c-6 torque converter - I want tire spin!

I'm what you might call a beginner in the racing business. I've got some basic questions as to which torque converter I want for my 1970 torino GT set up.

I'm running a ford 351 C with headers, factory pistons, a lunati bracket master II cam (.50 is 224/234 degrees and gross lift is .536/.562), an edelbrock 750 carb; I'm guessing this combination is putting out around 300 h.p., maybe a little less. My problem is getting the h.p. to the wheels. When I power brake, rpm sets at 2000 and the tires don't spin. That is the problem. This engine doesn't wake up until 3000 rpm. The torque converter I'm running now is supposed to be higher stall than factory, but it obviously isn't enough. Since I wan't 3000 rpm in a power brake position, do I wan't a 3000 rpm stall speed converter?

I know the obvious is to go with lower gears, but let's just say that isn't an option. I wan't to leave my top end alone. I need to fix this with a converter.

Which converter do I wan't. Anybody help?

What I experienced with stall converters is that they usually flash stall aroung 1000 RPM higher than brake stalling. With the big Cleaveland heads and the weight of your car, I'd go deep gears and a loose converter.

Good brakes you have there [img]/phpBB/images/smiles/icon_lol.gif[/img] if your happy with the performance you have other than the no-spin issue just install a line-loc.
[addsig]

Go to the post:
Precision Industries Torque Converters
And read my reply.
It is a down and dirty lamens TQ lesson.
[addsig]

3200 stall minimum, at least 3.73 gears on a 26-28 inch tire.
[addsig]

Does this torque converter fit my needs? This is an ebay link.





http://cgi.ebay.com/ws/eBayISAPI.dll...e=STRK:MEWA:IT

Here is the post I did recently.

Here is quick rundown on TC basics.
Number one you need to decide what you want.
Mileage and drivabilty or Torque and raw acceleration.
You cannot get without giving.
Number two you need to match your cam and TC stall.
You will need to know your Cams torque and Horsepower curves.
(Dyno 2000/2003 is perfect for estimating this)
For "Acceleration" you will need to determine where your peak torque occurs in relation to RPM. Also you will need to determine where your Peak Horsepower occurs in relation to RPM.
As an example:
My 289 and cam the Torque peaks at 5500 RPM and the Horsepower at 7000.
Horsepower will "Pull you thru" the loss of Torque. This equates into acceleration. If you have a cam with a flat torque and horsepower curve then you will not accelerate because the torque is acceleration. If you reach your torque and flatten out you will not continue to accelerate. Your engine will "Bog" at this point because you do not have torque contining to rise.
(Yes I am going to hear about this)
Here is where the TC comes into play.
All TC's are rated at Flash Stall. This is the RPM that the TC slips to before it starts its lockup. The actual Lockup occurs appx 500 RPM lower after it Flashes to the rated RPM.
So during your shift from gear to gear you Flash to the RPM. What you want the TC to do is to Flash about 1000 RPM below your max Torque. So in my example I would want my TC to Flash about 4000 RPM. This way the Torque after the shift will continue to accelerate my vehicle as opposed to flattening out.
The Horsepower will carry me thru the shift until I reach my Flash again.
Now that is Pure continued acceleration.
Here is the give and take portion.
If I have a 4000 RPM Flash Stall then my actual lockup would be appx 3500 RPM.
If I am using the vehicle as a daily driver the lockup of the TC at 3500 RPM would place me at what speed while I am piddling around town? With my setup of a 3.55 rearend in 3rd gear (1:1) with a 26 inch diameter tire this lockup of the TQ (3500) does not take place until 76 mph (use Virtual Engine Calculator to figure this).
This does not equate into milage and drivability at all.
So I must compromise.
I want my lockup to occur around 40 mph (which is the average speed I will be driving around town). For this to happen I will have two choices.
Lower my Lockup RPM with the TQ which will affect my acceleration performance.
Or lower my rearend gearing.
Or Both.
It is a compromise situation.
The best all around compromise for my example I feel would be a 4.11 rear gears and a 2800 RPM Flash Stall TQ.
That places me at appx 40 mph lockup for drivability at the cost of max acceleration.
Give to Get.

Now you want tire spin?
There are alot of variables as you can see.
[addsig]

Plugged in your given specs to Dyno 2003 with Stock heads and valves (Since you did not mention them I assumed) Large tube headers with mufflers, and single plane manifold. Also assumed a 109 lobe center, solid lifters, and 9.5 compression.
It estimates your max Torque at 366 at 4000 rpm and max HP is 329 at 5000 rpm.
Here is the torque/hp curve:
http://www.xmission.com/~ixtlan/lunati351.jpg

Here is the numbers:
http://www.xmission.com/~ixtlan/lunati351b.jpg

Enlarge the pics to view the numbers.

Draw your own conclusions.

_________________


<font size=-1>[ This Message was edited by: ixtlan on 6/1/05 8:44am ]</font>