bushings.  These are a common failure though they will never come apart completely, they just cause dynamic toe changes as you drive which causes an otherwise good alignment to exhibit bad tire wear.  Upper bushings, look for movement the same was as you did the forward lower control arm.


Here’s an example of a lower ball joint on an 1IS/2GS front suspension. The two holes on either side of the ball stud are where it mounts to the steering knuckle, the hole far left is for the tie rod end.

Lets Talk About Ball Joints on the IS and GS chassis – a quick rant

I see it all the time.  Someone posts a picture of one of their front wheels all laid back with the front fender dented in from it.  It usually has a caption that reads something like “What a POS, I was just driving along and my ball joint broke.

To be completely truthful, the way I read that is “I forgot to do some basic maintenance and inspections on my car, I want someone to feel bad for me.

Ok, so, ball joints.  Pretty amazing little piece.  They are responsible for supporting the steering knuckle (that the wheel bearing and ultimately the wheel itself) are bolted to, while it is turning, accelerating, braking.  It is undergoing all sorts of vertical, lateral and twisting loads.  Add to that, the suspension is designed for it to have one specific angle at rest, and then we lower our cars, which changes that angle.  This puts even more stress on the part.

Owners manuals.  Who reads those things?  Who on Earth would care to read the maintenance suggestions?  I’m here to tell you that there is some great information in there.  As much as I know about cars and I still sat down to read mine cover to cover for the GS I just bought.  The best part, I think, is where it says the car should be inspected, like, really inspected from time to time.  Every 30k miles or more frequently, actually.  Ball joints (and the rest of the steering/suspension components are listed, as well as pretty much every other mechanical item on the car.)

The good news is that these parts are relatively easy to change and even easier to test properly.  I will run down how to check the front end of a vehicle that anyone with a prybar and a jack can do.   That’s the next installment though, for now, here are some pictures of other cars that have had some ball joint issues.

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Making an A650 Transmission Survive on the Cheap – Part 3

Alright, so, we’ve talked about it and the theories behind how it works.  Now for some show and tell.


When you first remove the transmission pan, this is the first parts you see.  The grey thing in the middle is the screen.  Used to call it a filter, but it really doesn’t work that way anymore.  Circled in yellow is the pressure setting.  In this picture, it is turned up all the way.  It is normally in the middle setting.  To adjust, simply push in and turn.



Just a view without the filter or wiring in place.





This ball and the plastic piece / spring that comes with it is pretty important.  Make sure it goes back in.



Just a shot of the accumulators.




Here is a shot of all of the springs and accumulators and where they go.  Also pictured are my home made shims.

For the hard data, here is what you need to know.  I personally shimmed mine 12mm – yellow, 12mm – red, 15mm – green and 15mm – blue.  These shims were acceptable for daily driving with much firmer than stock shifts but not clunking in to gear.  Now that I’ve learned a lot more about these transmissions recently, I might have some ideas to make them more reliable still.  Also, it is very important to install the shims inside the aluminum pistons, not in the cylinder itself – doing this would block the fluid holes in the bottom.


Update: 5/12/2018, a couple local friends have documented this on video with some clarification as well:

RaceCar and Chill

IS300 Turbo Build


Dyno’ing your Automatic IS300 – the right way.

Dyno’ing a manual transmission car is easy.  For those with no experience on a dyno, the general idea is to get the tires rolling, slowly shifting up through the gears until you get to the gear that is closest to 1:1.  Most cars, this is 4th in a manual transmission.  Once rolling in 4th at about 2000-2500 rpm, you press start on the dyno and floor it.  Once you get to terminal engine speed (whatever you have chosen as max RPM), you let off, and the dyno slows down.

If you try flooring an auto trans car at 2000-2500 rpm, the car will downshift, no matter what gear you have selected.  Many dyno shops will simply floor it and let it run through the gears.  The problem with this is that you don’t get a good idea of the hp/tq curve below about 5000 rpm.  You will get peak HP and depending on turbo / engine setup, maybe peak TQ as well, but, like everything else we do on this website, there is a better way.

