The VR-B2 system for the C5 Corvette has evolved several times over the years for added performance and ease of filter maintenance. In the latest evolution,of this record setting system we have made advancements for both Quality and ease of installation. Our customers have asked for it and we have delivered. Here is just some of what we have changed.
The Upper Air box
We have retooled the upper air box completely, The filter flange area has been increased to enclose the new cotton gauze filter properly, The seating radius had been altered to lower the box quarter inch and allow for more uniform compression across the filter surface area. We have added a perimeter gasket around the filter, encapsulating the filter creating an air tight seal every time, so NO leakage! The box material has been changed to more impact absorbent material.
In the case of all VR ram air units, true power output will never be able to be measured on a dyne as they are designed on a race track (to be moving). All are tested at varying speeds with multiple multipliers in them in order to function at the desired speed and pressure levels, not noticeable on a static dyno (if you like strong dyno numbers instead of unbelievable on track performance simply disconnect the ram tubes or contact one of our tech staff to find out how to adjust the VR for your power needs). What it comes down to is during the design process you must determine if you are building a ram air system or a system to pull numbers on a dyno. The reason being, each property PULLING or PUSHING, has its own internal aerodynamic package. The VR-B2 has a multiplier system in it (this will hurt pulling air flow static, due to there shape, this can be negated by using an extra half inch step in front of the filter but then it will delay the ram effect as well). This is similar to a blower drive or turbo multiplier. It is applied to airflow at each given speed. Example: say you had an after market cold air box that at 75 Mph was 90% efficient. The VR is over 100% efficient at that same speed. Now at 100 Mph the cold air is still at 90% (more than likely is has slipped to 88% efficiency, typical of this type of setup). The VR is at well over 100% efficiency and climbing! This is a gain that you will never see on a dyno.
All ram air boxes are about the same aren't they?
We love answering this because in the after market it seems that very few ever care to really talk about or emphasize to you the customer that if you want a fast car you need power and torque developed under the curve. Everyone is so concerned about peak power on a dyno that they forget two things: 1. The car needs power under the curve to accelerate. 2. The intake system must be able to recover, build and maintain air pressure as quickly as possible. This means making the intake as efficient as possible NOT at PEAK but during shift recovery under the curve requiring proper air box design and internal systems to increase velocity pressures to help offset any head loss incurred in the system. As independently dyno tested by Cartek and C5 Super Tuner shootout winner Danny Pop, the VR-B2 made anywhere from 2-4 rear wheel Hp more than this competitor at peak but at 5000 Rpm they both saw 5-10 Hp more while sitting on a dyno on stock and modified cars. The VR-1B was designed to perform under the curve. The system will typically gain the same or more torque than Hp depending on the filter used and the year of the car. Take a look:
(the test car is a 98 A4 with 2.73 axle, other than these intakes, car is stock) Initially the VR is already maintaining +.25 Psi more at this recovery point, in 1.5 seconds the VR is +.34 Psi from its competitor. Now let's talk about Hp differences using the same Hp/Psi formulas as mentioned elsewhere on this page.
This car pulled 299 Hp at -.89 Psi with the competitor and 302 Hp at -.89 Psi with the VR (this car averaged +2-5 Hp under the curve with the VR depending on the Rpm). This will yield 21.657 Hp/Psi and a 21.874 Hp/Psi respectively. At shift recovery that equates to 303.19 Hp, the VR produced 311.70 Hp. That's a 8.5 Hp difference at just shift recovery from pressure alone, not including any difference on the dyno we will use the lower numbers (2-5 Hp @ 5000 Rpm). That's a 10.5-13.5 Hp difference. 1.5 seconds later there is a +.34 Psi difference, 14.21 = 307.75 Hp vs. 14.55 = 318.27 Hp. Now we are looking at a 10.52 Hp difference from pressure only. Once again you add the dyno difference using the lower number at 5000 Rpm (+2-5 Hp) and you have a 12.52-15.52 Hp difference and we are only at about 80 Mph. Now peak Rpm, the last second before 90 Mph. 14.54 = 314.89 Hp vs. 14.74 = 322.36 Hp and now add the dyno difference at peak (+2-4 Hp) 322.36 Hp +2 Hp = 324.36 or a difference of 9.47 Hp. The only problem here is that as speed rose (not shown on the chart) to a typical C5 trap speed the competitor lost -.14 psi (caused by air spillage pointed out elsewhere in this discussion) bringing the VR back to the full +15 Hp over travelling through the ? mile traps. If multiplied by a 15% correction factor for an automatic car that would be a +17.25 Hp difference travelling through the ? mile (remember the Mph difference of 1.7 Mph).
If you had to put an percentage to it 60-70% of the time in gear a VR is 12-15 Hp stronger and the last 30% its 12-9.2 Hp stronger than its competitors. This is the current area of racing engine development that is being concentrated on. In the old days you used a dyno. These days it's used for general measurement and to run engines in before being installed in the cars. If someone has designed a ram air system on a dyno then it has a 90% chance of not working well at normal road speeds. It will simply take too long to pressurize or the ducts will be to short and air spillage will occur and the pressurization will be nil and all that you will have is a filter hanging in the wind.
A proper ram air system is a very complex item to make function properly at road speeds below 100 Mph. We spent over 2 years developing the Corvette C5 unit but our parameters were for OEM, not all-out race use. Our competition makes around 28-32 Hp through a 1/4 mile. The VR on a standard C5 or Z06 averages 35-43 Hp through that same 1/4 mile but the VR will make power and torque faster enabling it to be much quicker even on a dyno. "We picked up 5 more Hp at peak over the Donaldson on our basic 390 rear wheel Hp car on or chassis dyno. " Cartek Racing in Garwood, NJ using a VR set up for their cars (1 inch spacer in front of the filter vs. standard 1/2 inch), they were seeing 2-4 Hp more at peak Rpm with a VR-B2 but at 5000 Rpm they were seeing as much as 10 Hp more with the VR unit. Here in lies one of the many reasons why the VR is so quick. The system was designed to be adjustable by simply increasing or decreasing the plenum volume to suit a given cars power needs static. This feature combined with the low pressure drop across of our competition air filters allows the system to make more power under the curve and with a very efficient internal duct package it will force feed more air at lower speeds making for a much quicker and faster car.
It's no wonder the guys at Cartek have the fastest head and cam cars in the country. Some of our customers with stroker motors have gained up to 30 Ft-lbs of torque and 18-22 Hp more than a Donaldson. The reason here is simple. Proper air box design engineered to out flow the competition all the way to 700 Bhp or 8000 Rpm!
Instructions, Here we spent a great deal of time adding many helpful hints and shortcuts to make the installation fast and easy. We have added ALL NEW pictures, that are large and clear, greatly improving the ease of installation over older kits.
We hope that you have enjoyed this small look into some of our R&D and If you have any questions feel free to contact us.
A lot of companies talk about performance in the automotive after market, but at VaraRam, we guarantee it! We have been doing it for racing teams for years and now we are doing it for you.
The new VR-B2 unit is the third generation of our record setting VR-B2 system. This ram air system is over 110% efficient which allows the system to build manifold pressure at very low road speeds. This will improve acceleration which will lead decreased zero to 60 times as tested by Vette magazine. Our system will decrease you 1/4 mile times by 3/10ths - 1/2 second, Guaranteed!! or we will buy it back!
Note: Some 2004 Models will require custom tuning do to increased air flow.