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-   -   Torque dip common to NA boxer engines? (https://www.ft86club.com/forums/showthread.php?t=62827)

zdr93523 04-08-2014 09:06 PM

Torque dip common to NA boxer engines?
 
1 Attachment(s)
Here's some food for thought... It appears that our torque dip is common to NA boxer engines. It is just very apparent in the twins because the hp/tq is so low. Here is a shot out of my Cayman S owners manual. You can't feel the dip in the Porsche.
Attachment 73654

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Kostamojen 04-08-2014 09:09 PM

Subaru's have always had the torque dip. Its due to the intake manifold configuration and can be eliminated with ITB's. This was discussed here on this forum even before the car came out, LOL!

zdr93523 04-08-2014 09:10 PM

What I'm getting at is that it isn't just Subarus. It's the general nature of the boxer.

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FR-S Matt 04-08-2014 09:15 PM

Or it can be eliminated by an intake, good header, and full exhaust. Find a good tuner with those parts and your dip is gone. Otherwise, get FI. ITB's I have not researched so I can't comment on them.

Also, let me emphasize GOOD tuner.

zdr93523 04-08-2014 09:17 PM

I agree that it can be easily eliminated. Just wanted to add to the knowledge base of the forum for those who assumed the dip was unique to Subaru motors.

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wparsons 04-08-2014 10:14 PM

A lot of non boxer DI N/A engines have torque dips as well. Oddly, the 2015 WRX has a dip as well, which I figured wouldn't show up with the turbo.

zdr93523 04-08-2014 10:35 PM

Yea that's kind of strange.

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zdr93523 04-08-2014 10:35 PM

Those Porsche charts are not DI for what its worth.

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Black Tire 04-08-2014 10:45 PM

Quote:

Originally Posted by Kostamojen (Post 1658520)
Subaru's have always had the torque dip. Its due to the intake manifold configuration and can be eliminated with ITB's. This was discussed here on this forum even before the car came out, LOL!

Cool!? :iono:What's an ITB?

Luis_GT 04-08-2014 10:50 PM

Quote:

Originally Posted by Black Tire (Post 1658753)
Cool!? :iono:What's an ITB?

Independent throttle bodies

Trettiosjuan 04-09-2014 08:19 AM

Quote:

Originally Posted by zdr93523 (Post 1658505)
Here's some food for thought... It appears that our torque dip is common to NA boxer engines. It is just very apparent in the twins because the hp/tq is so low. Here is a shot out of my Cayman S owners manual. You can't feel the dip in the Porsche.
Attachment 73654

Consider the left graph. Look at the scales, the torque scale has the bottom 170Nm cut off, in other words, the torque fluctuation is amplified a lot. The actual torque dip here is 10Nm at most before it rises again. Or 4% of total torque. Nobody would notice that. On the S, it's relatively even smaller.

On the FRS, the torque dip is aorund to 40Nm. That's around a 20% reduction. Like someone lifts off the trottle for you...

FRSure 04-09-2014 08:48 AM

Quote:

Originally Posted by Luis_GT (Post 1658772)
Independent throttle bodies

This may sound dumb but... If it's easily fixable, why don't Toyota/Subaru does it for us? Is it for emission ?

86-tundra 04-09-2014 09:12 AM

Quote:

Originally Posted by FRSure (Post 1659502)
This may sound dumb but... If it's easily fixable, why don't Toyota/Subaru does it for us? Is it for emission ?

ITBs are not an easy fix, unfortunately

FRSure 04-09-2014 10:50 AM

Quote:

Originally Posted by trevorovert (Post 1659515)
ITBs are not an easy fix, unfortunately

I see headers and tune get rid most of the dip. Why didn't Toyota do it? :bonk:


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