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codesx codesx is offline
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Posts: 682
Join Date: Feb 2018
Car: 2008 335i Vert (E93, N54)
Default Ideal Launch Method, Retaining Performance but Hardware Longevity focused (School me) - 08-09-2019, 10:45 AM

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?


--

2008 335i Convertible, E93, N54, A/T (190,000+ km)
Wheels: 322 | Tires: R.275/35r18, F.245/40r18
TUNE: JB4/Trebila | 24 PSI | 100% Meth via dual BM5 | 94 Octane
BMS: JB4, Map 6 | WMI | 5" FMIC | OCC | DCI | Cowel Filters
TMAP: 3.5 barr
xHP Stage 3 (v2.0)
VRSF CP | HKS BOV
RB PCV Valve
NGK 5992 Plugs @ .020

Maintenance:
2018 - A/T Replaced | Plugs | Ign Coils | Walnut Blasting
2019 - Index 12 Injectors | VCG | OFHG & O-rings | Alternator w/ Clutch Pulley | Water Pump & TStat

Last edited by codesx; 08-23-2019 at 01:54 PM..
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