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RoadiJeff and BigBadWilly,

You’re both right. Some background: Higher octane gas takes higher temperature and pressure to self ignite, burns more controllably, and “burns slower”. It is possible to gain more power and fuel economy from higher octane fuel.

Ideally, you set you ignition timing so that you can get the maximum power from the combustion. If your timing is too advanced, the combustion opposes the rising piston, causes a knock or ping, and reduces power. If your timing is too retarded, you will not efficiently use the combustion to push the piston away from the head, loose efficiency, put more hot gasses into your exhaust, and you can actually hear a little different exhaust note if you have a free flowing exhaust. For example, timing is retarded when you first start your engine to put more heat into the cats to help light them off.

I have seen manufacturers establish their ignition timing in a few different ways:

1) Design the timing for 86 octane gas but recommend 87 octane gas. This is a conservative approach to minimize the chance for knock. So, if you add higher octane gas here, you’ll lose fuel economy and power.

2) Design the timing for 88-89 octane gas but recommend 87 octane gas and rely on the knock sensors to actively pull back timing to optimize ignition timing. This approach can result in a more efficient fuel burn, but you are always relying on the knock system to protect you. So, if you add higher octane gas here, you’ll gain power and you can gain fuel economy in some cases because you can shift to a higher gear sooner and reduce your frictional losses.

3) Design the timing for 88-89 octane gas but recommend 87 octane gas and rely on the knock sensors and a learning process to adapt to the “best” timing for the current source of fuel. In this case there are two timing tables – a max and a min. Timing is started at the max and if knock is detected in a particular operating cell, timing is slowly pulled back and “learned” at a new level so you don’t get knock in the future. After you add, perhaps a ½ tank of fuel, the learning resets to the max timing table, and the learning process starts again. So, if you add higher octane gas here, you’ll gain power and you can gain fuel economy in some cases because you can shift to a higher gear sooner and reduce your frictional losses.

So, depending on who did the tuning for the manufacturer, either you can gain or lose power and fuel economy using higher octane fuel.
 

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If your Jeep is a daily driver, you want to make sure that the intake doesn't allow water to get into the air box. Looking at the pictures of the underside of the hood this looks like it could be an issue. Might be a great hood for off-road, but depending on the climate you live in you could be asking for trouble.
You are referring to the RK hood I mentioned in my previous post? If that is the case, I agree with you to a certain extent. The hood does like water could easily reach the intake. However, in my research I have read that RK designed the hood to drain the water before it reaches the intake. I have even read of one customer who supposedly sprayed the hood with a hose and still could not get water to the intake. And honestly, the theoretical amount of water we are talking about could be easily repelled by using a prefilter.

I do want to get this hood, but it probably won't be for at least a year. When I do decide to finally buy it, I will contact RK and ask about the water issue before I actually buy it. When I receive the hood, I will test it myself, and if it does not perform to my expectations, I will simply return it.
 

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Sorry for the double posts, but I did not want to mix these two posts because they cover different topics. This one covers my impressions of the Volant CAI so far.

So I recently installed the Volant CAI. One complaint I have is that there are no holes to drain water that could potentially enter the airbox. Simple fix was to drill a hole into the airbox. I drilled 2 just to be safe.

I did not notice a difference in sound just from the intake, and I recorded the engine sound (outside the Jeep and inside) before and after the install so there would be no mistake. I will say that I did not test the Jeep under load, and maybe if I had, I would have noticed a difference in sound then. I only tested idle sound and revving up to 6k RPM not moving.

I cannot speak of any difference in performance from just the intake, but I did test the performance of the stock vehicle vs. the Volant CAI AND the aFe axle-back exhaust system. Note that the purpose of my test was for comparison between the stock setup and the modified setup only. For your information, I have a 2015 2-door Sport. I was not trying to beat any speed records, and you will see what I mean if you look at the results (further down). But first, my test procedure:

I start from an idle in 2nd gear (yes, 2nd gear). Peddle to the floor, I rev up to 6k RPM and then shift to 4th gear (yes, 4th gear) until I reached 70 MPH.

Why did I test it like this? For one, I was trying to minimize human error by limiting the number of shift points since I have a manual tranny. 2nd gear is low enough for me to get started, but also eliminates any error from shifting from 1st gear. Also I started from an idle so there was no human error in engaging the clutch to start off.

I could have hit 70 in 3rd gear, but since this is a Jeep after all, I figured the data would be more valuable if I stayed in the lower RPMs where it matters, so that is why I shifted to 4th gear for the last stretch. My RPM range in the 4th gear was about 3k-4k, so about mid range.

