Best way to eliminate the torque dip

[KoolBRZ]

I have an OFT, a Tomei/Gruppe-s UEL header, 2.5" overpipe, resonated 2.5" front pipe, stock midpipe, and 2.5" axle-back single muffler w/dual exhaust. I don't have much muffling, so my car can be loud sometimes, but not with my current tune. My startup is quiet and at a low rpm, even cold. I don't have a torque dip because I don't use valve overlap for higher mpg through internal EGR. My power curve is smooth because my AVCS tables have smooth transitions. My advice is to get an OFT, then tune it till you like it.

[RJasonKlein]

If price is not your primary concern and you want gain the maximum horsepower and torque while converting the 'dip' into a 'bulge', go with an ACE Type A 4-2-1 350 catless header, EcuTek, and tune by Delicious Tune. Keeping it quiet will be a challenge, but your tune can be set to eliminate raised revs during cold-start, and if you use a resonated and catted front pipe (JDL Ultra Quiet) paired with one of the quiet exhausts (Invidia Q300), it'll probably work for you. Keep in mind that no cat-back exhaust will improve power, but the factory exhaust will sound pretty crappy with the header and front pipe, so you'll need to do the whole exhaust for it to sound pleasing.

There are cheaper solutions, but this addresses the issues you raised and will totally transform your car.

[RichardsFRS]

Keep your rpms high and dance on the clutch?

[JSube]

RJKlein, I'm new to the forum, have a 2015 STI I'm considering selling for the upcoming BRZ (love RWD, lighter sports cars, big power not an end-all-be-all issue with me.) I looked at the ACE header, which could hang framed in an art museum, so I have no doubt about the quality. But is your recommendation for that specific piece that it significantly outperforms other well-made headers or that it's equal in performance and better made than any other?

[steve99]

Originally Posted by JSube

RJKlein, I'm new to the forum, have a 2015 STI I'm considering selling for the upcoming BRZ (love RWD, lighter sports cars, big power not an end-all-be-all issue with me.) I looked at the ACE header, which could hang framed in an art museum, so I have no doubt about the quality. But is your recommendation for that specific piece that it significantly outperforms other well-made headers or that it's equal in performance and better made than any other?

Theirs no huge performance gain on these cars NA.

best results you will get with four simple mods

Good set of catless headers
tune (for e85 if you going E85)
E85 fuel
drop in air filter

that will get you arround 30 or so wheel hp over stock and eliminate torque dip.

after that you can spend a heap of money for little more gain and large increases in noise and raasp.

ACE are good headers and will produce better gains than most headers especially 91 fuel, bit better on 93, but once you go to E85 the extra gains are smaller compared to other headers.

have a read of the Basic bolt on Mods link below.

[Lantana frs]

With Crawford intake spacers and 93 tune the dip is minor, more like a plateau. I would listen to what our Aussie contingent says. They seem to have these cars figured out.

[RJasonKlein]

Originally Posted by JSube

RJKlein, I'm new to the forum, have a 2015 STI I'm considering selling for the upcoming BRZ (love RWD, lighter sports cars, big power not an end-all-be-all issue with me.) I looked at the ACE header, which could hang framed in an art museum, so I have no doubt about the quality. But is your recommendation for that specific piece that it significantly outperforms other well-made headers or that it's equal in performance and better made than any other?

@JSube, welcome to our community! @steve99 pretty much nailed it - there's no magic bullet and only a few meaningful modifications you can make while staying normally aspirated. I recommended the ACE header because it outperforms other headers currently on the market and it's what I chose, but I prefaced it as a 'cost no object' recommendation. There's been a ton of dialog on this subject and there are solutions that provide meaningful bumps in horsepower and torque for less money.

[JSube]

Originally Posted by steve99

Theirs no huge performance gain on these cars NA.

best results you will get with four simple mods

Good set of catless headers
tune (for e85 if you going E85)
E85 fuel
drop in air filter

that will get you arround 30 or so wheel hp over stock and eliminate torque dip.

after that you can spend a heap of money for little more gain and large increases in noise and raasp.

