Chrysler 300C & SRT8 Forums banner
1 - 18 of 18 Posts

·
Registered
Joined
·
375 Posts
Discussion Starter · #1 ·
I've been reading all of the "cold air" threads/mods etc.

Changed my oil today and decided to yank the stock silencer..and holy cow! That thing is HUGE! I looked it over, and it is actually 2 peices. The intake piece connects to the "baffle box/silencer" (no wonder you couldn't hear this car suck any air...).

I'm sure this has been done, but ..I got out the hacksaw and sawed off the baffles and the box peice. Now, there are 2 additional HUGE holes to suck some air. This should work MUCH better as modified to get some airflow into this beast....

I think I'll leave it like this and just get a K&N (was waiting on the K&N for a cold air kit). Sorry for no pics...my camera is awol.
 

·
Registered
Joined
·
6 Posts
Although the K&N flows a good amount of air, be very careful when it comes to the oiling of the K&N as not to get oil in the MAF
 

·
Registered
Joined
·
49 Posts
Maf?

When you say MAF are you saying Mass Airflow Sensor?? I dont think these cars have a MAF. Infact I read an article in Hot Rod mag that the 5.7 uses a speed density system that does not respond well to cold air induction changes. I believe the engine management system needs to be re-programmed if there are changes to the induction system. Here is a quote for Popular Hot Rodding comparing the Hemi to the LS6:

Unlike an LS6, which has a mass air system that allows the computer to adjust the fuel flow for any given airflow so that the mixture is always right (theoretically at least), the Hemi has a speed density system. This means that any increase in airflow into the engine goes unseen by the rest of the system. If a modification is done that increases mass airflow, such as a cold-air package, the computer has to be reprogrammed accordingly.

Here is the link:

http://www.popularhotrodding.com/enginemasters/articles/mopar/smallblock/0403phr_hemi/
 

·
Registered
Joined
·
6 Posts
Yes, I meant MAF.... Mass Air Flow (Meter). Thats interesting that this car uses a speed density system. This means that a forced induction kit might be that much easier.

AdamR
 

·
Registered
Joined
·
54 Posts
Hmm...that sounds pretty interesting. It will probably decrease the life of your filter..but sounds like a pretty good free mod.
 

·
Registered
Joined
·
13 Posts
If this computer system is anything like my Ram's system, (and I'm sure it is.) any air box mod's will only be a temporary gain.

The Ram's system will automatically recalibrate itself after a short period of time.

You might notice a difference at first, but like I said, over time the computer will reset itself. Here's a link to a thread started on the Dodge Truck World
forums that talks about it. There has also been many other discussions on it, but this was the first one I found.

http://dodgetruckworld.tenmagazines...5369-s-cold_air_intakesuseless_on_hemi_engine

Save your money on the any C.A.I's. (cold air intake). At least for now.
Wait for the aftermarket to really get going. Squires Turbo has been actively testing a turbo for the Ram Hemi which put out over 400 H.P. at the rear sneakers. http://ststurbo.com/dodge_ram_1500

The technology should spill over for all of us 300 owners.
Just give it a little time, and I'm sure this motor will be able to SAFELY put over 350 hp to the pavement, if not more.
 

·
Registered
Joined
·
54 Posts
I am really starting to hate this computer :mad:

Reminds me of when my LS1 first came out..couldn't do crap since OBDII was brand new.
 

·
Registered
Joined
·
116 Posts
I know that I am an outsider here on your forum but I had a K&N Air Charger Kit put on my Marauder today. We did five dynos before it was put on and five dynos after installation. I will tell you the medium gain was 5hp. We have found that on the supercharged Marauders they gain about 20hp. We did some tweeking to the chip and got about another 10hp with that and the K&N. I don't know if this is how your car will react. My car with a 410 gear, which cuts the dyno numbers was 265.6hp and 286.8 torque at rear wheels. The numbers at start was 256.7hp and 279.7 torque. I hope this helps you guys decide on the K&N. By the way, it sounds real good at wide open throttle. :)
 

Attachments

·
Premium Member
Joined
·
1,010 Posts
dam

Thanks for the tips slim. Nice car you got there by the way. The Marauder is one of the other return of the muscle cars and that you got to respect.

