I picked up a set of these RS4 TBB adapters for use with the metal RS4 throttle body boot. I’m planning on using the RS4 ‘pancake’ pipes, but I want to keep my options open for using alternative setups and these adapters were a limited production run so I figured I’d grab a set while I could.
You’ve heard about the J-Mod. You’ve wondered, ‘how can I get the J-Mod?’ Now, finally the J-Mod is available.
When performance at all costs is your goal, J-Mod can help get you there.
Everyone knows that air flow to your motor is what makes POWER! What few realize is that pressure losses before the turbo impact performance two and a half times as much a post-turbo losses. The money you were saving for those big honking side mount IC’s, forget it, pre-turbo pressure losses are where it’s at, and that’s precisely what the J-Mod targets like a fat guy going for the Chocolate fountain at Golden Corral.
Born out of flow bench testing, the J-Mod delivers measurable gains in intake airflow. Did we mention that air flow is what makes POWER!
The J-Mod development effort involved multiple specialized tools operated by dedicated craftsmen tirelessly working to uncork more POWER from your motor.
J-Mod transforms your car’s intake system from mild to wild and unleashes all of the ground pounding POWER you’ve dreamed about.
The cost for this service is reasonable for all of the POWER your S4 will gain. Contact us directly to discuss installment payment plans.
While not recommended, the following Do-It-Yourself section will give guidance to those desiring to try this at home.
Note: THIS PRODUCT IS FOR OFF ROAD USE ONLY.
Begin with your stock air box upper.
Got a steak? Get a fork ’cause you could cut it on that edge. Air doesn’t like sharp edges, and neither does the J-Mod. After the J-Mod your intake will look like this, smooth as a babies bottom.
The entire turbulence generating edge is wiped out, leaving behind a smooth curve that guides airflow along to your awaiting turbocharger.
From the inside of the airbox you can see how thoroughly the J-Mod addresses intake deficiencies.
The sharp edges above are wiped out, leaving behind a smooth path for the air to adhere allowing the airflow to remain laminar, minimizing intake losses and resulting in more POWER. Look below at the finished product.
Out of curiosity I thought I’d smooth the inside edges of the airbox up near where the MAF housing fits. Smoother is better than sharp in this location so I took a file and sandpaper to the plastic and smoothed the edge out. As the flow bench testing showed, it did make a difference, but is so small (about 3/100’s of a psi) I doubt it matters – but hey it improves airflow and that’s a good enough claim for most after market performance products.
As a follow up to the discussion about the Audi B5 S4 Stock Intercoolers here is a chart that illustrates just how effective all of the available intercoolers are at dropping the charge temperature.
The chart above is a composite of several pieces of data to be illustrative of how effective the intercoolers are at achieving temperature drop in the charge air.
The measured compressor outlet temperature rise and IAT curve showing a 12 degF rise were recorded together on a stock boost (8 psi) pull. The curve showing a 28 degF IAT rise is from an S4 operating at 21 psi of boost pressure with stock IC’s.
On a typical stage 3 S4 operating with K04 size turbo’s it would not be unusual to see the intake air temperature increase by 28 degF by the end of a FATS pull. This is the 28 degF curve shown above.
Under similar conditions an ER intercooler would be expected to show a temperature rise in the neighborhood of 12 degF, shown by the second IAT curve above.
Typically an Intake Air Temperature comparison would show these two curves with an appropriate scaling that highlights how the Stock intercoolers allow IAT to rise more the twice what ER’s do – the impression that the divergent curves give is that there is a substantial performance difference between the two intercoolers.
When the turbo compressor outlet temperature is included, as above, some additional perspective is available. It becomes evident that both the Stock and ER intercoolers are dropping the charge temperature a significant amount – with a stock boost level the IC’s lower the charge temperature by roughly 100 degF.
But as I pointed out, the 28 degF IAT curve was obtained with Stock intercoolers at 21 psi of boost – a case that I have not yet measured the compressor outlet temperature for. Based on predicted outlet temperature the blue dotted line shows what the compressor outlet temperature might look like at 21 psi of boost.
Knowing that stock IC’s show a 28 degF delta and ER’s a 12 degF delta when recorded on a FATS pull at 21 psi of boost, the amount of temperature drop from the compressor outlet is around 170 degF for stock IC’s and 186 degF for ER’s. As the far right markings on the chart show, there is a big drop in temperature whether by the stock IC or the ER, and the difference in performance of the Stock IC and ER IC is relatively small in comparison to the amount of total temperature drop being achieved.
Both of these intercoolers are doing a good job at temperature drop. The aftermarket intercooler is able to achieve greater temperature drop than the stock IC, but in the context of the overall temperature drop of the charge air the differences between the two products is not that great.