Launch control
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AudiWorld Super User
Joined: Nov 2016
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From: Illinois
Launch control
As many of you know, I have a Racechip in my B9.
Now, Racechip sent me a new update a few days back since the one they sent me two weeks or so back caused the start stop error once. They asked me to check it out and let them know how it is. There is a difference in the torque curve in the latest update (which I got maybe a week back). It feels slightly less punchy compared to the old one. I did maybe five launch controls between the two maps.
One thing I noticed today was that the latest update I got has lowered the launch control rpm!!! Earlier, launch control rpm was 2800 in my car. With the new map, it has been lowered to 1800. I first noticed it a few nights back (I record the speedo when I do it). I thought maybe I botched it up and didn't do it properly.
So today, I went out and did two more and realised that the launch control rpm was indeed 1800 and not 2800 as before.
My doubt is that whether a map could change the launch control rpm. Any idea?
Now, Racechip sent me a new update a few days back since the one they sent me two weeks or so back caused the start stop error once. They asked me to check it out and let them know how it is. There is a difference in the torque curve in the latest update (which I got maybe a week back). It feels slightly less punchy compared to the old one. I did maybe five launch controls between the two maps.
One thing I noticed today was that the latest update I got has lowered the launch control rpm!!! Earlier, launch control rpm was 2800 in my car. With the new map, it has been lowered to 1800. I first noticed it a few nights back (I record the speedo when I do it). I thought maybe I botched it up and didn't do it properly.
So today, I went out and did two more and realised that the launch control rpm was indeed 1800 and not 2800 as before.
My doubt is that whether a map could change the launch control rpm. Any idea?
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From: San Francisco Bay Area
Yes, that could very well be. Launch rpm is based on where peak wheel torque comes in and the range over which it is maintained and by how much wheel torque drops in the next gear. 1800 rpm does seem a bit low as once you launch, the rpm will drop some. With the stock tune, peak torque comes in at 1600 rpm. Unless the new torque curve has peak torque at a lower rpm, 1800 seems awfully close to the low end of the torque curve.
This is a good video to explain all that factors into maximum acceleration. It's simplified, because he doesn't factor in wind resistance. Ultimately for fastest acceleration at a given vehicle speed, you need horsepower. He has another video that explains that. I'll post it if I can find it again, but the formula for acceleration is a = HP / (v * m). a is acceleration, HP is horsepower, v is current vehicle speed and m is vehicle mass, so you can see that the more horsepower the car has the faster it accelerates at any speed.
This is a good video to explain all that factors into maximum acceleration. It's simplified, because he doesn't factor in wind resistance. Ultimately for fastest acceleration at a given vehicle speed, you need horsepower. He has another video that explains that. I'll post it if I can find it again, but the formula for acceleration is a = HP / (v * m). a is acceleration, HP is horsepower, v is current vehicle speed and m is vehicle mass, so you can see that the more horsepower the car has the faster it accelerates at any speed.
Last edited by superswiss; Feb 11, 2017 at 11:08 AM.
Thread Starter
AudiWorld Super User
Joined: Nov 2016
Posts: 3,324
Likes: 47
From: Illinois
Yes, that could very well be. Launch rpm is based on where peak wheel torque comes in and the range over which it is maintained and by how much wheel torque drops in the next gear. 1800 rpm does seem a bit low as once you launch, the rpm will drop some. With the stock tune, peak torque comes in at 1600 rpm. Unless the new torque curve has peak torque at a lower rpm, 1800 seems awfully close to the low end of the torque curve.
This is a good video to explain all that factors into maximum acceleration. It's simplified, because he doesn't factor in wind resistance. Ultimately for fastest acceleration at a given vehicle speed, you need horsepower. He has another video that explains that. I'll post it if I can find it again, but the formula for acceleration is a = HP / (v * m). a is acceleration, HP is horsepower, v is current vehicle speed and m is vehicle mass, so you can see that the more horsepower the car has the faster it accelerates at any speed.
This is a good video to explain all that factors into maximum acceleration. It's simplified, because he doesn't factor in wind resistance. Ultimately for fastest acceleration at a given vehicle speed, you need horsepower. He has another video that explains that. I'll post it if I can find it again, but the formula for acceleration is a = HP / (v * m). a is acceleration, HP is horsepower, v is current vehicle speed and m is vehicle mass, so you can see that the more horsepower the car has the faster it accelerates at any speed.
And yes. 1800 is awfully low. When it launches at 1800, the rpm drops to less than 1500 when I take off. Anyway. I've mailed Racechip asked them to send the previous update back since the new one loses out on the punch.
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Joined: Feb 2010
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From: Lawrenceville, NJ
Was your car fully warmed up? I find it odd that the launch RPM would be changed by a piggyback since all it does is fool the sensors. You need to actually change the ECU in order to program the change.
On a side note, how do you know when you get a new update? They told me I would be getting one but every time I open the app nothing pops up.
On a side note, how do you know when you get a new update? They told me I would be getting one but every time I open the app nothing pops up.
Thread Starter
AudiWorld Super User
Joined: Nov 2016
Posts: 3,324
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From: Illinois
Was your car fully warmed up? I find it odd that the launch RPM would be changed by a piggyback since all it does is fool the sensors. You need to actually change the ECU in order to program the change.
On a side note, how do you know when you get a new update? They told me I would be getting one but every time I open the app nothing pops up.
On a side note, how do you know when you get a new update? They told me I would be getting one but every time I open the app nothing pops up.
They sent me an update a week back after I told them about the start stop error I got. But it feels less punchy. I mailed them asking them to send me the previous update back since that was nice and punchy.
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Car was fully warmed up. Tried thrice. Same result. I had that doubt too since it was just a piggy back.
They sent me an update a week back after I told them about the start stop error I got. But it feels less punchy. I mailed them asking them to send me the previous update back since that was nice and punchy.
They sent me an update a week back after I told them about the start stop error I got. But it feels less punchy. I mailed them asking them to send me the previous update back since that was nice and punchy.
Thread Starter
AudiWorld Super User
Joined: Nov 2016
Posts: 3,324
Likes: 47
From: Illinois
Yup. Two updates ago, the car felt almost exactly as stock. But they did send me another update after I told them about this issue with CW being cheaper yet powerful and they sent a new map which was nice and punchy but it threw up a start stop error for me.
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Thread Starter
AudiWorld Super User
Joined: Nov 2016
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Likes: 47
From: Illinois
