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#496: 12-24-2016, 03:45 PM
 
 PDREALTOR
Title: Member
Location: Oregon
Car: XRT Tuned 2017 Legacy - Wicked CVT
Posts: 86
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Quote:
Originally Posted by surmiser View Post
What we could really use is a fundamentally different way to launch our cars, such as the launch control feature that's built into EcuTek.

In the absence of that, all we can do is max out throttle inputs, then wait for the revs to rise asap. That's what S# gives me. It's still a conventional approach. And still not ideal, but worlds better than what I had.

WOT from stop in S (stock tune) used to slowly roll me forwards while gradually building the revs. There was no way to speed up the process, and getting past 4k rpm was painful, though it was better after that point.

WOT from stop in S# (TH tune) now jerks me forward immediately. Then bogs down a bit as the transmission hooks up. And then picks up again with increasing urgency. Getting past 4k rpm is now a relatively brisk affair. Throttle response is so abrupt that I can't drive constantly in S#, which is why I find SI Mode so useful. It allows me to have an uncivilised mode just for fast launches and quick getaways, and two modes for regular driving. I couldn't imagine having to pick just one throttle map to use 24/7 because there really is no single best one that works for every situation.

One thing that's really helped with WOT launches is the Raceseng lightweight crank and water pump pulleys I installed a week ago. Revs rise faster so the car gets to the sweet spot sooner. I'll post separately about that mod.

What's WOT from stop like for you? Sorry I don't have any 0-60 times to compare yet. Haven't hit the dyno yet either.

It's really great that we're finally sharing experiences from different tuners here. It's a win for everyone.



Sorry, that's what I meant but you explained it far better. When the ignition is off, my car does revert to whatever mode it was in before S# was selected.
From what you're describing your take off in s# is how mine used to be in the earlier tunes. Jumpy.

I've really been focusing a lot of my attention and feedback to Ed (XRT) on CVT drive ability and take offs/low speed WOT hits as opposed to overall power, which has been increasing also but to me as the customer doesn't seem like the challenge for tuning my car.

Or in other words, for me and my habits, the tuning needs to be done in the areas we're discussing here (CVT optimization) more so than top end balls out power..... though it does all tie together in the end.

My take off and low speed WOT hits have changed 110% and the best rom I've gotten has only a couple tiny hiccups on a WOT take off from stop.

Here's how I can best describe it using an analogy (and the behavior is normal to other cars).

When I go WOT from a stop or slow speed in auto the car will now act like a human blowing up a large balloon. Think of how you would blow up a balloon and that's exactly how my car is now behaving.

Blowing up a large balloon I would take a deep breath, then release the air with fierce pressure until I had no air left.

That's exactly what is happening now when I push WOT from stop or very slow speed. The car hesitates (in a good way) as if it's take a deep breath, the RPM needle shoots up and power is applied, for the most part, very smoothly. Again, a couple hiccups but they are very minor.

The key here is that the car is taking WOT input and jamming that RPM needle into the power zone to be applied at take off.

If that doesn't make sense I can try to clarify a bit more.

Last edited by PDREALTOR; 12-24-2016 at 04:40 PM..
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surmiser (12-24-2016)