I was hoping that the K&N cold air was going to be like the filter i put on my Yukon. I got better pick up and HP for a 2000 75000 mile truck. If the DXC computer will just "repair its self" well then whats the point. Seems like a waste of money to me. Sounds like we need to find out if this is going to be the case with the 300 Hemi. Thanks for saveing me money SilverC. Cause im a cheap bastard. :D
Keep us posted on this thanks.
 

·
Registered
Joined
·
375 Posts
Discussion Starter · #11 ·
By removing the silencer, there is a little more growl from both intake/exhaust (what I wanted when I hacked the baffle/silencer off). My Borla system seems a little more what I was looking for now too. I wouldn't expect any hp gains by removing the silencer and adding a K&N drop in, but I do know air will flow better - with better air flow in and out = more power and better mileage. I actually found a thread on another forum where someone posted pics of this "mod".

As far as the Speed Density system not recognizing or learning how to "over-ride" or repair that there is more air - we all know that COOL air makes HP. air flow is air flow, if you improve air flow and keep the air cold, you will see minor hp gains vs hot air. This is why your car seems faster 1st thing in the am on a cold morning.

Interestingly, Ford did away with the Speed Density system on Mustangs in 1988 and went to the MAF sensors.....
 

·
Registered
Joined
·
77 Posts
I too removed the intake last weekend and really like the nice little increase in growl when I give it anything more than half throttle.

Just my .02 cents, in my experience a speed density system (which has a limited ability to deal with increases in air/fuel) works of off preprogramed tables based on the engines original parameters. Changing those parameters by adding more air (especially cool air) without telling the system to add more fuel will begin to lean the air/fuel mixture. Of course this increase in air might result in gains if the original speed density system is preprogramed a little on the rich side for safety. This unfortunately leaves us at the mercy of chip burners/programming modules to realize serious gains.

I can't wait till we get computer support like the LS-1/6 guys have (LS-edit etc) to play with.

Chris
 

·
Registered
Joined
·
13 Posts
As far as the Speed Density system not recognizing or learning how to "over-ride" or repair that there is more air - we all know that COOL air makes HP. air flow is air flow, if you improve air flow and keep the air cold, you will see minor hp gains vs hot air
It's not that simple:

Speed Density uses the old gas law PV=nRT to calculate airflow in the engine. By measuring the Vacuum in the intake manifold, the airflow can be determined using the gas law. Measuring engine RPM is not necessary and the Air temperature has less of an effect on the measurement since the density change of air with temperature also effects the amount of vacuum in the intake with a specific throttle opening.


So, for those who are about to spend $200-$300 for a new intake system it would be a waste of money, unless you already have a cat back exhaust system.....and a 180 degf. thermostat. Then and maybe then the intake mod would help over the long haul. The way the sensors are tied together on a typical Density system, the O2 sensor / the throttle position sensor / and the coolant temp. sensor, these three things (among others) in conjunction would or might work to add a few extra ponies. Forget about cams, lifters and any internal mods unless there is a complete remapping of the computer. Cams in paticular would adversly affect the vacum. Most motorcycles use the same system, I had to have a custom map built for mine just to add drag pipes and a velocity stack intake.

I believe someone else had dynoed their stock 300, and made 3 runs, the last run was with the airbox opened and only netted 1 extra H.P.

But then again, the polished intakes sure do look purdy, it would add a nice touch to the engine compartment,.......if nothing else.
 

·
Registered
Joined
·
99 Posts
Thanks SilverC. This explains why WHipple pussed out on the supercharger for the 5.7 Hemi and why Kenne Bell has taken so long to get his working and on the market...gotta crack and reprogram the computer to make it all work.
 

·
Registered
Joined
·
4 Posts
silverC said:
It's not that simple:

Speed Density uses the old gas law PV=nRT to calculate airflow in the engine. By measuring the Vacuum in the intake manifold, the airflow can be determined using the gas law. Measuring engine RPM is not necessary and the Air temperature has less of an effect on the measurement since the density change of air with temperature also effects the amount of vacuum in the intake with a specific throttle opening.


So, for those who are about to spend $200-$300 for a new intake system it would be a waste of money, unless you already have a cat back exhaust system.....and a 180 degf. thermostat. Then and maybe then the intake mod would help over the long haul. The way the sensors are tied together on a typical Density system, the O2 sensor / the throttle position sensor / and the coolant temp. sensor, these three things (among others) in conjunction would or might work to add a few extra ponies. Forget about cams, lifters and any internal mods unless there is a complete remapping of the computer. Cams in paticular would adversly affect the vacum. Most motorcycles use the same system, I had to have a custom map built for mine just to add drag pipes and a velocity stack intake.

