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Registered:
August 2005
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MX73 cressida/chaser front suspension conversion
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Sun, 07 August 2005 04:39
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HI everyone, I'm new to this forum. I have an 86'Chaser. I want to convert the front suspension to the MKIII supra double wish. I know this sounds crazy, but I have done a small amount of research and I think it may be possible. I am a Toyota tech. and have compared the front crossmembers. I realize there will be cutting & welding but minimal. I have never heard of this done before, But I want better suspension and bigger brakes. Was wondering what you guys thought? Any advise or nowledge on this?
Thanks
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Registered:
July 2005
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Re: MX73 cressida/chaser front suspension conversion
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Sun, 07 August 2005 04:45
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why not just do something much simpler like getting new spings/struts to revive that old suspenion?
get new blank rotoers, pads, bleed the brakes, maybe change the rubber lines as they woul dbe getting on abit too.
isnt welding suspension illegal?
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Registered:
August 2005
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Re: MX73 cressida/chaser front suspension conversion
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Sun, 07 August 2005 04:54
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Welding suspension is not illegal where I live. I am tired of having cars w/o double wishbone. and no matter how good of cond the brakes are in, they are not big or powerfull enough for downhill mountain passes and all out road racing, I have tried the things you've mentioned. Macpherson is great for the street & mild cornering, But the chaser is heavy. For racing, they need more strength and camber/alignment adj. for the front wheels. everyone does crazy engine swaps, I just want a susp./brake swap.
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I supported Toymods
Location:
Australia
Registered:
November 2003
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Re: MX73 cressida/chaser front suspension conversion
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Sun, 07 August 2005 05:52
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To the best of my knowledge you are on your own with this one.
The two setups are so far apart it will be a nightmare.
Have fun.
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Registered:
August 2005
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Re: MX73 cressida/chaser front suspension conversion
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Sun, 07 August 2005 06:42
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True they are far apart, but all of the MKIII susp. components bolt to the crossmember, and that can (I believe) be bolted to the modified chaser chassis.
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Location:
Brisbane
Registered:
May 2002
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Re: MX73 cressida/chaser front suspension conversion
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Mon, 08 August 2005 00:29
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It's not very hard to put MX83 struts in your car, which makes it easy to upgrade the brakes as I have done. This will be far easier than converting to wishbone suspension, and the brakes are much better than the MkIII brakes. Food for thought.
http://www.norbie.net/Project2JZ/BrakeUpgrade/
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I supported Toymods
Location:
Australia
Registered:
November 2003
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Re: MX73 cressida/chaser front suspension conversion
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Mon, 08 August 2005 00:31
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Its not like its hard to upgrade the brakes on the stock struts anyway.
Shitload cheaper too!
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Registered:
August 2005
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Re: MX73 cressida/chaser front suspension conversion
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Mon, 08 August 2005 03:56
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Great info Norbie. Unfortunatly Crowns do not exist in my country, so thats pretty much out of the question. I've thought of doing the MX83 strut/brake conv.,(Which I may do if the MKIII doesn't work.) That would take care of the brake problem but it is still a Macpherson strut, with limited adj, stength, & camber change under a load. The ballpark price on Norbie's guide is way more expensive than I estimate the MKIII conv will be. I may not have been clear on what I plan to do. On the Supra & Chaser chassis, all the front susp/brake components bolt to the front cross member. What I want to do is bolt the entire MKIII front cross member to the chaser. If it will work I will only have to modify the mounting surfaces where the member bolts to.
Thanks for the advice you guys
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Registered:
August 2005
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Re: MX73 cressida/chaser front suspension conversion
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Mon, 08 August 2005 04:00
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also forgot to ask what are the differences between the MKIII & The MX83 brakes?
Thanks
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I supported Toymods
Location:
Australia
Registered:
November 2003
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Re: MX73 cressida/chaser front suspension conversion
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Mon, 08 August 2005 04:07
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Don't forget you'll have to convert the 5MGE to a midrear sump like the MA70's 7MGE.
Btw, why are you going to these lengths?
Boredom? Bet? Motorsport?
The MX73 is not the best base for anything but pimpin and cruising.
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Registered:
August 2005
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Re: MX73 cressida/chaser front suspension conversion
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Mon, 08 August 2005 04:38
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Yes I am aware of the oil pan issue. The reason I am doing this is for motorsports racing. My MX73 has a very special drive train, and I want the susp/brakes to match. So far (believe it or not) this swap is the easiest & cheapest way to upgrade brakes & susp (that is if it works). And on the contrary I believe the MX73 is a great tuning base. Not many old school cars have
-4 wheel ind. susp.
