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How much do I need to detune?

GeicoGecko

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Hey all,

After scouring Google and the forums, I've found that I need to detune my stock 2020 Supra for a NASA event at Autobahn next week. For my weight and class, I need to be making a maximum of 310 HP at the rear wheels. Based on my research here and elsewhere on the web, although it was claimed to make 330 HP at the crank, it looks like it actually makes that at the wheels.

Based on my track testing last week, it seems in my best interest to dial the boost back (I hit 290°F oil temp on track). Does anyone have any experience reducing boost and the effect on WHP?

I'll be putting it on the dyno this week to ensure I have the appropriate HP for my class. I can dial it in then, but wanted to get at least an idea before I do that.

Cheers,

Adam
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bk5

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Short shifting is probably the easiest solution. It won't be as fun, but the engine has enough torque that you'll still have plenty of pulling power in 4th and 5th.

Have you asked the people hosting the event how to deal with this? Surely you're not the only beginner who wants to bring a car that's too powerful for the class. You might be able to get away with limiting your speed on the straights and generally not using all of the power that's on tap. Power-to-weight might be a proxy for lap times and top speed. So you'll probably be fine so long as you don't go balls out.

If you have to, adding weight via a ballast is probably easier/cheaper than trying to remove power.
 

i3igpete

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Short shifting is probably the easiest solution.

while OP has a 2020 which can be unlocked and tuned easily, he would need to ensure either boost or RPM is programmatically limited in the DME and it's reflected in the dyno graph that he submits (or at the onsite dyno, if there is one). you can't just tell the race director "I promise to short shift".

that being said, i agree that ballast seems like the easiest solution since he can fine tune it perfectly with gym weights. Just need to find a shop that can fab up a platform that will bolt to the passenger seat location.
 

ColonelAdama

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while OP has a 2020 which can be unlocked and tuned easily, he would need to ensure either boost or RPM is programmatically limited in the DME and it's reflected in the dyno graph that he submits (or at the onsite dyno, if there is one). you can't just tell the race director "I promise to short shift".

that being said, i agree that ballast seems like the easiest solution since he can fine tune it perfectly with gym weights. Just need to find a shop that can fab up a platform that will bolt to the passenger seat location.
Could just JB4 it, enable Bit 3, and run absolute targeting that tapers off boost at peak power. Generally 1 psi down from stock is 10-15whp reduction.

So that is a $400 solution if they allow it. I definitely wouldn't waste money on a custom flash that is slower than stock lol
 

bk5

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Just need to find a shop that can fab up a platform that will bolt to the passenger seat location.
Or build a little cage that bolts to the battery cover in the hatch and hold Olympic Weight Plates. They are a standard size, so it should easy to find off the shelf components to secure them at any big box store. That's probably doable for <$100 in materials, plus cost of the weights.
 

razorlab

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Or build a little cage that bolts to the battery cover in the hatch and hold Olympic Weight Plates. They are a standard size, so it should easy to find off the shelf components to secure them at any big box store. That's probably doable for <$100 in materials, plus cost of the weights.
Are you talking about the board? Yea, I would urge people to NOT bolt weight plates to that. It's just loose in the trunk.

So that is a $400 solution if they allow it. I definitely wouldn't waste money on a custom flash that is slower than stock lol
I'd be more than happy to create a custom ROM for the OP if he needs it. He has a 2020, so he should be tuning it anyway. ;)
 

Todday1

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Is this for a tt class. As 3.0 cars right out of the box usually fit in tt3 depending on tire choice. What class are you trying to run in ?
 

S2k

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MHD in “valet mode” map perhaps?

Not sure if there is any adjustment on this OTS map, but seem to remember the default is 60% power.

Others here will know better! ?
 

bk5

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Are you talking about the board? Yea, I would urge people to NOT bolt weight plates to that. It's just loose in the trunk.
I figured the "secure it to the car somehow" was implied, since anyone who removes it will realize it's just seeing there. But this is the internet, so you never know.

Thank you for saving me from a lawsuit.
 
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GeicoGecko

GeicoGecko

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Thanks for all of the replies. The car was on the dyno this morning. Initial pull showed 330 at the wheels. Backed down the torque between 4250 and 6500 by 6-7% and got it down to a clean 310.

It would normally be in ST3/TT3 but I’ve competed all year in another car in 4. I need to get experience in the car for OLOA but didn’t want to change class.
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