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WK2007 10-29-2012 12:57 PM

Performance upgrades and questions
Hi everyone,

I was hoping some of you people could help me in deciding on a few upgrades.

I own a 2007 GC Hemi with 95K miles. I am looking to improve the rideability, gain a few horses and save on gas without breaking my budget in upgrades. So far, the vehicle has had a new muffler from Flowmaster and the Diablosport Predator is supposedly in the mail due to arrive this week. I will be using the stock tune until money becomes more available. I am currently considering a CAI and a new resonator for the exhaust to optimize the air flow at both ends. So here are my questions:

Which is the better option in terms of exhaust?

A) To remove the OEM resonator on the exhaust and install a straight pipe.

B) To install a Flowmaster resonator and pipe.

In terms of the CAI, is there much more performance to be gained by using the Airaid Intake System compared to the Airaid JR Kit?
I know people have talked about the complete Intake System is vulnerable to moisture, which makes me favor the stock airbox kit with aftermarket air filter and intake tube. The Airaid JR Kit is nearly half the price compared to the full intake system, which is a great value, unless there are significant differences in terms of air flow between the two options.

Finally, what are the costs for a Custom tune and what company/tuning specialist is most recommended?

Thanks everyone for trying to help me out. I really do appreciate your help and this forum is just an awesome source for meeting great people and discussing Jeeps!


brentwoodkris 10-29-2012 01:18 PM

Re: Perfarmance upgrades and performance questions
Exhaust: better keep that resonator unless you want a LOT of drone, especially if you plan on keeping MDS enabled after installing your Predator.

CAI: Go with the Airaid Jr. kit w/ filter OR get a OEM SRT8 CAI (which is about half the price of the Airaid Jr.). You won't regret it. More reponse, and some intake noise. Many have reported a loss of low end torque and pick up with a full intake system.

Custom Tune: I've been lurking on this forum for a long time I think, and when I end up with a predator and a bored out TB, I'll be going with Flyin' Ryan (see vendors section on here). In all my reading, I've seen nothing but positive reviews for the guy.

*NOTE: obviously my opinions are biased because I did these mods to my rig. Waiting for others to weigh in.

WK2007 10-29-2012 02:22 PM

Re: Perfarmance upgrades and performance questions
Thanks for weighing in, Brentwood.

The main reason for purchasing the Predator was the ability to turn off MDS. I hate that system, as much as bad coffee. It ruins the driving experience and my Jeep seems to be unable to utilize it efficiently. Mine switches forth and back from off and on, even on fairly straight and level roads.

I installed the Flowmaster muffler and realized that I was unhappy with the drone when MDS was operational. I tend to just shift into 5th manually and leave it there, unless I am on a longer trip on the Interstate etc. The drone from the Flowmaster was not very noticeable in general, but I remedied most of that problem by insulating the trunk, adding much thicker floor mats. Worked like a charm and reduced the cabin noise levels dramatically. I may consider upgrading to other products, including Dynamat i.e. when time and money coincide.

In regards to your points of view on the Flowmaster resonator, I think they offer several models with different decibel levels, but I may be wrong. I was going to go with the lowest level of decibel output, but only if installing such a resonator would greatly benefit the performance of the car in regards to less air restriction. I would like the car to sound like a Borla system, as those have been said not to drone as much as Magnaflow etc. I know that most people may recommend a full exhaust system, but I just can not justify such an expensive right now.

I understand the principle that if you do not increase air flow at both ends of the vehicle, the potential gains from any type of tuning is limited. I just wonder if there is that much to be gained from installing any type of performance aftermarket resonator versus keeping the OEM one?

I agree that the Airaid JR Kit looks alot more favorable than the full intake system from the same manufacturer. At ~$160 on Ebay for the JR Kit, I can't really see the benefit of investing nearly $200 more for the Full Intake System. The difference between the two air filters do not appear to be that much greater in terms of surface area or ability to process air. In addition, both products offer the same tube, which promises and increase of 400 Cubic Feet per Minute, if I understand the information correctly. Finally, the issue of sensitivity to moisture with the Full Intake System is a concern of mine, especially when the recommended fix is to simply install a sleeve over it. I would think that a sleeve certainly would decrease the air flow to some degree, which is counterproductive to what I am intending to do. Plus, its an added cost to purchase the sleeve on top of the Full Intake System.

I hope more people can shed some light on my predicaments and help us newbies become enlightened :)

Thanks guys!

brentwoodkris 10-29-2012 02:31 PM

Re: Perfarmance upgrades and performance questions
If you're worried about the restriction from the exhaust resonator, a main concern of yours should also be getting the TB bored, as that's a generally accepted restriction point on our Jeeps. Just my $0.02.

DannyVtCa 11-02-2012 05:01 PM

Re: Perfarmance upgrades and performance questions
I removed my exhaust system, the resonator is completely straight through and causes no back pressure.There will be no performer gain from removing it.... I cut off the entire tailpipe and resonator and drove it around for about a day, was still as quiet as can be.

dmsfun 11-02-2012 05:02 PM

Re: Perfarmance upgrades and performance questions
Regarding MDS, just downshift to 4 and it disables it for intown driving. Then on the
HWY you still have it. Mine has 80k and I cannot even tell when it comes on and off. IT used to lag but not at all now after ported TB, seafoam treatment, new EGR and MAP. Your hemi probably needs attention in other areas to get it back to running right. Do that beore modding.

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