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Upgrade outline, ideas & suggestions

42K views 64 replies 32 participants last post by  1982 Dragon 
#1 · (Edited)
Since there seems to be quite a growth of MKI interest lately - I've been wanting to put a list of performance ideas together for everyone... Hopefully you'll find some of this useful:

As many of you know from my turbo MKI or w/ your own - the suspension is one of the biggest problems. For shocks, I think Tokicos are certainly the way to go. If you are looking for more of a selection - Camaro rear shocks are a direct fit, so that opens alot of options. For the fronts - I am pretty certain that I used MKII strut cartriges (in the MKI assembiles) way back when I first got my PP MKI - they are slightly different but do fit so that offers a few more choices. For springs, there are several choices depending on how you want to go about it. If you search for parts that are for the '81 and earlier celicas, you'll find that Dobison and possibly Whiteline still carry springs. Aside from that, Ground Control makes a coil over kit for the earlier celicas, but the other kits available for the MKII could work as well. Not sure how much stiffer or lower (if any) the PP (performance package) springs are - I never thought to compare them back in the day and now I dont even know which ones are what I pulled out of my PP MKI... MKII springs wont fit on the back and the front springs have an overall larger diameter but can fit - I've done it (my white MKI has Suspension Tech springs for a MKII upfront), but you need to use the MKII spring cap and I ended up cutting the spring slightly to get it to all sit right. Also, I have figured out a few ways to get the entire MKII strut assemblies on the MKI (that is what my black PP '81 has on it since the late '90s; I used tokico struts w/ K-Mac springs). It takes a bit of work and has some minor side effects, but the results are huge...
For rear springs, numerous other springs can work - in my PP MKI, I'm using MKIVtt rear springs; for the turbo MKI, I'm using '93 Mustang Cobra springs - both were cut slightly to get the ride height I wanted.
After that, the bushings seriously need attention - Energy Suspension makes everything needed, as does SuperPro. Swaybars are another real weak point - the difference from driving my '81 PP MKI to any of my other MKI's back to back is absolutely unreal (even from back when it was stock). Getting the PP bars is ideal. Even though the front bars are laid out basically the same as the MKII, the MKI is narrower so no luck there. Its been a while, but I think its Whiteline who carries upgraded bars for the MA4X.
After addressing all these issues, the wheel hop problems will be improved but you're going to see how the rear suspension geometry is all wrong and going to need to start getting creative. For the turbo MKI, I made new beefier control arms that also changed the pinion angle which really helped. T3 makes a complete set of adjustable rear control arms but they are expensive. They also have an adjustable panard bar as well (as does Whiteline if I remember correctly). I think its Whiteline as well who carries a front strut tower brace, but I just modified one to fit (I believe it was from an accord).
In general, there are many things that are available (or will work) for our MKI's, but much of it is just listed for the '81 and earlier celicas (as well as some parts for the solid axle '82-'85s).

Now the brakes - there isnt alot you can do w/ a small non-vented rotor, but.... On my turbo MKI, I used solid Brembo rotors - I would certainly stay away from cross drilled - they will hurt more than they help. A slotted rotor would work but for the price, you'd be better off just going w/ a high quality solid rotor. Brembos are the best available period, but they can be hard to get - often back ordered and listed oddly (be careful not to get the ones for the same generation celica as they are different). I've used Bradi's before and they are just as good (made in italy as well), slightly cheaper and were easier to get. I use Metal Master pads - I think they are the best available for the money and performance. I also had S/S lines made up front and back. You can use the MKII or MKIII brake masters as well. W/ all that, it will be a huge difference from the original stuff but still have its limitations. On my PP MKI, I have the MKII strut assemblies w/ the MKII brakes - w/ solid brembos and metal masters, it is my best braking Supra I own period! Its unreal how much difference it made.

As for more power - there is plenty to do w/ the 5M-E... I cant remember all the details of what all I have done to my PP MKI but I'll try. Using an '82 MKII AFM is a 'direct' swap - and then use a cone filter. I'd get rid of the intake silencer as well - I made a 3" 1 piece intake tube for my PP MKI (similar to the ones for the MKII). All of this made a huge difference. After that, the exhaust is a huge restriction - mainly those damn converters! I made a 2.25" mandrel bent exhaust from the manifold back to a Dynomax SuperTurbo muffler. For a header, there is one that is said to be a direct fit for the MKI from a company called Paeco but they are pricey ($400+). One for a 5M-GE could possibly be made to work - the bolt pattern of the exhaust manifold is exactly opposite of the 5M/6M/7M-GE's, the actual exhaust ports line up perfectly; the mounting flange could just be flipped over. The one thing I havent confirmed and am uncertain about is if there would be any clearance issues down by the steering linkage. I also can not say how this would effect the powerband as the headers for the 5M-GE are designed for a higher reving twincam motor... To upgrade the ignition, the '84+ coil and igniter set up can be made to work and would be worthwhile upgrade. I run NGK V-power coppers gapped between .040-.045. I made up some 8.5mm wires from Crane. W/ these mods and if your motor is in good condition, you can run the timing between 13-15 degrees (w/ premium of course), just make sure that the vac advance is working...
One thing I have yet to do but have half assed test fitted is use a 5M-GE throttle body. There is a huge difference in size (the one on the MKI is shaped like an hour glass w/ a butterfly about the size of a 50 cent piece - if that!). It has the same 4 bolt pattern and will work w/ out too much trouble....
I suggest using a 180 thermo as the single cam motors seem to run pretty hot... Both of my MKI's have MKIII rads in them but to be honest - the MKI, MKII and MKIII all have the same size core so its of little advantage. I use the 7M-GTE clutch fan set up on my PP MKI which helps...

