Pseudo's Guide to Adding Power to Your 4G
 

I've now run the gambit of the available modifications as of 04/2012 on my 09 SH-AWD, and wanted to put a "Noob" thread together for reference.

The Goal: I want my 4G TL to be faster.

First Modification: Exhaust.

I fully bolted my TL and did exhaust last. Everything felt choked until I did this. Based up on that experience, I would say - "Lead with Exhaust".

Options:

~$1100+Shipping - XLR8 CatBack
~$1500 +Shipping - ATLP CatBack
~$ 950 +Shipping - Comptech Mufflers (exhaust shop required)

I did the Magnaflows and I am not disappointed. It's not too loud in the car, it's very sporty sounding, and definitely unlocked the power of my other mods. I would refuse to believ that the ATLP catback delivers 10x the performance of my Magnaflows - with no disrespect intended to what looks to be a gorgeous exahust by them.

Second Modification: J-Pipe.

The J-Pipe is the lower section of the "headers" on your TL. This piece of plumbing isn't bad from the factory, but has shown major dyno improvements on the 3rd GEN TL, and is a noticeable pep-pick-me-up on the 4G. This pipe can be changed in the garage by yourself with proper sockets and hand tools, and done in under a couple hours. Most AZine members will tell you this is the best bang-for-your-buck option on the TL.

Options:

~$425 + Shipping - RV6 LongTube J-Pipe (Includes 3rd Cat Delete)
~$425 + Shipping - XLR8 J-Pipe (Leaves Factory 3rd Cat)

These have both been reported to be high quality pieces. I purchased the RV6 J-Pipe, and the welds/flanges/gaskets/bolts - everything is spot on and excellent quality.

The RV6 pipe should be a larger performance gain across the powerband than the XLR8. The trade off is if you live in an emissions state - you probably aren't going to be able to pull off the RV6 pipe. When Kentucky was an emissions state years ago, and my Civic at the time failed emissions (no cats, big headers) - I was able to give my receipts on the header and test pipe I purchased as "attempted repair to exhaust" for a voucher to pass - so don't rule this out as an option.

You will get some rasp from this mod. This will be "buzzy" at times and audible in cabin.

Conservatively, this is an 8-10 HP gain by itself. Perhaps as much as 10-15 HP.

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

10x the performance, eh ?

If true, let's say if the Magnaflows adds 7 hp to the wheels, then it will translate to ATLP adding 70hp to the wheels. :eek:

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.

Very thoughtful of you to put this thread together,it will probably end up being the go to thread for anyone who is looking for some hp gains.
I know that you have done more performance mods to your car,you should add them all here when time permits.

Fourth Modification: P2R Polished Intake Runners

The upper intake manifold of the J37 is magnesium. In previous generations, this has been standard cast aluminum Honda fare. The magnesium has a smoother finish, and the J37 stock upper intake manifold has been shown to flow very well compared to prior generations.

Beneath this upper manifold are a set of runners that channel the air from the throttle body to each cylinder's pair of intake valves. The lower manifold is cast aluminum, and from the factory, rough with very visible casting marks inside. P2R processes these stock manifolds and polishes them all to a brilliant shine, leaving a relief for the injectors as well.

In prior generations, this mod has shown a noticeable gain; but not so much with the 4G TL and the J37. I installed this after doing the SRI, and before any exhaust mods, and felt it might have opened things up a little bit - but nothing overly dramatic. One thing for sure, it's doesn't hurt anything to have the manifold flow better.

This modification is not just a simple bolt on; you have to dissect your intake manifolds down to the heads, including working around the fuel delivery system, and wiring harnesses. If you're competent in the garage, no worries. If it's your first time cracking into a motor - get help. Two to three hour job in good hands.

P2R also sells a thermal intake manifold gasket that spaces the upper magnesium maniflold and the lower aluminum runners. The purpose of the thick polymer gasket is to prevent heat soak from the engine from casting into the intake, allowing temperatures to stay lower in the manifold and increasing the capacity and oxygen saturation. With an aluminum upper intake manifold, this was a big deal; with the magnesium, not as much. I ordered this piece from P2R, and it was so poorly cut, that the holes lining up would have been obstructing airflow on 4 cylinders. Save your money and skip this gasket in my opinion, it's not worth it for a shoddy part.