Obviously this is not the ideal procedure to minimize my times, but like I said, it reduces human error as much as possible which is important for comparison. Now, the results:

Stock runs:
1: 13.4s
2: 13.3s
3: 13.4s

Volant CAI and aFe exhaust runs:
1: 13.1s
2: 13.1s
3: 13.1s

As you can see, it is not a significant difference, but the error between each run is so minimal that I concluded that there was an increase in power. I checked the weather on both days I did these tests, and the weather was as similar as it could be both days, so weather was not a factor.

From the data given, you can see a decrease of about 2.2%. What does this means in terms of power? It is hard to say, but we know that for a given percentage of power increase, the percentage decrease in acceleration time will not be as significant. In other words, a 2.2% decrease in acceleration time equates to more than a 2.2% increase in power. I estimate this percentage to be around 5%.

This is still not a huge increase, but remember, this is mostly in the low-mid RPM range, so that is still useable power, and as we know, the 3.6l reaches about 250 lb-ft of torque around 2k RPMs and maintains at least that torque all the way to nearly redline. A roughly 5% increase in this range equates to between 10-15 lb-ft in the low-mid RPM range. And who knows, maybe the top end sees an even larger percentage increase in power.

In addition, I have personally noticed an increase in low-end torque, but take that with a grain of salt because it is, after all, just a butt dyno. However, I am basing this statement on the fact that the Jeep feels less likely to stall when I am starting off.

Am I saying it is worth buying a CAI and exhaust system for that increase in power? No, you have to make that decision on your own. A supercharger will definitely give you more bang for your buck (and a LOT more bang overall) if you can afford it. But honestly, if my mind isn't playing tricks on me with this low end torque business, I'd say it was worth it to me.

I have not been able to make a judgement on MPG yet, but I will have an opportunity to do that this weekend, so stay tuned!
 

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My build went this way, RR low-rise. Much better low end torque and I get two birds with one stone. Maybe a bit of a mpg gain but I don't really pay attention to that as much as staying in OD on my commute.
 

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Those of you who are running the K&N CAI, are you using the dry filter black hawk or the oiled filters? Any reasons to use one and not the other? Thanks.
 

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I went an entirely different route. I like the idea of a "true" cold air intake but didn't want to reuse the stock airbox or intake tube with the chambers in it so I bought the new Injen "Amphibious Attack" setup. Stupid name I know. So, I could have bought the AEV snorkel with the 4" diameter top for 400.00 bucks and used the original intake box/tube which I didn't want to do. The Injen intake box/tube was 320.00 and very easy to install. It uses a dry cone filter and a larger intake tube that then goes down to what has to be the stock circumference since it couples to the stock throttle body. On the box has a little gauge that goes from green to red. If it's red then you clean the filter. Simple enough.
I also have a dynomax competition off road muffler that dumps before the rear axle (#39522 I believe). Needless to say the combination can move some air.
One of the first things I did not like about this Injen intake tube compared to other Injen products that I have used is that the tube is plastic and not metal so the MAF mount is nothing but a rubber grommet. That's fine and dandy if its just an intake tube but extremely underwhelming when you buy the snorkel part. I had to RTV the piss out of it to make it waterproof. Same with all of the airbox and snorkel joints. And since I used RTV I sure didn't want to tear it apart, clean the RTV off of everything to clean the filter so I bought a third piece. But more on that later.

I left out the snorkel. I bought this piece a week later and installed it three weeks after I bought it. Why, I really didn't want to cut my hood.......again. It was a little stressful when I cut my knew Jeeps hood to install the Poison Spyder louvers and I wasn't looking forward to it again. Anyway, I spent 320.00 for the snorkel and finally installed it. Nothing major happened other than the directions for the template placement on the hood had it 1" too far forward so I had to cut more out of my hood to make it right.

