AJatx

It's definitely louder than stock with just the TRD cat-back.
My friends with Runners like the sound. It's got some bass to it.
However, if you like the quiet ride, then you may not like it.
To me, it's quiet since I got used to a straight exhaust from my single-turbo RX-7. Now that's damn loud for a street car.

I'll try to get an audio clip of it.

I plan to get some headers soon (after I finish my track car).
TRD headers are close to $900 shipped. There are some other headers that run around $300 or so (my memory might be off).
TRD typically makes some quality stuff, but I'm not sure if it's worth an extra $500 - $600 though. Anybody else care to comment?

J

ManyMods

Jeff-
I have the TRD exhaust on my '02 w/o headers and, as some can remember, I HATED IT before my SC was dialed in. It is loud (a girl heard me drive up to where she was parked the other day and asked me if my muffler was broken or was that just my souped up motor?) ... and depending on the engine tuning can resonate some wicked drone, BUT when everything is running the way it should be, or at least 95% the way it should be it sounds good ... still loud, but good. The slant cut tip on mine is STAINLESS.

FYI, if you are planning to install the rear Addco sway bar in conjunction with the TRD exhaust you undoubtedly have a problem with the fit no matter what version sway bar they send you.

ManyMods

J -
I plan on getting the TRD headers because I too have heard they are well made and I want to stay Toyota / TRD with as many mods as possible. However, I understand that they have redesigned the crossover pipe because it was stress cracking and I will be sure to specify the latest design. Also, I bought another front cat (used) for my header install because you have to cut the down pipe for the header install. Why? Because I want to be able to return the vehicle to stock condition for resale if I need to. As I recall, the cat only cost me about $150.00 delivered and it was from a late model low mileage vehicle. I wasn't sure before but now that I have done all the other mods, I think the headers will really enhance the total package.

jwahaus

Peter,

Does the TRD exaust have a larger pipe? or is it pretty much just the muffler making the sound. I'm thinking that perhaps all I need is a high-flow muffler. I'm not really looking for more power and I could likely save $$$ just getting the muffler replaced.

Also, how hard is the TRD transmission cooler install? I'm thinking this would be a good idea since I'll be hauling around 4500 lbs of boat this summer. I didn't have any trouble with overheating last summer but I didn't really go very far with it.

midiwall

Running JUST a free-flow muffler with the stock exhaust manifold is certainly viable and a lot of folks do it. Magnaflow, Allied, Borla, Dynomax... There are many makes and models out there. fwiw, the TRD cat-back system is said to be made for them by Borla.

The tone of the exhaust system comes from everything in the exhaust system. The muffler and the length/size of the tail pipe is a LOT of it.

Also, if you run a tip on the tailpipe, get an adjustable one so that you can use it to tune the exhaust. Moving a tip over the space of 6-8" on a tailpipe can dramatically change the tone of the exhaust as well as the power curve of the engine overall.

Power wise... Anytime that you can make an engine like ours breath easier (either inhaling or exhaling) you will gain power. So moving to a free-flow muffler WILL get you power - even without headers. The exception is that our engines need a bit of backpressure to run right. So, don't use larger than 2 1/4" pipe on the exhaust (or 2 1/2" if you run headers).


It's very easy, and a good idea for towing.

But, before you spend the $$$ on the TRD system, know that the TRD cooler is (_is_, not "just like") the Hayden model 1678. Save a lot of bucks and get it from:

http://www.bulkpart.com/cgi-bin/miva...egory_Code=HCS


And... The TRD headers are very nice. There are also folks here running Edlebrocks and Downey's - which are both nice as well, and a whole lot cheaper. For example, ceramic coated Downey's can be had for under $400 including the crossover pipe:
http://www.truckperformance.com/vehi...UNNER&sf4=3.4L

Like this thread has talked about, install is a PAIN. Honestly, if you're questioning your skill level to install a tranny cooler, then figure on paying a shop to do the header install. Most folks are stating quotes for $300 or so.