A few random tidbits - the '82 MKII ECU works w/ the MKI (I cant confirm for the '79), but I'm certain it works w/ out issue in both the '80 and '81 - though I noticed no real gain using it. Also - the external MKII fuel pump will fit and work w/ the MKI - just have to extend the wires. W/ a little work - MKII P-type seats fit pretty nice in the MKI. The one bolt hole needs to be enlarged and the lower seat section needs to be narrowed slightly (just bent by hand).
I use W-58 tranny's as they are about 50lbs lighter and shift better than the original W-50 trans. The gearing is slightly different but its not drastic... The MKI clutch set up is much smaller than the 5M/7M-GE ones. You can upgrade to the later set up, you just need to use the matching flywheel. I didnt realize this at the time, so I just ended up using a MKI CenterForce DualFriction in my PP MKI - the only good thing about it is that the MKI flywheel is several pounds lighter...
The MKII LSD section is a direct swap into the MKI rear. It will work fine for a mildly mod'd car, but I blew up several of them w/ the 7M-GTE - though I account most of that from the terrible wheel hop and that I was just using random used units that I had. Many of us learned relatively recently that some of the Canadian MKI's have factory LSDs and would be good if you can get one - though it is a weaker set up/ older design than the MKII LSD so no idea how much it could handle. For anyone wanting to go beyond that, the trutrac, powerbrute, lockers, etc... will fit as well.

W/ much of what is listed above, my PP MKI has run 15.3 @ 93 mph w/ crappy 2.3 60' times. It has about 207K original miles on it now but back a few years ago it put out 145HP and 173 ftlbs of torque.
For more power beyond all of this, 5M-GE or 6M-GE swaps are actually pretty easy and are really impressive in the MKI. Getting the 7M physically in the MKI is just as easy, though its a little more involved to get it all to work. The real challenge is actually getting the rest of the car to handle the power.

Please take these suggestions for what they are worth; simply ramblings of my experiences. I did some of these upgrades 5-10 years ago on my '81 PP. I did the 5M-GE motor swap to my '80 back in '01 or so and then did the 7M-GTE swap to my white '81 shortly after - so I'm doing the best I can w/ the memory I got :duh:
 
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#60 ·
Good info! Be sure to check out the Ground control coilover and KYB AGX group buys I have going on - just what the doctor ordered!
 
#61 ·
oh man, this thread has me all sorts of excited. there was not any of this info available back in '90 when i got my first '79 supra. the only thing i could find for it then was the headers hooker made.

now i can't wait to pick up my new mk1 and start playing.
 
#62 ·
Hmmm...I just bought a running Mk1 up here in Alberta, Canada....1980 - 5 speed - not bad for rust and drives pretty good at moment

- looking for parts, advice, ideas....this has been a very cool thread...but i get the feeling that the time may have come and gone for working on the Mk1's....I note that no one has added to the thread for 2 years thereabouts.....

you tell me....are the upgrade parts now unobtanium?....has everyone moved on to newer cars?...are the Mk2's even getting too old to be practical?

I'm wondering on prospects of low cost upgrades to my 1980 Mk1 (4M motor probably)....with idea of having a reliable "survivor car" that has the ability to cruise somewhere beyond the legal limits and show tailights to fancy new cars...yet not spend a bunch of money on it...

I don't expect a lot without doing a motor transplant and not sure I want to do that quite yet..and I don;t expect that much out of the old car....just want it to run well for starters, and anything after that is bonus

It may be more reasonable to just be content with a decent running stock car....and savor the coolness of age, rather than the rush of speed and power. Is keeping it stock and driving it even a reasonable possiblitity these days?

Cheers...
 
#63 ·
Ive owned many toyota's, never a mk1 or mk2 supra's. I have had however 3 mk3's, 2 81 celica's including a gta coupe, ra6x celica's and ae86 corolla's. I do know about the 2nd gen celica's basically sharing the chassis with the ae86 corolla. I had ae86 front strut assemblies with vented front brakes on my 81 celica gta. All i had to do is put the ra40 strut top on the ae86 assemlies and they bolted right up. Where the strut assembly bolts to the ball joint/tie rod arm on the lower control arm is the key area.. There are 2 different size bolt patterns at this point. Which is going to tell you which way to go to upgrade the front suspension/brakes on a mk1. If the mk1 has the smaller bolt pattern like the same year celica u can use ae86 strut casings and they make tons of brake and suspesnsion upgrades. If its the bigger of the 2 your prolly gonna have to make a mk2 strut case work. Either way is not a bad way to go. once i find a mk1 i'll let u all know for sure. Ae86 coilovers would be a good idea..
 
#65 ·
Mega Bump!!
Damon, you are the man. Are you still around/alive?
About to take on a 6m swap in my Mk1. I am scared beyond belief... better start looking for some 82 engine parts by the looks of things.
 
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