Let me know if you go

Made my 2nd trip to the track today and improved a little bit. It was a cool 45f out when the racing began but unfortunately I soon found out that the IAT will still get up there when the car sits stationary in the staging lanes. First run of the day my starting IAT was 109 - not much better than my first trip when it was 30 degrees warmer out. This’ll come as a surprise to none of you, but these cars are hugely reliant on a cool IAT to make peek power. My 2nd & 3rd runs proved just this...

the 2nd run was a dud as I forgot to engage traction control and spun badly off the line. I decided not to waste my time and just cruised down the track @ 60mph. This brought the IAT down nicely and I pulled right back around and started my 3rd run with an IAT of 91. I ended up running a 12.59 @ 115.5 mph — about 3mph faster than any other run of the day. Unfortunately I squandered it with a 2.13 60’. Could’ve been a solid 12.4 with a good launch.

overall it was a good day with a best run of 12.57 @ 112.7 mph with a 2.00 60’. I gotta work on my launch but track conditions worsened as the day went on and it was a lost cause

I've only done 1 testntune, with a grand total of 3 runs. I'm gonna hafta go play that game again sometime. See if I can improve my 2.9 60'....

All things being equal.. a 10th in the 60' will net ~3 10th's out back. It's very easy to "make up time" on the front end of a run vice the back end.

wow if that's the case i can see how people managed to dip into the 11s bone stock w drag radials

this trip really highlighted how important the IAT is to get these cars to their full potential. i also thought a cool ambient temp would have more of an affect but with little to no airflow while in the pits/staging pretty much negates any of the benefit. i vaguely recall that guy who drifts his e55 mounting fans to his h/e in one of his youtube vids. might be a worthwhile first mod if you're into drag racing and it's not too difficult to do

split the intercooler system its never good to beat on a supercharged car with iats that are high. very cheap and effective is a 03/04 cobra tank like i have you can jam a few ice cubes in there and with stock pulley you will see about a 46 deg rise in act temps. 62deg starting 109deg at the end of the track.

I’ve noticed a drop of 5 mph after my first run if I let the car sit for 1+ hour it comes back. This is also with a very aggressive ice tank setup, no change in iat but loose trap speed.

Ive narrowed it down to the blower as a unit being hot.
Ice vs no ice I only see 1-2mph.

I’m making some phenolic spacers as an attempt to help this.

Not thread jacking but you seem to have a similar issue and nobody really gives a play by play on runs, just the slip for the glory run. Anybody else notice this?

First, don't get too caught up in your ET, pay attention to your MPH, that's your real measure of power. Also, as you look at your time slips, really start looking at each incremental, those also mean things, I know I said disregard ET, but the incremental do mean something. It gives you an idea of what the car was doing in each segment. Understand where and how the car is making power during the run.

I haven't had mine down a track just yet to see what it'll do.So little tricks on keeping it cool I haven't really explored. In my head.. an easy thing to do, even if you dont' want to split the cooling is to make sure the IC pump is in tip top shape, and I think doing whatever thing you need to do in the computer to turn the pump on sooner can only help. I think you're on the right track trying to control heat.. it will only help. Cool the car down between runs... push the thing through the staging lanes if you're not already.. only turn the car on when it's time to make a pass..

But what I've noticed is, by in large, Mercedes people aren't drag racers... don't do it enough to know exactly what their car is telling them. or just flatly aren't all that into it beyond staging the car and mashing the throttle and what happens happens... and there's absolutely nothing wrong with that. I'm curious to see what I can get out of the car with out really touching it. Mine's stone stock at this point, so, a true test I think. I'm a big guy, so I'll be slowing the car down with just me being in it. Lower power cars are FAR more affected by the 100lbs = One 10th in ET thing. So.. I will be giving up at least a tenth to the average size person. I'm not saying I'm the end all as far as drag racing goes.. far from it.. I do have a good number of passes under my belt, and have been a fair bit quicker than anything I've seen posted on this board. I just see things different I guess..

With your 115 mph, connecting on a good run would be enough to run a bottom 12 if not squeak an 11.99 out of it.

Looking at your sig.. who did the converter you were running? I have a rear main leak.. if I decide to keep the car, I will address it, and in a "since I was in there" thing I would do a converter. I would be using an Ultimate Converter Concepts piece, but I'm curious what others are using.

upd which i think is made by circle d, really fun on the street but tricky at the track to hook and worse when you change gears but again lot of fun to drive on the street.

there's a lot of contradictory info on the split cooling mod on this site. seems like a few years back everyone was doing it and claiming a 10 degree drop in IAT. threads from the last few years claim it's uselss.

I could see how splitting the cooling and jamming some ice cubes into the tank would be good for a one time glory run but since the cobra tank is just a fill tank, once it's full you're kinda sol.

odd that your IAT remains low but you lose trap speed. My times got considerably worse as the day went on and my last run was a 12.9 with a 2.2 60'

the announcer at the track mentioned the conditions worsening at the starting line and i saw a few cars on slick spin badly right off the line so i'm chalking my bad times on that. maybe you ran into the same?

@90lxracer good points. one thing you mentioned which seems logical but in my experience really doesn't help is letting the car sit/pushing the car through the staging lanes. the intercooler just gets heatsoaked from the engine/blower when theres no coolant flowing through it

i honestly thought my 115.5 mph run there was a malfunction with the track timing but i ran 90mph in the 1/8 which was a good 2 mph better than my other runs. amazing to see what a 20 degree starting IAT difference does in the real world

i realize there are mods to fix all of these IAT issues, but for now i'm going to keep the car as stock as possible.

Everything boils down to how serious you want to be about it... One could wire the radiator fans, IC pump, and even mount IC fans as well and all have them wired to run independent of the car running... Ice the blower between runs... what a person is looking for is warm oil and a cool engine..

As far as heat soak.. that doesn't make sense.. how does a car cool down? By not running... idling a car is heating it up.. because the cooling system is actually working.. These motors are all alum right.. let that dissipate the heat.. Bring/buy a carpet fan to blow on the motor to cool it down...

If anyone is hell bent on cooling the IAT you have to really step outside the box and attack it looking at all the issues you have before getting to the starting line. In my case a long drive to the start line from the pit's for 1/2 mile racing, and heat when sitting in line for a long time before the run had to be addressed so that what I focused on.