ManyMods

Jeff,
I want to respond in general to your question and midwall's comments. The TRD exhaust that I have has the muffler and a resonator can on the tailpipe and is finished with a stainless tip that is the same OD as the rest of the system. Although Borla was mfg'g the system for TRD, I was told by TRD when I researched my system that they are doing themselves now. I do not believe that. The biggest difference in the design is the outlet pipe bend from the muffler, it is not as radical and that is why it creates a problem with the Addco bar. Back pressure is important for proper engine performance and IMO, for our 3.4L engines either SC'd or naturally aspirated, the pipe OD should not exceed 2.25" --- even with headers. Also, the tip should not be larger than the rest of the pipe OD. The fart cans the kids are using actually hinder proper scavenging of the system. You can read about proper exhaust system sizing from companies like Flowmaster or Stan's Headers. Installing headers is usually a challenge, frustrating and not for the inexperienced mechanic. As you've heard, the TRD header install on the 4Runner is not easy but if you are willing to take your time and have the proper tools you can do it. You might want to have a buddy lend support with a second set of hands. I think that down pipe on the cat that has to be cut needs to be welded onto a header pipe, but I don't remember for sure. I guess the bottom line for you is that if you like to wrench, go ahead but if you are mechanically challenged then leave it for a professional to install and enjoy the results instead.

I found that this engine, like others, is very sensitive to changes in air intake and exhaust, so be careful. It is true that the better the engine breathes, the better it will perform but this is all relative to what you have done to the engine to support those changes with regard to fuel and timing.

Whether you use the TRD trans cooler or the Hayden cooler, I think it is a must for anyone who tows or is stressing the trans in any way. The nice thing about the TRD cooler is that it comes with all the little crappy installation parts so you don't have to mess around with fabricating brackets. The TRD cooler is beefy and the Hayden cooler is supposed to be even beefier. The installation is a cinch but you have to be careful when running the rubber hoses so that they do not chafe on the skid plates when they are reinstalled after the installation. You might want to install a FILTRAN in-line magnetic fluid filter in the rubber line when you are doing the cooler install.

jwahaus

Hey, thanks for the Transmission Cooler link. Very good price they have on the 1678. What additional parts will I need to mount it to my truck?

Also, I'm not exactly sure where on the truck it mounts. Do you have a picture of one installed?

MTL_4runner

Brian has a great writeup for this:
http://www.drawhorn.org/hayden_trann...er_writeup.htm

oly884

just for clarification, you don't need a tranny cooler on a manual transmission right?

MTL_4runner

Correct.

midiwall

Like Jamie said, check out Brian's write-up. Read through it a couple of times so you get a feel for what's coming up in the next step.

fwiw, I didn't have to buy any extra parts to install mine. The hose that came with the kit was plenty long, I installed mine at the upper passenger side in front of the radiator.

Hayden may have changed the length of the hose they include in the kit, or I just got lucky.

Something to add though - buy a quart of ATF II fluid to add into your tranny after you put the cooler on. You might need to make up for the added capacity of the the cooling system. Mine didn't show a real level drop for a couple of days, then the shifts started getting sloppy. I added fluid, and things got a lot better.


Good luck!

Mark

jwahaus

I looked at Brian's Trans. Cooler write up and that is a big help. It doesn't look very complicated. I'm not sure I would use zip ties to hold the cooler in place. Seems like they would eventually melt or break loose.

What does the TRD kit use for mounting the cooler? I would expect some sort of metal brackets.

Also, something that concerns me is putting the trans. cooler in front of the radiator is going to keep your transmission oil cooler at the expense of your engine. You're blocking a significant portion of the radiator which should result in less effective cooling of the engine.

rimpainter.com

That is a valid concern, but with proper operation of the thermostat, you really should not have a problem. Granted you are decreasing the available radiator surface area and its exposure to airflow, but it wont be enough to see on the temp gauge. If you are going to overheat on a hot summer day pulling a boat up a grade, it wont be changed by having a trans cooler in place.

midiwall

The zip ties are actually quite strong... I've had the cooler on for a few months now and there's no sign of the cooler loosening up which would be a sign of the ties stretching from getting hot.

