Warning about dragrace starts with torque converter

JimGnitecki · 06-07-2006, 09:17 AM

For those of you who go to the drag strip and have an SSR with automatic transmission, not the temperature warning for the torque converter in the following quote off a website that sells dragracing equipment:

"Stage control or starting line control cylinder and valve kit.
This is very useful for not only *DYO cars but class cars as well.
For DYO race cars it allows you to stage the car at idle with the throttle pedal all the way open. The valve opens the throttle wide open once the transbrake is released, then just before the delay in the box releases the engine is at the chip limit set in the MSD. This does several things. One it prevents someone from burning you down on the start line. This is not so much engine temperature but trans temperature. We have observed the temperature of the fluid coming out of the converter while at stage rpm will skyrocket from 160F to 280F in less than 2 seconds. This is not only hard on the converter and trans but causes inconsistency in the vehicle elapsed time. Neither of which is a good thing. The solenoid powers the cylinder in both directions. When you activate the unit the throttle pedal goes to the floor and the car continues to idle. When you release the unit the throttle pedal is already on the floor held there now by your foot and the cylinder is powered in the other direction to open the throttle. By installing a optional bleed valve you can regulate how quick the cylinder will open."

You've been warned . . .

This is why I NEVER use that "foot on the brake while revving engine up" technique.

Jim G

poppa · 06-07-2006, 10:01 AM

Quote:

Originally Posted by JimGnitecki

For those of you who go to the drag strip and have an SSR with automatic transmission, not the temperature warning for the torque converter in the following quote off a website that sells dragracing equipment:

"Stage control or starting line control cylinder and valve kit.
This is very useful for not only *DYO cars but class cars as well.
For DYO race cars it allows you to stage the car at idle with the throttle pedal all the way open. The valve opens the throttle wide open once the transbrake is released, then just before the delay in the box releases the engine is at the chip limit set in the MSD. This does several things. One it prevents someone from burning you down on the start line. This is not so much engine temperature but trans temperature. We have observed the temperature of the fluid coming out of the converter while at stage rpm will skyrocket from 160F to 280F in less than 2 seconds. This is not only hard on the converter and trans but causes inconsistency in the vehicle elapsed time. Neither of which is a good thing. The solenoid powers the cylinder in both directions. When you activate the unit the throttle pedal goes to the floor and the car continues to idle. When you release the unit the throttle pedal is already on the floor held there now by your foot and the cylinder is powered in the other direction to open the throttle. By installing a optional bleed valve you can regulate how quick the cylinder will open."

You've been warned . . .

This is why I NEVER use that "foot on the brake while revving engine up" technique.

Jim G

Jim
What do you recommend for a drag race start, if not power braking, just step on it?
Thanks
Poppa

JimGnitecki · 06-07-2006, 10:09 AM

Yes. On a STOCK SSR, this WILL produce slower results, but unless you are really "racing", the abuse of your evhicle is hard to justify.

Jim G

poppa · 06-07-2006, 10:21 AM

Thanks!!
Being from the "old" school I never would have realized that and probably damaged my tranny. Today is a good day. I learned something.
Poppa

Wildcat69 · 06-07-2006, 02:45 PM

Jim, Any ideas on who makes the best stage control kit for our SSRs?

JimGnitecki · 06-07-2006, 03:08 PM

Wildcat: Sorry, I'm not into dragracing!

I have too many friends whom I have seen do lots of damage over a period of dragrace outings!

Street vehicles are not engineered for that kind of use.

Jim G

BIG JIM · 06-07-2006, 03:34 PM

The Jim I guess it's a bad idea to do the burn out thing?

JimGnitecki · 06-07-2006, 03:58 PM

Burnouts are actually not too hard on anything except the tires, and they are replaceable for relatively low cost.

Torque converters and automatic tranmissions though are quite costly!

Tire slippage is viewed by most racers as a "cheap fuse" in comparison!

I7ve personally seen too many tranny's fried at the strip.

Jim G

Greg Ducato · 06-07-2006, 06:06 PM

The Torque Converter is the biggest generator of heat in an automatic transmission. Powerbraking puts the converter at it's highest stall speed generating lots of internal fluid friction and quickly elevating internal temperatures. The good news is it cools down pretty quickly too once you get moving. Another trade off in powerbraking from a standing start is that you are not allowing the best suspension travel and weight transfer to occur since you are preloading the suspension while you are sitting there generating all that noise and heat. You are really not doing your transmission any favors by powerbraking since it is hard on many of the internal components as well. If you like to launch then a higher stall torque converter is hard to beat. It will vastly improve off the line performance in the SSR and if you choose the right converter, will not adversley affect low speed driving, fuel economy or trans durability.

JimGnitecki · 06-07-2006, 07:22 PM

Greg should know what he is talking about - he owns and runs Phoenix Transmissions, and his team did the buildup on my own transmission, and installed my high stall torque converter.

I can confirm that there are no bad side effects to getting a high stall torque converter from a shop like Greg's where they know how far to go. I love mine. And, as Greg says, the off-the-line performance is so good that powerbraking would be an unnecessary thing to do.

Jim G

Wildcat69 · 06-09-2006, 06:20 PM

Thanks for the advise Greg and Jim. I'll stick with the higher speed stall converter.

