mmgwd

Hi everyone, I have a stock 2018 c43 (only thing added is K&N filters) and it clocks around 5.4 seconds (car is warm) 0-60 without brake launching, but on youtube I've seen several people with a c43 do the same thing (no brake launching) and get around 4.2. Has anyone had a similar issue that can give advice? I should be able to simply slam the gas from a stand-still (car hot) and get under 5 seconds 0-60 with our without brake launching or modifications, these dudes on youtube getting faster times in comfort mode than I get in sport +! Any ideas?

C43HeartBoost

What is your elevation? What was the ambient air temp and DA when you did your testing? What are you using to test 0-60? Your answers to each of these will impact your times.

As for technique and setup: What tires are you running, and at what PSI? What drive mode were you using? You should be in individual mode with all setting set to sport+ and suspension set to comfort. You should also have traction control shut off (not just in sport handling mode).

MaverickC43

4.2 without brake boosting on stock seems really good. But being under 5 should not be an issue
but again your altitude can be a huge factor

C43HeartBoost

Agreed.

1231ad7

Tire pressure and altitude can make a difference. What octane fuel are you using?

Herrerrera

no stock C43 is running mid 4 sec 0-60 with out brake boosting. I've tried once for fun to see What my 0-60 would be From just flooring it from an idle I ran 5.5 and 5.4 back to back . My best while brake boosting was 4.4 stock . And 3.7 with JB4 map 3

mmgwd

Thanks for the replies, I'm going to find the answers to all the questions that have been asked and come back and post them so we can figure it out. Here's one (there are several, this is not the only one) of someone with a 2019 c43 getting under 5 in comfort mode (he doesn't brake/boost launch). It's interesting that Herrerrera here said their 0-60 with just flooring it is the same as mine so maybe there's nothing wrong, or maybe we have the same thing wrong with our cars lol.

I'll update soon, it's been raining here

C43HeartBoost

I am not sure why your prospective conclusion is that something is wrong with your car. Please remember: test numbers from the main magazines and car websites flog the living hell out of a car, break boosting (or using launch control when applicable), many times over, while in sport+ mode, usually on a prepped track, and then take a one foot roll out (subtracting .2 to .3 from the times) while still using top of the line performance logging/tracking tools to come to the final posted performance figure. I would have assumed you could have answered my initial and very fundamental questions without having to think much. Either way, good luck.

MaverickC43

Herrera lives at like 7 miles above sea level. Lol
need to take that into consideration
I’ll try today and see what I get just flooring it

post ur dragy slips

MaverickC43

Its crazy that there’s a whole second difference between break boosting & not.
that’s like getting a stage 2 tune. Lol

Herrerrera

AWD launch baby!

C43HeartBoost

Yeah, mine is consistently .5 to .8 slower without break boosting.

MaverickC43

Running 4.8 no boosting

mmgwd

Hi everyone, been on a trip and wasn't driving, thanks for the responses. C43HeartBoost recommendations immediately got me to under 5 seconds at 4.8 without brake boosting. I could immediately tell a shift in power when I turned off traction control, thanks C43HB! At this point I don't think it's performance issues since I got the same times as Maverick did (thanks for testing and posting times).

However, I do have noob questions about brake boosting since I've never had to do this. I've watched some videos on it and tried it a couple of times but I'm unclear on:

1. How far are you guys having to press the gas pedal to get to 2500 rpm and build the boost? It seems like I have to press it pretty far down, are you pressing it all the way down?
2. It seems no matter how hard I press the brake down when I get the gas pedal pretty far down (say, halfway down) the car kind of budges forward and makes some sounds. Is this what you experience or does your car stay still without moving forward a tiny bit?

I've tried building boost at stop lights so far, haven't had a chance to launch from it. I'm going to test that out and will post times.

elevation: Elevation: 289–1,450 ft (88–405 m)
ambient air temp: 75F
What am I using to test: dragy
PSI: 34 (19" wheels)

Herrerrera

Yes press throttle down all the way. The car will make a lot of engine noise, hold for 2-3 seconds and release brake. Your car shouldn't be creeping forward though.

mmgwd

Thanks Herrerrera, the engine noise I hear sounds normal, the sounds I'm referring to sound like brake "groans." I assume those are normal sense the brakes are under a lot of stress but with this being my first times doing it it's a little concerning. I'll get over it

Herrerrera

Hmm, Hopefully someone else can help answer why that is. But also in case you weren't aware, If you were launching your car with just enough throttle to hover around 2000 rpm's the car would launch quicker than launching from an idle obviously but you would be launching with no boost built up. This is how you would launch a NA car or any turbo Rwd cars. If you brake boosted a C63 for example, you would just do a burnout and not go anywhere. But since we have the huge advantage of AWD we can get away with brake boosting with street tires.

18bora

Sport +, TC off.

C43HeartBoost

Congrats man, glad to hear it helped. Now it is seat time and practice to get your best and/or consistent results.

MaverickC43

not stock I assume.

C43HeartBoost

When he still had the c43 it was stock besides a JB4 (I believe map 6 at the end) and tires.

BMS

It's all in the launch technique! A JB4 doesn't hurt either.

Howyalivin

And WMI, but that was it. Fastest times were 11.1's.

MaverickC43

Wow!!!
11 is crazy!!!

mmgwd

Hi everyone,

so I've been practicing the brake boosting, with Herrerrera's advice above I'm now not creeping forward at all and I can see on the boost gauge that the car is building boost. Problem is when I let off the brake the car doesn't launch like I would expect. I'm still getting times of 4.8 and 5.2.

I'm pressing brake and throttle all the way down, when the boost gauge reads and holds at around half way to 3/4 full I keep the gas to the floor and then let off the brake. Is the timing of this really important? Do I need to let the car sit for couple of seconds with the boost built up before letting off the brake? From watching the videos above it looks like as soon as the gauge reaches around halfway I need to let off the gas. Am I missing anything?