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codesx 08-09-2019 10:45 AM

Ideal Launch Method, Retaining Performance but Hardware Longevity focused (School me)
 
I'm in the process of further dialing in my tune, with Payam. I'm freaking loving it.

I've read posts talking vaguely about launching/accelerating in such a manner as to not snap crank-shafts or bent rods.

I'd like to fall within the maxed out, but not snapping things category.


Please share your knowledge with me!

-I'm an Auto. Convertible, fat and heavy. (<- car)
-Map 6, 19PSI Flat (from 1500 RPM)
-Meth injection (ensuring clean timing all the way through)
-My rear tires are 275 wide, Indy 500, slick-like treads, grabbing great in the dry hot (and terrible when wet)
-I can spin my rears (easy enough), but can switch into second by 4500 RPM to minimize momentum loss
-Second gear holds (traction off) with just a mild singing if there is any mild deviation in the road
-I'm sure I'm under 4 seconds (edit: I think i am too optimistic here) to 60mph, calculations to come (logs show 3.5 seconds to 60mph from a 40' roll start, hammering at 10mph, zero boost at 'go')

Launching: Given the specifications; Out side of the A/T, is this enough power to damage the drive shaft (or other) if I brake-boost for 1 second? Should I strictly roll launch? Should I reduce boost in 1st to 15 PSI rather than 19? Should I graduate the currently Flat 19 PSI quickly rather than full 19 at 1500 RPM?

THE BEAST 08-10-2019 03:48 PM

Get Dragy and get your times from it. Its the only accurate way to get what you are looking for. Try a few runs with current settings, then try lower psi , etc and see if time improves. I havent ran my car much using dragy, but my 0 to 60 only showed 4.2 on my E93, but yey Ive smoked cars off the line that have 0 to 60 3.8 seconds time. Keep in mind that most cars published times are running back to back all day or even multiple days and they pick the quickest one. Hardly anyone runs 0 to 60 even on the streets, so kinda pointless IMO. Most cars I have ran are freeway and streets ROLLING. A few off the line, but its always been 5 or 10 mph roll in reality when you smash on the gas. I also have E93 as I mentioned to you b4. If you have whatsapp I can share a few videos.

THE BEAST 08-10-2019 04:09 PM

Forgot to mention, snapped an axle on a 2nd gear pull. Have video and pics of that as well. So be careful if your car hooks.

codesx 08-13-2019 10:04 AM

Hey Beast!

I always look out for your posts... another E93 driver!

I would very much like to see your videos, etc.
Interesting you broke an axle. The more detail on that hook up, such as gear, boost, tires, RPM, the better. 2nd gear Launch or just Pull? (I haven't tried 2nd gear launch since Meth introduction... I'm sure I hear my transmission calling out to me when I do it)

Draggy is immanent. Just not today.

I'll PM you shortly with my whatsapp info.

iminhell1 08-13-2019 10:51 AM

I'm 26psi and have done hundreds of launches, coming up on thousand.
No broken axles or anything.

Always 2nd gear launches.


Auto you really don't have to worry as much as manual. The trans will absorb some of the shock and soften it.

THE BEAST 08-13-2019 11:56 AM

Download whatsapp on your phone and send me your #. It was 2nd gear pull when axle gave out, not launch.

THE BEAST 08-15-2019 09:32 AM

So have you experimented with this ?

majorahole 08-15-2019 11:21 AM

I know with a manual you can pull the ebrake and preload the suspension/driveline by slipping the clutch just a bit to get load while the car stays still. then mash it and let of the ebrake simultaneously.

THE BEAST 08-16-2019 11:21 AM

Quote:

Originally Posted by codesx (Post )
I'm in the process of further dialing in my tune, with Payam. I'm freaking loving it.

I've read posts talking vaguely about launching/accelerating in such a manner as to not snap crank-shafts or bent rods.

I'd like to fall within the maxed out, but not snapping things category.


Please share your knowledge with me!

-I'm an Auto. Convertible, fat and heavy. (<- car)
-Map 6, 19PSI Flat (from 1500 RPM)
-Meth injection (ensuring clean timing all the way through)
-My rear tires are 275 wide, Indy 500, slick-like treads, grabbing great in the dry hot (and terrible when wet)
-I can spin my rears (easy enough), but can switch into second by 4500 RPM to minimize momentum loss
-Second gear holds (traction off) with just a mild singing if there is any mild deviation in the road
-I'm sure I'm under 4 seconds to 60mph, calculations to come (logs show 3.5 seconds to 60mph from a 40' roll start, hammering at 10mph, zero boost at 'go')

Launching: Given the specifications; Out side of the A/T, is this enough power to damage the drive shaft (or other) if I brake-boost for 1 second? Should I strictly roll launch? Should I reduce boost in 1st to 15 PSI rather than 19? Should I graduate the currently Flat 19 PSI quickly rather than full 19 at 1500 RPM?

