LLCOOLBEN

I just installed the larger throttle body on my 2011 2d. I took it for a quick spin but there was a lot of traffic so I will push it tomorrow morning since there is no traffic. So far, so good.

mycenae

Started driving like an average person (versus the grandma shuffle), don't let anyone pass me, hard starts, keeping up with maniacs on the freeway at 70-80mph.......basically enjoying the better trans and power characteristics. Average milage has dropped accordingly 15.5 (city/highway).

Before the TB change driving it harder like this was frustrating because I had to fight the trans and I didn't have as much power to try and keep up. I'm positive I have more power everywhere (versus some who don't notice a difference) so it could be my particular rig, setup, altitude location.

The last 4 days I've had "no" ETC/ESC during my commute where I come down in altitude by 2K ft (where my past CELs occurred.) I've never had CELs at home or climming in altitude, only when I approached Sea Level.

Maybe the ECM has finally settled in or possibly since I'm driving harder and feeding it more fuel it's happier. I'm going to try to go to Pismo this weekend and flog it on the dunes...should be a good test at lean conditions.

drumnatural

Anyone else notice the air/fuel ratio for the viper TB and exhaust combo gets richer at a lower rpm then stock?

Unless I'm mixing the colors up the stock setup runs roughly 14.5 until the upper rpms?

That just doesnt seem right to me especially if theses runs are all at WOT.

drumnatural

14.7 is the a/f ratio for cruising aka closed loop. At open loop/the gas pedal is so far down, the a/f will jump to the 12,11,10 etc as you get closer to redline. Every car is different with how rich they get in the upper rpms. I have never seen a stock vehicle stay that lean at WOT for that long in the rpm band.

In fact it looks like the gas pedal wasn't pushed all the way down until the a/f jumps into the 12s.

tslewisz

What are looking at?

Your post confuses me because 10:1 is richer than 15:1. A stock JK is too rich up top. Tuners gain HP by leaning it out. And timing changes, of course.

CJ7nvrstk

Was rummaging thru the garage looking for sway bar discos (damn, can't find anything since stuff is still boxed after the move) but I did find my Viper TB I took off my 08 before they dragged the carcas away. Hope to get it on my 11 soon.

drumnatural

Look at the colored lines at the bottom of the dyno. The red line(stock) stays leaner for longer then the other two colors. That would mean the stock setup runs leaner which doesn't make sense.

Cars I've tuned will jump into open loop once u get on the gas roughly half-way down or so. Once you do this your ECU will start dumping more fuel into the engine and a/f ratios get into the 12s or lower.

Vehicles run closed loop when on the gas less then half way down or so. Closed loop your a/f is generally around 14.7 or stoich. This the optimal a/f ratio for emissions.

So the stock setup staying around 15.0 for as long in the rpm band as it does in the dyno sheet is suspect.

Someone chime in if I'm not looking at this right.

CJ7nvrstk

Finally got the Viper TB installed last weekend. Butt dyno noted slight gains in mid range to upper RPM band. Wife said the same thing. Slight improvement in throttle response. Didn't notice as much gains as I did on my 08 JKU but had stacked mods on that. (tuner, KN filter) Can't really say have noticed a change in mileage as it's only been a week and didn't track mileage before anyways so don't have anything to compare it to.

And despite some of the common misinformation described by others, no problems or codes either. I don't expect any either since I didn't have any problems with it on my 08.

mycenae

Didn't make it to Pismo, but instead hauled the kids and their KX100 on a hitch rack to NW Mojave past California City. No problem going up the hill north of Rosemond in OD TQ locked (maybe 3% grade) at 65pm without downshifting. This same route stone stock it would always downshift with the identical load on board. No CELs, good performance, good trans behavior and 15mpg average round trip (that's with the extra weight of kids, full tank, KX, rack and gear).

Snow flurries came thorugh last night dropping this morning's commute down to 35 degrees. I took the same canyon route that caused CELs in the past....no more CELs...did lots of coasting (fuel saver mode on) to try and force the lean issue....still no CELs.

Seems as though the ECM has settled in so I'm going to start lining up my recommended fabricator to replace the 2.25 in y-pipe with a 3 in y-pipe. Just to be safe I'll ask him to try and keep the cuts clean so we can weld it back in if the ECM can't deal with it. If this exhaust mod works without issue I'll port match the upper plenum to the larger TB inner diameter. If the porting causes a CEL I'll try putting one of those TB spacers made for the larger TB with the (worthless?) swirl cuts. These swirls actually hang down in the port disrupting, altering (limiting?) flow so it may act somewhat like the stock port size.

barrett_fodder

This is what I posted in a seperate thread on the VTB, but just in case others havent seen it, and I have not yet nor has anyone who has riven my jeep experienced any faults or malfuncitons of any kind...

"I'll start with: I'm deployed and no I didn't pack my dyno sheets with me before I left. That said, I purchased and installed one of the viper throttle bodies on my jeep when the discussions first began on this site over a year ago. I have had no problems with it of any kind (7,000 miles) and did not notice the TB having much change in performance with any of the SC tunes loaded vs stock (read: the change in performance came moreso from the change in tunes and the TB had little impact one way or the other). This was prior to the availability of the "Trottle body" program some tuners are now offering so I cant speak to that. With my SC tuner and several runs on the dyno, regardless of tune set we observed a nominal 4hp and 7lbft difference in back to back runs. This was done with 3 runs with stock throttle body, add the new throttle body then do 3 more runs. We then swapped vehicles and did the same thing again with a completely stock JK. This difference was beyond the error/deviation in each of the 3 runs, thus a measurable gain beyond the accuracy of the equipment. On the topic of fuel economy I have noticed no real change one way or the other. The bigger impact is wind speed and right foot weight...

One thing to note is that on the VTB dyno sheets the torque peak did seem to move down about 50 revs in the RPM range.

On the butt dyno it does feel a little more responsive, that probably is based on larger volume of airflow with lower throttle position, similar after effect as changing the pedal responsiveness via a programmer or the like. The sound is difference and slightly lower on the intake side enhanced by a CAI more than the stock airbox as well.

Hopefully this helps those on the fence determine if 4/7 is worth $140, or at least give another users observances to add to the pile.

BF "