2021 baseline runs -- deep 11's with the basics

[AHP]

So do you think just the 2nd gear launch is what contributed to higher trap speeds in the last three runs?

No, seems to be related to heat soak. When I arrived I didn't let the car cool down at all. No one was running so I immediately went to tech and got in the lanes and hot-lapped. There were a few more degrees of ignition advance on the last 3 due to better AIT hence the MPH diff. Passes 2 and 3 were hot-lapped but AITs were back down by them time I got back to the staging lanes.

Thanks! I had no idea you could just toss in more etoh and the car would compensate. When you say lean, it’s because the factory fuel setup can’t keep up past around E40?

What’s the unit on the X axis of your graph, time? What’s the scale if it’s time?

Software limitation vs hardware (at this point). The DME trims are limited to +/- 25 (not sure if that is 25% or arbitrary) and once you max out the trims you'll get a lean code. With a proper tune you can extend that until you hit a physical limitation, hence being able to do E50.

No. While there are throttle closures at shift points, there are several more. They can be smoothed out a little bit, but these actually don't look all that bad. It never fully closes. JB4 will adapt a little bit over time.

@AHP how about that log file

I'll post a link once I have a chance to log back in and set to public. I also have some thoughts and assumptions on the throttle closure that I will cover when I have moment later today. I think it can be somewhat improved with a custom map and different launch strategy.

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[AHP]

Can you feel the closure like if you hit the rev limiter? Or it’s just computer things happening in the background that are unnoticeable unless you check a log file?

You can definitely feel it. On the launch it completely falls on its face, though I believe this can be partially solved with a different launch technique. It also bucks pretty hard on the shift which you can see in the logs. That too I think can be partially solved with the boost shift reduction but need to experiment further. All things that a proper tune would directly address.

 

[AHP]

@zrk

https://datazap.me/u/ahp/112-124?log=0&data=1-4-5-9-11-14-18-25-26-27-28-29&zoom=39-117

 

[Sereph102889]

First time out with the car to get some baseline numbers and start figuring out the 60'. Conditions were not ideal ~2000' DA and a gnarly headwind/crosswind but the track was empty and hooking, so can't complain. Goal was 11.5 or better but mostly concerned with getting data and seat time.


2021 Supra

• MST V2 intake
• AMS catted dp
• JB4
• E30'ish
• Titan drag pack - 305/45/17 MT ET S/S
• full-weight, nothing removed

First two passes were 1st gear launch, 2nd gear afterwards. Lots of takeaways so looking for 11.0's with a few tweaks and ideally better DA next time out. Next up axles and ECUTEK (early, unencrypted 2021 ), at least. I'm experiencing some pretty invasive and extremely annoying throttle closure and don't believe that can be solved with out a tune.








(quality is terrible since it was DM'd to me)

This is super impressive. I haven't taken my car to a track yet, so no prep, and the best I've managed is an 11.34 with a terrible 2.06 60foot. This was on old backroads. My car is MHD tuned, stage 2 on E40. Basically this is showing me how important a good 60' is and letting me know my car would probably easily hit a 10.9 or lower on a prepped surface.

Were you running traction fully off or one press off, and what RPM were you launching at when you were doing your second gear launches?

 

[zrk]

how important a good 60' is

one-tenth off a 60' is two-tenths off the back end. (on average).

 

[Sereph102889]

one-tenth off a 60' is two-tenths off the back end. (on average).

So basically, with my best pass of an 11.34 with a 2.06 60', that is an easy 10 second pass on any prepped surface. Good to know, I need to get my ass to a track.

 

[zrk]

So basically, with my best pass of an 11.34 with a 2.06 60', that is an easy 10 second pass on any prepped surface. Good to know, I need to get my ass to a track.

Yeah, that sounds about right. RIP your axles.

 

[Sereph102889]

Yeah, that sounds about right. RIP your axles.

Perhaps I shouldn't visit a track after all, axles be expensive!

