Enter your search terms Submit search form

How to upgrade your mk3

If you bought a Toyota supra mk3, and are looking to add some upgrades to make some more power, or just for fun, here’s a few things that I would recommend.

My current supra hasn’t yet been upgraded very much, but I had another one a few years ago that I did modify.

So, yes, I do have a little understanding of what you can do and what you shouldn’t.

So here are a few great tips, that I’m going to follow by the letter again myself.

 Ok, first things first. Check and replace if necessary. ALL the hoses and belts. When was your timing belt last changed? Think about it!
ALL the fluids! Radiator cap and thermostat. All of the electrical connectors and wires. Are the battery terminals clean?

What about your brakes? A car with a lot of power, but with defective or malfunctioning brakes, is simply a danger on the road! It doesn't matter how fast it runs, if it won't stop, right?

Great resource for parts: http://www.jscspeed.com/mk3/mk3_index.html?/mk3/mk3.htm

Also check front end parts, and alignment, and the radiator.

Now, first thing to do I guess is replacing the head gasket before anything else. If you don’t do this, and start upgrading immediately, you’ll be sorry afterwards.

Well, of course, you don't really need to replace the head gasket. Unless you are going for major horsepower upgrade, or if your car has a lot of miles on it.

It's a well known fact with the Supra's head gaskets, the headbolts were only torqued at 58 lbs. ,when they should’ve been 75 lbs. They tend to loosen up over time and the gasket wears out, normally in the 6^th cylinder. Toyota should have issued a recall on it like they did with many other cars.

Anyway, get ARP bolts to fix the head gasket. This should be fine with the stock HG. Unless you want to run massive boost. Then I'd get the HKS metal HG too.

Yet another resource: http://www.suprastore.com/

When you buy a used Supra mk3, and they did a messy job upgrading it, trying to get some major power without getting it back to stock condition is absolutely crazy. You could melt your block just because of a stupid mistake like a poorly functioning water pump or crappy belts. Adding power can be done as simply as by just changing your spark plugs to iridiums, and gapping them properly, seafoaming the engine, and changing ALL the fluids. The best mods don't make the power. Cars in good condition with proper modification do.

After this, I’d suggest you get some basic performance upgrades...intake, exhaust system... (Again, make sure your head gasket is ok)

Doing this, you will gain approximately 10-15hp. That’s generally the gain you can obtain, assuming that the car is in good running condition.

The car being in good running condition, meaning the exhaust system or the air intake is not restricted, and the car is well maintained.

Headers (OBX) are next.  Expect to gain at least 10hp from them! Oops… Gotta clarify one thing: headers are only used in non-tubos of course. Turbos just don’t use them.

For a naturally aspirated car you need to get a lot of air in.
This is what it basically comes down to : squeeze in a lot and get it out fast.

Also, getting new under drive pulleys is a good thing to do. For every pound you loose on the under drive pulleys you can gain about 1.5-2.5 hp.

The cams in the supra can really be left alone. Those are strong enough, in both the NA and the Turbo motors, to support high horse power.

You could also think of changing the flywheel, and the electric fan.

http://www.turboimport.com/ is also a good one to check out. I've ordered a few items from them myself. And they also ship internationally.

If the original intake or exhaust are in poor, or restrictive condition, you are losing horse power.

So intake, exhaust and ignition should be the next few things. OBX is pretty much the only, or the best way with the headers. Again, that’s for NA’s only.

K&N is often found the best choise for intake, although there are many many different brands who deliver decent air intake sets.

By ignition, we mean: good cables, changing your plugs to iridium, coil blaster and msd.

MSD stans for Multiple Spark Discharge. There are many different companies that make similar products. It’s basically like this : a high powered coil is controlled by a computer, allowing multiple sparks on several degrees for the duration of the spark cycle of each cylinder. This way, insuring complete ignition and combustion. This thus gives more power. It generally translates to better gas mileage. And you can also start your car easier.
I wouldn't recommend MSD for a turbo charged engine though. Since they have a totally different ignition system.

If you are buying a second hand Supra, you must also be aware.
Most of second hand supras have a blown head gasket, or bad piston rings. And probably about 90% has crankshaft bearing and crankshaft damaged...

Now, this I have kept for last. Because it’s certainly not my favourite.
For quick power, there’s always nitrous of course. Though I do not recommend the use of it, it’s just nice to have, for the show. But,  unless you are really going to go to the limits of your car, I would really not use it.

PS: Please note that links that leave mytoyotasupramk3.com will open in a new window. That allows you to check out the service and come back to see more in the category