Supra Forums banner
Cancel

Sound Performance or any AUTO whiz

989 Views 16 Replies 6 Participants Last post by  Casey James, 
Casey James
How do you all lock up the TC? You have a switch in the car that locks it up?

And when do you lock it up?

4th gear when cruizing? Do you have it locked-up going down the 1320?

Just wondering..

Thanks

Casey
Reply
Save
Like
1 - 17 of 17 Posts
Knightsport
I would also like to know more about the performance Auto aspect. When do you have to upgrade the tranny? I've heard 500rwhp?


Tanks,
Casey
Reply
Save
Like
Casey James
Hey thanks for the bump! :bthumb:

Casey
Reply
Save
Like
soarer 300
Yes, you are correct. There is an in cabin switch that elecronically locks up the t/c. Ethan (EBanks/700 hp Lexus) had problems with his t/c not locking up on the dyno, and slipping on the street. I don't think this is the same with the TT driverain because the T/C and transmssion are quite a bit stronger. I'm about 99% sure the factory auto tranny in the TT's is good to 525-550 rwhp but almost useless without an upgraded t/c. N/A's aren't worth much past 325 rwhp. There are a few guys on here that run the factory auto trans, with an upgraded converter...I'm sure they'd be able to help too.

Make this same post to Larry @ Sound Performance. He'd most definitely be the man to give you a good answer.

-c
Reply
Save
Like
G
It is a switch to lock up the converter in either 2nd or 3rd gear while drag racing. You do not use/need it for normal driving as the computer still locks up the converter. What it does is almost acts like an extra gear in the 1/4 mile under WOT because the tranny will not lock up under WOT.
With a high stall converter what you gain on the bottom end, you lose on the top end without a lockup switch. With the stock twins you will lose 3-4mph with a high stall if you do not have the lock up switch. With the lockup switch, you will have improved launching ability, and keep the top end charge (and less slippage/power loss) of the stock converter.
The high stall converter slips (even at high rpm) and puts less load on the motor, so at the same wastegate setting you will tend to get less boost, and put less power to the ground than you would with a stock stall at the same boost level. Typically when you hit the lockup switch you will gain 2-4 pounds of boost without touching anything else, so keep that in mind especially if you have a single running at the edge of octane/fuel system capacity.


Remember to to turn off the switch after your run or you will think your car is broken when you are driving slow in the lower gears.
See less See more
Reply
Save
Like
Casey James
So, lets say, after I launched at the track. It shifts into 2nd, I lock up the converter?

Then when I stop, I unlock the TC? And then lock it up again when im crusing in a higher gear?

So basically when racing, lock it up in 2nd or 3rd?

What if from a roll? lock it up in 3rd?

Casey
Reply
Save
Like
Casey James
Oh, I think I get it. The computer still locks it up under normal driving even with the switch? So basically only time you need to mess with it is when at the track or racing? Just lock it up in the higher gears?

I didnt know the computer still locks it up. Thats what threw me off. So lockup is only for our benefit in racing correct?

Casey
Reply
Save
Like
G
turbowash said:
So, lets say, after I launched at the track. It shifts into 2nd, I lock up the converter?

Then when I stop, I unlock the TC? And then lock it up again when im crusing in a higher gear?

So basically when racing, lock it up in 2nd or 3rd?

What if from a roll? lock it up in 3rd?

Casey
Click to expand...
You would lock it up in the middle/end of 2nd gear if your converter/tranny can handle it, you can also lock it up in the middle of 3rd. I never have to lock up when I'm cruising, the factory computer handles that. Under normal driving it locks up into overdrive like a factory unmodified Supra. My best times drag racing have come WITHOUT locking up the converter, but that is because I was not able to run past 24psi without EGT issues, so the couple of times I did try it and hit 28psi I let off the gas and coasted the rest of the way. I just redid my fuel system (I found some issue's with the way a shop installed it, design, high psi leaks and such) a couple weeks ago, and I plan on dynoing this weekend, so once I'm comfortable, I will use it at the track on a high boost run. I've seen it in action on Mark C's car at BPU and APU, and it made a big difference, esp at BPU. His best prior to the lockup switch was 11.73 @ 114, and after the lockup switch he went 11.53 @ 119mph on DR's. At APU he ran 10.20 @ 133mph, so it def works. It's something we stole from our Buick turbo cousins :D. After all they've been with the turbo/automatic thing much longer than us!
See less See more
Reply
Save
Like
Casey James
Ahh, cool thanks man.

Basics, Just lock it up in higher gears at track/racing.

Casey
Reply
Save
Like
G
Locking converters have only been around since the late 70s early 80s or so. Converters are only about 90% or so efficient. Where a clutch is 100% efficient. Back in the day, they invented the lock up converter so that the cars would get better gas mileage when the converter is locked up, making it 100% efficient. On most cars while at a light throttle the car would normally lock up a 45mph or so, some companies call this overdrive. When you go WOT the converter will never lock up because it puts alot more wear and tear on the tranny and converter if it was locked up under WOT. The idea with locking up a converter on the track is to get more MPH and hopefully with the 100% efficentcy the car will ET better also.
Reply
Save
Like
S
What stall was Mark C. running when he went 11.53 at BPU?

