Supra Forums banner

1 - 8 of 8 Posts
S

·
Guest
Joined
·
0 Posts
Discussion Starter #1 (Edited)
Hey! I just bought an 86 MK2 with a 6M motor and header pipe. What are the cheapest mods I can do to get some more power out of it? Any suggestions? It seems to run good, but isn't much faster than my 89 240sx. I really thought an inline 6 would be a bigger difference over that 2.4 12 valve. It tops out at about 125MPH. Shouldn't it be faster? It's no dog, but I just thought I'd get more out of it with the 3000 motor and headers. :confused:

BTW, aren't the 86 MK2's the rarest? They were only made for half a year, right?
 

·
2JZ Mk2
Joined
·
1,183 Posts
IIRC I think all '86s were only made in Nov/Dec of 85' after January they made MkIIIs. Nothing really special about '86s other than the 3rd brake light. As far as mods are concerned, the M series engine aren't really a major NA power maker. They seem to respond much better to forced induction. If your wanting to go that route check out here;

http://geocities.com/aarongarney/5mgte.html

If you want way more power than that the 7mgte swap will make a MkII a seriously fast car.

If you want to stick with the NA route I'd do the following..

Tune up
-Make sure everything is running absolutely perfect

Advance the timing 2-4 degrees from stock

K&N cone filter
- You can get a piece of 3" x 1.5" long or so exhuast piping and a 3" ID K&N filter and substitute this for the factory airbox

New exhaust
-probably 2.5" piping on the 6M. Magnaflow muffs with a resonator work really nice on mine.

Air intake tube
-Aaron Garney sells these (along with a K&N kit). Not a major power gain though maybe 5 rwhp gain at most
http://www.rapidchimp.com

Aluminum flywheel

After these things start to get expensive. BTW you should be run it to redline in 5th, assuming you not going up a hill or are way above see level.

Aaron I
 
S

·
Guest
Joined
·
0 Posts
Discussion Starter #4 (Edited)
Shit! Now I'm worried! It won't run in the red in 5th. That must be why I'm topping out at about 125? What could the problem be there? Is it just because I don't have an open air filter yet, possibly?
Thanks for the tips so far. I'm not a racer or anything....just want it to run as fast as I can make it. Maybe one day, when I can afford it (if ever :( ), I'll slap a turbo on it.

As for the changes to the 86, it appears the rear spoiler changed too. Not much, but the upper part doesn't stand as high.
 

·
2JZ Mk2
Joined
·
1,183 Posts
I'd try giving it a good tune up and just making sure everything is adjusted/working correctly. It's surprising what a difference it can make, especially if its been poorly maintained by the previous owner. Remember these cars are getting old, so they've been around the block a few times.
One word of caution about the MkII is that it's a good idea not to peg the speedo a bunch of times. The cluster has a speed sensor built in that been known to fail if you do peg it a lot. This will cause the cruise control not to work. Spoiler should be the same, the only difference is the 3rd brake light. Which is no longer available new so don't break it :( .

Aaron I
 
S

·
Guest
Joined
·
0 Posts
Discussion Starter #6 (Edited)
What it seems to be doing is, at about 5500rpm the power seems to flatten and it takes it forever to redline. Any idea what this could be? It seems to lose it's punch after 5500. :(
The engine has had a pretty good tuneup, since it was just installed. It was supposed to have less than 40K on it, but you know how that goes. Dude probably lied.
All seals and ignition have been replaced. I can't seem to adjust the timing much without it running worse. When I checked it, it's above the scale. I tried lowering it, but it just runs badly then. Damnit!
Is there any difference between the 5M and 6M throttle body? Because it appears that this is a 5M TB. It has some extra vacuum ports that are plugged.
Another thing, it's been sitting since '96, so I'm thinking the fuel lines might be slightly gunked up. I'm running some cleaner through it now.
 

·
2JZ Mk2
Joined
·
1,183 Posts
5 & 6m motors make most of their peak power close to 6000 rpm, so what you're feeling is probably correct. Although you should be able to bounce off the 6800 rpm or so rev limiter in the lower gears if you try. For a Toyota dyno chart check out this link;

http://www.geocities.com/MotorCity/Pit/9975/enginepix/powercurves/6M-GEU.gif

The throttle body on the 6m is a little different than the US spec 5m unit. The 6m one has less vacuum line provisions on it. Check here for a photo of it (4th one down);

http://home.swbell.net/pdupler/silver.htm

BTW, on the timing are you shorting out the check connector when checking the timing? It sound to me a litttle like you might have a slightly clogged fuel filter or a weak ignition part. You might also take a look at the spark plugs. 5/6m's like the factory Denso or NGK platinums. My MkII when I bought it had cheap Autolites and ran like crap. The fuel filters about a $30 Toyota part. It can be a bear to change your 1st time or two. It's located behind the drivers side engine mount. Easiest way to change it to jack up the car and slide in behide the wheel on the drivers side.

Aaron I
 
S

·
Guest
Joined
·
0 Posts
Discussion Starter #8 (Edited)
Yeah, I don't think they changed the filter when they put the 6M in. Might be a good idea. I haven't checked yet, but supposedly he put Nippen Platinums in it. I probably need to make sure they're the right plugs too.
But is the TB the same other than the extra vacuum nipples? I'm wondering if that's hurting me any.
Any idea where I can get a 6M ECU? I noticed the 5M's are cheap($50). If 6M's are that cheap, I might as well get one and solve that check engine light thing.
Also, what were you talking about in that other thread about playing with the AFM for the check engine light issue?

Oh yeah...the timing. I ordered a Toyota factory manual, but haven't gotten it yet. I think I shorted the right connector, but it didn't seem to make a difference one way or the other. How much diff should I notice on the scale with it shorted?
 
1 - 8 of 8 Posts
Top