Supra Forums banner

1 - 9 of 9 Posts

·
Supra OG
Joined
·
2,392 Posts
Discussion Starter #1
I have a BL tranny on my 94 supra TT and am using the AEM ECU. I just upgraded to a small single turbo on stock fuel system (tuned to 405 rwhp on pump gas, 487 rwhp on race gas). On the stock setup the stock ECU/Trac Control System/etc retards the timing and closes the sub-throttle during shifts to lower the engine torque. We have the AEM set up now to retard timing and on 1-2 shifts limit the boost to 12 psi (anymore and it just spins the tires anyway). What I want to know is how critical is it to use the sub-throttle on shifts on your built tranny to limit the engine torque. I'm a bit paranoid since I went through a stage 3 SP tranny in the first 5 runs on it at the dragstrip (it took out the 2nd gear sprague clutch). Thanks.
 

·
Registered
Joined
·
484 Posts
I beat the hell out of mine, no retard or boost cut at all, it hammers the gears just fine. I removed the sub-throttle.
 

·
Boost Junkie
Joined
·
12,614 Posts
Same here on a 67mm turbo with about 600 at the wheels.


Steve K.
 

·
Supra OG
Joined
·
2,392 Posts
Discussion Starter #5 (Edited)
racing fan said:
We reccomend running the stock transmission settings with the AEM. It is made for abuse....
Not quite sure I understand your response. You say it is made for abuse but we should set the AEM up to run the stock transmission settings. The stock ECU setup will retard the timing and close the sub throttle during shifts. With an AEM it is hard to close the subthrottle. So, by your response, "it is made for abuse", do you mean that the subthrottle can be left fully open during shifts???

Also, what are you doing different on the 1-2 sprag clutch to ensure it holds up to full throttle shifting with no backoff on engine torque? Like I said, my previous brand new stage 3 SP tranny let go on the 1-2 sprag clutch with less than 50 miles on it just from 5 passes on drag radials during drag racing on my previous stock twin setup running AEM with just 376 rwhp (and near that much torque) on race gas. We weren't retarding time, limiting boost, or doing anything with the subthrottle on shifts when that happened. Now I'm running with even more power/torque on pump gas daily driving. As I found out the stage 3 SP tranny still uses the stock sprag clutch; are you?
 

·
SupraForums Manufacturer
Joined
·
3,333 Posts
XCELR8 said:
Not quite sure I understand your response. You say it is made for abuse but we should set the AEM up to run the stock transmission settings. The stock ECU setup will retard the timing and close the sub throttle during shifts. With an AEM it is hard to close the subthrottle. So, by your response, "it is made for abuse", do you mean that the subthrottle can be left fully open during shifts???

I meant the defualt settings on the aem. That is what we use and reccomend. Give me a call for more details... I can much better answer them over the phone.
 

·
Supra OG
Joined
·
2,392 Posts
Discussion Starter #8
The answer is right above your post from racing fan. I have done nothing further on my AEM except introduce some (not noticeable from the butt dyno) timing retard on shifts and adjust the shift points for personal preference. I have raced the car twice at the drag strip and so far it is holding up good. I'd still like to hear why the stock 2nd gear sprag wont' go out sooneer or later from the raised torque/hp of my small single. I had one other built transmission eat it on the 2nd gear sprag within 5 passes at the strip (and this is with less than 100 miles on the transmission). Obviously, I'm concerned that it will happen again and lead to more months of down time. At this point, I'm only going to drag race occassionally to save wear and tear - this is my daily driver so I don't want break it.
 

·
Registered
Joined
·
205 Posts
What temps on the BL tranny is recomended.....low/max.

Just got the car running after turbo/fule/aem upgrade.Got a B&M cooler with fan and wounder if i need to get the fan working right away. Will be running alot of 1/4 miles this weekend and I want to run it safe :)
 
1 - 9 of 9 Posts
Top