-4 wheel disc
-front engine rear drive
-manual trans
-potent & tunible inline six
sounds like a good base for tuning to me-not to mention 4 doors w/room for 5 to make it practicle and w/ reasonable weight
am I wrong?
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I supported Toymods
Location:
Australia
Registered:
November 2003
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Re: MX73 cressida/chaser front suspension conversion
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Mon, 08 August 2005 04:54
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Yes, it has all that stuff, but the car was built for luxury and smoothness, at the expense of handling.
MA61 is a more performance based car, has all the same gear, 100+kg lighter, and will outhandle an MX73 no worries.
I've been there, I've started to do up an MX73 for some track work, I did all the suspension and brakes, but decided that I'd be miles ahead by starting with a slightly better base. The MX73's handling was very uninspriring, espescially when the exact same gear turned an MA61 virutally into a go-kart. MA61 was going to be the one, but that didn't eventuate, so MZ10 became the girl.
You might not even have MA61's or MZ10's there, so MX73 is probably the better.
MX83 would be a better choice for a 4door sedan. Easier for rims/brakes, better rear suspension, and only 100kg MAX heavier than MX73.
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Registered:
August 2005
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Re: MX73 cressida/chaser front suspension conversion
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Mon, 08 August 2005 05:37
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There are a few reasons I am so die-hard chaser.
-I already have one
-have tons of parts for it
-mine has a very special engine
But mainly I want an old school toyota 4 door cruiser that can also compete in hard core road racing.
I also actually own an MA61 along w/ a few other light weight 2 door toyotas I use for racing and they are great! Soarers are not availible hear and that sucks! I LOVE soarers!
I do not understand why the MA would "outhandle an MX73 no worries". Other than the vehicle weight, the suspension design and geometry is identicle, other than spring/damper rates which can easily be changed. I have not tuned the stock susp. on the chaser (because of this swap I plan),so I cannot speak from experience on this, But I don't see why an MA would out handle a similar setup MX. And the weaknesses you mentioned are the exact reason I want to do this swap. I did consider the MX83 but I prefer the styling of the MX73 and it is lighter
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I supported Toymods
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Australia
Registered:
November 2003
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Re: MX73 cressida/chaser front suspension conversion
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Mon, 08 August 2005 05:45
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I have no idea why the MA61 outhandles the MX73 either.
MA61 has a greater front track by 24mm due to wheel offset.
MX73 has a greater rear track (by about 30mm).
My mates car with a 2JZGE and manual, with ma61 kings springs standards, ma61 tokico shocks, and nolathane bushes, handled like a go-kart.
My car with 1UZFE and manaul, with ma61 kings springs standards, ma61 tokico shocks, and nolathane bushes, handled like a boat.
My car would have weighed about 50-80kg more, I had skinnier tyres, but they were a lot grippier.
I can't work it out either. I doesn't make sense, but it happened. There have been others who have been in both cars and can testify to this.
The difference was like chalk and cheese.
Btw, what is this very special engine of yours?
[Updated on: Mon, 08 August 2005 05:46]
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: MX73 cressida/chaser front suspension conversion
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Mon, 08 August 2005 05:51
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I've driven both CrUZsidas MX73 (UZX73) and Glens MA61 (JZA61) and the difference is night and day. My GA61 which needs new bushes but has the same springs and shocks is a lot more positive to drive.
There is something different which is affecting it, whether it be centre of gravity or something else I'm not sure. I doubt the suspension geometry is to the mm the same which would affect it perhaps adversely.
And lastly...wtf is this special engine? 
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Registered:
August 2005
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Re: MX73 cressida/chaser front suspension conversion
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Mon, 08 August 2005 06:13
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That is cool you have a 1uz in your supra! do you know how much power it makes? (dyno or guess)
and you said it handles poorly? could that be from more weight in the most significant spot? how is the weight positioned in respect to the axle, more forward or rearward than stock? is the V8 heavier than the inline six?
The engine going in my car is not quite finshed yet. but this is the setup
-5MGE
-rare japanese 2900cc 11 to 1 comp. pistons
-custom high rise header
-Six individual throttles from TWM
-custom ground cams
-Bullfrog engineering headwork
From what I have been told and from other tuning experience I should expect about 300hp in the 7000 to 8000rpm range. A setup like this is pretty much unheard of in the U.S. by the way the US market SUCKS!