ACE are good headers and will produce better gains than most headers especially 91 fuel, bit better on 93, but once you go to E85 the extra gains are smaller compared to other headers.

have a read of the Basic bolt on Mods link below.

Originally Posted by RJasonKlein

@JSube, welcome to our community! @steve99 pretty much nailed it - there's no magic bullet and only a few meaningful modifications you can make while staying normally aspirated. I recommended the ACE header because it outperforms other headers currently on the market and it's what I chose, but I prefaced it as a 'cost no object' recommendation. There's been a ton of dialog on this subject and there are solutions that provide meaningful bumps in horsepower and torque for a lot less money.

Thanks RJ, Steve, Lan. I appreciate the responses and the welcome. Seems like every sportscar I've owned and joined forums for has one or two main issues that generate the most discussion and I guess I've found one of them for the BRZ! I'll read the bolt-ons link and start the process of learning about this engine. I'm enjoying the STI power a lot, but a light car with a great chassis is a really rewarding experience for me. Don't want to redesign the car, just get a little power bump and a nice exhaust note. But I'll do my research and have more questions when I get the car.

[KoolBRZ]

Another option is to go the same route as the 2017 models. Change the Final Drive from a 4.10 to a 4.30. Speed is measured at the wheels, so it wouldn't even affect the speedometer. It wouldn't increase the power, so much as give the power better leverage. There is a complicated formula for calculating horsepower per revolution of the tire. Changing the gearing increases the horsepower per revolution. The drawback on MT cars is having to shift sooner and more often, while on AT cars it's an advantage, since the AT can shift quicker and easier when the stretch between gears is closer. It also takes some of the strain off the engine/trans/driveline/diff, and puts it on the axles/wheels/tires. It's a seesaw. When one end comes down, the other end goes up, with the pivot point at the differential.

[steve99]

Originally Posted by JSube

Thanks RJ, Steve, Lan. I appreciate the responses and the welcome. Seems like every sportscar I've owned and joined forums for has one or two main issues that generate the most discussion and I guess I've found one of them for the BRZ! I'll read the bolt-ons link and start the process of learning about this engine. I'm enjoying the STI power a lot, but a light car with a great chassis is a really rewarding experience for me. Don't want to redesign the car, just get a little power bump and a nice exhaust note. But I'll do my research and have more questions when I get the car.

If you have E85 fuel the best cheapest easyesy best bang for buck mods are
E85 fuel with tune
and drop in filter



you get 20hp and big reduction in torque dip with no pyhsical mods other than filter, thats with completly stock exhaust.

[Teseo]

Originally Posted by KoolBRZ

Another option is to go the same route as the 2017 models. Change the Final Drive from a 4.10 to a 4.30. Speed is measured at the wheels, so it wouldn't even affect the speedometer. It wouldn't increase the power, so much as give the power better leverage. There is a complicated formula for calculating horsepower per revolution of the tire. Changing the gearing increases the horsepower per revolution. The drawback on MT cars is having to shift sooner and more often, while on AT cars it's an advantage, since the AT can shift quicker and easier when the stretch between gears is closer. It also takes some of the strain off the engine/trans/driveline/diff, and puts it on the axles/wheels/tires. It's a seesaw. When one end comes down, the other end goes up, with the pivot point at the differential.

You think 2017 FD will fit on 2013 model?

[KoolBRZ]

For a MT, yes. For an AT, no. A 4.88 or 5.71 would be better.

[WWFT86]

Originally Posted by finch1750

Nope. the only answer is still get a Hellcat

I heard the Tesla ludicrous is woth looking into too

[finch1750]

Originally Posted by WWFT86

I heard the Tesla ludicrous is woth looking into too

You see the new P100D? 0-60 in 2.5 sec