Originally Posted by Pseudomaniac

Third Modification: Pre-Cat Deletes (PCDs) or High Flow Pre Cats (HFPC)

Your J35/J37 motor has the heads formed into a single exhaust outlet that feeds directly into a catalytic converter with each bank of 3 cylinders feeding it's own "pre-cat". This is effectively choking the engine (at the sake of emissions and noise) right out of the gate, and one of the single largest bottlenecks you can remove to gain power on your TL.

Caution: Removing these is no picnic. You will need to have an extensive set of sockets and extensions, knuckles of steel, a good place to work, and patience. This involves removing the electric cooling fan, and disassembling heat shields from the rear pre-cat on the car, working in between the firewall and the engine, and extracting a 7 inch diamter pipe out a 6.75 inch opening - It's do-able - but it's not fun.

PCD vs HFPC: The PCD is effectively a test pipe - no catalyst - straight through flow - wide open. The HFPC is a high-flow catalytic converter.

Will I have computer errors: With the HFPCs none have been reported. With the PCDs, which include spacers called "defoulers" - some have had codes thrown and RV6 was working on modified defoulers (free to purchasers) to correct the issue. I have had the RV6 PCDs on my car for a month with no codes to date. I think much of this depends on the install. Point your defoulers straight up.

Options:

~$559+Shipping - RV6 HFPC

~$359 + Shipping - RV6 PCDs

I went with the PCDs - but I don't live in an emissions state. The cost is less than the HFPC, and the power gain is greater. I have not had problems with codes. These will add some audible rasp to your exhaust. These will make your exhaust stink - noticeably. The power gains are debatable, conservatively 10-15 HP and 15-20 HP on the high-end.

The PCDs have a ceramic coating option that I opted for, to keep everything nice and shiny. I highly recommend it. These are also top-notch pieces and very well made. All gaskets, bolts, and anti-seizing for the sensor bungs included.

Other members have been very happy with the HFPCs.

Richie (RV6) does not communicate very frequently on the forum, but was very prompt when I directly contacted him via phone and email. Ships promptly too.

This mod is the concensus "most horsepower" for one modification on the TL. It makes sense to do the HFPC or PCD and the J Pipe at the same time. Acurazine users have mixed the HFPC and PCD with the XLR8 J Pipe without issue.

** I am not paid to endorse or slander any product; just speaking on opinion, experience, and observations - which makes me objective.

Originally Posted by alexpeters

Seeing all these mods and it seems like most people here are just sticking around the same framework of opening up the exhaust and a few minor things above that, but what about anything to really sheer some tenths off the quarter mile or add more serious power? It's been a good 9 years since the 4G came out, are there any decent forced induction options out there that aren't ridiculously priced (over like 7-8k) or other shit we can do??

Originally Posted by 4th_GenTLe0260

This thread needs to be deleted. I haven't read every post om this thread, but I cant find anyone who has effectively put there 4g 3.7 SHAWDYY on a dyno and seen anywhere near 30-40 hp or tq gains. Like almost every other thread on here will tell you. The j37 is basically maxed out as it comes. RV6 XLR8 blah blah blah. A good driver in a 5AT 4G TL can run with any 6MT full bolt on soup to nuts 4G TL any day. Tune or no tune.
Heres a link I'm sure many have come across.

https://hondanews.com/channels/acura...ra-tl-overview

After you read it you will see Acura built our 4G for practical daily spirited driving while keeping gas mileage acceptable and appealing along with 300+ HP. Enjoy your TL for what it is. Not what Psuedo tells us all adds power to our Honda/Acura motors while he drives around in his 500+HP Benz's. I'm not hating. I would never buy a Benz or anything German. Just saying hes comparing AMGs to SH-AWD. Be serious. 4th Gen TLs are awesome and that's why were all here on AZ.

Originally Posted by 4th_GenTLe0260

This thread needs to be deleted. I haven't read every post om this thread, but I cant find anyone who has effectively put there 4g 3.7 SHAWDYY on a dyno and seen anywhere near 30-40 hp or tq gains. Like almost every other thread on here will tell you. The j37 is basically maxed out as it comes. RV6 XLR8 blah blah blah. A good driver in a 5AT 4G TL can run with any 6MT full bolt on soup to nuts 4G TL any day. Tune or no tune.
Heres a link I'm sure many have come across.

https://hondanews.com/channels/acura...ra-tl-overview

After you read it you will see Acura built our 4G for practical daily spirited driving while keeping gas mileage acceptable and appealing along with 300+ HP. Enjoy your TL for what it is. Not what Psuedo tells us all adds power to our Honda/Acura motors while he drives around in his 500+HP Benz's. I'm not hating. I would never buy a Benz or anything German. Just saying hes comparing AMGs to SH-AWD. Be serious. 4th Gen TLs are awesome and that's why were all here on AZ.

