When you add a fueling box or say a downloader like a Smarty, you are increasing bottom end as well as overall fueling by quite a bit.
If it takes x amount of fuel/ RPM to go say.. 45mph and you alter your performance, shouldn't it take less RPM to cruise around at the same speed?

When you do this, doesn't it lower auto trans pressures and increase trans wear? Yes, no, or am I out of my gourd...

 

It will take exactly the same RPM for a given speed with same gear ratio and tire size.

 

It will take the same RPM but less throttle response (less movement in the accelerator) and that is why or how the boxes can damage a auto transmission easier.

 

Can you explain this to me? Are tranny line pressures directly related to throttle position?

 

So less throttle means damage to trans???

 

the rotation of the engine is coupled to the road speed by the gear ratios of the tranny, axles, and tire diameter. unless you change one of those 3 components the rpm compared to road speed will not change.

 

I think he means it's easier to damage the auto since a given throttle position causes the engine to make more power.

 

Yes, you can tweak it a little with the TV cable but only a little. If you try to move it one direction or the other too much the shifts will be off.

 

Yes and no. If you don't go crazy on hp increases the transmission can live a happy life. They use to recommend no more than an increase of 60 hp on the 305 and earlier engines and I think now they recommend only about 30 hp increase on the 325 engines.

It really depends on how aggressive the box bring the power on. The more aggressive at lower throttle movement the more damage may happen. If the power comes on at a higher throttle setting then it's less stressful on the transmission.

 

What I have typed is for the auto transmission. I should also say that the manuals will hold more power increase before the clutch slips, again it's all relavent to when the hp comes in and when it spikes as to when and how much damage may occure to any transmission auto or manual but is more taxing on the auto.

I keep typeing damage may occure and that's because I know of guys that have used higher hp boxes without immediate damage.

If you drive sencable and apply the power smoothly your transmission will live longer. Again it depends on how radical the power comes on.

 

If your refering to line pressure....no less throttle does not mean less pressure. Your VB has what is called Base Line Pressure...which means once the engine starts and the trans pump is running...it will supply that pressure period. Now if your low on at fluid you will see a drop in that pressure.

Richard

 

Remember that we are talking about 04.5 trucks and up in which you have NO control over the TV cable since it has been replaced by the TVVA accuator which is controlled by the ECM....Also, TV cable adjusments tend to control shift points and not pressures...those are controled by the VB.

Richard

 

The problem is that once you add all that extra power it is virtually impossible to keep from planting your foot on the floor and racing everything that will accept the challenge. That's just too much torque for stock trans parts to handle so they begin to fail one by one. The converter is usually the first to go. Once you replace it with a better one then the clutches and bands start to go. etc...etc...etc...

 

I think that if you add more power and drive it the same as when it was stock (like a grandma) you shouldn't hurt a thing. It's the way you drive it that hurts it, not the added power for the most part. Correct me if I am wrong.

 

True - like DodgeZilla said, it's nigh impossible to keep your foot out of the mods...