Now to go back a little, I just spent 650.00 for a very nice snorkel system that I water proofed using RTV and didn't want to tear apart to clean the filter. The stock Injen snorkel setup uses a ram top and works great on the highway to get that air into the engine and I did notice that my automatic transmission was holding gears better on the interstate (4.5" lift and 35x13.50x20 tires with 3.73 gears) but if that same air was on a dirty trail I would have problems. So as the old saying goes: JUST EMPTY EVERY POCKET, I decided I needed a precleaner. So, I got in touch with AEV and of course they were sold out of their precleaner (135.00) but were nice enough to tell me who made them (Sy Klone). Interesting company by the way. They wouldn't sell me one so I had to find another company with the one I needed. Unfortunately I did......CATERPILLAR. So instead of 135.00 I spent 230.00. Now my system has cost me 850.00. And this is what I have learned.
1. It looks cool!
2. I have to spend even more money to extend all of the breathers for my axles, transmission and who knows what else (onboard air) to the airbox so they are also water proof.
3. My gas mileage improved to 17.8 from 14.3 but as time went on the ECU found a way to get involved and took me down to 14.4 over the course of 1.5 months.
4. I needed a programmer.
So to waste more money I purchased the Superchips TrailDash1 for 300.00 and got to work. I have ran the Eco tune, 90 tune, and the 93 tune. I have also used the crawl tune even though it is pointless for this novel I have written. The programmer has changed the throttle sensor and it is peppy. It will break ground at a stop light and that takes a lot since each tire and wheel combo weigh around 147lbs. I can power brake it too until the nanny kicks in and eliminates it. If I am normal and us the 90 octane tune I was back up in the 17 MPG but as time has passed I am back down to 15.1 MPG.
I have come to the conclusion that no matter what you do with the ECU and the 3.6 Pentastar you will not get more power/MPG's. The only thing I can do short of forced induction is a throttle body spacer (pointless) and one of those Tornado thing-a-ma-jig in the intake tube (also pointless). But what's another 200 bucks.
To sum it up:
Injen intake: 330.00
Injen snorkel: 320.00
Caterpillar precleaner: 230.00
Dynomax muffler: 120.00
SuperChips programmer: 300.00
Total: 1300.00

Looks/sounds cool!
.8 MPG better!
I could have bought a good winch or roof rack for that price but instead I just need another set of tires.........Maybe I'll go to 37's.?
0117161606.jpg
:beerdrinking:
 

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I’ll offer another CAI opinion. First, the stock airbox has a few issues:

1) The airbox doesn’t flow too well. You are only using about half of your air filter.
2) The tube from the airbox to the throttle body flows OK. However, the resonator tubes sit directly in the hot air path from the radiator/AC condenser/tranny cooler and gets hot.
3) The air inlet air temperature sensor gets heated externally by the same hot air as in #2.

On an 85F day I have seen IAT temperatures at 165F in stop and go traffic. The ECM has a couple tables that modify the ignition timing based on inlet air temperature. You can lose 1 degree of timing for every 10F increase in inlet air temperature. So, an 80F degree rise results in 8 degrees of timing loss. What does this mean:

1) Less dense air making less power
2) Lower timing resulting in making less power
3) To get the same acceleration feel you have to press the accelerator down more resulting in:
a) Less pumping losses for slightly better engine efficiency (this is a good thing)
b) Your transmission control module sees the increased throttle and holds the gear longer (this is a bad thing for fuel economy)

The net result is less power and worse fuel economy.

My stock system flowed about 175 CFM (if I remember right) outside of the vehicle and flowed less inside the vehicle with the hood down (I forget the number). I modified the stock air box and picked up about 25ish CFM. I insulated the stock tube and dropped the max temperature excursion from 80F to about 45F.

I still wasn’t happy. So I did some research into CAIs for the JKs and bought the one that I felt had the most potential. I modified it to get cold air from the outside, modified the air box to flow better (the system is about 245 CFM now outside of the vehicle), insulated the tube, and insulated the inlet air temperature sensor from external heating. My temperature rise is about 5-10F during normal driving and I’ve seen a peak rise of about 20F. I used thermal insulation/noise dampening on the inside of two of the sides of the air box to help with conducted heat and to cut down the high frequency intake noise. My intake is pretty much silent until about 2500 RPM at >1/2 throttle then it starts with a very deep growl. One of my passengers remarked that it sounds like a V8.

I have the ability to dyno the JKU, but I didn’t after each design iteration. I’ll probably dyno, get a 0-60MPH time, and ¼ mile performance after I finish tuning the ECM to just see the end result.
What can I use to insulate this stuff? Would reflectix tape be good? I'm probably gonna stick to the stock intake for now but if I could pick up 2 or 3 degrees of timing advance it might be worth a try.
 

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Air Raid

I used to be a Harley wrench as well as doing mods on my own vehicles...so my experience although nowhere close to some of the members, I can easily say that a "good" CAI system will allow better air flow that results in a crisper accelerator response. The difference is not drastic enough to require re-mapping unless more exhaust or engine mods are done and even then, re-mapping is not always required. I never worried about gas mileage with the Harley's however, it does seem to increase about 1.5 - 2.5 mpg in V-6's and V-8's. I currently running an Air Raid CAI on my 2015 Wrangler. Daily drive is 14 miles to and from work. About half of which is thru town. The mileage meter on the Jeep always give me a better report than when I check it correctly at fill-ups so I'll use the real MPG....16-17mpg. If I get out on the highway and run 70 (or faster), the mpg drops to about 14-15.
 

