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Timing Retard Eliminator

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Resistor color codes What is a TRE? TRE and gear indicator TRE schematics Supplies Where to buy Special notes Installation Testing

Resistor Color Codes

Before we get started on the TRE mod, you'll have to make sure you have the proper resistor. Almost all the errors people have with the TRE are due to using the wrong resistor. Often, people use a 15 or 150 ohm resistor instead of a 15,000 because of error in reading the resistor color codes. You should get an "FI" error if you do this.

Just for clarity, then, the color codes you want for the TRE mod are :

Either a 1/4 Watt OR 1/2 Watt resistor is fine! Don't sweat the power dissipation. The worst case scenario is that you COULD get a maximum of 0.014 W of power through the 15k resistor, or 0.03 W maximum power running through the 6.8K resistor. And in real life you'll probably have significantly less than this. Use whichever resistor you have laying around in the drawer.

If you use a 1500 Ohm resistor by mistake, you'll NOT get an FI error, but you won't get a boost in performance. Actually you may experience WORSE performance now in the top gears. That is because 1500 ohms is the GPS setting for 3rd gear --- so you're setting the ECM to always retard the timing as though you were always in 3rd gear. It is my belief that people who experience worse performance or no boost in performance after a TRE mod have usually chosen the wrong resistor.

Therefore I cannot stress enough that you need to check your resistor with an Ohm-meter before you hard wire it into your bike. Now, here are those pesky color codes:

The graphic at left is from an excellent electonics website, previously Unfortunately that site seems to have been dismanteled so I cannot offer a link here.

resistor color code chart

The TRE Mod uses a 15,000 ohm resistor for the GSX-R600 and 750's. For the GSXR-1000, most riders use a 6800 ohm resistor ( to make your bike think it's in 5th gear, not 6th, and thus overcome the top speed limiter ). This is what your 15,000 Ohm resistor should look like. The stripes read in order tell the value of the resistor:

orangeX 1000
Tolerance (gold)5%

15 k Ohm resistor appearance

This image shows a 15K Ohm resistor with a 5% tolerance (i.e. the true resistance value is 15,000 Ohm +/- 750 Ohms, or somewhere between 14,250 and 15,750 Ohms). See if you can follow the color codes the see why it is a 15,000 ohm resistor


This resistor shows : Blue: Grey: Red: Gold. This means it is a 6800 Ohm resistor with 5% tolerance.

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What is "TRE" ?

piston picture

It stands for "Timing Retard Eliminator". Now, you should understand what "timing" is and what we mean here. We're talking about the "timing" of when the ignition spark occurs, relative the the postion of the piston. The optimum place for the spark of ignition to occur is just a little bit before the piston hits top dead center. If this "timing" is done just right, there is maximum torque provided by the firing of that piston.

If the ignition is timed too early (a long time before top dead center) then the fuel and air are ignited while the piston is still coming UP, so that a lot of energy is wasted battling this upward momentum. This is called advancing the timing.

If the spark occurs too late ( any time after top dead center) then the piston is ALREADY moving DOWN, the fuel/air mixture is NOT maximally compressed anymore, and less "push" is obtained from the explosion. This is called "timing retardation", or "timing retard". It gives you something less than maximal torque. So the proper timing is crucial to maximize the "push" to the piston (which translates directly into torque).


Suzuki has deliberately programmed the ECM for less than maximal torque in the first three gears. Presumably, this is done to protect the rider from the full power! What they've done is to "retard" the timing, or make the spark occur TOO LATE, on purpose, so that maximal torque is NOT acheived.

The "TRE" removes this "retarding", to set the ignition spark back to the place where it will give maximal torque, just before top dead center. Thus you have "eliminated the timing retard" -- the "TRE' mod. With this mod you will notice more power possible in gears 1, 2, and 3. You'll notice SMOOTHER performance of the bike without all that jerking and engine braking in those lower gears. And this mod costs you < $5 if you wire it yourself.

tre resistance values for the gear position sensor resistorvalues by jeffw resistorvalues by 2fasst

For those of you technofiles interested, 2 Gixxer riders have independently measured the resistance values output by the GPS, and it's nice to see that on different bikes and different models, those values are really identical. To the right is a summary of those findings.

Remember, only the LOWEST THREE gears are "retarded", unlike our politicians and lawyers, where the condition is apparently universal. So it will not matter whether you choose a 4th, 5th, or 6th gear resistor, the end result will be the same -- LACK of ignition retarding, and that's what you want.

In practice, you should choose a 15K ohm resistor for the 600 cc and 750 cc gixxers. Why? First, because that's what thousands of riders before you have done, and it works. Second, because that resistor value (1/2 Watt or 1/4 Watt is fine) is easily available for pennies at any Radio Shack.

