[need4speed]

Ok .. as you all know, I've been to the track many times in the last few months ....

I've tried all season tires, summer tires, as well as a drag radial (this one was 2" shorter overall diameter)

It seems, that no matter what I do, ESP on .. ESP off .. .GSM mod on ... off ... drag radials warm .... I just can't seem to get the power to the ground on the launch ....

There is no wheel spin off the line .... traction seems great, but yet, I can't get lower than a 1.8 or 1.9 60 ft, which some guys are doing on stock summer tires ....

How involved is the torque converter ? Is it somehow limiting the amt of torque that makes it the the rear on a launch somehow ?

Forgive my ignorance, as I've never really owned a performance Automatic before ....

 

[QuikSilver]

Ok .. as you all know, I've been to the track many times in the last few months ....

I've tried all season tires, summer tires, as well as a drag radial (this one was 2" shorter overall diameter)

It seems, that no matter what I do, ESP on .. ESP off .. .GSM mod on ... off ... drag radials warm .... I just can't seem to get the power to the ground on the launch ....

There is no wheel spin off the line .... traction seems great, but yet, I can't get lower than a 1.8 or 1.9 60 ft, which some guys are doing on stock summer tires ....

How involved is the torque converter ? Is it somehow limiting the amt of torque that makes it the the rear on a launch somehow ?

Forgive my ignorance, as I've never really owned a performance Automatic before ....

I would tend to agree with you!! I have a Tq monster (f/another manufacturer) and it will consistently give you 1.4-1.6 sec. 60' times.
The first thing I noticed with our SRT8's was the extreme low end Tq is lacking(hence-high 60' times) . A higher stall converter will definitely help!! Problem is, I don't know if anybody is doing it for our cars??
Help out there anyone??

 

[WhiteDiamond]

I have never seen a stall speed mentioned for a Dodge product, including my truck, so I have no idea where it is. If you brake the car and rev the engine up, you will get a fairly close approximation of where the flash point is by when it starts to pull through the brakes(or where the RPM goes to when you step on it).

Typcially, a stock converter is pretty low and nowadays they are set up for gas milage as well. Our truck and the MSRT8 seem to have very low stall converters.

I changed out the converter on a 1996 LT1 F-body(my last auto sports car) from the factory stall speed to a 2800rpm stall converter. I gained 4/10s in the quarter mile and it was all at the line, basically(showed in the 60').

The second issue with the SRT8 is the stock rear gears. DCX set up the gears for the low end torque this monster provides and not with track use in minds. Dropping to a 3.5:1 or steeper would improve your 60' dramatically as well.

Todd

 

[4DRHTRD]

It's weight, with a stall on my Impala and drag radials my best was 1.71. You can get into the 1.6's but it's hard to get 4200+lbs off the line.

Here's a 10 second Impala's times:
60' 1.617
330' 4.305
1/8 6.546
MPH 109.56
1000 8.486
1/4 10.138
MPH 136.22

I keep quoting Impala as the weight is very close between cars and TQ is about the same between the two motors.

Mike

 

[Weedo]

I don't know if anybody is doing it for our cars??
Help out there anyone??

This (along with gears such as 4.10's) is what I've been begging for a while. As I've stated before, a Stall (alone with Nitto DR's) netted .7 in the 1/4 mile on my Camaro SS (auto). It was a 3200 Stall. Just a cheap $400 stall (plus install). The car was better around town than with the stock converter as it made it more fun to jump off the line. At part throttle, it was completely fine as well. The converter locks up at a certain point so it's really not that much different feeling than stock when driving "normal".

You hit a 12.3....... With a decent stall, not even too big, say, 3200rpm or even 3000rpm, you should drop a good .6 off the 1/4 mile when running slicks and possibly DRs. In other words, 11's all day long! :banana:

 

[WhiteDiamond]

It's weight, with a stall on my Impala and drag radials my best was 1.71. You can get into the 1.6's but it's hard to get 4200+lbs off the line.

Here's a 10 second Impala's times:
60' 1.617
330' 4.305
1/8 6.546
MPH 109.56
1000 8.486
1/4 10.138
MPH 136.22

I keep quoting Impala as the weight is very close between cars and TQ is about the same between the two motors.

Mike

Mike,

It is important to mention that as you increase the power of the motor, the stall speed of the converter will actually change. A 10 second Impala SS is going to have a 'few' mods to the motor, so it isn't really a great comparison.

Just in general for you guys, todays computers actually tell the converter when to lock up. You can purchase a pretty high stall converter as long as it is compatible with that drivetrain.

Todd

 

[qictrk]

I agree that it's the weight. I had a pick-up that weighed 3800 lbs and turned the 1/4 in 12.4. My 60' time was 1.87. Your 60' time looks pretty good for the weight of the car. Cecil...........

 

[WhiteDiamond]

So the Ford F-350 TD that runs 10s and gets a very low 1.xx second 60' time isn't hampered by its weight why??? The weight is something that a street driven vehicle cannot change, but the torque converter can. The purpose of the torque converter is to allow the engine to run up to a RPM where it develops most of its torque rating and remain there while pulling the car off the line. It doesn't hurt that it multiplies the torque while doing it.

The SRT8 will benefit from a higher stall converter for the application Need4Speed wants.

Todd

 

[4DRHTRD]

I'm not saying don't put a stall in the car (once programming or EMS comes out). I'm just saying that you're going to have a hard time getting below a 1.6 60' with this car. Gears will also help but will effect the highway capabilities.
I'm glad I'm waiting through the first part of no parts being available for the car...

Mike

 

[HEMI~C~]

The stall actually isn't that terrible in our cars... I can hold mine to 2200, but a performance orientated convertor would shave a couple tenths for sure. The 60ft killer in our cars is the 2.86 rear gear. Even though we have a pretty steep 1st gear we will never make much progress on the short end with this gear. I second that you are doing pretty damn good given the gearing, weight and power.

Chris

Chris

 

[stang]

Weight ,along with some steeper gears and hookin' it up,should work just fine! :biggrin:

 

[WhiteDiamond]

The stall actually isn't that terrible in our cars... I can hold mine to 2200, but a performance orientated convertor would shave a couple tenths for sure.

You may think that 2200 rpm, or there about, is good, but that is crap based off the dyno tests on here. The engine should be well into the 3K rpm range to take advantage of the huge torque that starts developing around 3500rpm. Not that it is a slouch, but if you want to 60' in a drag race, you have to get the motor into its torque immediately and let it do the work. Gears certainly will help, as well. This is where those who want to race SRT8s will find issues. There just isn't an aftermarket for them right now.

Todd