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I am late getting into this but I have a simple question. I have the chance to pick up the MOPAR "CAI" for next to nothing and it is brand new, never used. Is it a decent intake and filter is my question. I plan on mating this to a custom throttle body spacer. A fellow Jeeper in my group did a similar set up and he noticed improved highway hill climbing. FYI both Jeeps are 3.8 Autos.
 

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I am late getting into this but I have a simple question. I have the chance to pick up the MOPAR "CAI" for next to nothing and it is brand new, never used. Is it a decent intake and filter is my question. I plan on mating this to a custom throttle body spacer. A fellow Jeeper in my group did a similar set up and he noticed improved highway hill climbing. FYI both Jeeps are 3.8 Autos.
Definitely top quality and it's made in the USA (at least mine was). I love it!

They run about $320 new, what price are you getting it for?

Oh, and it sounds really good to.
 

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TerryC6 - Fast forward 1 year: Still happy with the Volant product? Any insights to share on performance or related?

One area I am interested is your impression of the sound of the Volant under acceleration. Is it noticeably different than when running steady RPMs?
 

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TerryC6 - Fast forward 1 year: Still happy with the Volant product? Any insights to share on performance or related?

One area I am interested is your impression of the sound of the Volant under acceleration. Is it noticeably different than when running steady RPMs?
I am happy with the product, no doubt about that. But a lot of that comes from just knowing I have the Donaldson air filter in there. Performance wise there was a small improvement but IMO the cost does not justify buying this system. I think it would be money better spent on a snorkel system that would provide true cold air.

I have made so many changes in the last year its kind of hard to quantify any gains. What I can tell you is I get around 16mpg combined with my current setup which I consider to be pretty good. I have hit 20mpg if I keep my speed down to 55mph.

If you jump on it you can hear the induction noise but I have also changed the muffler so it gets drowned out now. What I do remember though with the stock muffler at cruise no noise at all.
 

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I had a volant with the box on my jk for a while with donaldson filter and pre filter. Although it provided more protection the open filters of the mopar, etc, i put the stock setup back on as it looks to provide the best water resistance outside of a snorkel. If you off road and do water crossings, I would not play around.
 

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Discussion Starter #97
I had a volant with the box on my jk for a while with donaldson filter and pre filter. Although it provided more protection the open filters of the mopar, etc, i put the stock setup back on as it looks to provide the best water resistance outside of a snorkel. If you off road and do water crossings, I would not play around.
There may be a little truth to this but without testing who knows. The stock box air intake is a couple of inches higher than the Volant but the stock box also has a hole in the bottom of the box where the Volant does not. IMO if you are doing any water crossing that are bumper depth or higher you need a snorkel.
 

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I did the MOPAR CAI, bought used here, after I bought 35's and a 2.5 TF lift, I could tell a different in performance, really lagged in 6th, with this intake I can tell a difference, in mid range power, it revs easier and faster, in 6th it actually will pick up speed, I don't plan on creek crossings so I'm not worried about that, I'm happy with it,
 

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Disclaimer: Everything im about to comment on is first hand experience with the actual part - before/after. No BS opinions. Turned many off the lot cars into street racers.

I bought the Volant 176366 PowerCore CAI for my 2015 sahara as a 4th mod (others being 4" lift kit, 35" tires and re-gear from 3.21 to 4.56) . Heres my impressions:

1. Sound is fantastic. If for anything else this can be a bargain replacement for replacing your stock muffler with an aftermarket growler. the stock muffler is not the restrictive air flow source you are lead to believe.

2. Your gains will be at the upper end of the RPM curve. The slightly increased throttle response gives the illusion of a faster Jeep. I would rather have a jeep that "feels" faster than one then one that slips on a 1/4 mile minutely faster. Its a Jeep not a flippin Corvette!

3. Never in the history of any sanctioned racing sport has a stock airbox EVER been present in a car. They DO make a difference even without a tune. A tune enhances it further obviously.

4. Donaldson built filter is top of the market filtration and quality.

Conclusion: worth it for the sound quality and slightly improved response. Cheaper than a muffler swap and built for longevity.

off topic...the BEST bang for the buck mod (sans S/C and re-gearing) is the Pedal Commander - PERIOD. Its all about throttle response on a sluggish trolling Jeep and this delivers. If you say otherwise, you havent any real world experience wit it and should just shut the hell up ;o)

Hope that helps!
 
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