Hello everyone,

About two months ago, I installed an Apexi mid-pipe and a Revel axle-back on my car. I had both components fully coated in black ceramic at a top-notch shop in Phoenix, AZ. The ceramic coating was done to retain heat and maximize exhaust velocity.

The results have been fantastic. For my setup, this combination is optimal. The Apexi mid-pipe offers the most significant performance gain and perfectly matches the internal diameter of the Revel axle-back. I confirmed this with the helpful team at Apexi before making the purchase. Although I prefer the sound of the Apexi axle-back, it's considerably more expensive as it requires a new rear diffuser, which makes the car stand out more—something I'm trying to avoid. I prefer my car to blend in while still achieving peak performance, and the Apexi axle-back is noticeably louder as well.

The ceramic-coated Apexi mid-pipe and Revel axle-back combination produce a much deeper and more aggressive tone than the stock setup. Interestingly, it's actually quieter below 50% throttle, likely due to the H-pipe design. However, above 50% throttle, it progressively gets louder than stock.

In terms of performance, there's definitely a noticeable kick, especially above 3,500 RPM. At 7,200 RPM with all my mods, the exhaust is absolutely screaming in an aggressive yet tasteful manner—it's not excessively loud at all.

Overall, I'm extremely happy with this modification.

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2013 GS350 AWD LUX, spare tire and tools delete, Tuned by Loi: 91 octane tune, Trigga Spec: Tundra 76mm throttle body w/spacer & coolant delete, Ported lower & upper intake manifold, aFe: Takeda stage-2 pro 5R oiled CAI, Apexi: Midpipe w/ceramic coating, Revel: Axle-back w/ceramic coating, High Spark: Premium coilpack, NGK: 94122, Konig: F3S 18x8.5 35+, Toyo: Proxes Sport A/S 235/45/18, RR Racing: USRS race edition, Air/oil separator, KYB: Gas-A-Just w/AVS all around, Stoptech: Sportstop cryo sport drilled rotors all around, Akebono: Performance ultra premium front, ProACT ultra premium back, Super Now: Lower differential mount collar, Spoon Motorsports: Subframe collars front, Anti-Gravity: Li battery, Non-stop tuning: Al water pump pulley, Mishimoto: Al lug nuts, DEI: Cool-tape, Xpel: XR plus nano ceramic window tint all around

 

See you did move forward on the things we talked about. Glad to see you felt a little improvement. Just to clear up a few things you posted here.....

The GS350 and IS350 2GR motors have been around for years and years now, and have had many, many different combo's of Exhaust, Intakes, and Tunes. Little do many know there are actually about 5-6 different Tunes that were available for that engine. Most are still for sale as either a plug and play, or a some what Custom Tunes, using a Dyno or not.

The Apexi Mid and Tanabe are both a good option. The pipe sizing are 60mm = 2.36 inches. The Takeda is a good Intake but also not your largest piping for air Intake as a choice. It's mostly designed to not create a check engine light, by restricting and placing the MAF way back as to not take it out of the parameters sending to the Stock mapped ECU. If in fact you go into doing ECU Tunes that are Data logged the better hp increase options would be The AEM full CIA and the Invidia midpipe & Axelback. The AEM is larger diameter, is flow bench tested and just provides more air resulting in better low-mid range and top end. The Invidia mid pipe, if you can find one still, (X pipe vs H pipe) and Invidia Axelback Mufflers are all 70mm = 2.5 inch. With a ported upper/lower intake and 76mm TB better to take full advantage of a range of additional hp of 12hp - 20hp more with the larger piping. Add Tuning and it just results in that more more increase hp.

There was multiple data measured, that was documented on Intake CFM flow numbers, and reduced Air temperature measures improvement increases on the 2GR. Also the least Exhaust Back Pressure you have on that motor, the more hp it produces without losing bottom, mid, and top. Of course with in reason, and sound, but valid, when comparing 60mm vs 70mm exhaust matched piping. Even the 60mm mid to a 70mm Axelback exit is a great match up to act as a Venturi, to siphon suck the exhaust gases from the Head exhaust Port, exit side chamber of the Heads, and provide a high Velocity flow to the exit. Remember the Midpipe removes the Center Secondary Cats, which increases rear flow quite a bit more. If you check you will find that Lexus even fitted the GS350 with a 1.90mm - 2.0mm center merge collector then continuing the exhaust gas flow to exit a 2.20 inch stock Axelback factor mufflers and pipes. There is also a step down in the Factory system that goes to the same Venturi siphon and Velosity flow. These things also take better complete advantage of a 76mm = 3 inches larger TB. The 350 2GR is well designed to handle the increased exhaust flow even with the stock cams which are ridiculously good even with a slight internal built up motor. The Exhaust waves on the Exhaust cams are very well spec'd out.

