I have a 355 TPI with Comp Cam 08-300-8

Is that enough to choose a converter for my 700r4?

Im still trying to figure out what the torque converter does exactly...

it waits until a certain rpm before allowing the tranny to shift? (correct me if im wrong)

How will converter choice effect my daily driving?



:lala:

 

A converter lets the tranny slip while in gear.

Basically if you have a cam with alot of duration & idles rough in gear, people get a higher stall so it slips & will idle better. Some larger cam will stall if you put them in gear with a stock converter know what i mean?

 

my car idles a little rough...but nothing to worry about I think.

It streeses the brakes a little and sometime at lights I just put it in nuetral. then when i put it in gear it jerks the entire car.

I wonder if i should upgrade the converter or stay stock.

 

Yep, when you put the car in drive and it goes fairly well with no gas pedle its time for a new converter. I'll asume your in gear rpm is normal 600/800 rpm, so you would benifit from a 2000/2500 stall.

 

so thats basicly what its for huh?

kind of "spares" the tranny...

2000/2500...?

what will happen if i get the wrong converter...>?




:lala:

 

You want a converter that stalls around where you make power. I reccomend 500rpm under the powerband , 2000-2500 stall is a safty area. most mild engines will handle this stall and with a fairly built engine this will put it in the sweet spot.
If we had the cam specs and your rear end ratio we could give you a stall speed that would match your combo.

 

i have a stock rear with 2:73s and an auburn posi.

 

talk to these guys, they will get you EXACTLY what you need.

http://www.coanracing.com

go to the tech info page, and then go to the transmission and converter spec sheet page. fill in all the info they ask for and submit the sheet. they will figure out exactly what converter you need and give you a quote. and remember, quality costs $$$.

 

Ill check it out..thanks

 

Ahh A 262 grind, thats an easy one.
you would benifit from a 2000 stall converter.

 

The torque converter is a fluid coupling between the engine and trans. Think of it as sort of like 2 fans, with one blowing into the other. If you put a speed control on the one, the other would do more or less nothing, until the first one reaches some relatively high speed, at which time the second one will start to move. You affect all these things by the spacing between them, the relative pitch of the blades, etc.

Stall speed is the approximate engine RPM that the converter will allow the engine to run up to before it hooks the power up fully to the trans. Obviously a car will launch harder if the engine RPM at launch is at a point where its torque is high than it will if the engine's torque is low. Bigger cams reduce low-end torque and increase higher-RPM torque, and so will actually kill a car's launch if there's so much cam that there's no power at the converter's stall speed.

Pro racers will usually set a trans & converter up to launch just below the motor's peak torque and shift at or near its peak horsepower, and they'll gear the car to go through the lights at just above max HP.

 

This car is my daily driver too...


its going to effect all shifts through out the gears right?

seems like a diff converter may make it less responsive...

but it will make better use of power correct?

 

The converter doesn't affect shifts.

It does not make it "less responsive"; it does make it feel looser, because the engine will wind up to a higher RPM at times, for example when you take off from a stop. If you are at a dead stop and floor the car, if the tires don't spin, the RPMs will go up to a certain spot and just stay there, until the car reaches enough speed to allow it to go faster. A higher stall converter will raise that RPM. The car will fell snappier when you punch it but kind of spongy when you drive gently.