How common is torque dip?
 

I am a car newb. I researched the fr-s before buying but only compared it to current production sports cars in it's price class. (The Genesis, mustang etc..) though none of the others handles as well as the FRs none seemed to have the power band issue this car has. How common is uneven power delivery in modern cars and is there anything specific about a boxer engine that make this one dip like it does?

Cayman's, while more powerful than the twins also have the dip in torque. Many cars have an uneven powerband. The ecoboost mustangs die out at the top rpm and any vtec honda has nothing down low until that signature "kick" at high rpms.

It believe it dips because of the transition between port to direct injection.
Not a boxer trait. But think of the torque dip as a trait not a problem. Every single engine design has a different power curve induced by its engineering and to meet a certain goal. But every engine type has a different torque curve due to design. I would not say many engines have a linear torque curve.

I'd like to add that the useful torque from 1500 - 3000 rpm is just fine. I drive my FR-S like an econobox around town utilizing the lower torque curve. Between 2000 and 3000, the engine responds well, will pull (albeit gradually) from in 5th gear quite nicely. I cruise below 40 mph in 5th most of the time and can shift into 6th at 40 IF I am not climbing a hill. I find I can short shift and get over 30 mpg consistently (as high as 34 mpg). However, whenever I want to run it up, then the powerband kicks in quite nicely above 4500 rpm.

Net, Net. I do not find the torque dip a particular issue since the engine pulls pretty well at lower RPM. I can drive the car up to 70 mph in 6th gear (3000 rpm) and still have decent highway acceleration. I can shift down to 4th for stronger acceleration from 45-70+.

My use of the gears:

1st - From a stop to 15 (nanny mode) or 35 (gonzo mode)
2nd - Accelerate up to 35 (nanny mode) or up to 55 (gonzo mode)
3rd - Constant speed at 25 mph (nanny mode) or stronger acceleration 35-50
4th - Constant speed at 30 mph (nanny mode) or stronger acceleration 45-70+
5th - Cruise at 35-40mph (nanny mode) or stronger acceleration 55 - 70+
6th - Highway cruise 40 and higher, decent acceleration above 70 mph.

Ooooh good point!

So, if say this is true, what is purpose for the dip on our twins? Btw, if anyone has a fa20 wrx turbo dyno chart (fa20 on wrx turbo has Subbies own DI+turbo) please post. Itd be nice to see if they have any type of dip. I know turbo might cancel it out, but still.

you get more low end torque in exchange for giving up the midrange.

you can get rid of it with tuning+headers+e85. Or just drive the car harder and keep it above 5k

Most cars dont have this. Even hondas don't, they have torque that builds from the low end and flattens out around 4k.

The dip is one of those cases where it looks way worse on paper then it is in reality. Ya it is there but it is just a 1/2 second blip in the acceleration not a total drop off of power that some would have you believe. In normal day to day driving most people would not even notice it (with MT I have no idea the impact on an AT). I just blow through it and pay no attention.

Lots of high rpm, NA cars have uneven torque curves.

FR-S/BRZ:
https://media.ed.edmunds-media.com/s...011123_600.jpg

987 Cayman S:
http://www.dragtimes.com/images_dyno...ayman-Dyno.jpg

981 Cayman S:
http://photos.stuttcars.info/upload/...ttcars-com.jpg

Mustang GT350:
http://image.motortrend.com/f/featur...gt350-dyno.jpg

S2000:
http://www.s2ki.com/s2000/gallery/pa...290__file__med

Ferrari 430:
http://oetuning.com/blog/wp-content/...-tuned-600.jpg

GT3 RS:
http://members.rennlist.com/nj_gt/GT3-Dyno.JPG

You can definitely feel it in the Twins, but not a huge deal. For daily driving, keep it below 3200 RPM. For spirited driving, keep it above 4500 RPM.

No dip in those, the only issue is our top end runs out of steam on the stock tune because of the small twin scroll turbo. OTS maps take care of this though.

Attachment 124452

Best visual ever!

Sweet! My 2nd grade teacher said my diorama/chart skills would pay off one day! :D

Well how often has it been said here that "other cars have dips/flatspot/etc in torque or HP as well" but nobody ever really illustrated that with visuals. Those very clearly show that some of those cars have a great or even greater dips but still manage to function just fine around them. The reliance on paper numbers has always existed but with the speed in which information can now be found I think some rely on them just a bit too much.

The torque dip isn't significant enough to be a problem. At most it feels uncomfortable for the brief moment it happens, then it's gone.

Thanks for post.


Thats vtaaaaak s2k dip though.