Seems you are happy with the improvements you did, and I think Loi Tunes are great. I actually had that Apexi midpipe and Tanabe a few years ago and was very happy with it. As I moved some step further up the hp improvement increases, I also learned that the more free flowing exhaust system match up actually provides 12hp+ plus more and, completely eliminated all Rasp and all Drone, as I installed Headers and switched out the Apexi mid and Tanabe axel back due to controlling sound waves while increasing the hp some even more.

 

How much louder would you say your vehicle is with the Invidia catback and PPE headers compared to Apexi and Tanabe combo catback and OEM headers? I am interested in the PPE headers of course but the ones I heard are unpleasantly loud. It sure is very tempting tough, the design of the PPE is so much better for airflow than the absolute junk OEM ones, comparatively.
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2013 GS350 AWD LUX, spare tire and tools delete, Tuned by Loi: 91 octane tune, Trigga Spec: Tundra 76mm throttle body w/spacer & coolant delete, Ported lower & upper intake manifold, aFe: Takeda stage-2 pro 5R oiled CAI, Apexi: Midpipe w/ceramic coating, Revel: Axle-back w/ceramic coating, High Spark: Premium coilpack, NGK: 94122, Konig: F3S 18x8.5 35+, Toyo: Proxes Sport A/S 235/45/18, RR Racing: USRS race edition, Air/oil separator, Vented CF badge, KYB: Gas-A-Just w/AVS all around, Stoptech: Sportstop cryo sport drilled rotors all around, Akebono: Performance ultra premium front, ProACT ultra premium back, Super Now: Lower differential mount collar, Spoon Motorsports: Subframe collars front, Anti-Gravity: Li battery, Non-stop tuning: Al water pump pulley, Mishimoto: Al lug nuts, DEI: Cool-tape, Xpel: XR plus nano ceramic window tint all around

 

When you install headers it gets loud. Installing the in midpipe line Cats helps some. You also need to install some good resonators that work. I will tell you this, it's not as much how loud as it is Drone and Rasp that are the battle. Is why a more free flow larger diameter piping help the exhaust gas flow and not back up or stack up exhaust and negative waves creating drone, rasp and a unpleasant sound.

The Stock Headers have those factory restrictive Cat right off the header. They keep the noise in check some from the start, and slow the exhaust waves down from the start right up front. They also count for reducing the noise quite a bit. I'll tell you I did not like the Tanabe anymore after the headers due to their restrictiveness, creating drone, rasp and the sound, is why I swapped out. If you search the IS350 there is a guy who posted the Headers with, Tanabe, before and after Headers, and he did not like the Tanabe setup with the Headers either the same. I think he added a very restrictive resonator to change the tone more liking, at the expense of slowing down the exhaust by blocking. That reduces hp and robs a bit is why I did not go that route. Doing piping that flows the most CFM to allow the Headers increase gas was the best route I found. It goes in, flows through and no unwanted noises.

One other difference is I am running a discontinued 2GR Maximizer Headers that was closer Equal length and bigger primary's and tubing than the PPE Headers. I liked the longer merge collector a bit better. for more mid to upper hp drive. I actually have a set of Ceramic coated PPE Headers and if my life long build ever finishes, I plan to swap and dyno each one day. If the PPE's make a bit more hp, I would swap out and re-Tune for them. The Power difference with the Headers is nice. A friend of mine also a CL member has a 15 GS350 with the PPE/Intake/Port/TB/RR Tune. As a test we ran, and I walked away from his car from a dig, 30mph roll, and 60mph, in Mexico of course. We were both kind of shocked although I have run some IS350, 370Z's, Chargers and others. I have a few other performance slight mods done also.

Headers
https://www.clublexus.com/forums/per...s-designs.html

Here are some Resonators I found and used that flowed through, but.... made the sound very pleasant to live with in my the Headers + 70mm = 2.5inch complete mid to Mufflers. With no back up. I use 3" Resonators only to reduce unwanted noise and sounds but not slow exhaust gas flow velocity very much at all. Frankly I had a battle to get the Header + Exhaust noise to where I wanted it, but it's there now, without restricting the flow.



