Intake and Exhaust Questions (upgrading) Options

[MyFirstCar]

I have a 94 GT and if I ever decide to do anything about increasing the performance, I will install an intake and exhaust system. But I have a couple of questions about both.

Intake: Are there intakes available to buy where I will not have to move anything in the engine to install it? And I see this term "forced induction," it that a type of Cold Air Intake or it that term related to a turbocharger? If anyone could give suggest a company to get it from (I was thinking K&N but it didn't seem they had any for my year celica). Or would it be better to get a SRI?

Exhaust: Say I was to get a cat-back exhaust system, what size should I get? Also, if i got a BIGGER exhaust, would it be a good idea to increase the size of the downpipe to that same size (if thats even possible) or should i just leave it alone?

Sorry for all the questions, but I am trying to learn as much as I can. Oh... and please don't give me any crap about how little horsepower i'll get. I'm doing it for the experience of working on my car. I was considering about using that honda accord intake but not sure whether I should try to mess with that.

This post has been edited by MyFirstCar: Apr 30, 2008 - 12:25 AM

[bccentaur3]

Forced Induction is when you force air into your motor for example turbo charger or supercharger.

When installing any kind of after market intake you WILL have to remove your factory intake set-up. Such as the air box and the tube going to the air box. Now theres a resonator box behind your front bumper in your fender well. You will not have to remove that, unless you want a factory look for your CAI set-up.

I suggest the CAI (cold air intake) because you are getting much colder air then having a sir ( short ram intake) because the sri will do the same thing as the factory set-up but will sound louder and cooler.

Now about the exhaust. If you truely want performance go from the primary cat all the way back with 2.5" piping and a tasteful sounding muffler. And if you are serious about making NA gains, get an after market header. Most people get this from ebay and I think it will eliminate the primary cat. I'm not sure about this because I decided not to mess with the whole NA power and went FI right away.

And if you are in it to learn, get the ebay accord intake and make your own CAI. Then go out and get a K&N cone filter.

[MyFirstCar]

Thanks. If i get one I think I'll go with the SRI or something with shorter piping because I use this car for everything and drive it through all weather and I don't want the CAI catching any water, mud or snow.

What does NA and FI stand for?

[MercuryFree]

What does NA and FI stand for?

Natural Asipiration and Forced Induction

[njccmd2002]

the Cai from accord and regarding the weather there are ways you can prevent hydrolock. a bypass valve.

i just got it in the mail and i will play with it.

[DEATH]

Myfirstcar - Sounds like you got the right idea. You seem to have researched these two things pretty well and you have weighed the options vs practicality and that's good. Now get the Accord CAI like the one above and get started. You can make an SRI/CAI where during the summer months you will use the whole thing and during the wet/winter months you will remove part of it and install the filter in the SRI fashion. You will just need to make an additional cut and get another coupler from Autozone w/e. Truthfully there is almost no gain from a CAI other than it looks cool [above an SRI that is - you will get some gain over stock intake - how much that is? Who knows but you will def feel an increase in throttle response and on the butt dyno so do it]. Notice almost none of the Turbo guys have CAI yet we all have 3x the piping a CAI does - that should tell you something.
As for DIY or premade - I say do it yourself. Get the one njccmd2002 showed you. It's cheap and there is a very detailed how-to on this site that will walk you through it. If you can use basic tools and a hacksaw [or are wlling to learn] you can do this.
For exhaust - a 2.25-2.5" diameter catback will do you fine. This should be the next mod to do after intake. Then I'd get a full NGK setup: Spark Plugs [at least platinum], Plug Wires, and OEM Cap and Rotor. Then, if you live in a state with no emisions testing, get yourself the ebay header and a Magnaflow Catalytic converter and get them installed.
This setup will make the car very fun to drive.

[MyFirstCar]

Why would the ebay header and Magnaflow cat not pass emissions?

[bccentaur3]

Probably because the ebay header eliminates the primary cat.

[njccmd2002]

now that we are talking exhaust.

say i lived in a state where they do check. What its the best combination.

