Help needed - Does anyone have stock C450 Dragy 0-60 times using 91 octane gas?
Does anyone have insight or Dragy slips to help me out so I can be sure my stock times will be similar.
I know the hand held you get from eurocharged allows you to, if I'm not mistaken. I only have a draggy for 93 Oct on their stage 1 to go by. Depending on this week's schedule I could swap tunes but it would be with 93. 91 isn't redial available in my area if you can believe that.
I know the hand held you get from eurocharged allows you to, if I'm not mistaken. I only have a draggy for 93 Oct on their stage 1 to go by. Depending on this week's schedule I could swap tunes but it would be with 93. 91 isn't redial available in my area if you can believe that.
The only issue I'm experiencing is a major boost cut, but only when brake boosting my launch. Boost gets severely limited and fluctuates up and down while slowly going up and might reach a max of 10.8 psi at redline. Once it shifts into second it all goes back to normal and pulls hard. I've got no other issues with the car whatsoever in any other driving scenario, including launching the car from a stop without brake boosting. I've troubleshooted the car a couple of times already, and recently replaced several things just to be sure.
I might be over thinking it on my stock Dragy times. But I'm going to get a stock 0-60 Dragy sometime this week so I can see if my car runs how it should in stock form. I'm guessing as long as it's within reasonable range for 91 octane and cool weather then I believe I can for sure rule out hardware as the problem.
I've got a friend with a C450, the same tune for 91 octane but with the special features package. His car doesn't have this issue and is impressive compared to mine. He can't return to stock without mailing in since he doesn't have the comport to do it. Otherwise I'd ask him to help me out real quick 🙂.
Oh and yes I'm working with my tuner on it. I just wanted to get an idea of stock numbers using 91 octane for myself since I got curious. I'm confident this will all be sorted soon enough though.
Last edited by BayAreaAMG; Dec 7, 2021 at 04:26 AM.
The only issue I'm experiencing is a major boost cut, but only when brake boosting my launch. Boost gets severely limited and fluctuates up and down while slowly going up and might reach a max of 10.8 psi at redline. Once it shifts into second it all goes back to normal and pulls hard. I've got no other issues with the car whatsoever in any other driving scenario, including launching the car from a stop without brake boosting. I've troubleshooted the car a couple of times already, and recently replaced several things just to be sure.
I might be over thinking it on my stock Dragy times. But I'm going to get a stock 0-60 Dragy sometime this week so I can see if my car runs how it should in stock form. I'm guessing as long as it's within reasonable range for 91 octane and cool weather then I believe I can for sure rule out hardware as the problem.
I've got a friend with a C450, the same tune for 91 octane but with the special features package. His car doesn't have this issue and is impressive compared to mine. He can't return to stock without mailing in since he doesn't have the comport to do it. Otherwise I'd ask him to help me out real quick 🙂.
Oh and yes I'm working with my tuner on it. I just wanted to get an idea of stock numbers using 91 octane for myself since I got curious. I'm confident this will all be sorted soon enough though.
Have you ruled out a faulty vaccuum pump? Holding boost may be an issue if that is malfunctioning.....good luck!
Haven't checked the vacuum pump but I also don't know what PID to look for in order to monitor it. I'll double check the different car scanner apps I have. I think my brakes will be affected too if the pump was going bad, but maybe not noticeable? I think the brakes are using the same pump, I guess I'll look into it
I'll see if I can check it soon if I can find the right sensor to monitor, if any exist on the apps I've got. It looks like heavy rain is coming Sunday so I'll have to try and return to stock by then for some Dragy runs.
Last edited by BayAreaAMG; Dec 8, 2021 at 04:57 PM.
I flashed back only the ECU tune and did more testing. It ran 4.35 then 4.39s in two runs. Then 4.46 and 4.47 on two other runs.
My friend with the same tune that I mentioned of before did 3.92s at best the first and only times he went out and tested his car. I think he might have been able to cut it down a tiny bit more with launching higher and summer tires. Same tune for 91 octane - just with the added "special features" package
Anyhow, I just thought that I should've tested Dragy without brake boosting while on the RV3.1 tune file and see how it compares to my times with brake boosting. I'm guessing it'll be the same times or faster compared to launching with boost since it doesn't cut the boost to 10 psi.
Update: I just purchased a used low mileage vacuum pump from a 2018 c43, and a new seal for it. Going to swap it in as soon as it comes late next week. There's a chance if the pump really is the problem with my car/tune, that this replacement pump might also be problematic. But it was cheap compared to the remanufactured pumps at the dealership so I'll entertain it.
Last edited by BayAreaAMG; Dec 10, 2021 at 06:05 PM.