Our a650e automatics are 5 speed transmissions as well.  That in mind, the 4th gear is the gear we want to be in to dyno.  It is exactly 1:1, which is ideal.  So, follow these steps to get the most accurate dyno possible.  Select manual mode and downshift as far as possible using the steering wheel buttons – you will be limited to 2nd gear.  Put the car in snow mode.  Power mode will make no difference on the dyno.  Get the tires rolling, up to about 20 mph and upshift to 3rd using the steering wheel buttons.  You should feel it shift.  Slowly accelerate more to about 3000 rpm in 3rd.  Shift to 4th, you should feel it shift and the decrease in RPM.  Now that we are confirmed in 4th gear, slowly accelerate to 3200 rpm.  The dyno operator should hit the start run button at this point.  Floor it.  RPM will climb – be ready though, at 4000 rpm, you will want to turn off snow mode.  This is when the fun really starts.  Obviously, let off when you reach the maximum RPM you wish to achieve.

Why does this work, and why snow mode?  Simple – snow mode prevents downshifts except at very low RPM.  Even as low as 3000 RPM.  The downside to snow mode, and the reason we have to turn it off at 4000 RPM is that is also limits throttle open percentage to approximately 60%.  Won’t make much power that way.

So, now you know the best way to dyno your automatic IS300.

This also works on the road when using software to interpolate horsepower and torque, such as Virtual Dyno.

Fixing a jacked up car, AKA – the right way to wire a standalone, Part 1

This will be a multi part series as I just received the car yesterday and I am sure I will have more surprises along the way.

The enthusiast that dropped it off to me complained of poor drivability, inability to stay running when warm, excessively hard shifts, as well as just a lack of trust in the shop that performed the work initially.

Before I even got to drive the car, I started a basic inspection.  First thing I wanted to see was how the standalone (an AEM V1) was wired to the stock ECU.


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In all fairness, those are disconnected because I started trying to straighten up the wiring.  Before, it was a mess, no zip ties on common bunches, etc.  I decided after I first started that I needed to start documenting everything I found

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Yes, that is electrical tape insulating the connections to the stock +12v supply.

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Here, we have a resistor just kind of hanging out.  It is supplying resistance to the crank sensor, but I’ve never had to do that when running a standalone in conjunction with the stock ECU – in fact, the resistors need removed from the standalone in order to make it work right.  Further inspection is required.  Either way, the resistor is not insulated and is just chillin.

Ok, so, you’re thinking, this isn’t all too bad.  Well, the shop did not wire in intake air temp whatsoever.  Who knows why, but I knew that one of the first things I would need to do would be to add intake air temp.  The enthusiast who owns the car had already purchased and started to install, but became overwhelmed with the wiring.  Just when I’m thinking this isn’t all that bad, I decide to snip the ziptie holding the AEM in place under the drivers side of the dash.

2015-04-04 16.04.07

At this exact moment, my heart skipped a beat.  What I thought was initially going to be a quick and easy fix just became a mini-nightmare.  I decide I’m in it this far, lets inspect a little further.

I detached the mainboard from the case via the 3 screws underneath.  Yes, I said 3.  One was missing, as there is clearly supposed to be 4.

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Ok, so, this is scary, but what comes next almost made me cry.

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Speechless.  I had to sit down for a solid 5 minutes and decide which way to attack this.  I don’t like spending other peoples money, but this is so not right, on a ridiculous level.

Alright, so, first thing I had to do was to order the correct ECU plugs. This is an EVO9 plug n play AEM V1 30-1320.  For those that don’t understand that part in an IS300, well, we can use pretty much any AEM (I personally used to use the 30-6101 Supra box).  To make this right, I ordered the correct ECU plugs and pins from a cool EVO-centric website  I even ordered more pins than I would need, but you can see the order below.

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Just $48 (plus shipping) to avoid wiring this the worst way possible.

Just a quick list of other things I found that need to be changed:

1) MAF clamp – since the stock MAF is kept in the loop on these dual ECU setups, it needs to be clamped.  I’ve had good luck with a simple 4.2v diode.  This could be the explanation for the hard shifts, as the stock ECU uses MAF signal for part of its shift algorithm.

2) Intake air temp – this will be added.  I’m not sure how anyone expected a speed density setup to work without a proper air temp sensor wired in.

3) He was told it was running 18 psi, but it appears the wastegate spring is 12 psi.  There is a connection for a boost control solenoid, but there isn’t one installed anywhere on the car.

4) The GM MAP sensor appears to be a knockoff.  I’ve experienced these and haven’t had good luck with them at all.  Will require further inspection.

There may be more and I will update this as time comes.

Part 2 will be published once I’ve started cleaning up the AEM to be installed correctly.




