Transmission Upgrade 01 Corolla

Unfortunately in this particular case, have to swap.

In theory, you could keep the same "case" just swap the parts, but the way the parts are installed in a transaxle, it must come apart to exchange those parts. Be faster and less expensive to swap in a 4-speed and associated PCM, wiring.

If you are talking about the 6-speed manual from the 2ZZ-GE powered cars, then yes - that will physically fit the 1ZZ-FE. You'll have to snag the ECM from the donor car, as the PCM for the automatic transaxle will not have any idea of what is going on.

The new automatic 6-speeds, completely different story - will not mate up to the 1ZZ-FE. Even if you got an adapter plate to allow it ot bolt up, you'd have to to get all custom axles + deal with the electronic nightmare of rewiring it, if it is even possible.

If you are sticking with the automatic - then the 4-speed A245E transaxle is the only real option for an 8th gen Corolla.

The amount of power gains from cams shouldn't overwhelm the transaxle. Still a good idea, even if the engine is bone stock, to add some auxillary cooling to any automatic transaxle. Even lowering the temperature a couple of degrees can easily extend the working life of the fluid and transaxle. Rough estimate, if you drop the temperature by 25 degrees, you automatically double the life of the transmission fluid and the transaxle.

Different throttlebody, exhaust, CAI to cool transaxle???? Nope, never heard of that - can't see how that will help at all with transaxle temperatures. But in terms of helping get the most out of the cams, then yes - improving induction and exhaust can definitely help - but only if you can tune for it. The stock tune should be conservative enough where you won't lean out, but it has a fairly narrow operating range - so it might not be able to account for the extra flow.

Exhaust header from the Celica GTS will not fit, will hit the firewall. The muffler might fit, but might need too much work, as it turns 90 degrees after the rear axle (acts as a diffuser on the rear of the car) - the Corolla is basically straight after the rear axle. Throttlebody, and especially the intake manifold is different - the 2ZZ-GE bolt pattern is close, but not a direct first. There are some that were able to bolt it up (either redrilling holes or just installing with holes that line up. Flanges didn't line up and some had clearance issues with the radiator fans. Throttle body is bigger, but doesn't match the stock 1ZZ-FE intake manifold. Might be loosing power there, as the air stream will be too turbulent.

Better option is to find the OEM composite intake from a 9th gen Corolla 1ZZ-FE. Those match the bolt pattern on the head, no clearance issues, plus considered a pretty cheap part (lots of 9th gen Corolla around). Plus its short runner design is similar to the 2ZZ-GE manifold - naturally favors higher RPM breathing which tends to align with more aggressive camshafts.

Crower stage 1 cams car not that much different that stock. Designed for low end to mid power, no need to update the valve springs, doesn't mess up your idle. Pushes the peak of the powerband to the right, so now power runs all the way to the rev cutoff instead of dying hundreds of RPM before the cutoff. Nice thing about that, is that you can get away with basically zero tuning, literally drop in and go.

The stage 2 cams are a little more aggressive, idle will be messed up and they highly recommend new valve springs (heavier to avoid floating), a their powerband favors the higher RPMs and is push much higher than the stage 1 cams. They make two different sets, one for forced induction - the other is for naturally aspirated engines. Both work best with tuning, the OEM ECM will be confused if you run these cams.

You haven't mentioned any tuning or your plans for tuning (any way you look at it, this will likely be the most costly single "part" of your mod). Assuming that you'll try it on the stock ECM at first - the stage 1 cams will be a better choice compared to the stage 2.

As for performance, the Stage 1 cams will out run the stock cams, as they are profiled and setup to make power in the same way - off idle to mid-band. Where the cam shines is the upper revs before the car shifts - the stock cam drops on power, while the stage 1 is still climbing.

Now with an automatic - you will not be able to take advantage of the high RPM power sell, as it will short shift every time. Even manually shifting, you'll likely hit the limiter before you can cleanly shift (that lag when you move the shifter lever and the transaxle responds) and end up running slower. Still, all other things begin equal - if launched and shifted the same way - the stage 1 cams will out perform the stock cams.

