tuning potential of an oldschool supra

[kachok25]

I am looking to build a low 11 second or high 10second street killer and I am hoping to find a good car to start with hopefully under 6k so the 93+ supras are way out of my price range. What would I have to do to a 92- supra to make it that fast, is the stock engine block/tranny/diffirintial up to the job if not how much would it cost to beef it up.

[TcmaBoy]

You should be able to get over 500HP out of one before you need to start doing internals.

[kachok25]

Originally Posted by TcmaBoy

You should be able to get over 500HP out of one before you need to start doing internals.

how about the driveshaft tranny and diff?

[TcmaBoy]

They can take it.

[kachok25]

Originally Posted by TcmaBoy

They can take it.

yea but how much more can they take? I don't plan on running stock internals long.

[TcmaBoy]

You don't need to worry too much about the R-154 trans or the diff. The only weak point I can thnk of is the center bearing on the drive shaft. I have heard of it binding or shearing out of its rubber mount when launching at a drag strip, though I have never seen it. You have to put some serious power to it to get it to break.

If you going for something over 550 or so then you could look into custom internals for the trans, and a one piece driveshaft. On the whole though the driveline is quite stout and can take some serious punishment before anything will break.

I've been thinking it over some other little things. A metal head gasket is a must, but that is a given in any high output applicatoin. Using head studs instead of bolts will help a bit with the 7Ms head gasket problems. The clutch type LSD is quite strong, but the torsen unit has been known to break over 400 HP. Not much to worry about there though. US cars came with the clutch units.

In short its a Toyota. You can usually produce between double and tripple the stock HP and not worry about things breaking. There are quite a few MK IIIs running the times you are looking for. She'll get you there.

If you are looking for specifics on a build up you can go to http://www.7mpower.com/ . Making power from the 7M is their thing. I wanted something that was a little different, so when my 7M blew up I just went with the 1JZ swap.

[kachok25]

How does the handeling on a mklll compare to the mklVs I know th enewer car is prob better but how much?

[TcmaBoy]

The MK IV is a bit better. The MK IIIs are a bit tail happy, but they can get the job done with some suspension work and big stickey tires.

[ForcedAirTurboPerf]

As far as the internals the steel head gasket is highly suggested but theactual stock internals will stand up to the job the biggest issue is fuel management, here is a link to a company that will set up a management system for your specific need,pre program it aswell to take the guiess work out of it for you

http://fuelinjectionpro.com/

they started specializeing in starion and conquest replacement injection systems,but they will design a system for any vehicle made !! i have had them make numerous systems for customers rides and it is actually a plug and play system,simply hook up power to the new system run the harness to the sensors (some stock sensors are reused) throw away the MAS Air meter and everything connected to the stock ECU isnt used,) and turn the KEY !!! ,i supplied them with all the vehicles info down to injector size and rear diff ratio and they set me up, and the cost was well under 600.00 for a system with a 3 bar map sensor and programmed up to 30PSI !! on a supra project for a customer, on this certain vehicle i used a distributor with a MSD instead of the DIS coil pac,they also set systems up for the DIS unit to be utilized but i chose the distributor style so i could use his MSD spark retard system ,he was real adimate about that being used,

The car (91 Supra wit a 7M engine) stock internals !!! ended up with 545 Rear wheel HP and 472 Ft Lbs or torque,running a stout best run of 10:89 at 134MPH running 23PSI out of a custom Turbo based on a 57Trim Turbonetics turbo T3T4 stage 5 turbine now moveing 65LBs of air per min. externally gated dumping to the atmosphere and 10:33 @ 146 MPH on 100 shot of NOS with the same setting listed above,these numbers were turned in wisconsin so at different altitudes the ET's will be different
now these times were turned with the new management system and im sure it would not have turned those numbers with a stock ECU even with a AFC Controller, so dollar for dollar thje system from fuel injection pros is well worth the little money they charge, another system that you can eassliy program yourself if you decide to passs on their system is an SDS(simply digital systems)
http://www.sdsefi.com/ ,these systems are very similar to each other and alot of online tech info for the SDS.
I had a SDS management system a while ago it was a EM3 it was on a starion and worked well and was user friendly,meaning very easy to program and fine tune

thanks and i hope this helps,

[ForcedAirTurboPerf]

Here is a link to a SDS page that has ALOT of how to do it yourself informatin from intake and exhaust manifolds to programing your management system, all the info is FREE

http://www.sdsefi.com/tech.html

[kachok25]

What did you have to do to get your stock engine block to hold of to 23psi of boost? Are you running race gas, or water/alke injection? Those are some impressive numbers how much did your buildup cost? Are you running the stock cam or an aftermarket? Are you running the stock tranny, driveshaft, and diff? Is the 1JZ GTE even tougher than the 7M? I have seen people swaping them.

[TcmaBoy]

The 1JZ is basically the older brother to the 2JZ. The main difference being that the 1JZ has a slightly shorter stroke giving it a 2.5L displacement. It is a different configuration than the 7M. It uses a big bore short stroke lay out which allows it to rev a little better. It also doesn't suffer form head gasket failure. It can be built to power levels well over 800. It also has a better engine management system. The 7M was a distributer based motor converted to run in DIS config. The 1JZ was designed to be DIS from the start. Mine came with MAP based system which makes for easy tuning. Early versions came with twin parallel CT12As. Newer motors (98+) came with VVTi and a single CT26. They are nice motors, but they are hard to find parts for. You have to go to a used JDM parts dealer, or Australia to find parts.

[kachok25]

So in your oppinion is the 1JZ or 2JZ worth the swap or could I spend that money and make the 7M an awsome motor? Do they make headgaskets for the 7M that can hold up to 700+hp reliably? OH and someone mentiond that the Mkllls are more prone to fishtailing then the MklVs is the problem in the weight distrabution, or in the suspention?

[ForcedAirTurboPerf]

The 7M engine is a 3 L engine, i have not heard of a 2.5 L toyota engine in a supra the smallest one I have heard of was a 2.8 naturally aspirated in my 85.5,as far as internals the head was race ported, stock cams and everything the turbo and engine fuel management did all the work as far as producing the HP numbers,the main issue when turbocharging is FUEL delivery!!!! without proper fuel delivery you will not produce efficent HP and get the most out of every pound of boost
NBOW you can run the stock ECU and reprogram it if you know someone who can perform the reprogramming,changing the fuel map and values to accomidate more boost,otherwise with a stock ECU and a AFC controller you may dip into the Hi 11"s but if you do not have the afc controller dont waste your money go to the web site i listed and have him set you up with an aftermarket management system you wont regret it, I simply changed the head gasket and thats it as far as internals,it is not recommended to run the boost levels I am but I make sure the fuel mixture is properly set and never look back and the customers engine has over 20 thousand on it since the first dyno pass and atleats 30 actual track passes and no problems!!! its your decision weather you want to run those boost settings or not<i always say as long as you have enough fuel turn it up !!

[TcmaBoy]

For the money the 7M is the way to go. A swap is more for bragging rights than anything.

ForcedAirTurboPerf

The MK III came with 4 engine options:

GA70 1GGTE 2.0L I6 twin turbo

JZA70 1JZGTE 2.5L I6 twin turbo

MA70 7MGE 3.0L I6 NA

MA70 7MGTE 3.0 I6 turbo

The MA70 was the only model sold in North America.