I am looking at eventually getting the viper throttle body for my JK due to the good reviews from people on the forum (thank all you guinea pigs!). Because of this I was wondering what the inside diameter of the S&B intake tube is for their intake. Since the S&B is one of the only CARB approved intakes I want to get this in addition to the viper throttle body to get the maximum gains. However if the intake tube of the S&B intake tapers to the same inside diameter as the stock throttle body then I won't upgrade the intake because there would be no point to getting the aftermarket intake if the inside diameter tapers to something smaller than the inside diameter of the viper throttle body.

And before anyone says anything negative about the throttle body or getting an aftermarket intake I honestly don't care about your opinions. I don't plan on driving through deep water any time soon.

What I am looking to do is give useful scientific info to the forum about the S&B intake and viper throttle body as far as performance and any MPG change. I plan on filling up my JK at a local gas station (to start off with a completely full tank). I will drive a 50 mile loop that includes mostly highway with one extended grade where my JK can't quite maintain 70 mph in 6th gear in it's current form. I plan on getting on the highway after filling up with gas, setting cruise control at 70 in 6th gear (so all acceleration and speed maintenance will be done by the computer). After completing the loop I will come home and install the S&B intake and do the same loop after filling up at the same pump and recording the amount of fuel used. Finally I will install the viper throttle body and do the same thing. I will record any changes in performance (can my JK maintain 70 up the extended grade after the changes?) as well as the amount of fuel used for the loop each time (showing any change in MPG).

 

so if you get the viper TB, what air inlet hose do you have to upgrade too to fit?

I know its not an answer to your question but it seems you've researched it, mind sharing?

 

From the looks of things most of the aftermarket intakes have 3 inch diameter intake tubes that are necked down to the bore of the stock throttle body by a rubber "step adapter" as most of them call it. If this is the case I will just get a rubber connector similar to those that people with the stock intake are running that simply doesn't step down the intake diameter.

As for dyno results, this is the reason why I am including a route that has hills that the JK just barely can't maintain speed on right now. Currently when I climb this local extended grade (about 3 - 4 miles long) my speed typically drops from 70 to ~62 mph by the top of the hill if cruise control is set in 6th gear. If after adding either or both of the upgrades it can maintain 70 or it only drops to say 68 or 65 mph, then this shows me that there is real-world usable torque to be had from these upgrades. Of course if I get back and my MPG is worse after these upgrades (which is very possible) but it can maintain speed on these grades then there is a clear trade-off that I will make everyone aware of.

 

Bump...anyone?

 

Hey, I just want to post up and say I appreciate your effort in actually testing out the different ideas. Good luck!

 

No problem, I did my masters degree in energy engineering with a focus in engine combustion, so this is kind of one of the things that I love to explore and have enough knowledge in to give a real contribution to the Jeep community. Plus with gas prices going back up and our naturally low mileage vehicles, any little bit helps.

Also bump for the dimensions of the intake

 

After looking at the s&b intake instructions the intake tube appears to be the same diameter as the stock throttle body. The rubber coupler slides over both and the tubes connect flush to one another...if u want exact dimensions why not just call s&b? Any aftermarket kit for the jk is designed for the stock tb. The intake tube will be either the same diameter or neck down to the same diameter. Either way you'll need a large>small sized coupler for the new tb, or a custom intake pipe.