My exhaust has the primaru cat, a secondary cat and the muffler. Its 97 + federal.

whats th best combination?

[bccentaur3]

See, I don't know. I live in MN where there is no such thing as emissions. I was running a gutted dp with no cat straight pipe to the muffler on my turbo set-up.

[njccmd2002]

oh man

so anyone who takes of the manifold for a ebay header, is running catless. But some celis have a second cat, would that be ok.

[99Celica]

depends where you live. Some states require both cats, (CA) some require none.

[DEATH]

I still passed here in Houston but they let you get away with 2 strikes on your test [3 strikes your out ]
It's gonna largely depend on the laws where you live. I'd check a local tuner site.
BTW - you can always install two carb legal high flow cats like Mgnaflow makes. Just make sure you position your two o2 sensors in the same place relative to the cats as they were stock. That should work just fine.

This post has been edited by DEATH: Apr 30, 2008 - 3:10 PM

[njccmd2002]

Myfirstcar, i feel bad for jacking your thread, but im in worst scenario, My exhaust system is not getting any youger and i think i have leaks.

Ill check that thing about magnaflow, but i also dont want to loose power.

I know the cat back system is pretty much all the piping after the 2nd catalytic plus the muffler, right?

some people recommend 2.5 piping, right? any ideas why we should not buy used catbacks.

so for a exhaust setup w/ no turbo, regular 5sfe: can have a ebay type header, 2 magnaflow high cats and then somthing like tanabe or greddy, keeping the relative location of the sensors. Will this trigger a OBDII code. That is pretty much waht they will check on me.

I live in Georgia. Took me hours to find the requirements. BTW for all those georgians

All 1996 and newer vehicles will receive a two-part inspection.
An OBD test to check your vehicle’s emission control performance history.
A fuel cap inspection to check for adequate seal.
If an OBD test is unable to be performed on a vehicle, it may be necessary to perform a Two-Speed Idle test (TSI).

All 1995 and older model year vehicles will receive a four-part inspection:
A visual inspection of the catalytic converter to check for tampering or removal.
ASM2 or Accelerated Simulation Mode Test - A dual-mode test including a 25/25 test = 25 percent load at 25 MPH and a 50/15 test = 50 percent load at 15 MPH.
A tailpipe exhaust emission test.
A fuel cap inspection to check for adequate seal.
An inspector can reject a vehicle for testing if it is considered unsafe to test. If the test has already begun when the safety problem is detected, the inspector may charge the full price of the test.

[DEATH]

so for a exhaust setup w/ no turbo, regular 5sfe: can have a ebay type header, 2 magnaflow high cats and then somthing like tanabe or greddy, keeping the relative location of the sensors. Will this trigger a OBDII code. That is pretty much waht they will check on me.

I never once popped a code in over 2.5 years with my header. Whether or not you will - IDK?

[MyFirstCar]

Sorry if this sounds stupid, but If you took out the cat on my 94 GT, it would lose back pressure and therefore would cause me to loose power instead of gain power, right? And isn't the point of putting headers is to get rid of back pressure, so again, you'd be losing power? And then the same thing goes for the high flow cat. All will cause you to lose power. Please correct me if I am wrong, I don't know too much about this stuff .

and since where I live i must have a catalytic converter, the best option for me would be to have the headers and high-flow magnaflow cat, or could i keep the original cat and still have increased power?

This post has been edited by MyFirstCar: May 1, 2008 - 12:27 AM

[CelicaST_CALI]

Back pressure is key for non turboed cars,you would lose a lot of power if u were to take both cats out,i think u could get away with the magna and stock cat.

[nightryder]

oh man

so anyone who takes of the manifold for a ebay header, is running catless. But some celis have a second cat, would that be ok.

well ya know, on our cars this is a very easy job....

one might be able to get the car inspected with the stock manifold then go home and have the header in a half hour later...

just saying

[njccmd2002]

do you guys think this will fit my celi. Its tanabe

came from a st204, i know its used and it has some dents...

[DEATH]

nvm

This post has been edited by DEATH: May 2, 2008 - 1:32 PM