Double-L · 06-10-2006, 07:26 PM

For one thing, Jim I don't know how you can mod your SSR and then not know what it will do in the 1/4 mile, I have a friend like that, Oh well to each his own, The money I have in mine I am at the strip, If it is going to break on the strip it will break on the street, Best way to bring one off the line is bring it up to 2,000 rpm's and nail it, The tires will brake lose just enough to be safe for the truck, After mods, Turn the traction control ON, Come off the line at a idle, Hope for the best, For real fun take mine with traction control OFF come off the line at 2,000 RPM's Light the rear tires up and try to do a full 1/4 mile burnout, You want win any races but the people love it, Thing I will start a a topic on who has been to the drags, Maybe you are right Jim, Not about hurting the SSR but that racing bug gets you and won't let go

AusTexKid · 06-11-2006, 01:10 AM

Using a higher stall converter (3000+) always produces more heat. Even driving around town heats things up because the converter is "stalling" and heating up the fluid just like Greg described. This is especially pronounced in a heavy and under-geared vehicle like the SSR. While I suppose one solution is not to lean on the converter to keep the heat down, this is sacrificing some of the performance you paid for. You really need to load the converter some to get the best launch.

Here is the solution I came up with to handle the extra heat and not damage the transmission. It is a B&M HI-Tek trans cooler (Part No 70297) This cooler is of the more efficient plate-and-fin design and has its own 500 cfm fan to generate air flow. It's a SPAL fan for those of you who are familiar with them. It can be made to fit the SSR and using just the fan will drop the trans temp 10 degrees per minute. While moving it's even better. It comes with a thermostat to control the fan and will activate the fan at 175 degrees. I also added a temp guage and a manual control switch for the fan for cool down between runs.

On a hot Austin night (90 degrees) and with me leaning on the converter quite a bit, the trans temp never went over 200 and mostly ran about 185. This is cooler than the factory set-up which runs the trans about 210. And with the fan on, it will even cool while stopped (or while staged at the track) Because I have it set up as a "pusher" fan in front of the radiator, it even helps with the water temp like Mike's fan kit.

The down side is that it is not an easy install. The area where it mounts is pretty tight. I had to remove the bumper and relocate the power steering cooler to get it in. You'll need to fabricate brackets and cooling lines and do some wiring to get it all set-up. Not rocket science, but I don't recommend it for the inexperienced mechanic.

I guess my point is, if you want to run at the track and lean on the converter it is possible to do it without toasting the transmission. You just need the right equipment. Stock street vehicles are not designed for this, but once you start chasing et's one modification leads to another (and another.....) Cooling is just another step in the process.

JimGnitecki · 06-11-2006, 07:57 AM

Once you have the supercharger heat exchanger in there, I don't think you could fit that cooler and fan assembly in there!

Randy and I have mine set up so that we have the supercharger heat exchanger and the stacked fin transmission cooler both being cooled by Mike's auxiliary fan. That required bending the power steering cooler a bit, and a difficult install where the auxiliary fan mounts from ABOVE, after the headlight trim bar is removed.

This worked REASONABLY well, BUT it has started to work a LOT better since we installed the dual Spal fan assembly for the main engine cooling! NOW that transmission temperature gauge actually stays visibly lower than before.

However, it does NOT stay under 200 as your does, because that supercharger heat exchanger adds both a lot of heat and a lot of resistance to air flow to that whole area.

Jim G

AusTexKid · 06-12-2006, 09:36 PM

I have not seen the cooler for the Magnacharger kit, but I'd have to agree that not much else is going in there with that cooler. The beauty of this cooler is that it does not have to be mounted in the air stream. The onboard fan will cool the trans even if the cooler is mounted horizontally. I watched it drop the temp 10 degrees a minute with just the fan. When my time comes to add the blower I'll have to relocate it. You have to remember that I am running the Yank SS3600 converter. It makes a lot of heat and this cooler kept the fluid at 200 or less even in 90 degree weather with me doing "practice" launches. I'm very impressed with its cooling performance.

But, putting it in the air stream did raise my water temp about 10 degrees above the pre-converter temps I was seeing. It is still putting some heat into the water, but not like it was when the trans ran through the radiator. I can keep the water around 190 and that will have to do until I do a fan upgrade. I plan to stay N/A for a while anyway. The current 112 blower they offer just doesn't interest me for the LS2. I'll wait for the larger "lung"

JimGnitecki · 06-12-2006, 10:08 PM

Austexkid: WHERE is that temperature gauge taking its reading? (I assume you are uoting the temperature displayed by the gauge you have added in the engine compartment, but where is the sensor located?)

Jim G

AusTexKid · 06-12-2006, 10:43 PM

The guage is a "mechanical" gauge (i.e. not electric). The sensor is located in the cooling line coming out of the trans. It is tied in at the point where the new cooler lines come off the factory lines. This is right in front of the crossmember where the lines are secured to the crossmember. It is getting hot fluid right out of the tranny. And before you ask, YES I did verify that I had the right line.

This is why I'm so impressed with its performance. It is actually cooling the OUTPUT temperature by 10 degrees a minute while sitting still!. I have run stall converters in drag racing applications for years and have used all sorts of coolers. This one is impressive. Lots of the rock crawler crowd swear by this cooler. They run at very low speeds with the converter under a lot of stress and it does the job for them. Its only down side is its size so far.