Stock Transmission Limit

[Reda90]

Hi everyone,

I looked around the thread and couldn't really find what I was looking for, but I'm sorry if I missed it and this has been posted before. I daily drive my Supra and am planning to get it tuned by Boostin Performance in the next couple of weeks, I have a CAI, downpipe, chargepipe w/BOV, Visconti Flex Fuel Kit and will have the fuel pump installed so I can run full e85.

My question is what are safe numbers for the transmission so I don't need to upgrade it or have it break as this is my only car right now, I know the engine should handle up to 800, so I'm not as concerned, but it seems like the transmission limit is somewhere around 600 tq.

Thank you

Tagging @zrk and @Marin@MarinTuned because it seems like you guys have the most knowledge on something like this, thanks!

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[MisterSkiz]

Its what I have read as well - around 600wtq.

Heat and torque kill transmissions, also commanding high power at low speeds in high gears is never fun for them either.

From what I have seen by someone who has a '21 and was tuned with E50 at AMS they were making ~525whp/~560wtq.

I basically have it in my head that Ethanol and stock turbo is the limit for the OEM trans - anything more and you need to upgrade.

Also, if this is your only car you really shouldn't be modifying it crazy...as soon as you modify it all bets are off.

 

[Reda90]

Its what I have read as well - around 600wtq.

Heat and torque kill transmissions, also commanding high power at low speeds in high gears is never fun for them either.

From what I have seen by someone who has a '21 and was tuned with E50 at AMS they were making ~525whp/~560wtq.

I basically have it in my head that Ethanol and stock turbo is the limit for the OEM trans - anything more and you need to upgrade.

Also, if this is your only car you really shouldn't be modifying it crazy...as soon as you modify it all bets are off.

Yea after the tune I don't plan on doing any more power upgrades, just trying to figure out how close I can get to 600 without problems.

 

[MarinTuned]

We have an article on our website about this actjally. I’ll post the link below.
It’s more so gear dependant as well. So when we caligrate the torque requests we change them based on the gear to help.

https://support.marintuned.com/supp...imits-car-randomly-revs-to-redline-wont-shift

 

[Reda90]

We have an article on our website about this actjally. I’ll post the link below.
It’s more so gear dependant as well. So when we caligrate the torque requests we change them based on the gear to help.

https://support.marintuned.com/supp...imits-car-randomly-revs-to-redline-wont-shift

Wow, that's an awesome read, thank you!

Would I be correct then, in thinking, I can limit the torque to 530-550, and then have the horsepower be 600-630, and have it be reliable still?

 

[suicidaleggroll]

I have a CAI, downpipe, chargepipe w/BOV, Visconti Flex Fuel Kit and will have the fuel pump installed so I can run full e85.

I didn't see it mentioned, but I'm pretty sure you can't run full E85 without port injection as well.

 

[Mason]

600 tq

Need port for e85

 

[EddieNel]

Great read. Thanks for sharing.

 

[jRuN]

600 tq

Need port for e85

Do you only need port, or do you also need an upgraded pump?

 

[Mason]

Do you only need port, or do you also need an upgraded pump?

You need port + pump to run full e85

 

[MarinTuned]

You need port + pump to run full e85

correct. With tweaking and pushing the car you can run E85 with port and a stock pump but it’s at the absolute limit IMO and it is a better better option to add a LPFP.

 

[MarinTuned]

Wow, that's an awesome read, thank you!

Would I be correct then, in thinking, I can limit the torque to 530-550, and then have the horsepower be 600-630, and have it be reliable still?

this is within reason yes. Liability wise this is still a “new platform” so I will say no gaurantees. I pushed my daily at 700wtq but we have advanced since then But my trans is fairly worn out. With our newer work we’ve found ways to make slightly more with less strain. We did push estimated 800-850 ish torque for a short period. We we’re surprised.

 

[Cyph]

this is within reason yes. Liability wise this is still a “new platform” so I will say no gaurantees. I pushed my daily at 700wtq but we have advanced since then But my trans is fairly worn out. With our newer work we’ve found ways to make slightly more with less strain. We did push estimated 800-850 ish torque for a short period. We we’re surprised.

Does the a90 chassis do well with 700tq (or even 600tq) and lateral inertia? Weird question but I’m curious of your input. I’m weary about pushing for more power beyond 480whp and 480tq currently on piggyback. I’m only assuming that 650 tq is the sweet spot for lateral shit without having to up axles and trans.

 

[Rekadae]

Yea after the tune I don't plan on doing any more power upgrades, just trying to figure out how close I can get to 600 without problems.

Just do E50 with flex fuel and you'll be faster than most cars on the road.

Once you want more than E50 power, it starts getting expensive fast. Trans $6k+ Port Injection w/ Controller $2500 minimuum

You can risk it and run port injection for more power and get where you want but your trans will be on borrowed time.

 

[Twisted Tuning]

I didn't see it mentioned, but I'm pretty sure you can't run full E85 without port injection as well.

yes you can definitely run full e85 without port. however, to maximize power available on E85, you would need port. we were running E85 back in 2019. but on stock HPFP and no port, its more of a simple mixing convienience, than a max power option.

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