What gives more HP?

[rbrick220]

goodtoknow about the intake mani... iwon't worry bout it unless i boost... i'm assuming that its still irrevelient with the s/c. I know with my 280z there are throttle body upgrades, all i'v seen for the tc are universal, which i'm not feelin, so i didn't know if other people have messed around with any of em. at this point i think i'm limited to pully's, cams, 25 sneaky pete, and get an awesome tune with the f/ic. i also saw someone talking about upgrading the injectors... any thoughts. i'm looking for about 240 to wheels if possible without cracking the motor.

[StreetBrawler89]

240 is attainable in the tC with the right mods, although most of those contain the Forced Induction or Crazy Cams route. The tCs stock fuel injectors are good enough as they are designed to be able to support the TRD S/C, while im not sure about the total flow they output(Streets to Navy, come in Navy) most people agree that the pump is the better upgrade. I know a turboed tC thats running a basic system at 250 at the wheels with a 255lph Pump and OEM injectors.

[navylife59]

Streets is correct, the OEM fuel pump will only get you to around 240WHP. It can support the 440cc injectors of the TRD S/C sufficiently at 10PSI, but when you up the ante to 15PSI and 550cc injectors it falls short under high demand. If I remember correctly (overseas and limited web access time), the OEM injectors are 380cc.

You can use readily available online calculators to find the right sized injectors and fuel pump size needs here.

Stealth 316 - Air/Fuel Flow Calculators
RC Fuel Injection

240WHP x 15% (drivetrain loss) = 276BHP
N/A = 456cc @ stock fuel rail pressure
S/C = 529cc @ stock fuel rail pressure
Turbo = 574cc @ stock fuel rail pressure

Note: Calculate with conservative BSF. Increase fuel rail pressure for max boost/WOT conditions will increase efficiency of injector near Max Duty Cycle up to saturation.

[CadenceScion]

If you are looking to squeeze more ponies out of your Scion tC I would start off with I/H/E as well. A throttle body spacer is another option. As far as the TRD Supercharger goes, I would refrain from buying one. The HP/Torque gains are way under rated and are no longer in production. Reason being is for issues with the bearings. You can still buy a supercharger on Ebay, and possibly from TRD Sparks.com, but they will tell you they are being (Recalled). I wanted a TRD Supercharger, but was told I can not run a header, or any aftermarket cold-air intake. I refuse to go back to a stock air box, but that is me. Also the heat from the header will heat up the bearings in the supercharger. If you want to go for big HP/Torque, go with a turbo kit. I would also look into a Decendant Intake Manifold and Uni-Chip. If you really want to spend the cash, there is always overhauling your engine with cams, bigger injectors, pistons, port/polish...etc.

Me personally, I plan on staying N/A, I am not to keen on killing my motor or the reliability for that matter.

[CadenceScion]

Why are we making fun of Honda's? Last I checked (2 nights ago) My best friend's new SI dominates the tC- my car their 200 hp and 139lb aren't great off the line but then it hits about 5k and there he goes. We probably shouldn't talk crap about a guy with .4 liters less than with a better breathing engine makine 40 more horses. (The lack of torque is almost unnoticeable once first gear gets to 5k. Every shift puts it right back in the high hp range). Believe me I race him all the time hoping for different results
Also, If I add I/H/E will that void warranty? I'm a total noob to new cars and warranties. Thanks!

I am going to have to disagree with what honda brags/boasts. I may own a 2006 Scion tC N/A Auto and I have had no probs putting hondas, neons, some BMW's and some Audi's to shame. I don't know how some of you are driving your scion, but I'll tell you this much... being in (D)drive isn't going to get it done. All Drive really is Over-Drive, letting the cars ECU control shift points. I have found that you get a higher rpm/torque with 3rd gear and sometimes 2nd gear as long as you not overworking the engine. Keeping your powerband and rpm's up works IMO. Furthermore there really isn't much difference between a VVT-i or Vtec-i, based on the same technology. I may be wrong, but I believe Toyota was first in development then Honda was soon to follow.

[CadenceScion]

I know a lot of you are talking about HP/Torque gains with after market bolt-ons. What some of us need to keep in mind is that our HP/Torque ratings are based off of the crank/flywheel, not the front wheels. To the front wheels we are losing 10-30% of that. Same would apply to a Subaru WRX STi. Rated 300HP Stock, its actually around 270HP. Since the WRX STi has 4 wheels turning rather than 2 wheels with our tC's, there is some loss in HP/Torque from engine to the wheels. Our tC's are rated @ 161HP and 162/163 Ft. Lbs Torque, its actually 141 HP and 142/143 Ft. Lbs Torque.

