Hirsch on Aerodynamics

Here’s a little more Hirsch material.

Hirsch Performance have just released a new aerodynamics package for the 2009 Hirsch Performance edition cars that will be sold in various markets aroud the world. These are Hirsch’s own notes about the new package and they’re good for not only finding out about Hirsch products, but also the importance of aerodynamics and the role played by various parts in the package.

Click any of the photos to enlarge.

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Improving the aerodynamics of the current Saab 9-3 was a real challenge, since the car has excellent aerodynamics already from the factory.

However, for this project Hirsch Performance enjoyed the co-operation and support of Saab’s master aerodynamicist HÃ¥kan Danielsson and his team, as well as renowned designer Taras Czornyj from Mutations AB, whose combined experience made it possible to develop a truly exciting aerodynamics package.

The final product range reaches from front splitter to an exclusive – limited edition – carbon fiber body kit for the SAAB 9-3 Performance special edition car.

Form follows function – Design process

The aerodynamics package was designed as a complete set of modifications to improve stability and reduce drag. In addition to the functional benefits, the aerodynamic modifications should also contribute to the car’s dynamic appearance.

During the entire development process, close co-operation between design, aerodynamics and engineering ensure that the end result creates the best possible experience, both when viewing the car from the outside and when driving at high speeds.

The design process started with the sketching phase, trying to get the most distinctive look possible while still integrating with the shape of the original car.

The sketches were then interpreted in clay, to ensure that the shape of each component looks good from all angles.

Once the basic clay design had been approved, the car was scanned using a 3D-Scanner, and the surfaces translated into 3D computer models.

Aerodynamic optimization – Wind tunnel test

Based on the computer models, aerodynamic test parts were produced and specially prepared so that minor adjustments could be made quickly during the wind tunnel testing.

Front splitters were added to reduce air flow under the car and in front of the wheels, thus creating down force. A larger front spoiler was integrated with the lower mesh grille, further reducing air flow under the car while also increasing the cooling air flow for the intercooler. Side skirts were added to reduce wake behind the wheels and keep the air flow under the car from leaking out. In the rear, a diffuser was added under the bumper to direct the air flow slightly upwards, thus reducing the wake behind the car while also improving rear stability.

For the Convertible and SportSedan, enlarged bootlid spoilers also help improve rear stability.

Perhaps the most interesting component, however, is the roof spoiler for the SportCombi, where a Saab innovation from 1961 was put to use again in a modernised form: the air slicer. The top surface of the air-slicing roof spoiler directs the airflow upwards, generating improved rear stability. In addition, an air slot directs a small portion of the airflow down onto the rear screen, thus reversing the semi-stationary vortex behind the car and thereby reducing the wake and the associated aerodynamic drag, while also helping to keep the rear screen clean.

This design was extensively tweaked and tested in the MIRA wind tunnel, to create an optimal combination of drag and stability.

Safety first – Homologation

Once both the design and aerodynamics targets were met, homologation prototypes were produced. All prototypes were installed on cars and sent to RDW in the Netherlands for homologation. At RDW, the parts were examined to verify that they will not influence the safety of the car or the safety of pedestrians in case of a collision.

All aerodynamic parts have successfully passed the homologation tests, and are included in the latest Saab 9-3 whole vehicle type approval, and can therefore be installed in all markets.

Carbon fibre body kit

Hand laminated in high quality carbon fibre and lacquered with a UV-resistant high gloss coating.

The limited edition complete carbon fibre body kit is available exclusively for the Aero trim level. As a sign of authenticity, Hirsch Performance logotypes in aluminium are laminated into the rear side skirt extensions.

The kit is available for all body types; SportSedan, SportCombi and Convertible, and consists of 8 pieces: Front splitters, side skirt extensions front and rear, and rear bumper extensions.

The front splitters direct airflow away from the front wheels. The skirt extensions help separate the airflow under the car from the airflow on the sides, and also reduce the wake behind the wheels, thus reducing lift and aerodynamic drag.