Do you have a log when you are launching ?

codesx 08-17-2019 07:40 PM

PM'd ya.
Will post basic 1,2 maybe into 3rd gear logs this week.

Honestly, I've been dialing in the exact meth/water ratio first.
I think I'm there with Map 6, thanks to Payam.
However, I'm doing a little personal playing with water/meth ratios.
I'd divulge here, however I'm trying to maintain discrete threads for details for the coherency of future readers.

THE BEAST 08-22-2019 10:21 AM

Quote:

Originally Posted by iminhell1 (Post )
I'm 26psi and have done hundreds of launches, coming up on thousand.
No broken axles or anything.

Always 2nd gear launches.


Auto you really don't have to worry as much as manual. The trans will absorb some of the shock and soften it.

Yes, but trans takes the beating as well as rods. There are a few factors of course.

THE BEAST 08-22-2019 03:35 PM

Quote:

Originally Posted by codesx (Post )
I'm in the process of further dialing in my tune, with Payam. I'm freaking loving it.

I've read posts talking vaguely about launching/accelerating in such a manner as to not snap crank-shafts or bent rods.

I'd like to fall within the maxed out, but not snapping things category.


Please share your knowledge with me!

-I'm an Auto. Convertible, fat and heavy. (<- car)
-Map 6, 19PSI Flat (from 1500 RPM)
-Meth injection (ensuring clean timing all the way through)
-My rear tires are 275 wide, Indy 500, slick-like treads, grabbing great in the dry hot (and terrible when wet)
-I can spin my rears (easy enough), but can switch into second by 4500 RPM to minimize momentum loss
-Second gear holds (traction off) with just a mild singing if there is any mild deviation in the road
-I'm sure I'm under 4 seconds to 60mph, calculations to come (logs show 3.5 seconds to 60mph from a 40' roll start, hammering at 10mph, zero boost at 'go')

Launching: Given the specifications; Out side of the A/T, is this enough power to damage the drive shaft (or other) if I brake-boost for 1 second? Should I strictly roll launch? Should I reduce boost in 1st to 15 PSI rather than 19? Should I graduate the currently Flat 19 PSI quickly rather than full 19 at 1500 RPM?

For yourself, and anyone reading this, this is why logs are needed. 19 psi flat from 1500 rpm. Your car, as most others, will not hit 19psi at 1500 rpm. Not without anti lag or something anyway. Yes, I would and I do use, boost by gear limit. Everyone will use a different limit. . Many people have different set ups, turbos, different fuel, different tunes, etc so some may use 10 psi max, others 15psi, etc. Meaning not everyone is making the same torque or whp at 19 psi. Hope this helps.

codesx 08-23-2019 10:35 AM

2 Attachment(s)
Hey Beast,

My intent with this specific thread is to better understand how to limit damage to the car, while still going 'almost' flat out.
I've read some threads where people say "as long as you shift right...", and have wondered what they mean about this.

Examples:
- I believe I'm learning that I should not put my A/T in Manual, put it in 4th at 120kph, then floor it and shift to 3rd at the same time. It hits like a rocket, but this is also how I shredded my serpentine belt last fall. (abrupt RPM change on the crank pulley takes 100-200~(?) ms before other pulleys have adjusted to the same. This can cause momentary stretching of the serpentine belt, causing it to jump one (or more) of 7 groves, resulting in super shredding and possible ingestion into the engine via the crank pulley seal.
- I'm still testing, but maybe manually shifting next to 7000RPM results in poor timing recovery, vs a manual (A/T) shift at 5900 RPM.
- Perhaps timing recovery is harder during shift with the xHP A/T tune? (the DME 'projects' RPM values as it calculates things, this is why, with the xHP A/T tune, you often need to set certain RPM values to "20,000"... not that it will reach this, but if it measures 800, 2000, 6000, it will project in the next 100ms it will reach 16000, meanwhile we are shifting and never get there (fact that some calculations with xHP (if not the transmission itself) use this 'projected calculation').

So, at this point, I'm trying to figure out how people shift, to lighten the intensity on the engine/tranmission/drive-line, while still being (almost) flat out.
(maybe some people let off the throttle by 25% as they shift to help timing recovery?)


--- Meth testing variations (BM10 & BM5) ---
To respond to your earlier suggestion of logs;
I respect it's annoying when someone asks for help and then they don't produce much when asked. This drives us all nuts.
I started this thread just before I realized my meth ratio detail was impacting Fuel Trims and Timing. I'm testing a variety of things, from timing recovery during shift at different ratios, etc.
Currently logging (all values meth/water)
BM10
30/70, 3rd gear pull, 1,2,3,4 pull for timing recovery review (done)
50/50, 3rd gear pull, 1,2,3,4 pull for timing recovery review (done)
70/30, 3rd gear pull, 1,2,3,4 pull for timing recovery review (Fri/Sat)
BM5
100%, 3rd gear pull, 1,2,3,4 pull for timing recovery review (Sun/Mon)
80%, 3rd gear pull, 1,2,3,4 pull for timing recovery review (Mon/Tues)
60%, 3rd gear pull, 1,2,3,4 pull for timing recovery review (Tues/Wed)

LOGs
I've attached generic logs (50/50, BM10) for 3rd and 1,2,3.
We can see that the timing doesn't recover over shifts. I had intended to create a unique thread for that subject after I completed gathering the relevant information.