For the GSXR-1000, use a 6800 ohm, 1/2W or 1/4W resistor (5th gear resistance) because that will overcome the top speed limiter. Hell -- for most of us, going > 186 mph is not on the list of "things to do", but, while sitting at the bar it's just a good feeling to know your bike COULD do it! Besides, I'm all for anything that sticks a thumb in the eye of governmental over-regulation.

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TRE and Gear Indicator

The TRE mod will not interfere with your aftermarket digital gear indicator. I have both mods installed on my bike, and I can verify that there is no problem.

The problem is that the TRE WILL inactivate the STOCK digital gear indicator found on 2005 and later GSXR's. Here's what will happen if you install the TRE on these newer bikes:

  1. In neutral, the gear indicator will correctly read out "0"
  2. With the TRE switched to OFF ("factory mode"), the gear indicator will function normally.
  3. With the TRE switched ON ("TRE mode"), the stock gear indicator will read out a constant "6" regardless of what gear you are in (or it will read out "5", if you chose to install the 6800 ohm resistor).

Sources of information:

  1. member arieso94z28, who installed this mod on his '08 600. Thanks for keeping us up to date ! thumbsup.gifpunk.gif
  2. JSD TRE information page. JSD TRE is just a pre-wired version of the TRE shown on this page. He confirms what is stated above.
  3. Ivan's TRE web page. Ivan claims to be the inventor of the TRE, which again is just a pre-wired 6800 ohm TRE, identical to what is shown on this web page. He confirms that this will make the stock gear indicator read out "5" in all gears except neutral.

If this "gear indicator issue" concerns you, I have four possible solutions to offer:

  1. Ignore it - from the invention of the first motorcycle in 1868, until the 2005 gixxers, no motorcycle had a stock gear indicator on it. And riders did just fine without it. I DO like having one, but I'd have to admit that I rarely actually use it. If strapped for cash, I would definitely have gone without installing one in the first place.
  2. Install a TRE with a switch - and just figure out which mod is really more important to you. You'll probably decide that neither one is absolutely essential, but that it is far better to have the TRE switched ON - and again, just do without the gear indicator function.
  3. Buy a pre-made TRE that has special circuitry to preserve your stock gear indicator function. Unfortunately, this littel gadget will set you back $139 + shipping - and that's a little more than the $5 you'd spend for a Radio Shack switch and resistor that you wire yourself.
  4. Of course you might install your OWN tre, then install an aftermarket digital gear indicator. But I do not suggest this.. The aftermarket gear indicator costs about $80, so it would eliminate some of the cost savings of doing your own TRE in the first place. And then you'd have to mount the aftermarket indicator next to your instrument cluster, as I did. So for $85 total, you've got a sloppy result, compared to just buying the $139 XTRE that keeps your stock gear indicator active. Given this choice, I'd go with the XTRE instead. It's just a little more money, but keeps your instrument cluster with a nice clean stock look.

In the mean time, if you have installed a TRE as on this page, on a GSXR 2005 or later that has a stock gear indicator, please let me know to tell me of your results - do you lose your gear indicator function with the TRE switched on? I sure appreciate your help, so that I can keep the other riders up to date here.

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original tre diagram by “jestersplace” modified diagram with bugman notes
Original diagram by “Jestersplace” from gixxer.comModified diagram by Bugman

There is always some confusion about DPDT switches, because they seem to work "backwards". Look at the Bugman diagram - when the switch is UP, the switch connects the center two contacts A,B to contacts 1,2 -- in this case a 15K ohm resistor. This puts you in TRE mode. When the switch is DOWN, the switch connects contacts A,B to contacts 3,4 -- so that you're in plain old stock, factory mode. You may want to remember how you've connected your rocker switch so that you know when you're switched to TRE and when you're switched to factory mode. Then you can test it after installation. But when you ride the bike, the difference should be VERY obvious. See below for testing suggestions.
Compare the Bugman schematic to this photo by “01gixxerJim”. This shows quite nicely how to connect your resistor to the switch, and the numbers and letters correspond to those on my of switch connections
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Supplies, Tools

Radio shack #275-695 The switch you want: Radio shack #275-695 DPDT Red Rocker switch, 10amp @ 125 VAC, 6 amp @250 VAC.
It has 6 contacts at it's base, and there is no central off position. $3.99.
You must see six contacts sticking out of the base or else you know that you do not have a DPDT switch.
Electrical wire: 22 gauge. Just use something thick enough so it won't break. The current flow here is miniscule -- on the milliamp scale, so no need to worry about gauge.
Resistor For GSXR-1000: 6800 Ohm
For GSXR 600 / 750: 15,000 Ohm
Standard tools: Soldering iron
Dremmel tool
Allen wrenches
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Where to buy your resistors.

