Alexus_300

iTrader: (4)

I've rebuilt a few A340e and A341E to support high hp successfully before and one thing that I can reassure you is that no matter what you do to the intermediate sprag, the transition from going from first gear to second will cause a dramatic shock which will roll the sprag. This is why all built supra transmission builder will tell you that if you are doing a burnout, leave it in first gear and first gear only. Then once you're finished then you can shift up.

JeffTsai

iTrader: (1)

What about just racing down the strip? You still need to do the 1-2 shift. I would think there is more of a shock when doing a 1-2 shift under full throttle while gripping VS 1-2 shift when tires spinning through a burnout pit.

SC400TT

iTrader: (4)

That is what I have been told...Never continue burnout from 1st into 2nd and suddenly hook up...That is when the sprag rolls.

Jeff, I most respectfully ask again, is there any possibility that sprag can be modified to fit the 2nd gear sprag on the A340 series?

Thanks,

Ryan

speedaddic

iTrader: (10)

and where could we purchase this sprag from?

JeffTsai

iTrader: (1)

I actually managed to break the sprags once again in testing lol. They need to be revised to be stronger. They are probably strong enough for most people, but it's not on par with my requirements. When it's strong enough to withstand my driving, then it will be strong enough for everyone else . I have my shifts in my valve body calibrated to be extremely harsh and that's probably whats snapping these sprags. It is shifting so hard on 2-3 shifts that the car lights up the tires and kicks out sideways on shifts lol

SC400TT, I can spec out the A340E size sprag if I have the sprag housing, sprag itself, and sun gear in my hand. This way I can measure it all out and spec out whatever needs to be sent to the manufacturer.

Speedaddic, sprags would be purchased from me, but R&D is not complete yet so I don't feel comfortable releasing a unfinished product for sale. Once the sprag R&D is complete, I will become a vendor here on CL so I can sell built transmission packages. All the sets I sell right now are for testing purposes, so no guarantee they won't fail. However, I am offering free sprag replacements right now for people that buy a test sprag from me if the sprag fails. I don't think anyone here bought the test sprags from me, but all of the sprags have been purchased over on My.IS.

sam430

iTrader: (10)

Great to see the IS crew is supporting this.. so, the sprag is the only major component a person needs if he's trying to do 400whp reliably (not your level ) ? ...well, including an extra tranny cooler.

if it's more, then we can leave it at that


come to the realm of the v8's...it's just two more cylinders and you won't have to boost too much

SC400TT

iTrader: (4)

Jeff I sent you a PM.

Ryan

Supraownzu

iTrader: (1)

are any of the AEM EMS users on here using the aem to control the transmission at all??? I have swapped my car over to a A340 and with the AEM controlling the transmission, I have been more or less having the EMS granny shift it for me (pulling timing ect... between shifts). Just wondering if in addition to the sprag, possibly we may be looking at more of a control issue with the transmissions. like jeff is saying, he feels the added snap of the valve body upgrade could be the culprit, so just wondering what your exact tranny setup is on your car jeff.

SC400TT

iTrader: (4)

ownzu:

I am planning more or less the same thing with my PCS stand alone for my A340. I will keep you all posted with how it works.

Ryan

Alexus_300

iTrader: (4)

I don't have a A340E transmission apart now to send you the sun gear and all the other parts but I however have a A341E which is a supra TT transmission that is apart if you need any measurement. I happen to have about 4-5 of the intermediate sprag laying around. Also, I wanted to ask you jeff if you are adding more friction material than are required because alot of HP transmission builder out their have the belief that more is better. Nero over at Titan and I have found that to be wrong. There's a reason why people who load up on friction material is boiling there transmission fluid over.

speedaddic

iTrader: (10)

interesting point. I'm using the Haltech 2000 and I believe it can also do traction control. you're using the 2 step LC on the AEM to pull the timing, etc?

SC400TT

iTrader: (4)

The Autronic SM4 also has launch control. I plan to tune that in as well to manage the transmission.

Supraownzu

iTrader: (1)

i dont have the laptop in front of me to remember what the hell aem calls that feature. its not really a 2 step, though i guess it does act like one. just pulls a selectable amount of timing (among other things) from the engine at shift points to help save the tranny. the factory supra tt auto ecu's do the same thing. I was actually lucky enough to get a map from a guy in australia with a supra setup similar to mine, and works awesome so far. just got the car off the dyno making 440whp at 18psi on a mustang dyno, so not quite jeff numbers yet, but thats what 10 more psi of boost is for

JBrady

Hate to see this effort die. Any updates? What do you think is the power/torque capacity of a stock A650e and also one built with the stronger sprags? Stock I am guessing in the 350rwhp/rwtq range.

The stock ECU pulls timing for shifts so maybe that would give some cushion here. Aftermarket tuning options to reduce the shock during shifts may also further the cause as noted by others above.

fastegg

Great to see some one doing all this development work... I used to do this kind of stuff when i was building and racing motorbikes. We used to get clutch baskets made from solid billet and specially made and hardened gears and selectors so i appreciate what your going thru....... Now having said that, if ever i get my baby supercharged i know who to contact about transmission upgrades...