I love old toyota twin cam engines
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I supported Toymods
Location:
Australia
Registered:
November 2003
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I supported Toymods
Location:
Australia
Registered:
November 2003
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Re: MX73 cressida/chaser front suspension conversion
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Mon, 08 August 2005 06:30
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| YotatoY wrote on Mon, 08 August 2005 14:13 |
and you said it handles poorly? could that be from more weight in the most significant spot? how is the weight positioned in respect to the axle, more forward or rearward than stock? is the V8 heavier than the inline six?
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Missed this bit.
Yes, handles poorly. Don't get me wrong, its a great deal better than factory, but nothing like the MA61.
The 1UZ is about 50-60kg lighter than the 5MGE (if not more), plus it was manual, so there's another 20+kg weight loss.
So it was much lighter than factory, and had a lot less weight over the front axle.
[Updated on: Mon, 08 August 2005 06:30]
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I supported Toymods
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Perth
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May 2002
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Re: MX73 cressida/chaser front suspension conversion
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Mon, 08 August 2005 06:55
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| CrUZsida wrote on Mon, 08 August 2005 14:30 |
So it was much lighter than factory, and had a lot less weight over the front axle.
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And still handled like a boat 
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Registered:
August 2005
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Re: MX73 cressida/chaser front suspension conversion
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Mon, 08 August 2005 07:03
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Well, all your testimonies to the MX handling poorly, only further enforces my plan to do this so called waste-of-time suspension swap. That is why I want to do it.
There are 2 options for displacement increase on the 5MGE.
-2900cc piston set and 3100cc piston/crank set
The 2900cc pistons are 85mm bore, which actually works out to be more than 2900cc.
The 3100cc kits are the 85mm bore pistons w/basically a modified 6mge crank.
These kits were produced by Japanese tuning companies during these engine's days. They were Japan only, VERY expensive & VERY rare. If you wanna now more contact toysport.
I got lucky finding my set from a collector/enthusiest who used to run a performance nissan/toyota parts importing business. He told me he was the only one in the US that could this brand of pistons and only imported 3 sets. So I want my 5M to be the best an N/A 5M can be.
I am using a triple sidedraft manifold that disables the dist. so I will be using a full EMS. That is last piece to my puzzle. Havent decieded which system to use. Any advice?
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Location:
Campbelltown, NSW
Registered:
November 2002
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Re: MX73 cressida/chaser front suspension conversion
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Tue, 09 August 2005 02:35
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Hey all
I dont know what the go is with everyone baggin out the handling of MX-73's.
I own one with a 1j, New bushes all round, Koni adj all round lowered springs, rear bar, and 17's and i think it handles quite good, it has supprised a few people when i am still right behind them after a few corners.
Dont know but that is just my opinion.
Cheers
Richard
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I supported Toymods
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Australia
Registered:
November 2003
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Re: MX73 cressida/chaser front suspension conversion
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Tue, 09 August 2005 02:36
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| pannelvan_screema wrote on Tue, 09 August 2005 10:35 |
I own one with a 1j, New bushes all round, Koni adj all round lowered springs, rear bar, and 17's and i think it handles quite good, it has supprised a few people when i am still right behind them after a few corners.
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Now get a second lot of all that gear, place into MA61, and watch it outhandle you with mucho ease.
It must just be a weight/CoG thing.
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Registered:
August 2005
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Re: MX73 cressida/chaser front suspension conversion
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Fri, 12 August 2005 05:50
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All I hear is you say it handles poorly. But you havent said why. Understeer, oversteer, to much body roll, ect... What type of spring/damper setup up do you have, What type of sway bars do have, & what size tires do you run?
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I supported Toymods
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Australia
Registered:
November 2003
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Re: MX73 cressida/chaser front suspension conversion
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Fri, 12 August 2005 06:15
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It understeers to all buggery, and body rolls to the sh!thouse.
I'm sure with time and money spent it could be done.
But the point I am trying to make, is that you have two almost identical case.
The MA61 and the MX73.
There is about 100kg weight difference, which isn't a HUGE amount when you look at the over all weight. Its only about 8% more.
Most of this will be from the firewall back, as I can't see anywhere from firewall forward where it could be.
And in the case of my car vs mate 2jzge ma61, I can guarentee you I had less weight over the front wheels.
Now put the SAME suspension in the cars, and the MA61 will reign supreme over the MX73.
Find out this reason why, and you'll be well on your way to getting the cressida to handle.
From what I could tell while comparing things, they run the same struts, the same lower control arms, (which are spaced the same distance apart), and the same camber, so I would presume that the strut tops are very similar in orientation.
The MA61 has about 2" more distance between the firewall and the strut towers, but the same distance between the strut towers and the radiator.
The MX73 has a longer overall wheelbase (driveshaft is about 2" longer, can't remember exact value)
I never really compared the rear end, but I doubt its very much different.