Front splitters for Aero and Vector

Available for both the 9-3 Aero and Vector/Linear front bumpers, front corner splitters were developed to help direct airflow away from the front wheels. The front splitters generate downforce at higher speeds and help to reduce the aerodynamic drag.

The Aero front splitters are available in two versions; hand laminated carbon fibre, as part of the carbon fibre body kit, and as individual components in high-quality PUR.

The Vector/Linear front splitters are available only in high-quality PUR.

The PUR front splitters are delivered primed, and can be painted – either as the designer intended in matte black – or in body colour.

Bootlid spoilers for SportSedan and Convertible

Rear lift forces cause instability at high speeds on sedans and convertibles, and the perfect solution to address this issue is to add a bootlid spoiler that raises the airflow and provides a clear separation point for an optimized wake behind the car.

The Hirsch Performance bootlid spoilers are optimized primarily to improve high speed stability, and therefore they are slightly larger and have a slightly steeper rake to produce optimal aerodynamic results.

The styling is functional and minimalistic with no grooves or decorations. The spoilers are delivered primed, and can be painted – either as the designer intended in two tone with matte black underside and body colour on top – or completely in body colour.

Roof spoiler for SportCombi

Most wing-type roof spoilers trade off aerodynamic drag to achieve better rear stability. The new Hirsch Performance roof spoiler for the Saab 9-3 SportCombi is unique in that through rigorous wind tunnel testing, it was possible to achieve both a reduced drag and improved stability, while in addition keeping the rear screen clean!

The styling continues the smoothly curved wing design theme established with the Hirsch Performance 9-5 roof spoiler.

The roof spoiler is delivered primed, and can be painted – either as the designer intended in two tone with matte black underside and body colour on top – or completely in body colour.

The kit includes brake light extension cables to be used with the existing brake light, which is positioned in the spoiler, and an extension hose and nozzle for the rear screen washer.

Mesh grill

Improved cooling air flow helps keep the engine temperature under control, and improves the performance of the intercooler. Therefore, the Hirsch Performance mesh grill kit has large openings that allow maximum airflow. However, the outer upper grills remains closed like on the original grill, to achieve lower aerodynamic drag, and ensure that splashing water does not enter the engine’s air intake snorkel.

The upper 3-piece grill is available separately, and fits Aero, Vector and Linear cars. The lower grill with integrated spoiler is available only for the Aero trim level.

The mesh grill is produced in injection-molded high-quality UV-stablized ABS, to ensure that the matte black finish remains beautiful for many years, with the best possible resistance against chipping and harsh cleaning agents. As a sign of authenticity, a Hirsch Performance emplem in matte chrome that matches the original grill frame is integrated in the upper grill.

Rear diffuser

With the installation of a diffuser under the rear bumper, the airflow under the car is stabilized and directed upwards, thus improving stability and reducing the wake behind the car.

The Hirsch Performance diffuser features two round openings for either the Saab Original dual exhaust or the Hirsch Performance dual exhaust. The diffuser has been specially designed to fit both the longer SportCombi and the shorter SportSedan/Convertible bumpers, as well as both the Aero trim level and Vector/Linear trim levels. The diffuser is compatible with the Saab Original towing hooks, and features markings for the required cut-out on the inside of the diffuser.

The diffuser is delivered in matte black high-quality UV-stablized ABS. The kit includes rivets for installation. The bumper reflectors (not included in the kit) are moved over from the original bumpers to the diffuser.

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12 thoughts on “Hirsch on Aerodynamics

  1. I like the rear diffuser, much better than the purely cosmetic one on the Turbo X. Not so sure about the hexagonal front grill though.

    Basically the 2009 Hirsch Performance edition cars in my opinion are going to be better than the Turbo X. More horses (300 vs 280) with the Hirsch tuned engine, nicer interior with Hirsch leather panel, handles, smart slot and hand brake, nicer exterior (personal preference) with the new body kit. It even has lowered suspension, upgraded brakes, 19 inch rims and XWD with eLSD to match.

