Engine Sawp 3ac to 4ac

dug320 · Post by **dug320** » Fri Oct 08, 2004 1:43 am

I would not say it is a boost of power, such as when the turbo kicks in, it is more power. There are a number of sitiuations that USED to require down shifting into fourth and sometimes third; not anymore.

After driving for over 600,000 Km on two 85's this is a huge improvement.

Why stop at turbo; supercharge!

Cheers

takza · Post by **takza** » Fri Oct 08, 2004 5:57 am

These are the Toyota engines with 1452 displacement:

3A SOHC 2 88 1452 62@4800 76@2800 3.05 3.03 9:1

3A-C SOHC 2 79 1452 62@4800 75@2800 3.05 3.03 9:1

3A-U SOHC 2 82 1452 80@5600 87@3600 77.5 77 9:1

3A-U SOHC 2 85 1452 83@5600 87@3600 77.5 77 9:1

3A-U SOHC 2 86 1452* 85@5600 87@2400 77.5 77 9.3:1

3A-U SOHC 2 86 1452 71@5600 83@2400 77.5 77 9.3:1
EU
3A-U SOHC 2 86 1452 63@5600 76@2400 77.5 77 9.3:1 US

3A-LU SOHC 2 86 1452* 83@5600 87@3600 77.5 77 9.3:1

3A-SU SOHC 2 85-88 1452 77.5 77

3A-SU SOHC 2 86 1452 90@6000 89@4000 77.5 77 9.3:1

I think maybe the 3AC engine has been detuned to allow it to meet emissions requirements?

Or the 3A-C was tuned for best power at lower RPMs?

My guess is that I'm getting + 75 HP by advancing the ignition and using heated fuel.

What is the difference between the first (3) 3A-U engines listed and the 3A-C???

tercel4wdrules · Post by **tercel4wdrules** » Fri Oct 08, 2004 2:12 pm

I would really like a turbo charger. Maybe it will increase horsepower by 45-50? I don't know I'm just guessing but I'm looking at that sort of stuff. Hey Nick, can you tell me we're I can find information or prices on turbos for 4A-C's? A 650 cfm Holley carburetor should improve things quite a bit as well as the hefty $1180 price and the manifold adaptor will be another problem.

GTSSportCoupe · Post by **GTSSportCoupe** » Fri Oct 08, 2004 5:54 pm

tercel4wdrules wrote: I would really like a turbo charger. Maybe it will increase horsepower by 45-50? Hey Nick, can you tell me we're I can find information or prices on turbos for 4A-C's?

OK, this is a very complex question.

First off, turboing a 4AC is possible, but would be fairly tough (because of the carburator design), and would drastically shorten the life of the engine as it is not designed for forced induction. (Unless of course you installed forged low compression pistons, custom rods, custom crank etc. = big money). Second, turbos (unless they are really small ones) spool up higher up in the rpms, meaning that your car would not have good power for 4wding at low rpms. Third problem is the torque generated by a successfully built turbo 4AC would probably be fairly hard on the drive train (depending on how hard you drove it).

Not to say it cannot be done. It would just take a huge amount of work, require someone with a lot of knowledge and skill in this area, and potentially take a lot of money. I would say that for a tercel 4wd it really would not be worth it, and there are better options out there.

If you really did want lots of power from forced induction, the easiest way to go would be to install a 4agze from an MR2. This would provide the car with tons of power, and good low end torque for 4wding. Again though, the drive train probably would not last too long.

Many people in the AW11/AE86/AE92 world do turbo their engines however. What they most often do is buy a 4agze and sell off all the supercharger components, and install turbo components. There are many aftermarket goodies available for this engine because of it's racing history and popularity. An aftermarket ECU, turbo header, turbo, etc can be purchased fairly easily. The 4agze is a bullet proof engine, and unless the ECU is malfunctioning or incorrectly programmed (a/f ratios), will last a long time on a turbo. 200hp is easy to reach (10psi), and some have gone to 350hp and beyond.

So if you really did want a turbo in you tercel, you could use a 4agze base and run a low boost quick spooling turbo (so as not to produce too much power, but still give you the torque you want in the low-mid range).

tercel4wdrules · Post by **tercel4wdrules** » Sat Oct 09, 2004 10:22 pm

OOps. I didn't know this was such as complex question. I really like the 4A-GZE, just the number/letter designation makes it sound mean. Wow, I didn't know that turbo stuff was so complex, but thanks to you now I now know more. It really does sound like turbo is not worth it on a 4A-C. That reminds me, I was looking on kp61.net, a website for Starlets and then I visited a member's webpage and he had successfully turboed the 4K-C engine from a turbo from another car I believe. Wouldn't the 20 V 4A-GE also be a good candidate for turboing? Then I remember that the Tercel has a fragile drivetrain.

tercel4wdrules · Post by **tercel4wdrules** » Sat Oct 09, 2004 10:40 pm

takza wrote: My guess is that I'm getting + 75 HP by advancing the ignition and using heated fuel.