I believe someone else had dynoed their stock 300, and made 3 runs, the last run was with the airbox opened and only netted 1 extra H.P.

But then again, the polished intakes sure do look purdy, it would add a nice touch to the engine compartment,.......if nothing else.

Ok assuming the theory is true how are cars showing substantial gains on the dyno? Even assuming the hemi has some miles before it plateaus the changes are drastic and consistently these “purdy” intakes add power… But why? I mean maybe you have forgotten a portion of the computer program or maybe there is another explanation?? I am not hacking but truly interested in what you "think". Remember this is the Internet so I am not sure who you really are and what your motives may be.

The next question is why will a exhaust help when a intake will not???

I am interested in your theory.

Ty
 

·
Registered
Joined
·
13 Posts
Speedguy:

No offense taken, it's good to question things.

For the most part, intakes do and will work very well on most other vehicles. But these "other" cars and trucks utilize Mass Air Flow metering system (MAF). These systems are much more flexible in their ability to compensate for engine changes since they actually measure airflow instead of computing it based on preprogrammed assumptions.

Unfortunatly for us speed density is actually a cheaper way to inject fuel, and that is what Chrysler has opted to use.

The thought of using an aftermarket or cat back system is to possibly "fool" the O2 sensor which is actually sort of a secondary meter which is checking for any fuel delivery errors. By uncorking the exhaust and getting better flow out the back first, it's possible to make the computer think there might be a slight lean condition and richen the fuel delivery. Then by using a 180 degf thermostat (I think a 190 or 195 degf. is used stock?) to help keep the manifold air and the rest of the motor a bit cooler and better vacum, now with a bit more fuel and better vacum the extra air would come into play.

Don't get me wrong, I'm no expert and all of my past dealings has been with Mass Air FLow. I had a '92 mustang that would run 12.3's all day long and was my daily driver for 3 yrs. MAF is nice because you keep making mod's and once you get a bit too radical from stock configuration, you just increase the injectors, fuel rail and fuel pump, and just keep going.

This is something most Dodge Ram Hemi owners have come to learn. Most who want significant H.P. gains and performance have opted to go to the nitrous route. Many still put CAI's on and without extensive and continued dyno runs the jury is still undecided. My main concern is spending upwards of $300 for a CAI that by itself may or may not give you extra umph :confused:

To be quite honest, I didn't buy the car to make it run 11's. It's more about luxury than anything else. But before I go slapping performance pieces on it, I'm going to wait for the Chip guys to come out with something. So far the chips have netted anywhere between 16-25 h.p. on the '03 Rams. So it's feasable that a chip should enable our cars to get close to 305 h.p. at the rear wheels. Now add a potential 8-11 h.p. with an exhaust, a couple more with a thermostat, CAI and maybe some underdrive pullies and were talking about possibly 320 or more at the rear. Now that would be nice, not too radical and still very streetable and simple.

Hope this helps a little. And Happy Thanksgiving to you and yours, and all the members and their familys.
 

·
Registered
Joined
·
4 Posts
The issue I have is with the way you posted the information.

Its not information as a fact so much as a opinion..a educated opinion but I have found some serious flaws and they concern me.

You don’t mention the air sensor having merit as a variable.

You don’t share the facts to back up the 1hp gain. No dyno.

Then in this last response you mention you don’t really know and the verdict is out??

So I will post some dyno numbers asap.

What is the time line before the relearn. Do you know?

I have seen other cars like the northstar caddy have actual losses with open underhood cone filters but gains with a stock modified system..

This is posted in the modification area and if you have no interest in mods that’s ok but really let people play and learn. I will gladly post the moment I find out your right…but I still believe that you are not entirely correct and will provide the proof once the holiday is over.

I forgot to mention the fact the current intake may actually be a variable and when removed lets the "map" have the airflow needed to provide its max.gain. Much like a computer gain its not so much a gain as it is a removal of a handicap. There is a limit to what you can “gain” from mild bolt on’s and that is the true capability of the engine. The only way to go up from here is to actually carve out the heads and add poweradders. That is when you are actually adding power.


Merry Thanksgiving..lol the Christmas adds are already pushing Christmas.
 
1 - 18 of 18 Posts
Top