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Pipercross Viper Dyno Test

Pipercross Viper Air Filter Test – This is a comparison test we carried out on a Ford Focus Zetec 1.6, 2001. We compared the Ford Focus standard air box against a Pipercross Viper Air Filter Kit. 

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Performance Filters, why bigger is better

The Test

We carried out 3 power runs on the Focus standard air box and took the maximum reading. We then replaced this with a pipercross Viper Air Filter Kit and carried out two runs, one with the bonnet open and the last one with the bonnet closed, as it turned out having the bonnet open or closed made no difference to the figures, they were identical showing that the induction system was shielding the hot air in the engine by from the filter.


A 5hp gain at the wheels or a 7% gain. On the road the car felt a lot more responsive, was more willing to rev and was better to drive, all in all a modification well worth the effort. Looking at the graphs it can be seen power drops of significantly after 5,500 rpm, this could well be down to the standard ecu. We will reprogram or replace the ecu at some point and see how much power we can get, if we can get the power to keep climbing up to the limiter we could be looking at 120bhp at the flywheel or 90bhp at the wheels.


The power gains seem quite impressive on paper but the reality is 5bhp is not a noticeable gain in power, it is not something you can feel.

The one standout feature of the kit was the throttle response. For whatever reason there was always a slight delay between pushing the accelerator and getting more power. This delay was reduced with the Pipercross Viper.

Another factor that could have played into the hands on the Pipercross in this test was that we were not comparing the figures against a new, clean paper air filter. A lot of the power gain could have come from simply fitting a clean air filter.

Pipercross Viper Background

This test was done around 15 years ago. At the time the Pipercross Viper was considered a very expensive intake with prices starting at over 200 GBP. Most intakes systems were selling for around 150GBP.

GruppeM was the big stand out at the time and 2,000 plus GBP for their intakes was considered stratospheric.

But times have changed and it is not unusual to see filters costing over 2,000GBP being quite popular. In many ways the Pipercross Viper was ahead of its time both with regards to cost and the use of a carbon fibre cannister for the air filter. Some models of the Viper were even available with a reverse filter housing which you see some air filter companies today claiming it is a new thing that they thought of.

Does the Viper still stand up in today’s market?

Yes and no.

The design of the filter is still up to date

The price is lower which could be argued is unnecessary

The size of the casing is perhaps too small, maybe not for performance but for asthetics.

Replacement filter elements seem to be hard to get hold of

As it stands at the moment, the answer is probably more no than yes.

Reviving the Viper

If Pipercross were to make the unit much larger, supply the kits with more substantial fitting accessories (eg use of rigid ducting instead of hoses), make replacement filters obtainable, make sound a much higher priority in the design eg by altering the placement of the canister (or it’s ducting) in the engine bay and increase the price by at least 50% I think they could be onto a winner.

Find performance parts on ebay

This page was last modified Apr 14, 2021 @ 7:16 pm

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