You should put your Tercel on a dynamometer and see if you do get 75 HP, don't you think Takza?

takza · Post by **takza** » Sun Oct 10, 2004 3:56 am

I can just hear the snickering now...he...he...he....here comes that guy with the Tercel....... :rolleyes:

I've developed my own cheapo dynometer that measures power output....30 to 55 MPH in 5th gear. I think it is pretty accurate....IF runs are made under the same environmental condtions and the timing is done carefully.

I gained about 20% in power when changing the timing from OEM specs....62 HP + 20% = 74 HP. I also gain some from heated fuel.

Problem is that I was using Bosch plugs and had pinging below 1700 RPM under full throttle...have since moved to NGK plugs which reduce pinging, but still don't allow a "full" advance without some pinging. I am now into avoiding almost all pinging where possible.

GTSSportCoupe · Post by **GTSSportCoupe** » Sun Oct 10, 2004 9:04 am

takza: What octane fuel do you use? I had my timing quite advanced at one point, which did really improve the power. I did find that the only way to stop the pinging was to use 94 octane fuel. I did this for a while and then decided that it was not worth the money for the extra power. So now I just have the timing advanced a bit and use 91 octane instead. Still a decent improvement over stock power. Pinging is (as I'm sure you know) really hard on an engine internally.

tercel4wdrules: I know a fellow who did manage to turbo a 4k-c. It was a lot of work for him, and actually ended up being fairly expensive. I ran good for a while and had decent power. Really hard on the engine though.

A 20V 4age is actually an awesome candidate for turboing, but it is best done using lower compression pistons. The nice thing about the late 4age's is they have a knock sensor connected to the ecu. This can be used to detect pinging. The ecu will take measure (such as retarding timing/ enriching fuel mixture) to prevent engine damage. This is one of the reasons that using an EFI engine to turbo is the best option. The first generation 20V has the same crank/rods/block as the last generation 4agze. Both of these engines came in the AE101 in Japan. All that has to be done internally is install low compression pistons. If you are really careful, you can run low boost (7psi) on the stock high compression pistons. The reason that 20Vs are such a good candidate for turboing is the high flow capabilites of the heads. People with as little as 7psi boost on a stock 20V are reporting around 220hp to the wheels!! (multiply this by 1.15 to get how much hp at the crank).

I hope to buy another AE86 or AW11 and build a 20V turbo for it. Or I'm going to buy an N/A SW20 (last body style MR2), and install a 3rd revision 3SGTE from an imported rear clip. This would make it into a very capable MR2 turbo for a very low cost (better than the best stock MR2 available in North America for half the price).

Thereminator · Post by **Thereminator** » Sun Oct 10, 2004 2:06 pm

Takza,are you @ 13%?Im @ 11%-NGK-87oct-and I get very minimal pinging,lugging~uphill B) .

tercel4wdrules · Post by **tercel4wdrules** » Sun Oct 10, 2004 10:13 pm

GTSSportCoupe: Didn't you have an AE-86 Corolla that you put a 4A-GZE? Do you about how much did the turbo run for the 4K-C fellow? I've also heard about the 4E-FTE being a very good turbo engine with 130 horsepower, the strongest 'E' series engine as many people know how terrible the Tercel 3E and 3E-E engines are. 20vTercel said that the 3S-GTE would fit the Tercel as well as the Tundra quad-cam V8. Or maybe convert it to a Chevota? No, I don't think so.

takza · Post by **takza** » Mon Oct 11, 2004 5:45 am

I'm probably set at around 14-15 BTDC, but when temps are warm...it will still ping.

The pinging I hear with the Tercel engine is more like a "ticking" sound...very distinct. Doesn't sound too bad...but I'm SURE it doesn't do the engine any good.

Probably will leave it that way till spring...then set it back to where I don't get much pinging and the leave it there all year. Probably around 10-12 BTDC.

I time it by ear...occasionally I put the timing light on it to see where it actually is.

I use 87 octane.

Have heard that using a higher octane when not needed causes carbon buildup.

Also supposed to get better mileage with lower octane.