Aside from higher stall speed, I'm trying to figure out if a protorque torque convertor will do anything else from me. Will my hp/tq numbers will go up anywhere in the rpm band? I figure based on increased torque multiplication they should... but I'm wondering if anyone can let me know what they saw with an aftermarket TC on their cars... that's assuming they dynoed

Thx!

 

All I know is the LS1 guys swear by them so they must help somewhat

I have no clue just thought I would chime in.....

 

I believe it's supposed to give you some more power through the low and mid range.. But you seem a loose a tiny bit up top.

 

there is a page that shows before and after dynos for ls1's I believe. They seem to lose a few hp, but on the low end the torque multiplication is great. They have it timed from start to redline for many different converters, and the aftermarket ones let the engine rev alot faster. I will see if I can find the page.

 

http://www.converter.cc/dyno_shop.htm

They've dynoed their cars before and after a TC install. Also if you were building an all motor VQ, best stall speed would be around 4000-4400rpm . Throw in a 4.17 final gear with some slicks and that would be an awesome setup, however it will never drive right on the street.

 

Is it my total imagination, or are there adjustable TC's out there? I could have sworn I either read something or saw something about it on the net...


Anyone?

 

It is your imagination. The only way to change the stall speed is to either increase engine torque or swap TC internals.

 

Good stuff guys, I really appreciate the extra info.

That below URL has pretty much helped me make my final decision.. I was doing some research and found another bit of interesting info : with increased stall speed and torque multiplication it's likely that the higher end of the RPM range will lose some power / TC loses some efficiency... thus even though your low end power figures can up substantially you would end up losing a few %'s in power around the end of your power curve (we're talking 1500-2000rpm).

Fortunately after looking at tonnnnnnns of dyno graphs it seems that most high stall TC's (including protorque) design the TC's well enough to account for that potential lost efficiency... hence you may only lose a little bit at the top end if at all.

So, protorque TC here I come

Now comes the other question which I will prolly post in another thread later.. why does the VQ30 in teh 5th gen lose so much torque over the vq30 in the 4th gen I've noticed a trend of 5th gens dipping their TQ figures by 20+lbs-ft past 4500rpm or so... ah the mysteries of life.

 

I have a question? If your stall speed is 4000, does that mean your car idols at 4000? Or can you torque break to 4000? I really don't get the concept?

 

The torque converter allows the engine to run in gear without moving the car. As engine rpm comes up, the converter starts the car moving.

The higher the engine has to rev to get the car moving, the higher the 'stall speed' of the converter.

A 'looser' converter stalls at a higher rpm. This allows the car to take off at a higher rpm.

A car with slicks that can take advantage of the harder launch provided by the higher rpm launch will 60ft and et better at the track with a higher stall speed converter.

As a side note, a converter with an 'advertised' stall speed of 3000rpm for example will still move the car at lower rpm, it just won't be locked up all the way. It would probably start moving the car at around 1500 rpm, and you could probably brake torque it to around 2500 or so. You usually need a trans brake or something to reach the full 'advertised' stall speed.

As far as street cars are concerned, don't choose a converter that stalls higher than your cruise rpm... or it will be in a constant state of 'slippage' while driving down the road. This kills efficiency (fuel mileage) and heats the trans fluid to the point of doing transmission damage.

Any aftermarket converter installation should be accompanied by the installation of an aftermarket transmission cooler.

Maximas (with their stock cams and intake manifolds) generally make enough lower end power, that looser converters aren't really required. If yours is mainly a 'track' car and uses slicks, an aftermarket converter can be a very nice addition though.

Good Luck!

 

hey i've got a protoque converter and vb mod and it was the most worthwhile mod iv'e put in my car. it is very streetable(you cant tell it's in driving normal)but when you torque brake it revs up to 3000RPm and let off and you're gone. BTW it did't sacrifice power anywhere from 0 to 140 mph

 

whats your stall rpm?

 

3100rpm. if i torque brake it it'll rev to 3100rpm. it was custom built by matt(maxiumum tunings tranny specialist)for high power nitrous setups.

 

I'm getting a 2500 stall converter