 

[AHP]

This is super impressive. I haven't taken my car to a track yet, so no prep, and the best I've managed is an 11.34 with a terrible 2.06 60foot. This was on old backroads. My car is MHD tuned, stage 2 on E40. Basically this is showing me how important a good 60' is and letting me know my car would probably easily hit a 10.9 or lower on a prepped surface.

Were you running traction fully off or one press off, and what RPM were you launching at when you were doing your second gear launches?

Everything off, all the time. It will only allow me to stall up to ~2800RPM; the throttle closure keeps it from going higher and building more boost. I believe brake boosting and holding it was a mistake. A tip I got, which I will try as soon as the weather cooperates, is to go WOT and as soon as the converter flashes side-step the brake pedal. The constant holding that I was doing only exacerbates the issue. With a proper tune that should not be an issue, but the stock calibration is not pleased with that approach.

With your setup you should be deep into the 10's in decent DA on a tire and/or track that hooks. What MPH?

 

[AHP]

one-tenth off a 60' is two-tenths off the back end. (on average).

Ehh... It really really REALLY depends on what's going on -- bogging vs spinning, etc.. Frankly I have never seen a 2:1 ratio; more like 1.25 - 1.5 absolute best, but it really depends on a lot of factors. In many cases it's 1:1.


RE: axles -- this is highly debatable. Ask 3 people and get 4 answers/opinions. I'm aware of the failures with basically stock cars, but I also know of a few that never had any issues with many passes until getting into the 1.4s or better. 2nd gear launches are ostensibly safer due to the reduced TQ multiplication. I do plan on axles and the driveshaft or at least guibo support to future proof, but I have good sources saying not necessary until make real power on the hit.

 

[somekindafuzz]

If you strengthen/switch out the giubo, but leave in the stock driveshaft, won’t that make it more likely to fail? I thought without the flex in the coupler, the driveline would be subject to more initial force. I was worried about changing mine without going for a stronger single piece shaft.

Do I have this backwards?

 

[Sereph102889]

Everything off, all the time. It will only allow me to stall up to ~2800RPM; the throttle closure keeps it from going higher and building more boost. I believe brake boosting and holding it was a mistake. A tip I got, which I will try as soon as the weather cooperates, is to go WOT and as soon as the converter flashes side-step the brake pedal. The constant holding that I was doing only exacerbates the issue. With a proper tune that should not be an issue, but the stock calibration is not pleased with that approach.

With your setup you should be deep into the 10's in decent DA on a tire and/or track that hooks. What MPH?

Ok so I just found the dragy run and I mispoke. It was 11.43 @ 125.70 with a 2.06 60ft. So it wasn't 11.34, it was 11.43. But that 60ft is still garbage!

 

[AHP]

If you strengthen/switch out the giubo, but leave in the stock driveshaft, won’t that make it more likely to fail? I thought without the flex in the coupler, the driveline would be subject to more initial force. I was worried about changing mine without going for a stronger single piece shaft.

Do I have this backwards?

The issue I'm trying to mitigate is if the rear guibo fails the driveshaft whips around and will burst the fuel tank. Titan has a safety loop that should address that, but I'd prefer to prevent a failure to begin with.

 

[zrk]

Ehh... It really really REALLY depends on what's going on -- bogging vs spinning, etc.. Frankly I have never seen a 2:1 ratio; more like 1.25 - 1.5 absolute best, but it really depends on a lot of factors. In many cases it's 1:1.

if you're on a decent pass, it's typically 2:1. At least at every event I've ever been at.

RE: axles -- this is highly debatable.

Indeed, some fail early.

2nd gear launches are ostensibly safer due to the reduced TQ multiplication.

This is the opposite of what I've seen. I've seen more broken axles on 2ng gear launches than first.

I've only seen MKVs run a couple hundred passes all in, though, so I do understand my sample size is very low,

 

[AHP]

Ok so I just found the dragy run and I mispoke. It was 11.43 @ 125.70 with a 2.06 60ft. So it wasn't 11.34, it was 11.43. But that 60ft is still garbage!

MPH is certainly there for a solid 10 provided you can 60' the car.

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