BPRacer

iTrader: (1)

OK, I realize that was not a very eloquent way to phrase the question...

I'm not even sure what it is called: The system that cuts a significant portion of the engine's power as soon as it senses the brake pedal being applied. The reason you can't powerbrake to heat your tires at the dragstrip or show off for your girlfriend in the Sonic parking lot. The reason I can't left-foot-brake when trying to dodge cones while keeping the rear end somewhat behind the front.

I realize I can bypass it by unplugging the brake light switch at the pedal, but that's a pain in the ***, plus I always forget to plug it back in afterwards. Do any tuners address this circuit? Or is there any fairly easy way to eliminate or bypass it while keeping my brake lights?

I would gladly search, but I can't seem to remember what it is called, and I obviously can't describe it in a google-able phrase (see title of this thread...)

Thanks for any help!

frankie945

iTrader: (35)

try searching brake boosting there is more...
https://my350z.com/forum/forced-indu...-ftw-11-a.html

BPRacer

iTrader: (1)

Thanks Frankie, I posted a query over there regarding the mod.

OCG35

iTrader: (2)

This topic has been around a log time and it baffles me that some don’t believe or realize it happens... I'm AT and can’t brake torque launch at the drag strip because the power cut kills my 60' time...

Anyway - I've been after a couple aftermarket companies to find a fix (they will remain nameless) - but one (that I've only recently talked with) has agreed to take a look at it! I data logged some stuff over the weekend at the drag strip and am emailing tomorrow...

Hopefully a fix will be coming soon!

ajcool2

iTrader: (11)

Hmm whats your best 60' time and what are your mods?

OCG35

iTrader: (2)

2.1+ (often 2.2) - lately I'm struggling a bunch with heat soak form headers - I data logged intake temps and for those that think it doesn’t matter because once you are moving the air flow will take car of the temps, WRONG! I measured 115 at idle, and it took over 5 seconds at full throttle to drop 10 degrees, by the end of the 1/4 mile it was still 91... on a different run I idled all the way through the staging lanes (usually I push the car or stop & start to move) - by the time I got to the tree intake temp was 154F!!! At launch it was 149F, it took over 1 second to get to 138F and another second to drop to 129 so by the time I had gone 60' I was still at nearly 130F intake temp!!! By the end of the 1/4 mile it got down to 102F

Horribly bad heat soak issues.

To answer your question about mods - I have an AT sedan: Stillen CAI with thermal coated Z tube and gold foil around pertinent parts of the remainder of the intake; inner bore grooved throttle body spacer; machined upper plenum, 1/2" plenum spacer, machined (MREV2-esque) lower collector; JWT S2 cams (revup rod bolts, JWT springs, revup oil pump); Crawford headers (that get crazy hot even though they are jet hot coated); Crawford HFC; Stillen cat-back exhaust; Osiris tuned - also have 3.692FD and Quife ATB differential... and some other stuff that isn’t engine or drive-train related.

Best ET at Autoclub Dragway in Fontana (1200 ft elevation ambient temps upper 70s lower 80s) was 14.002 at 101+ mph on pump gas and street tires… density altitude was probably around 2500ft or higher – horrible track actually.

ajcool2

iTrader: (11)

Yeah the heat and DA is bad combo. It took me a while to figure our motors are not heat friendly. My maxima would run about .4 tenths slower when heat soaked. My Z isnt as bad with about a .1-.2 tenth difference. I always bring a big bag of ice with me to the track and let the car cool off for about 45 minutes which sucks on crowded track days. The thing is my 60's arent affected as bad. I'll have to go through some of my slips to see how my 60's differ from my first run to my last. I've tried removing the brake fuse a few times and my 60's were still 2.0's and I've pulled a few 1.9's without removing it. It did however help spin the tires faster which I didnt really need since I was on street tires. I do think it would help with Dr's and slicks though. What wheel and tire combo are you running?

OCG35

iTrader: (2)

this is going off topic... I will post progress in regards to the brake torque mod once the data logs have been evaluated and the solution is made.