The MX73 also runs 2mm thicker swaybars front and rear compared to the MA61
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I supported Toymods
Location:
Australia
Registered:
November 2003
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Re: MX73 cressida/chaser front suspension conversion
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Fri, 12 August 2005 06:16
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Oversteer was not in the MX73's vocabulary, unless I forced it too.
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I supported Toymods
Location:
Perth
Registered:
May 2002
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Re: MX73 cressida/chaser front suspension conversion
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Fri, 12 August 2005 06:19
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I concur  My driving experience in said car was very much the same. Body roll was massively present, understeer was flavour of the day and oversteer was only provoked by being stupid with the wheel and the throttle.
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Location:
Perth
Registered:
April 2004
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Re: MX73 cressida/chaser front suspension conversion
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Fri, 12 August 2005 09:12
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I like the sound of that 5mge it would be cool to have somthing like that. good luck trying to get the beast to handle my suspension is stock and I find u get more over steer than under but that is just me( at the point of over steer u think ya gona roll the thing tho  )
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Location:
Montrose, VIC
Registered:
May 2002
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Re: MX73 cressida/chaser front suspension conversion
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Fri, 12 August 2005 12:59
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The idea of putting the MA70 suspension in isn't impossible, and it'd be a great little project to do it, just that it's not the easiest way to get the best out of your boat. Another thing to remember is that the rear suspension on the MX73 is slightly less than ideal.
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Location:
Brisbane
Registered:
May 2002
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Re: MX73 cressida/chaser front suspension conversion
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Sat, 13 August 2005 04:08
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| mrshin wrote on Fri, 12 August 2005 22:59 |
Another thing to remember is that the rear suspension on the MX73 is p00.
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Fixed.
As an MA61 owner I'm not a big fan of trailing-arm IRS.
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Location:
Central Coast, NSW
Registered:
February 2005
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Location:
Montrose, VIC
Registered:
May 2002
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Re: MX73 cressida/chaser front suspension conversion
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Sat, 13 August 2005 12:41
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| Norbie wrote on Sat, 13 August 2005 14:08 |
| mrshin wrote on Fri, 12 August 2005 22:59 |
Another thing to remember is that the rear suspension on the MX73 is p00.
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Fixed.
As an MA61 owner I'm not a big fan of trailing-arm IRS.
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The tyre wear and lack of traction isn't exactly good, but sometimes it feels a bit better than a live axle.
Although old Celicas and 180B's (1600s too) do seem to make the best bang-for-buck paddock/hooning-on-dirt-road cars in the $50-$250 bracket...
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Registered:
August 2005
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Re: MX73 cressida/chaser front suspension conversion
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Mon, 15 August 2005 07:49
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| mrshin wrote on Fri, 12 August 2005 22:59 |
The idea of putting the MA70 suspension in isn't impossible, and it'd be a great little project to do it, just that it's not the easiest way to get the best out of your boat. Another thing to remember is that the rear suspension on the MX73 is slightly less than ideal.
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By the sounds of this, you must have tried it. Please explain in detail to me why its so impossible. And whats the easiest way to get the best from my "boat"?
What would make the MX rear susp. ideal? I don't care about tire wear because most susp that's purpose is for extreme cornering doesn't wear tires evenly anyway. It provides good neg/pos camber when the wheels are loaded/unloaded, That's a lot more than you can get from a solid axle.
And did any of you think of the posibility that the reason oversteer doesn't occur is because the rr susp has good wheel geometry when loaded?
I realize some oversteer is useful, but I want a car that sticks to the track, not a drift machine. You said it doesnt oversteer unless you are stupid with throttle/steering. sounds like pretty good susp to me. Which leaves the front susp understeer problem. Which I, AGAIN, remind you that this is the exact reason for my quest for a better susp design than macpherson.
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I supported Toymods
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Perth
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May 2002
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Re: MX73 cressida/chaser front suspension conversion
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Mon, 15 August 2005 07:57
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| YotatoY wrote on Mon, 15 August 2005 15:49 |
Which I, AGAIN, remind you that this is the exact reason for my quest for a better susp design than macpherson.
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I wouldn't be blaming the Macpherson strut for your problems, go have a look at a Porsche Boxster or Cayman, two of arguably the best handling cars in the world.
The problem lies more to do with possibly the setup of said strut design, the components used throughout, balance, track etc. If I was you (which I realise I'm not ) I'd go about setting up the suspension correctly (ala Norbie) rather than make it difficult for yourself and try a complete swap which to be honest I see more problems setting up than the benefits.
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