If tuning and internal mods comes into the picture - then the higher staged cams will, by design, start to build more power. Idle will be different, sounds rough or lumpy, you'll loose the lower end powerband, but make up a lot more at the top end. Since the engine doesn't have a whole lot of displacement - the powerband will tend to be strongly peaked at the upper revs. What you have to deal with here is your automatic transaxle, as it will now bottle neck the performance gains of these cams (need to modify the stall speed on the torque converter, possible update the line pressures inside the valvebody, change shift strategy, etc.) Fortunately, Monkeywrenchracing does sell the updated transaxle valve bodies on their site.

They'll call them performance valve bodies. http://www.monkeywrenchracing.com/product_info.php?cPath=25_136&products_id=1983

Run something like $600-$700 for a valve body + core charges. Basically its that block of metal with oil passages, solenoids, springs, and check balls that control the flow of fluid to the appropriate clutch packs inside the transaxle to allow gear changes. You'll probably have to contact them, as the link only points to the U341E transaxle. If you have a 4-speed 8th gen automatic - you'll need one for a A245E transaxle.

Sounds steep, but probably the best bang for the money on an automatic transmission - if you need to get more control over shifting. Otherwise, you'd have to turn your entire transaxle to LevelTen or similar shop for a couple of months, while they rebuild all the guts inside for a couple of thousand.

They also carry higher stall speed torque converters as well. http://www.monkeywrenchracing.com/product_info.php?cPath=25_111&products_id=1036

Usual recipe to beef up an automatic: higher stall torque converter + revised valvebody + auxillary fluid cooler with good fluid. That will get you about 80-85% of the max capabilities of the transaxle. Clutch packs/friction bands - don't need those unless the existing ones are beat up and worn, or you plan on running crazy amounts of power.

Crankshaft on the 1ZZ-FE is pretty decent - the guys running stroker kits on their forced induction 2ZZ-GE actually use the crank from the 1ZZ-FE. Ours are already stress-relieved (shot peened) at the factory.

As for transaxles - any manual one that will mate up to the 1ZZ-FE will make it feel "more lively". If anything, it will be the almost automatic 75-100lbs weight savings to jump between the automatic vs the standard shift transaxle.

The 6-speed should be a good match up for the 1ZZ-FE. The powerband is a little on the low side to take advantage of the shorter gear spacing, but many have reported that was a non-issue. This sort of swap will be WAY cheaper/easier than trying to get a 6-speed auto from a different Toyota platform to fit the 1ZZ-FE.

^^^ That's one way to do it!

Keep one as a daily driver, the other as your project / fun car.

For some, that can be the same car - but once you start blowing up parts - trying to get replacement parts/get to work on time without having a spare vehicle on hand gets old, really fast.

As long as the Celica GT-S hasn't been beat on - should be fine. The 2ZZ-GE were not known to be oil consumers - but if they weren't taken care of, they did have a reputation of grenading their oil pumps.

As for Scion tC vs Toyota Celica GT-S, depends on what generation tC and what you ultimately want from the car.

If it is the first gen tC (2004-2010) with the 2.4L 2AZ-FE engine - then it might actually consume more oil than your 8th gen Corolla's 1ZZ-FE. Those 2.4L engines were common on many Toyota platforms, and most have oil consumption issues. I have one in my 2009 Matrix XRS - started consuming oil at around 41K miles, but I've kept it in check with close oil monitoring.

If it was the 2nd generation 2.5L 2AZ-FE - then you should be fine (knock on wood). This is the same engine that is in my 2009 Rav4 - no signs of oil consumption and power/fuel economy is actually surprisingly good - routinely turning 35+ MPG on long road trips, in heavy DC metro traffic, I have consistently averaged 28-30MPG.

But these engines, though torqueier, don't hold a candle to how the power flows from the 2ZZ-GE. You'll have to drive them back to back to really see the difference. Only thing I can say about the two - Scion is a larger car, which can be good or bad, depending on your requirements.

Aftermarket support - both have pretty decent support compared to other Toyotas/Scions. Suspension, bolt-on mods, overall reliability - both are pretty much even, IMO. As for overall engine power - the 2ZZ-GE responds well to both naturally aspirated and forced induction engine mods, even simple bolt-ons can help out with power. The Scion engine responds just OK to bolt-ons, some actually can hurt power - but forced induction projects can really make this engine shine.

Stock for stock - the Celica is a the more capable car of the two. But since they have a strong following, they both are good choices for a project car - from simple to extreme.