A/T Limitations, Mid 12s easily?

[gregmondro]

ok guys, heres the deal, im buying a new engine and gonna do almost everything I can to it other than 2g rods and pistons.

i'm aiming for mid 12s

thinking of either using a FP Green or similar turbo to achieve this.

for the transmission, this is where everyone has been telling me that it would be my bottleneck in reaching mid-low 12s.

are DSM automatic transmissions capable of this? what would i need from IPT to achieve this other than a converter and the rebuild kit they sell?

[TURFNNSURF]

Well, I'll find out if my auto GSX can make it into the high 12's in two weeks at the Mitsubishi Shootout, at Raceway park in Central NJ. I have done a bunch upgrades (see mods list). The car is now dyno tuned for about 330 flywheel HP/248AWHP @ 18psi on a 50/50 mix of 94/100 octane gas. I'll post time slips after the shootout on 4/24/04.

[gregmondro]

what have you done to the transmission?

a converter or anything?

[TURFNNSURF]

NO upgraded converter yet. I have a few more upgrades to the motor and a larger turbo to install before choosing a high stall converter. As of now my trans is stock with the exception of a shift kit and end clutches installed by John at IPT here is a link to his site where you can read more about all the upgrades for our A/T's.
http://www.importperformancetrans.com/

[1st_gen_dsm_fan]

hey guys... look here's the deal. I have been getting alot of shit from my DSM friends for buying an automatic. it is a 95 TSi AWD. Is it worth the money for mods?

[TURFNNSURF]

Your car is still going to be faster than any of their 15, 16 and 17 second 5 speed Honda Civics. Even if they do Intake/Header/Exhaust you'll still be faster then them. Plus you have AWD, challange any of them to a little race on wet roads. They'll be spinning tires while your gone and waiting for them at the next light.
I haven't lost to a N/A Honda since I bought my GSX, even when it was stock...

[jspekter7]

Originally posted by TURFNNSURF
Your car is still going to be faster than any of their 15, 16 and 17 second 5 speed Honda Civics. Even if they do Intake/Header/Exhaust you'll still be faster then them. Plus you have AWD, challange any of them to a little race on wet roads. They'll be spinning tires while your gone and waiting for them at the next light.
I haven't lost to a N/A Honda since I bought my GSX, even when it was stock...

He never mentioned his friends having Honda's ... DSM friends is what he said.

I would have no idea of the possible times on a quarter mile for these cars as this is my daily driver, if it's a FWD, I'd go for it, some of my friends who are into DSM's and have AWD have broken a transmission drag racing (mainly because that sort of launch is really difficult on a transmission made to turn all of the wheels). Same with my Subaru friends, lol.

[Rice Over Wheat]

Originally posted by TURFNNSURF
As of now my trans is stock with the exception of a shift kit and end clutches

I'd say you're playing a high risk game there with your tranny. Especially if you're pushing 250 awhp now. Have that tranny built! Also your torque numbers will go way up with a good torque converter. Running like 75 more wheel horses on a stock tranny...gonna kill it quick.

ROW

[stangtt]

Originally posted by Rice Over Wheat
I'd say you're playing a high risk game there with your tranny. Especially if you're pushing 250 awhp now. Have that tranny built! Also your torque numbers will go way up with a good torque converter. Running like 75 more wheel horses on a stock tranny...gonna kill it quick.

ROW

I have only a shift kit, endclutch and upgraded cooler with around 380-400 whp. The trans has handled it fine for a while so far.
I'd say as long as its taken care of, his should last just fine with his mods.

[Rice Over Wheat]

You're a braver man than I. Transmissions are the achilles heel of Mitsubishis. The 4G63 supposedly can handle 500 whp on stock internals but I sure wouldn't try it...better safe than sorry you know.

ROW

[stangtt]

Originally posted by Rice Over Wheat
You're a braver man than I. Transmissions are the achilles heel of Mitsubishis. The 4G63 supposedly can handle 500 whp on stock internals but I sure wouldn't try it...better safe than sorry you know.

ROW

I cross my fingers and hope everytime I step on the gas that it will stay together. :laugh:
I did have it around 260-300 whp for 40k miles or so with no problems whatsoever. So I know it will handle those levels quite well.