Search Ebay and other China sites. They are a internal Turbine design packing.




BTW: Do you have the Resonated Apexi Midpipe, or the Non Resonator Midpipe????

 

I have the resonated mid-pipe installed, and I must say, the sound quality is excellent—very refined and quiet.

So, you’re running the 2GR Maximizer Headers with an Invidia catback, along with two 3" resonators and high-flow cats on the midpipe? And it’s not obnoxiously loud? That’s fantastic news. I’m seriously considering going the same route.

This turbine-design resonator you mentioned—is it different from the Vibrant bottle-type resonators? I’ve used Vibrant resonators before, and while they do an okay job, I’m curious if this design offers a noticeable improvement.
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2013 GS350 AWD LUX, spare tire and tools delete, Tuned by Loi: 91 octane tune, Trigga Spec: Tundra 76mm throttle body w/spacer & coolant delete, Ported lower & upper intake manifold, aFe: Takeda stage-2 pro 5R oiled CAI, Apexi: Midpipe w/ceramic coating, Revel: Axle-back w/ceramic coating, High Spark: Premium coilpack, NGK: 94122, Konig: F3S 18x8.5 35+, Toyo: Proxes Sport A/S 235/45/18, RR Racing: USRS race edition, Air/oil separator, Vented CF badge, KYB: Gas-A-Just w/AVS all around, Stoptech: Sportstop cryo sport drilled rotors all around, Akebono: Performance ultra premium front, ProACT ultra premium back, Super Now: Lower differential mount collars, Spoon Motorsports: Subframe collars front, Anti-Gravity: Li battery, Non-stop tuning: Al water pump pulley, Mishimoto: Al lug nuts, DEI: Cool-tape, Xpel: XR plus nano ceramic window tint all around

 

Yes. Very familiar with Vibrant. While they do a decent job, its not nothing game changing that much when you are trying to reduce Header exhaust noises. In fact the Vibrants are not much diff than the Apexi res on there now.

The Turbines are good to put in line if you delete the Secondary Cats to calm drone and rasp on that long unfiltered pipe, The Other Amazon 20inch one in 3" do great on the back end where your Apexi ones are now. They flow better and reduce a bit more. Be aware wanting to keep velocity up, when you do Headers it will get louder. Just have to find what you can live with. I made changes that were acceptable to me, and went more towards a Deeper sound. Personally I hate very Loud exhaust.

BTW: Apexi does have a 70mm = 2.5 Muffler also.
https://www.ebay.com/itm/265577251738

By comparisons that's why the Invidia 70mm = 2.5 whole Axel back is a great deal and flows and controls noise very well still.
https://shop.redline360.com/products...T6iXRGHkaTITIm

Invidia 70mm = 2.5inch Discontinued Midpipe. I have this one now. Replaced the Cats with G Sport High Flow Race Cats.
https://www.clublexus.com/forums/4ge...gs350-rwd.html

 

Sweet man, thanks for the info, it will come in very handy when I'm ready to trade a little quiet for a lot more power.

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2013 GS350 AWD LUX, spare tire and tools delete, Tuned by Loi: 91 octane tune, Trigga Spec: Tundra 76mm throttle body w/spacer & coolant delete, Ported lower & upper intake manifold, aFe: Takeda stage-2 pro 5R oiled CAI, Apexi: Midpipe w/ceramic coating, Revel: Axle-back w/ceramic coating, High Spark: Premium coilpack, NGK: 94122, Konig: F3S 18x8.5 35+, Toyo: Proxes Sport A/S 235/45/18, RR Racing: USRS race edition, Air/oil separator, Vented CF badge, KYB: Gas-A-Just w/AVS all around, Stoptech: Sportstop cryo sport drilled rotors all around, Akebono: Performance ultra premium front, ProACT ultra premium back, Super Now: Lower differential mount collars, Spoon Motorsports: Subframe collars front & rear, Anti-Gravity: Li battery, Non-stop tuning: Al water pump pulley, Mishimoto: Al lug nuts, DEI: Cool-tape, Xpel: XR plus nano ceramic window tint all around

 

What's you opinion on the 2gr-fks move from the FSE's conventional header design to new integrated 3-to-1 exhaust manifold into a single header? Do you think the move to this design has limited or reduced the performance? I personally think that the FKS is the perfect engine to build a twin turbo since there's the smaller exhaust packaging.

