sl65amg2008

After reading Any SL track advise? thread by
jbusa95te I may already have part of my answer but just thought I would post this anyway for other possible feedback. This weekend I had my first encounter for fun on the local Interstate with what I "believe" was a ZR1(huge hump in the hood). I saw him come up from the rear and pulled along side and could tell he was looking for a challenge. Anyway all seemed OK until we hit about 110 and then he took off like a shot and what seemed like only seconds he was only a spec in the distance. I guess he was just toying with me. I bowed out at about 135 knowing this wasn't even a contest: no sense taking any further risk. I knew the vettes were faster but this wasn't even close. Is the ZR1 that much better or is there a possible problem with my SL65? The ZR1 was probably modded as well; sounded like thunder when he punched it.

alx

ah.. the zr1 is faster, but you should not just fall back all of a sudden. methinks your iats went up and comp dialed back timing and power. check your heat exchanger pump. it might be dead.

the zr1 is very fast... but should not just run away...

sl65amg2008

Fairly new at these cars; how does one check the heat exchanger pump?

cal1

I agree with alx. Your big V12 should be in its element at those speeds. Not that you would take the ZR1, but definitely hold your own. The ZR1 guy probably needs a kidney belt for long drives and I am guessing cant blow cool air on his butt like you can or drop the top for that matter. Trade offs trade offs.

sl65amg2008

Guess I will have to take her into the dealership or at least make an appointment; now I have two gripes. I happened to have a get together this weekend at my home for some of my GF's friends and they brought their husbands. Just so happened one of the guys is one of the MB mechanics at my local dealership where I bought the car. He gave me a lot of the inside scoop what goes on behind the scenes; " but that conversation never happened". He spotted right away that the "Certified Preowned" classification I supposedly paid for may not be valid. No Yellow sticker on the drivers side door post. He also told me "who" gets to do the precerts . He looked at the tires that came off the car and he said somebody been doing a bit of strenuous driving, certainly not the little old lady from Pasadina. Inside edges of both rear wheels had chunks torn out of them and the centers were bald. I asked if he would like to do some (mod) work for me but I couldn't convince him Now it sounds like I may need new Intercooler pumps. Should have been checked under the "Certification".

falconsprint

one way to diagnose IAT is to get a data-logger and attach it to the ODBII port. I use scanxl and a PC. There are others that work with smartphones.

http://www.scantool.net/software/scanxl-std.html

sl65amg2008

Thanks Falconsprint! That will certainly give me a heads up before I go any further. Where is the ODBII port usually located on these cars?

falconsprint

ODBII port is located under dash on driver's side. Look for a little plastic flap.

allenjdmb

the ZR 1 is really, really strong. I have owned 2 SL 65's and 3 SL55's. A good friend had a ZR1, and although it's not for me, it was remarkably fast. that being said, the 65 does need to be set up just right to get the most out of it. Proceed with caution...

the head

And don't forget - it's a Chevy and mods are cheap. Judging from the noise and the results it probably was. FWIW, I had a CTS-V with just a tune and air intake pull me noticeably when my intercooler pump was out.

sl65amg2008

Just placed my order with Scantool.....hopefully when I receive it I will get some answers.

sl65amg2008

Just got my Scantool today and plugged it into the OBD port. It found no trouble codes stored or pending. I also ran the car at idle and watched all numbers rolling by but of course the engine was cold. Not sure what I should be looking for as far as IAT numbers and would I have to have this plugged in while I was running hot? Would something be stored as a trouble code if the IAT's ran high due to an intercooler pump failure?

cal1

Not sure if we share similar pumps in the 55k, but when my IC pump was bad, it did not fail completely, it just had significantly reduced flow. THe SA said it was very common. Maybe you have the same issue and it just is not enough to code yet.

sl65amg2008

Is there anyway to tell if there is reduced flow before it codes. I have heard the MB intercooler pumps are the achilles heel of these V-12 engines. I would love to change over to the RennTech kit with heat exchanger but not sure I want to get into disassemling the front of the car. I wish there was a RennTech dealer local to me.

Benz-O-Rama

Do a long 3rd gear pull on the highway, and report back what your IATs were, as well as ambient temp. If your tool has the ability to datalog your run, do that and post it.


Also, datalog your IATs, while just cruising on the highway and some stop and go traffic.

That'll give us a good idea how well your pump is working.

The V12 cars run very hot. Stop and go traffic, your intake temps should be 40-60* over ambient. As soon as you stab the throttle, they should drop to 10-20* above ambient then slowly rise. Highway cruising will be 20-40 above ambient.

