what's the quietest way to flatten the torque dip? - Toyota GR86, 86, FR-S and Subaru BRZ Forum & Owners Community

autobrz · 07-29-2013, 12:20 PM

What's the quietest way to flatten out the torque dip?
I don't care about power gain or cost, just the torque dip?
I think the obvious answer is supercharger on stock exhaust and intake. What about n/a options?
What kind of header is quieter? 4-1 EL? 4-1 UEL? 4-2-1 EL? My previous experience on an i-4 motor is 4-2-1 long tube is a lot quieter than 4-1 shorty headers.
is it enough to get just header + overpipe + catted and resonated front pipe?
I'm wondering if a tune is necessary or the stock tune will also run with much less torque dip?
also which header is tuned more for mid-range vs top-end? I know the smaller diameter primaries tend to produce more torque and choke a little up top. There is just a lot of info and I hope to see what is the minimum I have to do to flatten out the dip some.

ShadowSeraph · 07-29-2013, 12:28 PM

By just replacing the stock header with my Borla UEL.. or any other header of your choosing will flatten it out quite a bit. I changed the header first with stock exhaust still there and noticed a huge difference in the dip range. After the header back exhaust change out, that torque dip was even less noticeable. Dyno Charts on this forum can back this up

Edit* Exhaust is probably the least expensive and if you get a resonated cat, decently quiet... though "quiet" is subjective to how each individual perceives audible levels.

xjohnx · 07-29-2013, 12:39 PM

If you want to stay NA then a catted header and reflash will keep things nice and quiet and flatten out that torque curve quite a bit.

Since cost is no issue, you always could throw a supercharger on there as well. That will surely eliminate the torque dip, while staying relatively quiet and producing quite a bit of power. Robispec is running his innovate on stock exhaust I believe.

Bullnettles · 07-29-2013, 12:49 PM

OP, I've got close to the same issue you have for a quiet exhaust and power. I installed an SP Elite first, and it was almost not noticeable (wasn't, at idle). Then I did a UEL and overpipe, and the volume increased a bit, but idle was still quiet. I then did a catted front-pipe and it went from mild to wild (for my tastes). I had to remove it. I think a UEL with an overpipe, and stock from there on back, would be your best option. I have no tune.

autobrz · 07-29-2013, 12:54 PM

thx for the info on the front pipe is the stock one resonated?

dabocx · 07-29-2013, 12:58 PM

Perrins exaust is pretty quiet, you could pick up that and a catted header with a tune. Would be pretty quiet and solve your problem.

Or just throw a S/C on the car and leave everything else stock.

jamesm · 07-29-2013, 01:06 PM

turbo. it's a muffler as well as it is a power adder

mid_life_crisis · 07-29-2013, 01:09 PM

If all you want is to eliminate the torque dip under acceleration, you might want to watch the thread on the electric supercharger. Ridiculously easy installation and zero need to mess with the exhaust. It is looking like it will require a tune, but nothing is perfect. It is for fun on the street and not to make your vehicle a race car, but it might be what you are looking for.

Bullnettles · 07-29-2013, 01:10 PM

Quote:

Originally Posted by autobrz

thx for the info on the front pipe is the stock one resonated?

I believe so, but it's been a few weeks since I swapped them, and I have a memory of a goldfish.

FastLane1000 · 07-29-2013, 01:51 PM

Quote:

Originally Posted by autobrz

thx for the info on the front pipe is the stock one resonated?

The stock front pipe has a small resonator at the rear and cat at the front. The sound increase in swapping is probably due to the high flow cat in the replacement. I'm running the FA20club header with cat, motiv overpipe and motiv high flow cat front pipe with stock catback and FA20club tune. I'm very happy with the sound and performance improvement. I also wanted rid of the torque dip. I want to keep things quiet as well.

xjohnx · 07-29-2013, 02:23 PM

Quote:

Originally Posted by mid_life_crisis

If all you want is to eliminate the torque dip under acceleration, you might want to watch the thread on the electric supercharger. Ridiculously easy installation and zero need to mess with the exhaust. It is looking like it will require a tune, but nothing is perfect. It is for fun on the street and not to make your vehicle a race car, but it might be what you are looking for.

doesn't that work only under WOT?

Toma · 07-29-2013, 02:42 PM

Phantoms electric supercharger. Not only flattens it but obliterates it.

mid_life_crisis · 07-29-2013, 02:57 PM

Quote:

Originally Posted by xjohnx

doesn't that work only under WOT?

Sure, that's why I said "fun on the street" and not race car.

Toma · 07-29-2013, 03:22 PM

Also works at low speed during some part throttle conditions.