  2. An Ice Blue Metallic sport combi with the Hirsch stuff is, without doubt, awe-inspiring.

    Hoping that SAAB would offer/deliver the Hirsch stuff in the US.

    Hmmmm, perhaps, it’s cheaper just to move to Germany, go to Switzerland, order the dream car, and envelop myself with this rapture everyday!

    One can only dream . . . .

  3. About the diffuser – that’s how Saab should have done it first time with the Turbo X.

  4. As usual, every single bit of Hirsch component is exquisite to say the least !!! What is it with these guys that no matter where they turn to they’ve always manage to add the classy, tasteful and unique enhancing touch ??? Any such bits for your standard Saab will have a huge lifting effect on any model. Surely, these and other items can be sold loose in any market without any permits ??? However, I would not alter any of the exterior bits on the Turbo X whatsoever as this will remove an element of authenticity. Nevertheless, I am waiting holding my breath to see if Hirsch does indeed release some special parts exclusive to the Turbo X. On the inside, the dashboard carbon fascia is almost a must. Asking this bit to Santa for Christmas may push the family distribution boundaries to its limits. We can only live in hope that one day it may happen though.

  5. Swade, if you need a correspondent in Switzerland, don’t hesitate to ask for it. I take the plane and go there…….xDDDDDDDDDDD

    With that and the TurboX in my garage, I will be the happiest guy in the world.

    greetings

  6. Some sacrifice there Eduard.

    Come to think of it, Jeff lives right on the Swiss border, he could easily go. The problem is that I’m unsure if he knows how to drive a car with power steering, much less all of these gizmos.

    I would be very interested in some of these mods if I were a 9-3 owner, and I’ll bet they would bring people into the Saab dealerships, much as with the aftermarket suppliers for Scion.

    Waiting patiently for the 9-5 and the attending Hirsch goodies.

  7. Hirsch is pretty much a division of Saab, they share designers, engineers etc, except they are supposed to be a separate company. Which is just weird, because if Saab actually sold their cars with Hirsch parts as stock or even as options straight from the factory (the Hirsch Performance edition is a great start), no one will complain about Saab’s interior and exterior compared to an equivalent Audi, BMW, Jaguar or Mercedes.

    One of my major complaints about the Turbo X is that for the amount I paid, the interior was not on par with similar priced European cars. Just compare the new Jaguar XF with the Saab, heaven and earth. Adding the leather instrument panel and leather door handles, smart slot cover and handbrake will make a world of difference.

    I like the Hirsch rear diffuser alot but I am pretty sure it won’t fit on a Turbo X because of the exhaust shape and even if it did, as mentioned by Joe Lobo, ithe Turbo X with a Hirsch rear diffuser will lose some of its purity because a main part of what makes a Turbo X is the body kit.

  8. One other thing, I am not sure if the carbon leather instrument panel will go well with a Turbo X because that will result in the interior having 3 very different kinds of surfaces. Leather for seats etc, carbon fiber trim and carbon leather for the instrument panel. I think the Napa leather instrument panel will be a safer option because it will match the rest of the leather surfaces.

  9. Well, I am not sure if every single supposedly superior interior from alternative Europeans are indeed that much better looking and ergonometric as the Turbo X one. I agree that a few extra carbon bits will not be an overstatement. I have seen some pictures of the new A4 and quite frankly the materials may be better in terms of the thickness of these but the design and layout is appalling. No offence to our Yank colleagues but the latest such Teutonic resembles a bit of an Oldsmobile or even a Mercury. Maybe I am still in cloud 11 fully mesmerized with my Turbo X but I do not feel that sense of inferiority when inside, I quite like it. But granted, a few extra bits of Carbon Fiber would have finished the job perfectly. Hirsch may come to the rescue after all.

  10. Can’t go wrong with more carbon and leather. Especially when the quality is as good as that of Hirsch.