[stonerboi27]

nope not hard at all .. my boy removed my passenger wheel and used some tools that i've never seen before and within 15 minutes the old one was out and my Agency Power was in .. i was on the computer in his office 5 minutes after he started so i didnt see the full process .. sorri .. but no its not hard bro

glad u like this forum .. where here for u

thats great to hear. i was wondering if i needed an engine lift... which is undoubtedly beyond my capabilities

[navylife59]

Good info there Cadence with squeezing more out of your slush box. I would not blow the money for the Decedent or the WR intake unless you are going F/I or cams and head work. OEM flows just fine for N/A or NO2.

As far as the TRD S/C goes, I have been running mine since October 2005. I do have a header and an aftermarket SRI. You can still run an aftermarket header. The problem with the oil seal and the bearings are not directly related to heat. The oil seal becomes prematurely worn from improper torque sequence of the torque tube. This causes the seal edge to wear ellipitically causing the leak. Remember that the S/C gearbox is fed via a pressure reducing orifice so there isn't alot of oil pressure there. You can wrap your header or build yourself a heat shield for insurance against any possible heat damage problems.

The bearings that are failing are actually the ones on the end of the torque shaft (pulley side). The entire torque shaft and pulley system was designed and specified by TRD, not Vortex who only supplied the S/C unit. These are sealed bearings that are completely inadequate for the load and speed. Using a smaller pulley to increase S/C compressor speed (PSI) only furthers to exacerbate the issue. You can, however, purchase high-speed bearings to replace those OEM units.

[CadenceScion]

Navylife, I did notice that you had the TRD S/C with a SRI and aftermarket header. I was told numerous times by TRD and another website that adding a header or CAI wouldn't work with the S/C application. How did you manage to make your application work w/o issues? Why does TRD or the dealer tell you not to run a header or CAI with the S/C?

I was also told by TRD, and other people I have talked to that the TRD S/C's are now discontinued due to the flaw with the bearings. If you are able to still buy a S/C, you'd probably find some laying around on Ebay.

What is the truth behind all of this?

[StreetBrawler89]

TRD Discontinued the S/C because of a fundemental flaw within Toyotas Financing Corp. You could by a new tC and have a shiny supercharger, but the 5k to have it installed had to come up front. You couldnt get it financed in with the price of the car which drove alot of people off because Scions are Low-Mid price range cars, and most of us dont have 5K just laying around to spend on a S/C the day we buy the car. Basically there wasent enough demand for the S/C because most people couldnt get it the day of and at the dealership so TRD(Who lets not forget is run by TFC) decided that the stockpile of parts that most dealerships had accured would last them through the end of 2009 and that the Supply/Demand ratio was not enough to continue the product-This I know from my friend who runs the Scion department of a Toyota Dealership.

And as for TRD telling you not to use anything but TRD stuff and that it wouldnt work, I would imagine that has something to do with the fact that TRD is obliged to say things like that to avoid lawsuits in case someone blows there engine sky high trying to run a 45PSI pulley on there S/C or fails an emissions inspection after adding a freeflowing cat-back or something along those lines-But thats just my guess.

[navylife59]

The word that I got from Ken over at Sparks Toyota was that the TRD was a slow seller and with 2010 supposed to have been the model changeover year, the TRD units were to be pulled from the shelves. These were to be destroyed so that they could not be sold and parts used for warranty repairs. Companies destroy units on discontinued items to claim as a business loss. Complete waste, I know.

TRD and Dealerships stating that an aftermarket header and CAI/SRI cannot be installed was for various reasons.

Header - All aftermarket headers (save one) do not have a TWC. This would have caused the car to fail emissions with the S/C. Aftermarket headers also do no have heatshields as the OEM header does. TRD was unsure, in the beginning, how the torque tube assembly would fair with the exhaust heat. This is why they had problem in determining the issue with the oil seal leaks and the bearing failures.

Intakes - Changing the airflow across the MAF via an aftermarket SRI/CAI caused the engine to run lean. The TRD maps were calibrated to a certain amount of arflow across the MAF. Using a wire mesh screen just before the MAF corrected this to a better level. Running more boost and larger injectors also resolved the problem.

[CadenceScion]

Now with all this being said about the TRD S/C and also set aside, what would be your opinion/s about adding a performance chip (Uni-Chip) and also an intake manifold (Weapon-R/Decendant) Pro's and Con's?

I ask this because I have gotten mixed opinions from other Scion owners and also some techies pertaining to the two. Some say whether or not your running N/A or Forced Induction you should see some improvement in HP/Torque/MPG. Now with the plug/play system (Uni-Chip), the vehicles ECM/ECU will adjust as you add modifications, plus your given the option to choose regular fuel or a higher octane fuel setting. When I first bought my tC, I was told that all the chips on the market were a big gimmic and didn't work.

