DEAD HORSES AND LOW IAT QUESTIONS

10-05-2016 | 09:47 PM

#1

EREBUS

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From: Keller

clk63, cls55, ml63, (w210) E55

DEAD HORSES AND LOW IAT QUESTIONS

Quote:

Originally Posted by Hotsauce55

My thoughts, looking for more experienced folks to comment. This could be used as a basic guide for folks & since the E55's biggest performance obstacle is controlling IAT's I figured it was worth a conversation:

This sh*t needs to stop. lol. 12 degrees of timing pulled at 180+ IAT's costs you, maybe, 30-50 hp. (220 IATs disengages supercharger) Please understand that fuel dumping cools cylinder combustion and helps with ignition due to avoiding pre-ignition and AFR leaning (knock). So it really isn't as extreme of hp loss as some might think. For example:

Monitor your timing and watch it adjust as the conditions vary. Timing gets pulled for various reasons that your ECU sees fit. Not just for IAT's

Too many variables during combustion that many overlook. So let me, once again, reiterate that it's a battle not worth losing sleep over.

Here is some data on IATs and options to lower them.

The correlation between chasing low IAT's and Obsessive-Compulsive Disorder:

They correlate. Move on.

Using Nitrous to drop IAT's

30-50hp dry shot is somewhat safe (wet shot is safer, of course) with a slightly rich AFR non-nitrous tune.(then again, you just tune for safety with nitrous) Let's make something perfectly clear, though.....estimated hp nitrous spray delivery/output varies due to:

1) cylinder compression
2) nitrous bottle temps
3) nitrous set up of location of bottle and nozzles.

My point? Skip the headache unless you plan to track a lot. Besides, once you win with nitrous the other guy will automatically assume is was a 500 hp shot. Just say'in.

Quote:

Originally Posted by Hotsauce55

1. Killer chiller

This one is simple. Good choice if:

1) you live in a location that never gets hot
2) you don't track your vehicle
3) like to race no more than 3 seconds at a time
4) consider humidity a beautiful thing while driving

If all above is you? Get a meth/water injection kit to compensate the other 80% of IAT cooling needed when your A/C turns off during WOT.

This guy is an a*s at times. Some of his info might help though?

Quote:

Originally Posted by EREBUS

Reservoir tanks:

1) Trunk tanks are good for track days WHEN using ice
2) Trunk tanks add more fluid.....but take longer to cool (no ice)
3) Large trunk tanks add a lot of weight. We don't need more weight. Period.
4) Engine reservoir tanks are small and absorb engine heat
5) Small reservoirs need coolant lines on the bottom so flow does not cause air pockets near cap.
6) ^^^^^^^Regardless of what you choose.....try to use larger fittings and hoses so upgrades later will be easy.

Heat exchangers:

1) You're good. Move on ( The intercooler is the problem...not the contact area for ambient temps to attempt to cool off the heated intercooler water. Why? Its called diminishing returns. There is a point when you increase boost (13+psi....ish) and the hot compressed air will not get cool enough flowing through the inefficient intercooler core that is using above ambient water. Period.)

Meth/Water Injection:

1) 75% water/ 25% meth ratio
2) @13 gph worth of nozzles is safe for a nicely modded M113K
3) Nozzle locations? That is another battle for another day.
4) Use at LEAST a 2+gallon meth tank. You're going to use it.
5) Go simple and use a boost pressure switch for activation of meth/water
6) DO NOT TUNE FOR METH/WATER.

Quote:

Originally Posted by Hotsauce55

Not sure about the following:

1. Headers (they reduced IAT's a fair bit in other applications)
Not really. They reduce boost that reduces heat.
2. Porting supercharger (in Grand Prix's that used to net huge temp reductions!)
I just posted on this recently, actually. Our blower is pretty damn efficient for a factory blower. Well, kinda. Regardless, porting gained me an average 3/4 psi and no noticeable IAT drop.
3. Bigger rad options?
You got me on this question. Only "rad" I know was a horrible bmx movie back in the 80's ?

As always, I like to have fun and mean no ill will if I offended anyone. Working on lowering IATs is a time vampire.

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