Here are some places where you can buy resistors to do your home made TRE mod. You are looking for "carbon film resistors" with a current rating of either 1/2 or 1/4 watt - either is fine. Use the 6800 ohm resistor on a GSXR-1000. On a GSXR-600 or GSXR-750, Use a 15K Ohm resistor.

rs.jpg digikey alltronics
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Special Notes

Installation Instructions

This is not a big project at all. All you need is the ability to solder a couple of wires together, and to drill a small hole in your plastic for your switch. If you can do that you're all set to go !

unplug the ECM connectors How do you get access to that pink wire, and the B/W wire that you have to cut? I think the best place is right at the ECM. This photo shows the view as you've taken the seat off, and you look down at all the wires going into the ECM.


You're facing the tail of the bike. Both wire harnesses have been unplugged from the ECM. The one you want to examine is the harness and plug on the left of this photo (as you face the rear of the bike, so it is actually on the right side of the bike). See also the special note above for changes in the 2008 models.
tre wires shown in bundle Here you can see the pink wire , and the adjacent B/W wire. These are the ones you want. They are both in the right wiring harness and connector. This means that in the photo, and as you face the rear of the bike, it is the harness on your left.
Find the solid pink wire with no stripes Make sure you find the SOLID pink wire -- my finger is on it-- there is only one of these in this ECM bundle. DO NOT select the pink with blue stripe, nor the pink with white stripe. The P/W wire is visible at the top of the photo -- definitely the wrong wire!
cut ends of pink and b/w wires shown. The two cut ends that are closer to that black plastic ECM connector are connected to the A,B in my TRE diagram above. The two ends at the bottom of this picture, which lead back to the Gear Postion Sensor (GPS) are connected to contacts 3,4 in that diagram.


Then connect your resistor to contacts 1,2 in the diagram, and you're all set !
cut wires numbered Here's the same picture showing exactly how to connect your switch. Just connect wires A,B and 3,4 in this picture to your switch as shown in the TRE diagram above. Remember your resistor goes on positions 1,2 in that diagram.
tre setup done by gixxerjim Here's a great picture by 01gixxerjim. Just match up the letters and numbers to the same letters and numbers in the schematic diagram I showed above. Note that the plugs A and B are actually connected to the B/W and the PINK wires at the ECM.


Don't be confused because 01gixxerjim was tricky and used red and black connector wires here.


Likewise plugs 3 and 4 get connected to the B/W and the PINK wires that travel back to the GPS. This photo demonstrates a great example of making these connections to the switch. You can also see quite well where the resistor is connected.


Also, you can consider puttingyour resistor on with "quick disconnects", because you may want to switch the resistor later (like if you make a mistake and install the wrong one!).


That happens SO commonly -- please remember to TEST your resistor value with an Ohm-meter before you go soldering it to the switch!
dealer mode and tre switches together on left side of bike The final product. The red rocker switch in the front controls the TRE. The square red push-button next to the trunk lock is for my "Dealer Mode" switch.
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Testing your TRE

People will often ask "How do I know if my TRE mod is working?" . Here are some things you can try, to reassure you that you've done everything correctly.

  1. After the bike is warm - like 120°F - flick the switch on and off. When the TRE is on, the RPM's will drop by 300 - 500. This is why you will want to install the switch, so that on cold days, with hard starting, you have to option to turn the tree off . Then turn the TRE on after the bike has warmed up.
  2. With the bike warm and idling in neutral, pull the clutch lever in and the RPM's will go up by 700 - 1000.
  3. The reverse effect on RPM's will be seen if you rev the bike first. Rev the bike to 3000 RPM and hold the throttle as steady as you can. Pull the clutch in. You'll now see that the RPM's go down by 1000 - 1500. Releasing the clutch (which is actually re-engaging the TRE) will make the RPM's go back up to 3000.
    Note that this is the opposite behavior of what is observed if you're not revving the bike first (see number 2 above).
  4. Ride it -- when you open the throttle in gears 1-2-3, the bike will now completely PEEL the skin off your face. If you get back from your ride and your face is raw and bloody, then you've done the TRE correctly. Well all right, don't take this one too seriously. Some guys feel they get little or no performance increase. I think it makes a small improvement. I really like the final point (engine braking) the most, and this is really why I use the TRE.
  5. Engine braking should be almost entirely gone with the TRE engaged. Ride in 1st gear only. Accelerate to 20 mph , then release the throttle. If the TRE is off, you'll be thrown right off the bike onto your face, which is already raw and bloody from number 3. If you land on your face, the TRE is off. If the TRE is on, you will gracefully decelerate without being thrown from the bike like a retarded cowboy
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