If your pump is failing, your numbers will be significantly higher.

alx

every sl i've seen has codes. those are dirty-minded cars - pun intended

if you are not seeing codes your scanner might be too generic. but you at least should be seeing iats. benz-o-rama guidance on temps is spot on.

sl65amg2008

This is the software I have:
http://www.scantool.net/software/scanxl-pro.html

As soon as I get some time and figure out how to store data in my laptop I will try what Benz-O-Rama suggested. If anyone is familiar with this program and can steer me in the right direction on how to store data and save me some time I would appreciate it. Time is always my enemy. I was able to watch real time IAT's in my garage but couldn't figure out how to save it.

falconsprint

There's a red record button on the bottom center of the window. To be frank, you need to put a little more of your own effort into this. The software has a manual and examples on youtube. There's other software that will work with the ODBII/USB convertor that came with your scanxl. Some work with iPhones and Android smart phones.

If time is your enemy then maybe you need to give the car to a technician to sort this out. High IATs was just one of the things suggested for you to look at. Take it to a dyno, take it to a drag strip and measure 1/4 mile times. Or perhaps you ran up against a modified Corvette and nothing is wrong with your car.

sl65amg2008

It's OK to be frank and I appreciate your help and I plan on putting a lot more effort into this as time permits, especially during the winter months. Just trying to sort out the IAT situation for starters; problem or no problem.
I already tried the Red Record button at the bottom of the screen but when I go under the file to look at it, it's blank; no data stored. Secondly, you can only buy this program as a download so there is no manual unless there is one on the website somewhere; I will check. The only instruction that came with the purchase instructions was to go to website and ask questions on the forum or email one of there techs if you have problems; not exactly what I would call a manual. I will check out these options today and see if I can get anywhere since I would like to try to sort some of this out tonight since it is the only evening I will have off this entire week. If I can't figure out how to get it to record I always can just watch the numbers roll as I am driving and use old fashion pen and paper so I can get some numbers to see if IAT's are a "potential" problem. It is all just a starting point and I do appreciate everyones help.

hyperion667

zr1 is friggin amazing! top speed around 200!!
cool you got to go agaisnt one!
kind of like a 'mig' LOL.....(top gun joke)

sl65amg2008

I am not sure if this tells you anything but here is some data from last evening. The handwritten print is what I was attempting to do but not necessarily acheived. Truck traffic on the interstate, trying to operate a laptop and driving at the same time is worse than texting The run where I tried to duplicate the speed acheived when all this started gave IAT's of 122 degrees, 70 degrees above ambient (53 degrees Farenheit). Open for questions and answers.

Benz-O-Rama

IATs look just fine.

Your pump appears to be working as it should.

Benz-O-Rama

So, here's your IATs after converted to F*

44 degrees Celsius = 111.2 degrees Fahrenheit


48 degrees Celsius = 118.4 degrees Fahrenheit


78 degrees Celsius = 172.4 degrees Fahrenheit


46 degrees Celsius = 114.8 degrees Fahrenheit


33 degrees Celsius = 91.4 degrees Fahrenheit


40 degrees Celsius = 104 degrees Fahrenheit


41 degrees Celsius = 105.8 degrees Fahrenheit


50 degrees Celsius = 122 degrees Fahrenheit


45 degrees Celsius = 113 degrees Fahrenheit


Throwing out the reading from when you were idling for 30 minutes (That tells you nothing, since there's no air flowing across the heat exhanger), your IATs ranged from 91.4 to 122*. Right inline with what they should be.


You just got beat by a much faster car. Stock SL65's generally run mid-high 11's in the 1/4 @120ish , The new ZR1s, run high 10s to low11s @ 130ish. That 10 mph difference in 1/4 times, equals bus lengths.


A simple ECU/TCU tune on your car will put you in the low 11s@125ish, but the ZR1 is still a car that you just won't be able to come around.

sl65amg2008

Thanks for the help and analysis Benz-O-Rama. Glad to know things are as they should be. I guess that was just one bad a$$ modded ZR-1
I am planning an ECU/TCU tune and lowering module from RennTech this winter when the 65 goes into its 3 month hibernation. I was under the dash last night checking out the 30 and 48 pin connectors to see what is involved in removing them to connect the lowering module

Benz-O-Rama

No problem, that's what we're here for. The ZR1 was probably stock though, that's just what they sound like.

Here's Jaime Furmans, 100% bone stock ZR1. Stock down to the tires!

http://www.youtube.com/watch?v=hxXqW...layer_embedded