Supra / IS300 2JZ Shimless Buckets

Its almost a requirement to upgrade from the shimmed factory buckets to factory shimless buckets.   The stock shims have a tendency to fly out of the bucket under high rpm operation.

These are the toyota part numbers for MR2 Spider shimless buckets which are compatible with 2jz.

All measurements of buckets are in mm.

13751-46030 5.06
13751-46040 5.08
13751-46050 5.10
13751-46060 5.12
13751-46070 5.14
13751-46080 5.16
13751-46090 5.18
13751-46100 5.20
13751-46110 5.22
13751-46120 5.24
13751-46130 5.26
13751-46140 5.28
13751-46150 5.30
13751-46160 5.32
13751-46170 5.34
13751-46180 5.36
13751-46190 5.38
13751-46200 5.40
13751-46210 5.42
13751-46220 5.44
13751-46230 5.46
13751-46240 5.48
13751-46250 5.50
13751-46260 5.52
13751-46270 5.54
13751-46280 5.56
13751-46290 5.58
13751-46300 5.60
13751-46310 5.62
13751-46320 5.64
13751-46330 5.66
13751-46340 5.68
13751-46350 5.70
13751-46360 5.72
13751-46370 5.74

You can easily purchase these from Curt @ Elmhurst toyota or the supra store.

Making the A650e transmission survive on the cheap.  Part 2

One of the most common misconceptions about the IS300 (and other cars that share the 5 speed Lexus automatic) is its ability to handle some real power.  In this article, I will outline what it takes to make it handle some power on the cheap, mods that almost anyone can do.  Everyones mileage will vary, no doubt, and part of its longevity rests with you, the driver, but this will be the best thing you can do without spending a ton of money.

There are a few theories on how to make automatic transmissions last.  I knew, going in, that my stock transmission might not last too long, so I was prepared to do some experimenting.  What I have ended up with is a transmission that was amazing at a 560 whp level (over 500 ft lb of torque also), and today, is still holding up to 650 whp, once in 3rd gear and above.  I have not modified the valve body in any way and the transmissions guts have never been removed.  The transmission pan and valve body will need to be removed, but that is it really.  How, you say?  Well, I did a bunch of research and found that it is a delicate balancing act to make these transmissions work right with some real power behind them.

The first problem I ran into was hitting the rev limiter under power.  Stock rev limiter is around 6200-6300 and the transmission starts its shift around 6100.  Doesn’t really give much time to do its thing, but it works just fine at the rather anemic stock power level.  There are two ways around this – raise the rev limiter or make it shift faster.

The best way without a full transmission build, and even without a valve body replacement is to modify the accumulators.  Accumulators are the small piston like devices that allow fluid to accumulate, in order to dampen shifts.  The springs need to be stiffer to make the shifts firmer, but they still need to be in place to maintain a little bit of shift damping.  There is no need to be chirping tires for a quarter throttle 2-3 shift.  I was never able to find good information on stock spring rate, or even find a good source for stiffer springs that would fit properly.  Instead, I simply shortened the space the spring could travel.  Unfortunately, I do not have measurements, as I simply did not take them when I was performing this mod 3 years ago.  Some day, I will pull her apart and get exact measurements.  To shorten the travel, I simply made bushings for the springs.  Anything metal that fits inside the accumulator will work.  I shimmed all 4 of mine approximately 15 mm.  That was attempt #2.  Attempt #1 was about half of that and though it helped, shimming more helped more, but is still not harsh.  There are small holes inside the accumulators that you do not want to block, but the a650 design prevents that to an extent.  One more quick mod related to this is to simply turn line pressure up.  On the side of the valve body, there is a pressure control – simply use a straight edge screwdriver to push in and rotate to the next detent.


here are the accumulators in an a340 circled – the a650 is extremely similar

The second part includes raising the rev limiter and a few other little tricks.  Even with the above listed modifications, getting the trans to shift too quickly will not be good.  At the power levels required for these types of modifications, hopefully you are running some sort of standalone already.  The 2jz is very capable of spinning higher than the stock 6300 rpm redline.  That redline is put there because the stock cams and naturally aspirated motor just simply don’t make much power past that.  We can safely spin a stock head / cams / valvetrain car past 7500 rpm, and probably higher than that if necessary.  I have my redline set up through the AEM Infinity I run at 7300 rpm.  One other thing I do is retard timing during the shift.  Since no standalone will control the auto trans, what I’ve done is drop timing to 0 at the shift point.  This reduces power just slightly (low timing keeps the turbo spooled though) until the lower RPM after the shift point is realized and the timing is obviously much higher there.  These mods are enough to allow my transmission to survive at 650 whp / 610 ft lb.  It doesn’t do so well in 1st and 2nd, mainly because the power comes on so strong, but once in 3rd, it holds together extremely well, all the way to redline in 5th.

