skullbox15

First time I've ever run any of my AMGs at a legit strip. Hit up speedworld in Orlando last night.

2014 Sedan
74k miles
Renntech ECU
Pilot Sport 4 AS

My first run was 12.88 in manual mode traction control completely off. 112 mph trap speed. It hooked perfectly, I just shifted early through one of the gears. Oil temp after was 220F.

2nd run 12.55 using launch mode (Sport +). 111 mph trap speed. Felt great and I thought it was going to be even faster than 12.5. Oil temp was 235F after that.

deadlyvt

Pretty slow to be honest what was the da?
I ran a 12.17 in a bone stock p31 car with a bit of tire spin in first. Shifting early can definitely hurt a run.

lo-fi

You ran the 12.17 on your first day at the track in the AMG? His times are pretty good for first day.

BLKROKT

That sounds about right for a non P31 car stock. But tuned? Mph is really low for a tuned car. Orlando DA has to be negligible.

deadlyvt

first day in the amg yeah(wasn't even my car)
I think it was 113mph if I remember correct
so tuned 111 seems pretty slow and that's why I asked if the da was messed or something

BLKROKT

Looking at the 1/4 mile list, tuned cars mph typically start around 115mph. Stock cars are 111-112mph. I would check to make sure your tune wrote correctly.

roadtalontsi

Or it could that it's 100* in Orlando right now lol. Likely even hotter pavement surface. Everyones car isn't a worlds fastest stock / tuned blah blah...
Good runs, no one ever runs the times "they should" run. Even magazines cheat there times and do 100s of attempts to get certain cars in favor. Glad you're enjoying the car!

skullbox15

Here's the slip. I don't know what a "DA" is.... Yes it was very hot.

GarlicBread

Essentially its a reference to the air quality and conditions during the time in which you conducted your "experiment" if you will.

"Density Altitude: The altitude in the standard atmosphere at which the air has the same density as the air at the point in question. An aircraft will have the same performance characteristics as it would have in standard atmosphere at this altitude."

From your time slip, you're losing out on the top end of your run.

You'll notice you did a good job launching the car and maintaining the car in the early part of the run, your reaction time was nearly twice as slow as your opponent yet you were ahead of him/her most of the run, this means you did a good job launching the car and your counterpart did not.

However, they came around you around the 1000 ft mark meaning their car was not "falling off on power/torque" nearly as hard as yours.

Willing to bet they had a power adder of some kind?

Also, everyone losing their minds over the MPH seems irrelevant since you pretty much hooked entirely I would imagine. 2-3 mph difference at that E/T range is indicative of traction in the hole or not so...seems like the car is performing correctly but yeah you don't make a lot of power and your car weighs 4,000 lbs without you in it.

Seems pretty standard over here but I'm no certified expert just been around tracks alot.

skullbox15

Yes it was hot and humid. The other car was a C8... guy said he could hook up in the street but not on the track... total opposite of me. He was struggling to get traction the whole time, and started to reel me in near the end but didn't have enough track left.

Also, the 12.5 was my 2nd run. Oil temp was 225F when I started, 235F when done. Not sure if that had any impact on top end performance.

GarlicBread

Right, pretty easy to tell that from your time sheet.

Also explains why he did not fall off as hard as it weighs less has better gearing, aero etc.

Hot and humid is usually not the best regarding DA or entropy in general.

Dunno, seems normal to me but again I don't study the time sheets for mods on these cars but just looking at the pieces themselves this seems like your car is performing how it should given the circumstances.

GarlicBread

Also C8 must have been driving through the water or that lane was terrible.

Makes very little sense he couldn't stick the launch on a track but can on a street...

Don't go through the water unless you're on a D/R or a slick, you'll just spin, only need a little burnout for street tires, big one and you'll probably spin cause your tires are a hot mess.

BLKROKT

Nobody is pissing on your effort here. Awesome that you got out there and had a great time, that’s what it’s all about. But whoever said a 2.025 60’ time on street tires is “hooking” is wrong, and that certainly doesn’t have anything to do with your low mph. There are plenty of folks who got 1.7-1.8 60’ out of their street tires and their mph is in the correct range. Neither does the heat, Orlando is at 160’ elevation and even at 100F the DA at the track couldn’t have been more than 800, which has an immaterial impact on times/trap. There are dozens and dozens of time slips on here to reference, and for a supposedly tuned car, your top end is all wrong. I would have your car looked at, starting with the tune.

GarlicBread

Have you ever competed in a drag racing competition/event?

Just curious.

BLKROKT

Don't be an idiot. Try to add something constructive for once.

GarlicBread

That definitely answers my question.

chrisridebike8

no i agree with BLKROKT. At sonoma I ripped off 1.8 60’s. 2.0 isn’t that great, but 60’ doesnt affect the trap speed. That’s a low trap which means the car is down on power somewhere. I know the renntech tunes are usually softer than other but that one maybe needs to get looked at.

roadtalontsi

MPH is Likely renntechs soft tune and temperature related. Most good tuners will turn down the excessive intake air temp timing retard at very hot temps. I don't know what amg standard settings are, but I know from doing lsx stuff anything over 110* intake air temps it pulled 3+ degrees of timing. Knowing damn well that's just a heat soaked sensor by adjusting this in the Texas heat is night and day difference on power output. Heat kills everything. It's just less noticeable on N/A engines.

eightysixtuned

the factory tune pulls A LOT of timing when under hood temps rise. i'd assume renntech's tune keeps those maps as is for safety where as other tuners don't seem to be affected by this through their own means. timing can vary easily 6 degree's of timing being pulled when the computer calculates that under hood temps are high due to high ambient temps.

roadtalontsi

6* of timing is massive. That can kill 100hp easily. I think we solved the mystery. Renntech softies FTL

RNS-11Z

You can tell something is killing it in the big end. I’m surprised no one mentioned it. It’s only picking up 20mph after half track where is it should be 25-30mph.
for reference when I went 121mph I was doing 93/94mph