Hrmm 8... let's review your goals:
1) Additional power (enough to feel)
2) No rice sound
3) No FI/etc
4) No headaches (error codes, no black soot spewing from tailpipe, etc)
5) Works with other mods (Strut bar, etc)
Here's a plan that I think meets all your goals:
1) Intake:
Get something like the
PLP SFI or a black
JoeZ, and a
drop-in filter (TRD, K&N, etc).
Cost: $150-200
Installation: Self, 30 mins
Why?
Both intakes above retain the stock airbox... they simply replace the OEM pipe which runs between the airbox and the throttle body. The OEM pipe has a resonator and some baffling in it, which keeps the intake very quite but also slows and disrupts the airflow a bit. There are a few HP to be freed up by replacing it with a smooth pipe... and then replacing the OEM dry paper filter with an aftermarket oiled one will add some more power. In addition, staying away from an open element intake/short ram (which removes the stock airbox) will keep the noise levels down AND make sure that your intake system will work with any front strut tower bar you choose to purchase. Also, keeping the stock airbox and replacing the pipe with a black pipe makes it much less obvious any work has been done to the car... both the PLP and JoeZ intakes look like they could easily be OEM equipment... one less red flag to someone inspecting your car for emissions. Not a great pic, but
see if you can point out the PLP pipe in the red car:
Header:
You really can't go wrong with a
Toyomoto Gen1 (also known as
HP Racing, $300) or
TurboEast (also known as
OBX, $300-$450). Some packages include not only the header, but also a ypipe, o2 sim, and gaskets.
The difference between the Toyomoto/HP and the Turboeast/OBX headers is theoretically that the TE headers are a "short runner" design, which is supposed to give you more power in low RPM ranges while sacrificing some power up high. The Toyo headers are a long runner design, which gives more power up high but theoretically makes less down low. We don't have any hard fact to support that, but the theory seems to be sound.
IMPORTANT:
Whatever header you get make sure it comes with an o2 simulator. When replacing the stock header it is
required that you get an o2 sim to keep the CEL (check engine light) in your car from coming on. The car's ECU has numerous sensors in the exhaust flow, watching the amount of oxygen and fuel retained in the exhaust gasses to make sure all your catalytic converters are working. When you put in aftermarket headers, you remove the catalytic converters, so all of a sudden the car's ECU thinks they have all failed, and will throw error codes. An o2 simulator "simulates" a good sensor reading to make the ECU think all the cats are still in the car and functioning properly.
If you're industrious and aren't scared to turn a wrench... you can install the header and o2 sim yourself with simple mechanical and soldering skills. Call up a friend and get to work... 3-4 hours later you'll have the new header in the car. IF you don't feel like doing it... expect to pay a shop $200-300 for their trouble.
What about the
Ypipe?
As I said, a lot of header packages come not only with a header, but with a Ypipe as well. The stock Ypipe has one catalytic converter in it... and most aftermarkets don't have any at all (The Turboeast Y is the only known exception... you can custom order it with a cat). For more details about the OEM vs aftermarket Ypipes,
check out this link. Now.... what to do?
Sell the Ypipe! That's right. If you want to retain a cat for emissions, and keep far away from a ricey sound... replace the stock headers, but
keep the stock Ypipe. Keeping that one cat in there will tone down the exhaust note quite a bit, and look good for emissions, AND keep the back end of your car clean (you'd know what I meant if you had ever driven around a car with no cats... ewww).
You can get $100-125 by selling the ypipe from the kit... if you pay a total of $300 (ToyoGen1's, shipped, from Toyomoto)... all of a sudden you've paid only ~$200 for your header setup. Take the wife to dinner with the money you saved.
Exhaust:
Ask around for OPINIONS on what exhaust sounds good... keeping in mind that sound is a
qualitative property. What sounds "Awesome and not too loud" to one person might be insanely loud and ricey to you... it really helps to hear a few examples in person before making a decision. Be wary of video clips you see floating around the internet... the software compression used to decrease the size of online video can severely distort the sounds you hear. Also, you might see a video or two of someone sitting with a car in neutral rev'ing the motor. Believe it or not... an exhaust can sound completely different when the engine is not under load (in neutral) vs when you're actually driving down the road. Hear the exhaust IN PERSON if at all possible.
As a matter of personal opinion, I feel you can't go wrong with a
L-tuned exhaust. It's one of the quieter exhausts out there, designed by Lexus/TRD to be shipped as OEM equipment on the IS300. IT might be a little more pricey unless you can find one used... check around, you can sometimes pick one up for $300-$400.
The exhaust is easily self installed... a jack, 30 mins, and a 14mm wrench will have you sporting your new gear.
TUNING: You've got an intake, header, and exhaust... how to squeak out the last of the power? 2 things you can adjust on the car without getting too crazy: Air/fuel mix and exhaust cam timing.
Optional: Switch to an
adjustable exhaust cam gear. This won't do anything too crazy to emissions or sound, and will squeak an extra ~10 bhp and btq out of the motor.
More details here... my pizza is going to burn if I type too much more.
I'd view the cam gear as optional... expect a total project cost of $300-400... parts, installation, and tuning.
Air fuel mix:
Finally... tune everything out. Of course, coming from the factory your luxury sedan is going to be running very conservative tuning... purchasing an Air/Fuel Converter (AFC) can allow you to maintain that conservative tune for 99% of driving, but give you a little more oomph when you want to mash out the pedal on the right. A popular model is the Apexxi SAFC II (it's called an "S" AFC because it's super!). An SAFC will run you $200-300... can be self installed if you can follow directions and aren't scare to solder. Expect a shop to wrangle $100-200 out of your wallet for installation...
The SAFC needs to be dyno tuned. While you might be able to "get close" by using the same settings as someone else with similar mods... the only way to ensure you get the most bang for your buck is to strap the car down to a dyno and a let a tuner have his way with her. By adding the SAFC, you gain the power to change the amount of fuel the ECU is spraying into the motor by tricking it into thinking it's got less air entering the intake than there actually is. This will cause the ECU to spray less fuel, resulting in a "leaner" mix. LEaner mixes make more power than richer ones (they burn hotter and more completely)... the downside is that if you run it too lean you'll start melting things and causing all sorts of other problems. Ask around for a local shop that might be able to help you out... and expect to part with another $100-150 for the tuning time.
Finally... most shops charge by the hour for tuning time... with a 1 hr minimum. It doesn't take a full hour to tune an SAFC or tune a cam gear... so if you decide to do both you might try to work it so both are tuned at the same time on the same day... savings: ~$100-150. Take the wife out to dinner again, and let her know how much money you're saving by making the car faster.
Damn. My pizza is burnt. :blush:
Too late to rescue it now, so to review:
1) PLP Silent Flow or JoeZ Intake, $150-200 self-installed
2) TRD/K&N etc drop-in filter, $50-75 self-installed
3) Toyomoto Gen1 Header + o2 sim, $300 self-installed or $500-600 shop installed
4) Sell the YPIPE! -$100!
5) L-tuned exhaust, $300-400 self-installed
6a) Adjustable Exhaust Cam Gear Professional Installation ONLY- $350-450 parts, installation, and tuning.
7) Apexxi SAFC II, $250-300 self-installed, $450-500 shop installed, either way you need +$100-150 of dyno tuning
8) Tune the AFC and cam gear at the same time! -$150!
Total Cost: $1300 self-installed bargain-hunter - $2300 shop-installed buy everything new
What to expect:
The
NEW 260-275 hp IS300. Luxurious, quiet, and clean... LEXUS DIY... The Passionate Pursuit of Horsepower.
Hope this helps. Off to buy another dang totinos.