Bad ideas – One of the most popular “mods” to these transmissions is the rods that go in the accumulators.  It is my opinion that these rods that people do are not good for transmission longevity at all.  The fact is, they make the transmission slam into gear pretty much every single shift.  This is not good on the internal components of the transmission.  Things like this are what causes the infamous sprag gears to roll over.  An instantaneous hit of power is much harder on the sprag than applying the power smoothly.  (Drop a hammer on a piece of glass versus lay a hammer on a piece of glass).

Good ideas – Don’t let the transmission slam into gear.  Use the transmission selector buttons to maintain the gear you want.  Prevent the transmission from downshifting if at all possible under full throttle.  If the engine is below 4000 RPM, applying full throttle will invoke a downshift, no matter what gear you have selected.  There is one way around this – the snow button.  If you have snow mode activated, you can go full throttle as low as 3000 rpm, but will be limited to 60% throttle until snow mode is turned off.

Making the A650e transmission survive on the cheap.  Part 1 – Cooling

One of the most common misconceptions about the IS300 (and other cars that share the 5 speed Lexus automatic) is its ability to handle some real power.  In this article, I will outline what it takes to make it handle good power on the cheap, mods that almost anyone can do.  Everyone’s mileage will vary, no doubt, and part of its longevity rests with you, the driver, but this will be the best thing you can do without spending a ton of money.

Part 1:  Transmission coolers – Keeping transmission fluid cool is one of the most important keys to transmission longevity.

The stock cooling system for the transmission lives in the lower portion of the factory radiator.  Fluid is simply pumped out of the transmission, through the radiator (you’ll notice two 5/16” hoses along the lower edge) and back into the transmission.  There is very little fluid pressure here – the return essentially falls into the transmission pan.  There is a factory temperature sender on the outlet of the transmission.  This can be monitored by obd2 scan tools with live data ability.


A wide variety of external transmission coolers exist on the market place.  You can’t have one too large, with regards to cooling, however, there isn’t a whole lot of space for large coolers without some ingenuity.  Many will simply attach to the front of the condenser, behind the intercooler (on a forced induction car).  Behind the drivers rear tire, there is some room for auxiliary coolers as well.  Some have fans as part of their design, some will add external fans.  No matter which you choose, it is a good idea to plumb the cooling system in such a way so that the fluid flows through the radiator based cooler first, then through the additional coolers.  This provides for the best chance for the fluid to cool before returning to the transmission pan.


My personal setup has transmission fluid routed through the radiator, then to the rear of the car.  Behind the drivers side rear tire, there is an unused space, away from anything else that produces heat.  Here, I have two transmission coolers stacked, with an 8” cooling fan on them.  Ideal transmission fluid temps are 175-225 degrees.  I monitor transmission output temp through the AEM Infinity, and when transmission temps reach 175 degrees F, 80 degrees C, the auxiliary cooling fan is turned on.  Sustained operation above 225 degrees will shorten transmission life, and any operation above 240 degrees is extremely detrimental, as the fluid itself begins breaking down.

20140901_211627(excuse the poor picture and dirty shield)  

A few key things that everyone needs to know with regards to this.  First off, make sure any fluid lines used are rated for transmission fluid.  More commonly available at parts stores is fuel injection hose, which will break down over time when used with transmission fluid.  It is a good practice to use high quality fuel injection hose clamps instead of the more traditional worm gear clamps.  I can’t say this is all I’ve ever used, but these are stronger, provide more consistent clamping pressure and once you use them, you will understand why I advocate for them.  Next on the list is fluid type.  Toyota T-IV fluid is the only transmission fluid to be used in most Toyota transmissions.  It is relatively inexpensive at the dealer and it works great.  Many manufacturers do make generic import transmission fluids that will work, but in general, they are the same price or even more expensive than the genuine fluid.  Last but not least, no amount of cooling will help if you are are hard on the transmission and do high powered pulls and races back to back.  Monitor temperature and allow the fluid to cool if it is getting unnecessarily high.