Options:

~$379+Shipping - P2R Polished Intake Runners

Don't expect super impressive gains from just this mod. I suspect the flow characteristics of the engine once the cats are off will really benefit from it though.

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

Great thread.

Nice job. :thumbsup:

awesome thread!

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.

Sixth Modification: Lightweight Crankshaft Pulley

This is one I haven't done on the 4G myself - but have done on my prior TLs and CLs. The installation is relatively easy. If you can change a serpentine belt, you can do this. Jack the front passenger side up, take off the front passenger wheel, pop the splashguard off, drop the belt, remove the pulley, pop the new one on in the correct position, and reassemble.

The logic is that by reducing the weight of the pulley, you're unlocking the power of the engine to do other work. Removing this type of "parasitic" load is a common theme in performance mods. Lightweight wheels, lightweight lugs, lightweight brakes, carbon fiber and aluminum axles and driveshafts; lightweight flywheels; anything to reduce driveline weight.

Remember though - the lighter it is, the easier it is to spin up - AND spin down, and unless you're quick on the clutch - or have an awesome auto-box, this can hurt you as well (getting too light).

I am working with Ray at Ralco to identify which of the existing J series pulleys he has will work. The rationale being - his pulleys are billet aluminum, excellent quality, and he retails these at around the $100 mark - which is fair for the limited runs of items he produces.

Unorthodox makes one for XLR8 that weighs one pound. The factory J37 pulley weighs 5.5lbs.

~$200+shipping - XLR8 Stock Diameter Crankshaft Pulley

Install time should be under an hour. Don't expect rocket-like results - just a little more pep in the throttle, and climbing the revs a bit quicker.

I'm pleased to see that XLR8 has come down from $250 to $200. Everyone's got to make money, but this still makes this a pretty high $ for low hp mod.

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

Seventh Modification: Short Ram or Cold Air Intake

Historically on Honda/Acura vehicles a short ram intake (SRI) or cold air intake (CAI) are everyone's first modification for instant performance increases. The sound from under the hood is great, and normally an easy way to pick up 5-10hp with an hour or so of work.

This has NOT been found to be the case on the J37. I cannot speak for the J35, but feedback has also not ben overwhelmingly positive. The factory intake on the TL is a grille mounted cowl that feeds a very free flowing intake box and the best intake manifold that Honda has produced for the J motor.

Options are currently limited to SRI from K&N or Takeda. They are comparably priced, and effectively the same thing. I am hopeful that an AEM full CAI with modified MAF sensor will be available for our vehicle, and that Comptech is working on an icebox, both of which will be released with dyno tested performance on our actual vehicles.

The current SRI options, particularly with nothing else bolted on to the car, do nothing but make the intake of the engine more audible and sound "meaner". It's a pricey noisemaker.

It may pay more dividends once you have done the intake runners, spacers, the PCDs, J-Pipe and an Exhaust - but as a stand-alone mod, or even paired with the P2R runners and spacers, I can personally attest I felt nothing more than a little more grunt down low, and a perceived loss of top end power on my 3.7.

In other words - if you don't already own this or aren't getting a stupendous deal, I'd wait to see what Comptech and AEM are cooking up if anything, or possibly a full CAI that takes advantage of the factory cowl.

SRI install will only take you an hour or so with common hand tools. Only tricky parts are the PCV hose and where it meets the intake manifold, and just being careful to get all your vac lines where they belong.

The Takeda is aluminum and available in black or polished aluminum finish. It includes throttle body couplers for both the 3.5 and the 3.7 throttle body diameters.

~$250+shipping - Takeda SRI

~$290+shipping - K&N SRI

The K&N Part number also shows that it works with both the 3.5 and the 3.7 engine, but I have not personally installed this to confirm such is the case.

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

Thread of the year, thanks for providing us such an informative list.

eazyrider should take note on this..

