Toyota designed the airbox on your Celica the way it was for a reason. Of course you're going to get problems in the long run by running an aftermarket Intake
. Air/fuel mixtures have already been optimised for the design of the engine. Yes you can increase horsepower ever so slightly with a larger Intake
system but you can guarantee the lifetime of the engine will suffer as a consequence. Thats why in the UK, such changes aren't allowed under the manufacturers warranty. Even changing the exhaust can be a problem, particuarly on the GTS. Its a complicated design that has been optimised for the cars performance, hence the reason why Veilside can only offer a suitable back box.
Sorry to put a damper on things but engine mods DO jeopardise the longevity of your engine
Okay T-Sport. I understand how the laws in our respective countries work, but seriously, you've obviously never wrenched on a car before. If so, you'd realise that none of the technical stuff above is in the least bit true.
A larger Intake
allows the engine to inhale freely, and exhaust bits, like headers and axle-back sections allow it to exhale freely.
The engine is essentially a big pump, it sucks in air and fuel, and exhales exhaust gasses. Letting the motor "Breathe" actually takes stress off the engine, believe it or not All engines will gain longevity by adding an aftermarket exhaust/intake setup
This is not to suggest that a perticular method of tuning is legal or not, or that it can't have complications, but the truth is, if you perform engine upgrades properly, they can become more reliable than their stock bretheren.
True, you can run a little lean, this can be fixxed by upping your octane level or tuning the fuel and ignition. not enough exhaust backpressure pressure to keep the exhaust valves sealed properly from that header? Just add a set of heavy duty valve springs.
What breaks down a car is poor tuning and a lead foot! the fact is, most tuners build up their car and just pound on it, this delivers the misconception that tuned engines burn out quicker, which in fact is because the engine fails from excessive abuse of the engine and drivetrain. My last car had about 120K miles on the odometer, never had any major problems (Save for a belt tensioner and a EGR valve, regular maintainance bits) and it was tuned up the arse! Ran better the day I sold it than the day i bought it. the new owner still drives it to this day, and has never had a complaint about it.
Long story short, proper tuning and use will make your engine happy!
treat it like a lady, not a Ho! It'll last a lifetime.