83 MKII Toyota Supra

I have really been enjoying this site and have been learning as much as possible.

I have begun to work on an 83 Supra for ITS... but in all the websearches and reading I've done, I have yet to see even one MKII Supra.

For those not familiar with the car... it is a front engine, rear drive set-up with MacPherson struts up from and IRS rear.

The engine is a 2.8L inline 6 with factory 150 HP. The wheelbase is on the long site for IT as 103".

Any comments on this car?

One thing I have noted is that the factory weight is at 3960# on the door... I am allowed 2890 or 2980 (forget which)... but it seems impossible to get to that weight within the IT rules.

I want to have the experience of building a racecar with my son... but I ultimately would like to be competitive... or at least not repeatedly lapped (over time as I learn to drive of course).

... the reason I have this general feeling that the car should be in the ballpark, is that I had an 85' 300ZX and an 85' Supra, and both were comparable bone-stock... in fact, I prefered the less tail-happy Supra. As well, I see a lot of 240sx, 260z, 280x Nissans... so it seems they must be good.

Thanks for your time.
Matt

Don't know much about those cars in IT, but the weight on the door is NOT the weight of the car. That is the gross vehicle maximum weight if I recall correctly.

Can't remember a lot about the Supra but I imagine you'll get below min weight when you ditch all the stuff you don't need - seats, interior, power stuff, etc.

Weight is still your enemy on the car though - it weighs more than a BMW 325 and won't have that sort of power. Now if you can get a killer weight break like the BMWs did then you'll be in business.

Good to see a different sort of car joining the field!

R

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Ron Earp
NC Region
Ford Lightning
RF GT40 Replica
Jensen-Healey ITS
1/2 a 260Z ITS

[This message has been edited by rlearp (edited April 15, 2005).]

Matt, first, that sounds like a great project to do with your son...I wish my Dad did stuff like that with me when I was a kid!

That said, I have to fall into the voice of reason...just a couple comments, I am sure you've heard them all before, but, just in case...

First, it's way cheaper to buy an existing car than to build one...lots of good info can come with that car, and somebody has already made lots of mistakes on their dime! LOL

Second, ITS is a pretty serious class. Take a walk thru the paddock at some of the bigger IT events, and you will see some serious cars and $....winning is tough, and expensive.

I haven't seen many Supras run, none competively....at 2900 pounds roughly, it aint light, and will be tough on brakes and tires. In terms of power, your target would be the E36 BMW...it runs roughly the same weight, and the best examples are putting down near 220 or so to the wheels.

So.....the Supra has it's work cut out for it. I am sure the stock weight is less than the 3900 you mention, thats probably the max rating for the car loaded.

So, if you want to run at the front, be prepared for an uphill battle. If you are OK with the car being relegated to second fiddle, and having good racing in the pack, then go forward with that in mind. But beware, between two cars that turn identical lap times, the one with better power will often win the race as it is impossible to pass on the straight, and holds you up in the corners!

The main Nissan contender in ITS is the 240Z which has a TON of aftermarket support and research behind it. It does well due to a favorable power to weight ratio, and good handling. Braking is OK, but not spectacular. We have some Z car experts here who can speak volumes about it.

In any case, be sure to do your due diligence, and make the results align with your goals.

Either way, you and your son are in for a good time.


The car will be safe, that's for sure!



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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

Add to that - the Z's are making the same power, have very similar suspensions, and weigh hundreds of pounds less. The reason nobody runs a MkII Supra is they are NOT competitive. About the only thing you'll see of them is their wheels - the factory 14x7 GTS wheels are fairly popular among Z-drivers on a budget. http://ITForum.ImprovedTouring.com/wink.gif At 2900#, I'd think they'd be a fair candidate for ITA.

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Norm - #55 ITA, '86 MR2. [email protected]
http://home.alltel.net/jberry/img107.jpg
Website: home.alltel.net/jberry

Spec weight is 2890. My 85 with 1/4 tank and my fat butt in the drivers seat hits the scales at 2980. There is nothing else I can legally remove. But my cage was built with .120 thick tubing instead of .095. In race trim the car is 60/40 front biased.

