Having trouble with reaction times lately.

During a normal, weekend bracket race with not much time between passes, reaction times make sense. Nothing crazy, all what I consider normal.

During a two-three day race with a lot of time between passes, I've noticed that the deeper in rounds I go, the quicker my reaction times get- by .025-.030. I put in a trans temp gauge to see if there's a correlation, and there sure seems to be- if trans is colder (stage at 140 or less) r/t is a lot slower than if I stage with trans at >180. So far a couple transmission guys have told me that's not what causing the trouble- but I've got a couple weekends of data that sure seem to prove otherwise.
Trans is a glide, BTE pro brake, big pump, running Hygard fluid. K&R box (new last year) and I don't think it's me, at least not on a practice tree, and like I said at a single day event with not much time between passes, lights make sense.
Been doing this off and on over 20 years and never had this problem that I'm aware of anyway, but this is the first trans I used hygard in.
Data log don't show any difference in converter flash so far, havent checked the logs from Saturday yet however. Using the two-step built in my grid.
Could my grid be screwing up, is it me, or is it trans fluid temp?

I think what you may have discovered is related to the fluid. At 140 deg, it is just not flowing as seasily as at a higher temp.

A more interesting question would be how it performs when it gets REALLY hot. I did have someone tell me that conventional fluid breaks down at high temp and will affect your reaction time. I think it is less likely that it is fluid, but more likely that the heat is changing the tolerances within the converter.

Use a good synthetic fluid to help reduce this effect.

Colder trans fluid = slower reaction times and lower stall and the opposite is also true for hotter fluids. If your converter is right you could see slower ET's with hot fluid!

The bottom line is your deal with a fluid couple and the viscosity of the fluid impacts performance.

quote:

Originally posted by TOP38:
Use a good synthetic fluid to help reduce this effect.

The bottom line is your deal with a fluid couple and the viscosity of the fluid impacts performance.

This^^^

Synthetic fluid's viscosity remains stable from cold to hot.

This is why we developed the fluid we did. To stabilize pressure throughout a very large temperature range! take a look. And we have free freight right now.
http://ftiperformance.net/High...ission-Fluid_c73.htm

Greg

anything below 140 you can bet you will be a little slow, IE .05-.08, once you get above that and in between 140-210 it is consistent, after about 210 you will start to see reaction time loss of .03-.7 per 15 degrees, we have been at 260 and been .030 off and the car will also slow down.

quote:

Originally posted by FTI:
This is why we developed the fluid we did. To stabilize pressure throughout a very large temperature range! take a look. And we have free freight right now.
http://ftiperformance.net/High...ission-Fluid_c73.htm

Greg

Think you can get me some here in say, about two hours?
Got a Thursday Night TnT/$500 bracket race tonight, I'm going to stop on the way home from work and try to find some Type F somewhere, and try to watch my trans temp real close tonight.
I know my converter needs freshening up, AJ runs a lot of the same races I do and his FTI converter/combo is flat out nasty consistent. Tried about every other three-letter converter company, may just give you guys a try at freshening up this old 8".

Go get some dex6 that is a good fluid as well!! should be able to get it at any parts store.

Greg

I sort of came to the same conclusion as others mentioned.

I switched to a light weight Racing Synthetic Type F and just from a "seat of the pants" feel, it seems better or more consistent.

This is from a guy who has spent and spends plenty of time assessing shift quality and performance of multi disk clutch packs.

As an aside, all current OEM have switched to lighter weight oils. Do some digging and compare various ATF's centistokes at the standard rated temperatures of 0C and 100C.

Good luck with whatever you choose.

I've been using Mobil 1 Synthetic trans fluid forever, 20 years or more.....

I just bought 6 gallons of the FTI fluid to try in both cars this year with fresh convertors and transmission. We shall see how it works. I never had any complaints with the Mobil 1.

quote:

Originally posted by Mike Beck:
I've been using Mobil 1 Synthetic trans fluid forever, 20 years or more.....

I just bought 6 gallons of the FTI fluid to try in both cars this year with fresh convertors and transmission. We shall see how it works. I never had any complaints with the Mobil 1.

I would like to know if you can tell any measurable difference.

Mike,I would like to know exactly which mobil1 fluid you used. Looking for something to pick up local and not having any luck on Allison transynd.

Update...grabbed some dex6 and changed fluid before I went tonight.

Same deal. Warm trans up to 185 or so, .50x bulbs. Accidently rocked in a fuzz deep in the 2nd round, was set up for a .510, went -.498. Wasted the bye run I earned from my first round r/t. Oh well. Noticed it shifted harder than it ever did before, and we had some good air but I believe based on log book data it picked up a couple hun.
Made a test hit after they ran the finals, trans at 145 when I staged, same 1.023 in the box, felt like a good hit...551.
Had mostly hipster brakes in the past and used regular ol' Type F, and I dont remember temp affecting r/t that much.
Surely not a solenoid problem, or possible that the solenoid needs shimming a little?

quote:

Originally posted by Iforgot:
Having trouble with reaction times lately.

Data log don't show any difference in converter flash so far, havent checked the logs from Saturday yet however. Using the two-step built in my grid.
Could my grid be screwing up, is it me, or is it trans fluid temp?

You have Grid so try using the Data Acquisition feature. Take your -.498 and .551 RT runs and zero both to launch release. Then overlay the runs.

Here’s what else you can do with Grid. Take the Pink Step 1 wire and run it to your TB button input on your delay box. In Grid Data Acquisition / Start Recording tabs program Engine RPM above to a value slightly less than engine idle and program the AND to be Step1.

This is what happens. When you push the TB button after you stage, Grid will start recording.

