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Because I'm a transportation road rider, I run between 3,000 to 5,000 rpms without lugging on a bike specifically modified to produce more low rpm torque.

These are the torque mods I did:

1. Tuneble Exhaust. Running three tuning plates produces the most low rpm torque.
2. FMF MegaBomb Header. The expansion chamber increases exhaust volume to produce the low rpm torque of a long header in the space of a short header.
3. Longer midpipe. I extended the midpipe 10 inches into the muffler making it 25% longer for more low rpm torque. Long Pipe = More Torque
4. Secondary throttle plate delete. Deleting the ECU controlled secondary throttle plate gets rid of that restrictive "dip" you see in the dyno chart above.
5. Primary throttle plate control delete. This disconnects the ECU from controlling the primary throttle plate making the throttle body solely operated by cable.
6. Delete PAIR valve.
7. Smog delete.


All of these mods working together make for a highly responsive engine without needing to "spool it up".
:-)
:)
 

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I just did another mod today, that's related to the secondary throttle plate delete. I removed the spring on the ECU cam follower which acts on the primary throttle plate. this completely disconnects the primary throttle from ALL ecu inputs, and leaves the mechanical throttle cables as the ONLY input.

(with spring)
IMG_0885.JPG.aa21b7d684a27f6d58fa69c15801a68d.JPG

(without spring)
IMG_0894.JPG.7aeb5e0563e07973eee3db58896f0d7d.JPG

The follower is that curved arm with the round knob on it, and the ecu rotating cam is that elliptical shape which rotates to move the arm. The spring between them keeps the two in constant contact. So removing the spring isolates the primary throttle plate from any ECU controlled input making it solely mechanically operated by the hand throttle.
The ECU control on the Primary throttle holds the primary throttle plate open for a while even though the throttle has been completely closed. This creates a "soft close" whenever the throttle is released. It makes for slower shifting because the engine revs float and there is also less engine braking upon deceleration.
However, with both these mods the engine is much more responsive and requires less throttle input for the same rpms and engine load. I really like how the bike decelerates faster with more engine braking.
The ECU throttle disconnect also makes for faster more precise shifting as the engine rpms drop immediatly upon throttle close between changing gears.

It's like riding a different bike! 🙂
Could I remove this spring and have any gain without removing the secondary throttle plate, I don’t feel comfortable mechanically doing that yet haha
 

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Discussion Starter · #24 ·
Could I remove this spring and have any gain without removing the secondary throttle plate, I don’t feel comfortable mechanically doing that yet haha
You can't hurt anything. :)

Removing the spring simply allows the primary throttle plate to close immediately upon closing the throttle, instead ot the ECU holding it open for a "soft close". You'll notice increased engine braking, and that's all. The engine won't be any more responsive on acceleration, because when you're opening the throttle, the fast idle cam is not acting on the spring.

If you are not satisfied with the results, you can always put it back on.

Removing the secondary throttle plate is what makes the engine more responsive on the way up. Removing the spring alone makes the engine more responsive on the way down.

Doing both is a real game changer.
 

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You can't hurt anything. :)

Removing the spring simply allows the primary throttle plate to close immediately upon closing the throttle, instead ot the ECU holding it open for a "soft close". You'll notice increased engine braking, and that's all. The engine won't be any more responsive on acceleration, because when you're opening the throttle, the fast idle cam is not acting on the spring.

If you are not satisfied with the results, you can always put it back on.

Removing the secondary throttle plate is what makes the engine more responsive on the way up. Removing the spring alone makes the engine more responsive on the way down.

Doing both is a real game changer.
Have you added a tuner yet and if so what kind? Also, where did you source your mid-pipe and is the Supertrapp a universal slip on as I can't find one specifically for the 300? Thanks
 
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