Performance parts are not common but can be found if you are willing to wait 4-6 weeks or more for an order to arrive from Japan. The engine horsepower numbers are not that impressive it IT legal trim wich is some what offset by the low end torque. If you get the weight balanced so you can get the rears to hook up you can really launch out of the corners.

Even if you build the bottom end perfect don't expect to get more than 6000 rpm. The hydrolic lash adjusters can not keep up at high rpm and the valves tend to float.

Camber is not adjustable. The good thing is the more you lower the rear the more the negative camber increases. Up front you will have to do coil overs and camber plates.

Check out www.celicasupra.com and the forums on the website for about the best sorce of info around on the MK II Supra.

[This message has been edited by jhooten (edited April 16, 2005).]

I think I'd look at the 'rat' motor 240sx before a Supra...

K

Jhooten,

What is the deal with the Supra motor? I'm not familar with them. Pretty good size for IT and it would seem that they'd make good power, but I don't know much about the head design, stock cams, etc. That RPM limitation seems like a problem though, 6k isn't a whole lot.

Kirk, I really want to build a 240 myself, I think out of all the "modern" cars in IT this is one of my favorites. Don't think you could go wrong with one of these as it'd be decently compentent about everywhere and have an advantage on some tracks.


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Ron Earp
NC Region
Ford Lightning
RF GT40 Replica
Jensen-Healey ITS
1/2 a 260Z ITS

I agree, it is the one car that i would get if i were to bail on the mid pack at best car I now own, and go for something that could have a legit chance..

But.....

I understand they are not simple builds, and the parts can get pricey.

Any thoughts from the collective wisdom??

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Jake Gulick
CarriageHouse Motorsports
ITA 57 RX-7
New England Region
[email protected]

Thanks for all the wisdom... anyway, I am looking to have a lot of fun... so if I can run in pack that would be great. Winning is not really my greatest priority.

In racing, someone always has a bigger budget anyways.

For instance, I will probably run the Toyos from discussions on this thread... so I am not willing to spend the extra $$ for the extra second or two... at least not at this point.

I am in the Detroit area, and there are a lot of good tracks within about 5 hours.

Getting track time is my main concern for the first two years. If I am any good, I may indeed try to buy a top car someday... and perhaps the Supra will become a good training car for someone else.

The building part is half of the fun for me, as I want my son (and me) to learn from it.

Thanks,
Matt

It is ancient history but a Supra won some ITS races from the Rebello powered 240z's in the SF region in the very late 80's. The car was sponsered by Thompson Toyota.

I am also preparing a supra for ITS, I have an 85. It is definitely on the heavy side but I am trying to fill out a proper VTS sheet and have the weight looked at in light of current power to weight ratios in ITS. If you are going to rebuild the motor get pistons from an 84.5 to 86.5 the compression ratio went up from 8.8 to 9.2 and power went up to 161hp and 169ft-lb. I have heard stories of it being very competitive but I haven't seen any actual results.

I am glad to hear you are going to build the car. I don't know if it will ever win any ITS races, but I really enjoy the challenge of developing a car that is an oddball.

As for the 240sx, I drive a 95 240sx everyday and it is an awesome car, but the supra seems less prone to oversteer and feels very well balanced in stock form. Also, my 240 is way to reliable right now to sacrifice for racing. I have to make it to work if I want the money to keep building a racecar!

Good luck with the build an feel free to email me with any questions.


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Russell White
Indianapolis, IN
'85 Toyota Supra
ready for ITS in 8 months....maybe

rlearp,

The 5MGE was designed as a truck engine. It makes good torgue. As it was designed as a truck engine the designers did not see the need for high rpm. The valve train is good and has room for improvement. The cam does not act directly on the valves. It pushes on a rocker arm. One end of the arm is on the valve stem. The other is on the lash adjuster. The limiting factor is the hydrolic lash adjusters (not lifters). There is a pressure regulator to control oil flow to the lash adjusters. At high rpm the lash adjusters tend to go soft. When that happens is the valve springs are stiffer than the resistence offered by the lash adjusters so they colapse preventing the valves being opened fully. Or so my engine builder explained it to me.

Sorry for the double post.

[This message has been edited by jhooten (edited April 18, 2005).]

GT240sx, thanks for the note.

Since the cars are the same, I will be able to hear your comments on different things.

I hope to hit the track next season after getting my liscense.