Great info for all, definitely goes appreciated since you put the time and effort.
thanks Pseudomaniac

Very nice pseudomaniac, glad that someone took their time and effort to start a thread like this to help those who want to get power out of their TL.

Great thread- stickied.

Great thread!

In summary?
 

Overall about how much horsepower and torc has been added as a result of your modifications?

It's a difficult call. The car is near impossible to dyno or I'd have numbers to back it up.

I'd speculate 340hp @ the crank on the low end and 355 on the high end for a net gain of 40-50 HP over stock @ a cost of about $2000 total. Call it 50HP for $2k so about $40 per HP.

It is noticeably quicker in the powerband, though I'd advise anyone with an A/T not to expect your 1/4 miles times to be much better. The trans doesn't have much love for the faster revving.

Great Tthread! I recently purchased a 2010 SH-AWD TL w/Tech and am looking forward to doing some if not all of these mods. Thanks for taking the time to post this.

Great Thread bro....definitely paved the way on how I should start enhacing my performance on my TL. Is it 2000$ with out install? Because that would be steal. XLR8 is 15 min from house, so should I have them put everything on or would DIY be better? Sorry for all the questions, just excited about my new TL

Thanks for the "to do list" ... Just saved me hours of research lol

do they make those Jpipes for 2012 TL 3.5 FWD?

Nice write up. I plan on swinging by my old job once they finish moving into their new building to get a baseline run.

I think your numbers are overly optimistic since you have not changed any parameters in the computer. I only say this because ive spent plenty of dyno hours doing before and after pulls with and without tuning.

Best thread for TL mod lovers! Thanks for putting all this together.

Great info, thanks. I wonder how much more (if any) power would be felt by the butt dyno between the 5spd of your 09 and the '12 6spd auto. I'm tempted by the jpipe, but not sure I want to change the stock sound. At full boil I love the stock growl. I think mods that help move the rpm up faster would be my top priority. 3K seems to be the magic number in my car

Great info. Does all of this cary over to the 12 3.7. 6at Everything I see is for earlier years. For example K&N has an intake and only lists fittings for the 10 model. Thanks.

The 6 speed gearbox and the minor exhaust changes are all that I'm aware of; otherwise they're identical. But as I described; don't waste your money on the SRIs.

almost like a bible for HP gain.....way to go Pseudo.....
:thumbsup:

I installed K&N drop-in air filter this afternoon and no, I don't feel anything nor can I hear a more aggressive engine noise; but it was fun to do little things like this. plus my air filter came free this time. lol

This helped so much, I had no clue where to start.

Nice post, been looking into some mods for my TL. Unfortunately I would not trust myself to do such mods. Any ideas what a dealer would charge to install some of these?

I always advise with these types of things that if you're not comfortable doing the wrenching, then you're opening up lots of potential headaches and doubling the cost of modding. It's one thing to bolt on a set of PCDs and a J-pipe in the garage one evening yourself, it's another thing to pay someone a few hundred dollars to do it, and then if one rattles, or breaks, or a sensor has an issue, etc.

It's all on what you're comfortable with.

Stealerships aren't going to be interested in doing probably any of the work on any current mods. Might get lucky with the comptech supercharger that's forthcoming and some tier 1 dealers, maybe with comptech mufflers - but I wouldn't count on much else.

can u use all the same parts on the 3.5 fwd? cause i look it up at the dealer and it looked like i could just double checking be for i buy anything

The dealer would look at you crazy . Like he's tearing up a brand new car. Just do minor mods like Catback, lights, intake. Than you won't have to worry about check engine lights and stuff like that. I've been working on cars for a while . My friends in the field tell me to leave the car alone . To late already did drl led 6000k upper Cree fog lights led lisence plate painted calipers black . Getting an exhaust soon probably xlr8 maybe ct ice box than I'm done.

Most Helpful! Great tip on where to start. Thread of the year, hands down.

Thank you Pseudomaniac for the awesome thread.

Go gen3!

im getting the xlr8 exhaust fpt my 10 tl. now is it true about the gains the jpip will do bc then ill order it??