[bOOstd GSX]

Well in about a month I will be running my new engine, rebuilt auto tranny (alto rebuild), translab and im debating on which high stall to get. Looking at an IPT custom. I'll be making around 375hp to the wheels without the juice so we'll see how it goes.

[transdude]

Hi Guys,

I posted this somewhere else on this forum a while ago, perhaps its relevant to this discussion:

Anyway, the focus of what we're talking about here are the Mitsubishi built turbo transmissions, the W4A33 (AWD) and the F4A33 (FWD).

Internally, these two transmissions are very similar so I'll lump them together for the purpose of simplicity.

These relatively weak transmissions can be made suitable for performance use. As with anything else, there are varying degrees of what can be done with them.

At the entry level of making these transmissions able to cope with more horsepower is the installation of a shift kit or modified valve body and the addition of an upgraded end clutch kit.

The valve body mods are really the foundation of any performance trans rebuild. An automatic transmission utilizes a network of valves, servos, solenoids, orifices and passages that control and route hydraulic pressure to the appropriate places to apply the clutches and bands.

Without going into elaborate detail which would fall outside the scope of this thread, suffice it to say that modifying the valve body effectively changes the rate of clutch and band apply and also increases the clamping force with which these components have to work with. This is why shift kits and modified valve bodies produce that firm performance type shift that increases the transmission's capacity for power handling.

Next up is the installation of a performance end clutch kit. The function of the end clutches are to help produce an overdriven gear ratio (4th gear). Due to original factory design and vehicle space considerations, this clutch pac is designed to 'fit in the car' rather than to be durable. The steel reaction plates, which are sandwiched between the factory clutches, are too thin and of an inferior material. This problem makes the plates very subject to warpage and subsequent failure when exposed to excessive heat.

The performance end clutch kit helps to rectify this situation by increasing the thickness of the steel reaction plates and also utilizes a superior Kolene material which is almost impervious to heat. In addition, the clutch plates also utilize a high performance 'red' lining that also greatly increases clutch holding ability.

The beauty of the first two modifications is that they can both be accomplished with the vehicle still in the car.

The next thing to be considered, from a durability and a performance standpoint, is the addition of a performance torque converter.

As well as being made with many strength improvements over the factory piece, a performance converter enables a vehicle to better take advantage of the RPM range at which maximum power is made. In simple terms, a properly designed converter will allow a vehicle to launch under more power by increasing the rpm at which the launch takes place. In essence, a torque converter is an infinitely variable transmission in and of itself, and altering it's torque multiplying characteristics becomes absolutely necessary when other variables in the vehicle are changed (bigger turbos and bigger cams).

Converter designs range from the strengthening and restalling of the factory core- all the way to reduced diameter customized pieces made with a cover that is machined from a piece of steel billet.

The ultimate step in improving that automatic transmission is a full performance rebuild.

First off, the transmission needs to be disassembled, thoroughly cleaned and inspected. During this process all questionable parts are discarded. Many of the parts that are reusable then undergo various processes such as heat treating, Meta-Lax stress relieving, and cryogenic treatment (freezing them in liquid nitrogen to 'reset' the part's structure on the molecular level).

Next, all critical support bushings are replaced to insure that the centerline of the transmission runs in perfect alignment with the centerline of the crankshaft. Ignoring this step puts a lot of undue stress on the internal transmission components.

At that point, all of the required seals and gaskets are changed to materials that are better able to cope with the heat and stress that is common in high power applications. Performance clutches and steel reaction plates are then installed and their clearances are then set to much more exacting specifications than those that are used by the factory.

The aforementioned valve body modifications are performed and the remainder of the transmission undergoes a precision reassembly and blueprinting process where more critical clearances are checked and adjusted and, of course, all fasteners are torqued to spec. This is somewhat similar to what is done during engine assembly.

The W4A33 and F4A33 are an excellent starting point for the foundation a performance transmission. They have relatively 'beefy' hard parts and gearsets and feature quite a lot of clutch and band surface area, which is critical when it is time to handle increased power.

The 500 horsepower level is achievable with these units with the right components and modifications, but certainly not in factory form.

-John

[98TalonTSi]

Originally Posted by transdude

.

The 500 horsepower level is achievable with these units with the right components and modifications, but certainly not in factory form.

-John

You mean not without blowing it up first.