Good question, Thats something I need to ask them. Ok ya I will let you know man

 

If they didn't before, I'm sure they will when their intake is on there

 

the first time i threw mine on the dyno, it kept down shifting into 3rd, and the numbers were really low. Once my tuner was able to disable the speed limiter, he kept it in 4th, and tuned it made the pulls there. Stock it put down 280 hp and 279 tq to the wheel. After the dual exhaust, intake and a tune, i was putting down 317hp and 346tq. Keep in mind the numbers a little low because it was done on a mustang dyno, but the gains where pretty impressive with just intake, exhaust, and a custom tune. Guess mustang dyno's are a like 10% less than other dynos so that would put be at about 348hp and 380 tq to the wheels.

Made me wonder why toyota left so much room for gains with this motor. But im sure dodge is probably doing the same thing with their hemi.

 

Really?? The R/T stock is only putting down 304hp to the wheels? I thought that loose converter was suppose to get rid of a little more of the loss through the drive train as it is suppose to be the quickest ram produced in 09.

You guys are running through the same drive train as the 3rd gens so I would be suprised if you saw in the parasitic loss in upper 20% range

I need to get my truck back up on the dyno. Last time it was at 276rwhp and 301rwtq with the superchips at the standard 91 tune running 0-60 in around 6.05 @ 95 degrees out. With the new converter and modified Diablo tune in I've dropped my 0-60 times down to 5.73sec. @ 108 degrees outside.

 

Higher stall converters are actually less efficient, but they keep you in your power range longer.

That's not in "the upper 20s" thats 22% (304 is 78% of 390)

 

I dont think I can agree with you there, The stock converters on the rams are horrible as far as parasitic loss, they are around a 14% loss by them selves. And since they did not change the drive train form the 3rd gens to the 4th gens that loss is stil going to be there. The aftermarket converter I just put on, by numbers, should drop that 14% loss down to a 6% loss, making it more efficient than the stock converter even though it has a higher stall.

I would assume that the upgraded converter in the R/T's are going to be more efficient that the standard converter at getting power to the ground as well. So for an R/T a 22% loss sounds about right, but giving the fact that you guys still have the same drive train, with the stock converter I would not be suprised if it hit the upper 20% range.

That is unless they did something else to improve the drive train in the 09's?

 

Not all converters are created equal, but generally higher stall converters are less efficient because of how they work...they slip more, they create more friction, more heat, more loss. They keep you up in the rpms so you're in the power more, but it's not as efficient...at least when it's unlocked.

 

That was true with the converters of the past with the older cars/trucks, however the converters in our trucks are made to work with the overdrive we have. Basically there is an internal clutch inside the converter that allows it to lock up under light acceleration and cruising conditions so they don't create more friction so there is less heat. Think about it, if the converter in your truck was causing more friction and heat you wouldn't have the base trans cooler in it, you would have the HD cooler or another performance based cooler. Also, if you really want to think about it, the stock stall is around 2300rpm, under cruising conditions (65mph) a stock truck is maybe around 1800 - 2000rpms meaning that it would be constantly slipping without that internal clutch.

 

I don't think it would necessarily need a larger trans cooler. I mean, most vehicles don't have one at all, but the trucks do for towing.....and the R/T is rated to tow 4k less than a similar rcsb 2wd slt. This is listed as standard equipment on the R/T:
What gears does it lock up in? If it's like the Toyotas it's only in the top couple gears. Depending on how it was dynoed the stall still could have messed with the numbers. I'm not saying the efficiency definitely changed the numbers, but I think it's a possibility. I had a 4th gen Camaro with a lockup stall and it wasn't even close in efficiency to the stock(even with a small dia. converter).....but when I hit the go pedal it took off

Add that to the fact that it was K&N doing the testing,and they are gonna want to make the "After" numbers look as appealing as possible, I wouldn't put all my stock into that number.

 

If looser converters are more efficient, just put a 5000 rpm stall converter in there. Think of how efficient it'll be then-you'll probably almost never need to stop for gas!

The converter clutch has absolutely nothing to do with the efficiency of the converter when it's not locked up. ANY converter with a clutch has 100% efficiency when it's locked up. The difference between the r/t converter and the non-r/t converter is that the regular one is tighter when it's not locked up. The advantage of the looser r/t converter is not that it's tighter and more efficient-it's not. Instead, the looseness of it allows the engine to rev higher, which means the engine is operating at an rpm where it makes more power. This increase in power more than overcomes the reduction in efficiency imposed by the looser converter. The net result is that more power is available right off launch and up through part of the rpm band. The tradeoff is worse fuel economy when not locked up, and more heat generated when not locked up. In fact, that extra heat IS the extra gas that was burned-lost to fluid slippage in the converter. A loose converter is very efficient at turning gasoline into heat.