Did you get the sound deadening material off all the floorboards?

Have you figured a way to bypass the air flow meter? That appears to be the weak link in the track.

On the hydraulic lash adjusters... can you increase oil pressure to them? That would hold them up for higher RPM.

Write me at [email protected]

Thanks,
Matt

"Did you get the sound deadening material off all the floorboards?'

It came up easy with and air chisel


"Have you figured a way to bypass the air flow meter? That appears to be the weak link in the track."

No legal way to do so under the IT rules.

"On the hydraulic lash adjusters... can you increase oil pressure to them? That would hold them up for higher RPM.'

Up to a point. The regulator is not adjustable. You can tinker with the spring in the regulator to change the pressure but is a best guess type of deal. Also it becomes a flow rate problem as much as a pressure problem.

I can give you the name and number of the retired Toyota mecahnic who did the build on my engine if you like. He can explain it better.

jhooten

The lash adjuster info is uncharted territory for me at this point. I am in the middle of building the engine and I am struggling to get good technical info.

I am still trying to find the piston dish/dome volume. I have tried to measure the volume with a graduated cylinder and the best I am coming up with is about -1.5cc. Also, the combustion chamber volume looks close to 50cc. Any of those numbers in your engine book?

I also asked two machine shops here in Indy and neither of them could come up with a serviceable limit on the cylinder head or the block. Have you run across either of these numbers?

I would also like the number of the toyota guy if you don't mind. I can't find anyone around here with experience on the 5MGE.

mckeaaan, I will send you an email later on, but the sound deadening was a pain on my car, an air chisel does work very well, or just a hammer and chisel.



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Russell White
Indianapolis, IN
'85 Toyota Supra
ready for ITS in 8 months....maybe

I feel your pain. (Damn did I really just use a BC line?) I have been trying togather the info needed to submit the VTS sheets to see where the Comp board you put us in production.

If you don't have a copy of the TSRM here is a link to an online copy of the 86:

http://www.cygnusx1.net/supra/library/TSRM...MKII/index.html

The contact info for the Mechanic is:
Bayside Services Company
PO Box 53
Bacliff TX 77518
(281) 339-5487

Ask for Jeff.

BTW, he also does the service work on Jeff Watson's very fast 94 Supra running in Super Production.

And come to think of it I have a Chilton book around here somewhere. I'll have to find it and see if it has anything the TSRM doesn't.

If your injectors need serviced I found a place in WA that cleans and flow test them for $12 each.
http://www.witchhunter.com/

Now to get some neg. camber in the front.

Russell,

You just got the full treatment by the celicasupra.com crew. You must remember that while most of them mean well, some have a reading comprehension problem.

A, did you look in the book?
Rus, yes
B, would the book help? here is the link.

Anyway read through the Brake/Suspension section. Use your BS filter and you can find some useful stuff on suspension mods and parts sources. Ground Control does have coilover kits and camber plates wjen you get ready for them.

[This message has been edited by jhooten (edited April 19, 2005).]

Yeah, that was pretty pitiful. It seems like a lot of those guys have done engine rebuilds, but they aren't stuck within our rules structure so mods are much easier. All the aftermarket people I talk to just say, "put a 6M bottom end in there, no one will know", oh well, hopefully someone will have some detailed info on this engine so I can build it properly.

I have been through the brake/suspension section and I have found some pretty good stuff. I tracked down carlos who lives here in Indy and he faxed me the plans for the camber brackets and the spherical bearings and sleeves for the trailing arms. I can send those your way if you would like them.

Are you still switching over to ITE?

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Russell White
Indianapolis, IN
'85 Toyota Supra
ready for ITS in 8 months....maybe

Since my plan is to request classification in production as soon as I can gather up the info for the VTS and submit it, I have satarted doing some LP type prep to the car early, like door glass, that would make me illegal in ITS so yes I am going to run the rest of this year in ITE and hope to get the reclass done before the points races start for next year.

And since the limited prep engine rules are the same as IT i don't have to worry about another engine build just yet.

Yeah, no one will know until you go to ARRC and get torn down. Then you get to live with the CHEATER label for the rest of your racing career.

My fax is 512 304 0100 if you wouldn't mind sending along those plans. Or scan and e-mail to [email protected]. Thanks.