Best fun for the buck. Just tuned another one last night 181lb ft where the torque dip was. Lol

07-29-2013, 12:20 PM	#1
autobrz Senior Member Join Date: May 2013 Drives: Mazda 3 Location: round rock, tx Posts: 413 Thanks: 487 Thanked 108 Times in 74 Posts Mentioned: 4 Post(s) Tagged: 0 Thread(s)	what's the quietest way to flatten the torque dip? What's the quietest way to flatten out the torque dip? I don't care about power gain or cost, just the torque dip? I think the obvious answer is supercharger on stock exhaust and intake. What about n/a options? What kind of header is quieter? 4-1 EL? 4-1 UEL? 4-2-1 EL? My previous experience on an i-4 motor is 4-2-1 long tube is a lot quieter than 4-1 shorty headers. is it enough to get just header + overpipe + catted and resonated front pipe? I'm wondering if a tune is necessary or the stock tune will also run with much less torque dip? also which header is tuned more for mid-range vs top-end? I know the smaller diameter primaries tend to produce more torque and choke a little up top. There is just a lot of info and I hope to see what is the minimum I have to do to flatten out the dip some.

07-29-2013, 01:09 PM	#8
mid_life_crisis Senior Member Join Date: May 2013 Drives: FR-S 10 #103 AT Location: NC Posts: 1,519 Thanks: 101 Thanked 599 Times in 347 Posts Mentioned: 5 Post(s) Tagged: 0 Thread(s)	If all you want is to eliminate the torque dip under acceleration, you might want to watch the thread on the electric supercharger. Ridiculously easy installation and zero need to mess with the exhaust. It is looking like it will require a tune, but nothing is perfect. It is for fun on the street and not to make your vehicle a race car, but it might be what you are looking for. __________________ Necessity may be the mother of Invention but Desperation is quite often the father. “Sex is like Bridge. If you don't have a good partner, you'd better have a good hand.” - Mae West Papa said, "son there's a lot of evil temptations out there. Best to try 'em all so you know which ones to avoid."

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07-29-2013, 12:39 PM	#3
xjohnx Grip>Slip Join Date: Jun 2012 Drives: 13 SWP BRZ Ltd - Innovate Powered! Location: RVA Posts: 3,563 Thanks: 656 Thanked 1,717 Times in 1,031 Posts Mentioned: 45 Post(s) Tagged: 3 Thread(s)	If you want to stay NA then a catted header and reflash will keep things nice and quiet and flatten out that torque curve quite a bit. Since cost is no issue, you always could throw a supercharger on there as well. That will surely eliminate the torque dip, while staying relatively quiet and producing quite a bit of power. Robispec is running his innovate on stock exhaust I believe.

07-29-2013, 12:49 PM	#4
Bullnettles Senior Member Join Date: Apr 2013 Drives: Scion FR-S 2013 Location: Houston, TX Posts: 257 Thanks: 89 Thanked 32 Times in 26 Posts Mentioned: 2 Post(s) Tagged: 0 Thread(s)	OP, I've got close to the same issue you have for a quiet exhaust and power. I installed an SP Elite first, and it was almost not noticeable (wasn't, at idle). Then I did a UEL and overpipe, and the volume increased a bit, but idle was still quiet. I then did a catted front-pipe and it went from mild to wild (for my tastes). I had to remove it. I think a UEL with an overpipe, and stock from there on back, would be your best option. I have no tune.

07-29-2013, 12:54 PM	#5
autobrz Senior Member Join Date: May 2013 Drives: Mazda 3 Location: round rock, tx Posts: 413 Thanks: 487 Thanked 108 Times in 74 Posts Mentioned: 4 Post(s) Tagged: 0 Thread(s)	thx for the info on the front pipe is the stock one resonated?

07-29-2013, 12:58 PM	#6
dabocx Senior Member Join Date: Jan 2012 Drives: Scion FRS Location: United States Posts: 1,267 Thanks: 564 Thanked 261 Times in 191 Posts Mentioned: 9 Post(s) Tagged: 0 Thread(s)	Perrins exaust is pretty quiet, you could pick up that and a catted header with a tune. Would be pretty quiet and solve your problem. Or just throw a S/C on the car and leave everything else stock.

07-29-2013, 01:06 PM	#7
jamesm Banned Join Date: Mar 2013 Drives: 2013 FR-S Location: Orlando, FL Posts: 2,929 Thanks: 1,166 Thanked 2,293 Times in 1,180 Posts Mentioned: 313 Post(s) Tagged: 4 Thread(s)	turbo. it's a muffler as well as it is a power adder

07-29-2013, 02:42 PM	#12
Toma Senior Member Join Date: May 2013 Drives: Viper, Mustang, FD RX7, FFR GTM Location: Calgary, AB Posts: 260 Thanks: 7 Thanked 89 Times in 52 Posts Mentioned: 19 Post(s) Tagged: 0 Thread(s)	Phantoms electric supercharger. Not only flattens it but obliterates it.

07-29-2013, 03:22 PM	#14
Toma Senior Member Join Date: May 2013 Drives: Viper, Mustang, FD RX7, FFR GTM Location: Calgary, AB Posts: 260 Thanks: 7 Thanked 89 Times in 52 Posts Mentioned: 19 Post(s) Tagged: 0 Thread(s)	Also works at low speed during some part throttle conditions. Best fun for the buck. Just tuned another one last night 181lb ft where the torque dip was. Lol

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