 

What do you think about Borla's S-Type exhaust, I currently have them installed on my stock GS. I plan on doing power upgrades in the future, maybe go FBO depending on how Maryland will treat people without cats now and in the future. What should I go with if I want to maintain a deep growl, I hate v6 rasp/drone.

 

Borla's history was exhaust design that was quite, but out flowed most every other exhaust still. Then came the new loud sound kids. Borla to sell exhaust still, went to forget flow design, and produce sound design only. The GS Borla is designed to sound like a Mustang and has less than Idea flow. It's obnoxious even at start up. Those sound built chambers impede flow. It's also loud as hell if you do any other exhaust changes all the back to Headers.

 

The OEM headers for the 2GR-FKS engine are a significant improvement over those found on the 2GR-FSE, which are notably poor in terms of flow dynamics in their stock form. However, PPE headers for the 2GR-FSE far surpass both in performance. The 2GR-FKS uses a 3-1 header with very short runners, making it less suited for peak performance, but it is still vastly superior to the OEM 2GR-FSE headers, which lack any serious flow dynamics considerations.

My understanding aligns with jgscott regarding Borla exhausts, as they are among the worst aftermarket products in terms of flow dynamics for these platforms. That said, there are even worse alternatives, such as poorly crafted custom exhausts. In particular, some welders produce subpar work, leading to frequent and significant issues like exhaust leaks.

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2013 GS350 AWD LUX, spare tire and tools delete, Tuned by Loi: 91 octane tune, Trigga Spec: Tundra 76mm throttle body w/spacer & coolant delete, Ported lower & upper intake manifold, aFe: Takeda stage-2 pro 5R oiled CAI, Apexi: Midpipe w/ceramic coating, Revel: Axle-back w/ceramic coating, High Spark: Premium coilpack, NGK: 94122, Konig: F3S 18x8.5 35+, Toyo: Proxes Sport A/S 235/45/18, RR Racing: USRS race edition, Air/oil separator, Vented CF badge, KYB: Gas-A-Just w/AVS all around, Stoptech: Sportstop cryo sport drilled rotors all around, Akebono: Performance ultra premium front, ProACT ultra premium back, Super Now: Lower differential mount collars, Spoon Motorsports: Subframe collars front & rear, Anti-Gravity: Li battery, Non-stop tuning: Al water pump pulley, Mishimoto: Al lug nuts, DEI: Cool-tape, Xpel: XR plus nano ceramic window tint all around

 

So what do you guess recommend me doing in terms of sound and performance mods? And can I still keep a deep tone with a more performance oriented exhaust system?

1. What axle back should I run with tone and performance in mind? Or should I get a custom exhaust system made?
Note: I plan on adding a GSF style diffuser and in turn, GSF style exhaust tips.

2. Regarding FSE vs. FKS, I assume that the traditional header design on the FSE would allow better flowing catless headers than the FKS' catless headers. But at least FKS catless headers are significantly cheaper than PPE headers for them FSE folks.

 

1. For the FSE platfrom, Apexi is porbably the best, but loudest, Invidia has an option too. Revel makes a very good one too that I can personally vouch for. I'd stay away from custom systems unless you have an excelent welder, generally they perform a lot worse than a mandrel-bent properly made one.

The problem with the axlebacks generally is the mid-pipe to axle-back flange. Any system that is meant to be bolted onto the OEM midpipe or axleback will have a very large restriction there. Apexi people pointed this out to me when I called them.

2. The catless PPE headers are much superior to the catless OEM FKS headers which are superior to catless OEM FSE headers.

 

You might as well just get a cheap ebay $290 muffler delete straight pipe axel back delete pipes. You are not going to gain anything performance wise to start, unless you do something intake pipe wise. The best cheap performance gain is some kind of intake pipe, a Axel back and the 2nd set of Cats delete. (Off road track use only, for the record).

Also there are some nice gains to be had still using the newer 2GR single 3 to 1 outlet merge Headers. All Lexus stock Headers are very restrictive. Altho lots of ppl are not aware of that design. Honda and others have been using that single out the head Exhaust manifold for a long time now. Honda is going 4 into 1, vs Lexus 3 into 1. I actually built a weld in custom Turbo on a 2.4 DOHC i-VTEC Accord a few years ago and it was very, very fast.

 

Wow! A lot of great onformation here!