You could also fashion your own brackets out of aluminum sheet (Lowe's, Home Depot, etc) if you wanted to.


Nope... not an issue. This is the classic location for all of the cooler installs that I've seen. The only alternate was where there was a thread here that a guy put his up behind a rear skid plate. The downside of that was actually the lack of airflow.

Like Chistian said, the cooling system will take care of itself (given that it's not plugged). If the engine needs to bleed off some heat, then the thermostat will open and coolant will flow through the radiator. What you may find with the tranny cooler on is that the thermostat spends more time open than it used to.

No biggie though.

It's also worthwhile to point out that the inlet to the radiator is on the bottom for our trucks. With the tranny cooler mounted up high, then you're leaving the most important area of the radiator fully expose to the airflow.

jwahaus

Here are my before and after shots of the SC w/7th injector install.
Ain't she purty?

jwahaus

At WOT my setup was kind of surgy. It was very smooth at moderate throttle but
I didn't really like the surging it was doing at WOT. I changed from the recommended
setup by moving the vacuum line connected to the Fuel Pressure Regulator from the
intake silencer to the boost port on the SC. It now seems a good bit smoother at WOT
but it also seems to have less power than before (just my butt dyno measurement).
Perhaps I just need to let the ECU re-adjust to the new configuration.

jwahaus

Okay, after a couple of day of driving it configured this way I think I'm going
to switch it back. It seems to have noticeably less power now. I guess
the FPR is overcompensating for the boost it is seeing and killing performance.

It was only at WOT that things were not as smooth as I would like before.
Since most of the time I'm not at WOT I don't want to sacrafice power
at moderate throttle for a smoother (but weaker) max and mid throttle.

Perhaps a programmable ECU is in my future. It's tood bad the TRD
piggyback ECU is not programmable (or is it?)

I'm sure it has a ROM or Flash part that could be re-programmed, but
without knowing the format of the data in use it would likely be too
much work.

midiwall

Nope. (read on)


Yeup, this is the issue. "Many" folks have pulled apart ECUs from various brands/makes of vehicles and some are easier to reverse engineer than others. Toyota has theirs fairly well locked down.

Actually, the onboard FLASH is writeonce; and I think it's a security part that burns the I2C line when flashes so that you can't read it back through the programming port.

There are folks like Jet which have hacked enough to at least be able to modify the fuel/timing tables, but they're far from being able to write new code.

If you want control, then you'll need to move to one of the piggyback programable units that tweak the information feeding the ECU hence being able to fake the ECU into doing what yoou want it to. But, I don't know that anyone's tried using one with the 7th injector kit. This is why the alternate method of replacing the injectors & fuel pump is still viable - you can control that setup tp your heart's content.

jwahaus

Now that I've had a few thousand miles to evaluate the SC and the
way it is performing I have to say that overall I'm very pleased with the
setup. I've now figured out that what appeared to be the engine bogging
down at ~3000 RPM was actually the torque converter locking up. (I have
an auto) If I keep an eye on the speed it becomes obvious that the rate
of speed increase is still relatively constant under WOT but the RPM's will
appear to "lag" at around 3000 RPM (in 2nd or 3rd gear) due to the
torque converter increasing the drive ratio as it locks up. My ear also
notices this as the pitch of the engine tone is constant for a short period
of time while the torque converter is locking.

I still have the stock exhaust in place (due to lack of time) and some
times I think I want to keep it nice and quiet but eventually I come to my
senses and realize that I really need a free flow muffler with some rumble.

Supercharged

Glad to hear that you have good experience with the 7th injector. I should have mine installed soon. Have you dyno your ride yet? A drawback with the TRD catback is that you can sneak out of the house at night to go have a beer with your buds anymore- wife busted me a couple of times.

2003 DC /TRD SC/ TRD CAT /TRD AT cooler / TRD headers /TRD boost gauge