Is there any truth behind any of the following and would either performance upgrade be beneficial whether you have a N/A or Forced Induction Setup? Although most people I have discussed this with have said that no proven dyno results have surfaced... as of yet that is.

Thank you! :-)

[StreetBrawler89]

Chips are one of those upgrades that seem to come up as either the end-all be-all of tuning or a a necessary evil. The ECU in the tC is "Learning" or more properly "Self-Correcting", that being said the car gains almost nothing from the addition of a chip or even a full piggyback system as there is no change in the intake, its charge, or the amount of exhaust being emitted. The OEM ECU is able to adjust itself to the minor changes introduced by the I/H/E system and the notion that you are going to see even marginal benefits from tuning that mild of a set-up come from the early days of the Tuner scene before VVTI or VTECH where the OEM ECUs were a great hinderance to the newer freer flowing air. They would often throw code or the like at even these basic setups, now adays an aftermarket ECU is needed when upgrading to things like F/I or some Nitrous systems in order to control the influx of pressure hitting the engine, this is especially true for Turbochargers to control the boost levels during daily driving and keep them at a safe level. But on a stock or semi-stock 2AZ-FE with the tCs ECU there is no usable gain, and alot of headache and walletache to bying an aftermarket "Performance Chip".

[stonerboi27]

Now with all this being said about the TRD S/C and also set aside, what would be your opinion/s about adding a performance chip (Uni-Chip) and also an intake manifold (Weapon-R/Decendant) Pro's and Con's?

I ask this because I have gotten mixed opinions from other Scion owners and also some techies pertaining to the two. Some say whether or not your running N/A or Forced Induction you should see some improvement in HP/Torque/MPG. Now with the plug/play system (Uni-Chip), the vehicles ECM/ECU will adjust as you add modifications, plus your given the option to choose regular fuel or a higher octane fuel setting. When I first bought my tC, I was told that all the chips on the market were a big gimmic and didn't work.

Is there any truth behind any of the following and would either performance upgrade be beneficial whether you have a N/A or Forced Induction Setup? Although most people I have discussed this with have said that no proven dyno results have surfaced... as of yet that is.

Thank you! :-)

http://trdsparks.com/displayparts.ph...&parts_id=3234 -website
http://trdsparks.com/images/2620021Dyno-05SciontC.pdf - dyno chart
is this credible evidence? its still $500 for a hit or miss mod, which is why im asking.

[StreetBrawler89]

Really its up to you, but as most people have already said, there is no usable gain from it unless you already have some serious modifications. Every part has a dyno showing its awesome "Gains" but your car is not on dyno so you wont know. IMO NO its not a good investment as a starter mod.

[navylife59]

Streets is absolutely correct. Nothing much is going to be realized on our motors due to the efficiency of the ECM. The Uni-Chip is yet another piggyback computer. As such, the ECM will eventually limited it to only WOT. This is why Kenny Tran has been on me to go with a Stand Alone. There was the PNP Hydra but it had very mixed reviews and since faded away from the Scion scene.

Toyota spent alot of money perfecting the 2AZ-FE with the current technology of 2005. It has now been surpassed and evolved into the 2AR-FE sporting a dual runner intake and dual VVT-i. On any motor, just replacing the intake manifold is not going to see significant gains. An intake designed to flow more air is going to have the need to flow more air; ie larger profile cams, larger intake valves, head port/polish, higher compression, F/I. Remember, your engine really is only just a big air pump. Without something trying to flow more air, there really isn't the need for larger intake runners. Changing runner design, size, and length with the stock cam profiles might net some slight increase in HP/TQ in the powerband but will cause a detrimental effect someplace else in the powerband. This usually manifests itself in poor throttle response on the low end. Think of it like that Anime 'Full Metal Alchemist'. The show is based on an Alchemy premise of the law of equivalent exchange. In order to gain something, first you must loose something of equal value.

WeaponR, Descendant, Kenny Tran, any hot rodder will tell you this.

[spillingvoid]

What is 'All aftermarket headers (save one) do not have a TWC.' The TWC is what I'm interested in. I know it has to have something to do with emissions, probably in California but what.

[navylife59]

It was the Megan Racing headers. They have trouble (of course) with failure after failure of the cat they used. It turns out that it was not a TWC and was not designed to handle the heat of being in the header.

[mtnbk]

TWC is the term Toyota uses for Three Way Converter. See the attached Toyota drawing.
http://tijil.org/Scion_Docs/Scion_06...r/2azfeexh.pdf