Originally Posted by 4th_GenTLe0260

Ok so 25hp and 17ft lbs of tq. That's nothing to brag about like I said I didnt read every post, the cost that some people are averaging it to be around 2k and 100$ per 1.3hp. None of that is accurate buying the jpipe the hfpc and the tune is going to cost alot more plus labor bc let's be honest as much as we all like to say we are DIYers most arent. In my post I said no1 is gaining 30-40 hp let alone anywhere near those torque numbers. I love my 4G and would love to make it faster. The dollar value just isnt there unless you have plenty to spend and in that case you most likely wouldn't be driving a 09-14 Acura TL. I appreciate the feed back and I'm not trying to say anything bad about our cars. I'm just a realist, after investing that type of cash into a 4G then running a G37, 335, or Genesis Coupe and getting burned you realize it's just not worth it.

Originally Posted by dopeboy1

No one is gaining 30 huh? 25 hp with just hfpc, jpipe and ktuner. that's only 5 away from 30. You can't imagine that adding pcd (instead of hfpc), polished runners, throttle body spacer, thermal throttle body gaskets, catback exhaust and lightweight pullys can add another 5 hp combined?

Of course it is a lot of money for little gains but everyone already knows that. You don't mod this car expecting to beat everyone on the streets. Just make it a little more fun.

Originally Posted by Pseudomaniac

Fifth Modification: P2R Throttle Body Spacer and Thermal Throttle Body Gaskets

The P2R Throttle Body Spacer is an easily installed modification to give your throttle body the ability to "gulp" more air. The idea is this; by placing this on the back of your throttld body, you're giving the intake system more immediate capacity to pull in air. The throttle body becomes more efficient. The throttle body opens with a press of the gas pedal; you're pressing the gas pedal less to get the same amount of air in as you would if you pressed it more without the spacer. More efficient, and more power on tap.

The P2R Throttle Body gaskets go with the same logic as their thermal intake manifold gasket; put a buffer between the hot engine heads and the intake systems so that they stay cooler. Cooler intake = More Oxygen = More Power

The factory intake on the 3.7 flows very well. This isn't some "VTEC JUST KICKED IN YO!" type of mod, but you'll notice the throttle benefits, and perhaps some MPG benefits if you can stay light footed.

You can use this with a factory intake, or with the Takeda SRI and K&N SRI intakes.

You will need to be comfortable in removing the throttle body from your car, and backing the throttle body studs out of the intake manifold (butt the two throttle body nuts together on the stud tightly and then use them as a bolt head).

Installation in under an hour.

Throttle body diameter on the 3.5 and 3.7 are different - so be sure to order the right spacer and gaskets.

~$115 Shipped - P2R Throttle Body Spacer and 2 Throttle Body Gaskets

You need two gaskets to install in this order from left to right:

Intake Manifold - P2R Gasket - P2R Spacer - P2R Gasket - Throttle Body.

A can of gasket remover might come in handy to get the factory paper gasket off - and you need to remove it to get a good seal.

Unlike the P2R Intake Manifold gasket, the set of these I received was properly machined.

** I am not paid to endorse or slander any product; just speaking on opinion, experience, and observations - which makes me objective.

Originally Posted by 4th_GenTLe0260

This thread needs to be deleted. I haven't read every post om this thread, but I cant find anyone who has effectively put there 4g 3.7 SHAWDYY on a dyno and seen anywhere near 30-40 hp or tq gains. Like almost every other thread on here will tell you. The j37 is basically maxed out as it comes. RV6 XLR8 blah blah blah. A good driver in a 5AT 4G TL can run with any 6MT full bolt on soup to nuts 4G TL any day. Tune or no tune.
Heres a link I'm sure many have come across.

https://hondanews.com/channels/acura...ra-tl-overview

After you read it you will see Acura built our 4G for practical daily spirited driving while keeping gas mileage acceptable and appealing along with 300+ HP. Enjoy your TL for what it is. Not what Psuedo tells us all adds power to our Honda/Acura motors while he drives around in his 500+HP Benz's. I'm not hating. I would never buy a Benz or anything German. Just saying hes comparing AMGs to SH-AWD. Be serious. 4th Gen TLs are awesome and that's why were all here on AZ.