Here’s what you’re going to be looking at in your Data Acquisition after the run. From the time Step1 input “de-energizes” or goes low to the time the Launch Input goes low, should be “very close” to the same amount of time that you have programmed into your delay box.

What you want to do is get several acquisitions, zero to Step1 release, and then overlay them. Knowing the programmed delay for each run the differences in release should be the same time period from Step1 release to Launch release. You’re looking for any inconsistency in this time period.

Not to hi-jack the OP's thread, and on a similar subject regarding transmission temps and E.T. performance, I will share my findings with transmission temps.

First off, some specs with my car. It's a 72 Nova, 406 SBC on gas, mainly a Footbrake ride with some occasional top bulb racing. Powerglide with 1.80 straight cut, 8" Convertor, 9 Inch Ford rear with 4.86 gear, 28 x 9 x 15 slicks running 6.50ish range 1/8th mile. My transmission lines still go into an aftermarket aluminum radiator with OEM fittings with I believe its -6AN line and fittings.

I read people's post about temperature ranges getting up in the 200 degree range. I'm gonna be completely honest, its all I can do to get my temps to 160 degrees, even hot-lapping from being double entered at some events. I installed a transmission temperature gauge last year for another "tool" to better predict my car's performance. It reads directly from the aluminum deep pan. I have for several years (approx. 10 plus years) ran straight Hydraulic oil in my transmissions. The Multi-trac version used in John Deere hydrostatic mowers. I believe its the AW-32 or AW-46 (I can check later, if the difference between the 2 are important). I would try to warm the car up to the 150-155 range, stalling the car several times to get the temp up to range. Usually by the time I run the car for first time run the transmission temp is back down in the 130-135 range. I say all of this to get to my points here...If the motor is cooled down to same temperature range 140-150 and the transmission temperature is in the 130-140 range, my car would not vary much (a few thou) from run to run. With the motor at same 140-150 range but the transmission temperature in the 145-155 range, I can normally expect an .015-.020 quicker ET in my car. Hotter, thinner fluids is my conclusion to that. I wouldn't notice any noticeable difference in RT's but there again I'm mainly footbraking.

Which leads me to my second and final point. I saw the advertisement for the new FTI fluid and I'm a sucker for anything that's suppose to help improve performance and consistency. So I purchased the fluid and filter package and installed over the winter. My thinking and goal was to see if the new fluid would do away with that ET difference in the different temperature ranges that I was experiencing with the straight hydraulic fluid?? Well I'm a little over a month into the racing season and I still have the same ET difference with the FTI fluid. I'm by no means "disappointed" or "dissatisfied" with the results I've received so far. Its one of those things to where you don't know til you've tried. I'm just sharing the results of what I've experienced so far, and it might just be the "combination" of what I have as a race car. Its not a state of the art ride and I'm ok with what it does as long as it stays predictable. I may have the same ET difference regardless of what I use for transmission fluid. There again just sharing my real world results so far.

Sorry for the long post and hope the information helps someone who may be interested.

Lizzard,
Thank you for sharing your detailed info. So you don't run an external trans cooler, just the one built into your radiator tank? Or did I misunderstand. That is quite remarkable that your trans temp stays so cool. I run alky, so my engine does nto get hot, but my trans fluid sure does, double entries in the summer are tough.

quote:

Originally posted by markemark:

You have Grid so try using the Data Acquisition feature. Take your -.498 and .551 RT runs and zero both to launch release. Then overlay the runs.

Here’s what else you can do with Grid. Take the Pink Step 1 wire and run it to your TB button input on your delay box. In Grid Data Acquisition / Start Recording tabs program Engine RPM above to a value slightly less than engine idle and program the AND to be Step1.

This is what happens. When you push the TB button after you stage, Grid will start recording.

Here’s what you’re going to be looking at in your Data Acquisition after the run. From the time Step1 input “de-energizes” or goes low to the time the Launch Input goes low, should be “very close” to the same amount of time that you have programmed into your delay box.

What you want to do is get several acquisitions, zero to Step1 release, and then overlay them. Knowing the programmed delay for each run the differences in release should be the same time period from Step1 release to Launch release. You’re looking for any inconsistency in this time period.

Awesome!! I had been trying to figure out some way to do just that, but couldn't see the forest for all the $&)/! Trees!! I will be doing that tonight- going to hit Gulfport tomorrow if all goes well. You'd think a dude that programs DDC controls for a living would've thought of that but I never thought of doing it that way.
I had been doing the overlays, the grid is a fine tool for figuring out what's going on during a pass..thanks for the info!

^^^^^^^^^ In Stop Recording, you might have to program the Engine RPM Below to 500 to keep the DA running.

quote:

Originally posted by LIZZARD
the transmission temperature is in the 130-140 range, my car would not vary much (a few thou) from run to run. With the motor at same 140-150 range but the transmission temperature in the 145-155 range, I can normally expect an .015-.020 quicker ET in my car. Hotter, thinner fluids is my conclusion to that. I wouldn't notice any noticeable difference in RT's but there again I'm mainly footbraking.

I Seriously doubt your consistency issues have anything to do with transmission temps! Regardless of which fluid is in it.

After 40 degrees celsius, viscosity changes are minimal. 40 degree C is only 122 F. Also check your trans temps on the return road and not the staging lanes.
DEX III Chart

According to the Data, Lightweight Racing is the best for consistency!

This message has been edited. Last edited by: Pro_ET,

quote:

After 40 degrees celsius, viscosity changes are minimal. 40 degree C is only 122 F.

Agreed. You don't get significant changes in the graph over temp until down to 20 degrees C. We simply don't use our trans fluid down at that temp.