1989 Toyota MR2 SC 4AGZE

[curt705]

Hello all! Nice forum you guys got here. I'm new to the site and will be using this site to find out information on a buddy of mines car that I am going to be working on with him. As you can tell from the topic title it is a 1989 Toyota MR2 with a 4AGZE supercharged engine. He wants to do some performance work to the drive train...he says its not fast enough right now lol. Anyway, I have done some looking around on the site and have found a few threads about twin-charging....

My first question is...what is the best route to go for this engine? Should we get more boost out of the stock supercharger, go with a turbo setup, or do a twin-charge setup?

My second question is...I get the feeling that parts are hard to come by and no basic kits are made...so a lot of custom work will have to be done. What turbo exhaust manifold could be used for this vehicle and are there any other sites or companies I should be checking into specifically for these parts (manifold, piping, computer system...either stand alone, piggy back, or stock)...etc

thank you for the help!

Curt

[palos]

After making certain the engine is properly tuned, the easiest way to develop more horsepower is purchasing an oversized crank pulley kit such as the following: Twos R Us - Parts for Toyotas from Club MR2. You will need to make a small modification to the vacuum lines. Then I would consider a different cat back exhaust. The OEM muffler is large and heavy.

Instead of body kits, improve the handling of the car and its brakes.

[curt705]

Originally Posted by palos

After making certain the engine is properly tuned, the easiest way to develop more horsepower is purchasing an oversized crank pulley kit such as the following: Twos R Us - Parts for Toyotas from Club MR2. You will need to make a small modification to the vacuum lines. Then I would consider a different cat back exhaust. The OEM muffler is large and heavy.

Instead of body kits, improve the handling of the car and its brakes.

Thank you for the info..I will check into the oversized crank. I believe he already has an aftermarket exhaust. However, as I said in my original post we are looking to do performance upgrades to the engine/drivetrain right now. We will improve the handling after that. He is either wanting to do a twin charge setup or scrap the SC and go with a turbo setup...so I am trying to find information on those two options and where I can get parts to accomplish them...

[85SuperGZE]

NST (non stop tuning) sell one as well, comes with all you need for around 300 bucks................In my opinion, David Hawkins, Twos R Us, is a *****, I would never buy anything from him.
In no way am I paid/compensated by NST for this answer.

[mr2tim]

Having been a 1989 S/C owner and competition driver since I bought the car new off the showroom floor 20 years ago. I have to agree with Palos that increasing the crank pulley diameter appears to be the easiest and most cost effective way to achieve extra performance.

If you will take the time to review this Club's archive Forum discussion posts you will find much information on this topic. Go to "Home" section and poke around.

Experience seems to indicate 200-225hp should be the maximum output that the stock OEM internals can safely handle and it quite easy to achieve with the original running gear.

Of course, as in all mods the higher output from the engine the shorter lifespan of it's componenets and the engine as a whole.

With a pressurized engine expect lots of piston ring "blowby" which mandates oil changes when ever the oil turns dark indicating particulates in the oil.

Since I did much Road Racing and subseq

[mr2tim]

Since I did much Road Racing and subsequent Autocrossing I found that adding a "Zerk" fitting to the front bearing caps virtually ended the endless bearing failures and allowed me (the pit crew?) to grease front bearings as needed.

The Semi-Metallic S/C clutch is a good one as are the axles and gave me service well past 200,000 miles!! I greased rear bearings at 6 month intervals successfully.

You might be interested in knowing that 14" Goodyear Sportsman Racing Slicks will fit into the front and rear wheel wells quite easily on the OEM S/C aluminum rims.

I would advise upgrading beyond semi-metallic brake pads if you intend to run any hard competition at high speeds, the discs are quite adequate and do not require replacement.

Happy Motoring Ya'll

mr2tim
Supercharzed Toyz Race Team
Boca Raton, Fl

[Jackstand Queen]

Tim:

You mentioned Zirk fittings for the front bearings. You were talking about front wheel bearings? Right?

[mr2tim]

Yeah, after I started a 2 driver high speed race team I was going thru front bearings like freakin' crazy, I paid $110 for the new hubs and bearings then with $40 for machine shop work. Grrr.....

I dropped the suspension 3" w Suspension Technique springs and it stayed the same.

There is a bronze cap on the inside of the hub, I installed the grease fitting here. Gave it a few light pumps from the gun every other race and the problem disappeared forever.

I have no clue? It worked to solve my problem so I keep wantin' to pass it along to other Mr2 owners, especially hot foots like me (and you)

Originally Posted by Jackstand Queen

Tim:

You mentioned Zirk fittings for the front bearings. You were talking about front wheel bearings? Right?

[mustclime]

lol at a 3 inch drop.....have you ever read anything about roll centers and mcpherson strut suspensions?

[328FTW]

I've never had a problem with front hubs on my racecar, all I did was pop the cap when I got it and scooped out the factory grease and replaced it with better stuff that kills wildlife right left and centre if you dump it (normally means its good) that's a metal and carbon(graphite) mix grease and never had issues with hubs. Although my right rear is whining now but not surprising dirt got into that one one meeting when the wheel came off....don't ask I don't think I even know.

[countersteer]

thanks for the tip on the zerk fitting trick. I've had to replace mine several times due to track days etc.

[Papo J]

Curt, if your buddy wants more power he should ditch the SC and build a turbo kit. You can easily get into the 200-225whp range with a small turbo, stock electronics and maintain almost the same response as the SC. It is much simpler than trying to build and accommodate a twin charged.
Larger pulleys are nice but won't get you anywhere near what you can make with a simple turbo setup.

[mr2tim]

Actually, the springs were free. Who can say no to free race parts? I wanted a car that could race at high speeds and feel like it was on rails. I added some really big sway bars next, that was all I needed. Didn't know anything about roll centers only that I didn't want any side to side sway at 100mph so I fixed it.

This all happened maybe 15 years ago, I had no idea what struts were before I bought the car. I'm from Detroit, we didn't drive imports there.

In 20 years I've filled my house with lots of race trophies so maybe it turned out ok for me, accidentally.

Question for you though? If I'm out of suspension travel and experience no sway what does "roll centers" mean in my car?

Originally Posted by mustclime

lol at a 3 inch drop.....have you ever read anything about roll centers and mcpherson strut suspensions?