I'm considering a 3800 - 4000 converter, but I also like to race around the street a bit/cornering. How is a high stall converter at low RPMs during cornering?

If you lock it up does it downshift easily?

I think I may even want to go a bit lower...say 3200, but I'd like to get opinions of those in the know!

I appreciate the feedback!


Stage7 said:


You would lock it up in the middle/end of 2nd gear if your converter/tranny can handle it, you can also lock it up in the middle of 3rd. I never have to lock up when I'm cruising, the factory computer handles that. Under normal driving it locks up into overdrive like a factory unmodified Supra. My best times drag racing have come WITHOUT locking up the converter, but that is because I was not able to run past 24psi without EGT issues, so the couple of times I did try it and hit 28psi I let off the gas and coasted the rest of the way. I just redid my fuel system (I found some issue's with the way a shop installed it, design, high psi leaks and such) a couple weeks ago, and I plan on dynoing this weekend, so once I'm comfortable, I will use it at the track on a high boost run. I've seen it in action on Mark C's car at BPU and APU, and it made a big difference, esp at BPU. His best prior to the lockup switch was 11.73 @ 114, and after the lockup switch he went 11.53 @ 119mph on DR's. At APU he ran 10.20 @ 133mph, so it def works. It's something we stole from our Buick turbo cousins :D. After all they've been with the turbo/automatic thing much longer than us!
Click to expand...
Reply
Save
Like
G
3800rpm stall. If you go single, I doubt you will be happy w/3200, unless you go w/SP57 or something smallish like that w/small housing. My stall is 4k.
The car is great around the corners (it's like fanning the clutch to build rpm's w/o downshifting), although I do not road race. If I wanted to road race I would have bought a 6spd.



Spool said:
What stall was Mark C. running when he went 11.53 at BPU?

I'm considering a 3800 - 4000 converter, but I also like to race around the street a bit/cornering. How is a high stall converter at low RPMs during cornering?

If you lock it up does it downshift easily?

I think I may even want to go a bit lower...say 3200, but I'd like to get opinions of those in the know!

I appreciate the feedback!
Click to expand...
Reply
Save
Like
S
True, true. However, I could not pass up this car...it was totally stock with 18's and stereo. I do like the auto though...ver relaxing to drive and runs like a scalded dog.

The converter will be a bandaid until the single goes on. At that time I will decide to convert or build the auto, nearly the same in cost.

Does the converter cause the tranny to downshift often or unwantedly?

Until then, I'll get the PI Dragon 3800/4000 converter so I can be more competetive on the street and track!!

Thanks!


Stage7 said:
3800rpm stall. If you go single, I doubt you will be happy w/3200, unless you go w/SP57 or something smallish like that w/small housing. My stall is 4k.
The car is great around the corners (it's like fanning the clutch to build rpm's w/o downshifting), although I do not road race. If I wanted to road race I would have bought a 6spd.
Click to expand...
Reply
Save
Like
G
Stage7 said:
3800rpm stall. If you go single, I doubt you will be happy w/3200, unless you go w/SP57 or something smallish like that w/small housing. My stall is 4k.
The car is great around the corners (it's like fanning the clutch to build rpm's w/o downshifting), although I do not road race. If I wanted to road race I would have bought a 6spd.
Click to expand...


Roberto
Are still runnign the T66?How long have you had your 4k stall TC? do you have an upgraded transmission? and by whom? What is the temperature of you transmission in stop and go traffic and what is the safe temperature range for drag racing? Sorry for all those questions, I just want to learn more about my newly acquired single auto w/3200 stall TC.

Wayne
Reply
Save
Like
K
Hey Stage 7. Didnt you have your tranny done by Pro-Tech transmissions in Harriman,NY?? If so, how would you rate the work they did and what kind of customer service they have? I have heard quite a few good things about them.
Reply
Save
Like
G
KJSUPRA said:
Hey Stage 7. Didnt you have your tranny done by Pro-Tech transmissions in Harriman,NY?? If so, how would you rate the work they did and what kind of customer service they have? I have heard quite a few good things about them.
Click to expand...
Yes I did. My tranny feels great and has survived dozen's of 10 sec passes. It still feels tight and solid. Their customer service was excellent as well. I highly recommend them.

Wayne- I replied to your email.
Reply
Save
Like
Casey James
Stage7, how much did it cost from them for rebuild? Can email me private if you want. Id really like to know.

Thanks,


Casey
Reply
Save
Like
1 - 17 of 17 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Supra Forums
Supra Forums is the largest online Toyota Supra MKI, MKII, MKIII, MKIV and MKV owner's club community. Discuss DIY, modifications, and upgrades.
Full Forum Listing
Explore Our Forums
MKIII (1986.5-1992) MKIV (1993-1998) Other Cars Members Rides General Supra Forum
Top