THE BEAST 08-23-2019 10:55 AM

Quote:

Originally Posted by codesx (Post )
Hey Beast,

My intent with this specific thread is to better understand how to limit damage to the car, while still going 'almost' flat out.
I've read some threads where people say "as long as you shift right...", and have wondered what they mean about this.

Examples:
- I believe I'm learning that I should not put my A/T in Manual, put it in 4th at 120kph, then floor it and shift to 3rd at the same time. It hits like a rocket, but this is also how I shredded my serpentine belt last fall. (abrupt RPM change on the crank pulley takes 100-200~(?) ms before other pulleys have adjusted to the same. This can cause momentary stretching of the serpentine belt, causing it to jump one (or more) of 7 groves, resulting in super shredding and possible ingestion into the engine via the crank pulley seal.
- I'm still testing, but maybe manually shifting next to 7000RPM results in poor timing recovery, vs a manual (A/T) shift at 5900 RPM.
- Perhaps timing recovery is harder during shift with the xHP A/T tune? (the DME 'projects' RPM values as it calculates things, this is why, with the xHP A/T tune, you often need to set certain RPM values to "20,000"... not that it will reach this, but if it measures 800, 2000, 6000, it will project in the next 100ms it will reach 16000, meanwhile we are shifting and never get there (fact that some calculations with xHP (if not the transmission itself) use this 'projected calculation').

So, at this point, I'm trying to figure out how people shift, to lighten the intensity on the engine/tranmission/drive-line, while still being (almost) flat out.
(maybe some people let off the throttle by 25% as they shift to help timing recovery?)


--- Meth testing variations (BM10 & BM5) ---
To respond to your earlier suggestion of logs;
I respect it's annoying when someone asks for help and then they don't produce much when asked. This drives us all nuts.
I started this thread just before I realized my meth ratio detail was impacting Fuel Trims and Timing. I'm testing a variety of things, from timing recovery during shift at different ratios, etc.
Currently logging (all values meth/water)
BM10
30/70, 3rd gear pull, 1,2,3,4 pull for timing recovery review (done)
50/50, 3rd gear pull, 1,2,3,4 pull for timing recovery review (done)
70/30, 3rd gear pull, 1,2,3,4 pull for timing recovery review (Fri/Sat)
BM5
100%, 3rd gear pull, 1,2,3,4 pull for timing recovery review (Sun/Mon)
80%, 3rd gear pull, 1,2,3,4 pull for timing recovery review (Mon/Tues)
60%, 3rd gear pull, 1,2,3,4 pull for timing recovery review (Tues/Wed)

LOGs
I've attached generic logs (50/50, BM10) for 3rd and 1,2,3.
We can see that the timing doesn't recover over shifts. I had intended to create a unique thread for that subject after I completed gathering the relevant information.

Maybe try a custom tune ? I see you dont hit 19psi until 3500 and then fall off well before you get to 6000 rpm.
Never the less, I would limit 1st gear boost. Try 12 psi and launch. If it hooks, try a little higher boost, if tires spin, try 10 psi, etc.
Early shifting to minimize momentum loss as you mentioned earlier will kill your time. You want absolute traction for better time.
Im also xHP and always drive in manual mode, shifting down to 4th, hammering the gas, and downshifting to 3rd is not the best thing to do. If you are roll racing, you will do better smashing in 3rd and then upshift to 4th DEPENDING on your actual launch speed of course (im just going off your example), downshift or upshift kills time as well. Even if its a fraction of a second, you are still losing time.
If you want, you could try a different value in auto shift reduction vs letting off the throttle before shifting. There should be no need for that. The videos I sent you are 100% floored through all gears.
As far as breaking things, the more the car hooks, the more the driveline takes the hit. So either traction slips a bit and you get not so great track times (and helps save driveline), or get better times with tires that hook and risk breaking parts.
Also I believe thats a typo on your manual vs manual shifting from 5900 vs 7000rpm. You should absolutely be shifting IMO at no more than 6k given your logs posted, for better E.T. Personally, I would shift around 5800 rpm for your particular set up to stay within powerband.

codesx 08-23-2019 01:38 PM

Quote:

Originally Posted by THE BEAST (Post )
Maybe try a custom tune ? I see you dont hit 19psi until 3500 and then fall off well before you get to 6000 rpm.


I will try Trebila now, as you suggest.
We'll see!


** EDIT ** First step, learn how to spell it (corrected above). Then contact...


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