Season 2 – Episode 9

Exhaust systems are one of the first modifications people make with their cars and as such there is great variation in options available and just as many opinions of which is best. With this in mind we bring you a test of several of HPF’s more popular exhaust combinations back to back on a 6.2l LS3 powered VE HSV.

This is the first time Horsepower Factory have done a back to back comparison like this and the results were definitely surprising. Plus, with Rob running through the exhaust systems and the variations in components there is plenty of tech content for those with a thirst for knowledge!

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  1. Ian Haines says:

    A Very informative well constructed video from you guys, well done cheers Ian.

  2. michael says:

    this is the best tv series i think ive ever seen, excellent work boys

  3. Damian says:

    Great episode

    Any chance on there being a comparison one day regarding X, H pipes, kiss pipes and no merg (true dual exhaust) after the cats?

    keep up the good work!

    • OzGarage says:

      It would be great to compare but may be outside the scope of what HPF typically do. We’ll keep it in mind though, thanks.

  4. Kev says:

    Another excellent episode. When you overlayed the Dyno
    sheets between runs with the different exhausts; were they aligned
    for the same rev ranges? ie to show same torque curves or were the
    4-1 headers developing the power higher in the rev range?

    • OzGarage says:

      Sorry for the delay, I think this got stuck in the spam filter for some reason. There was actually no noticeable difference in the torque curve with the 4-1s. In fact the large pipes gained everywhere.

  5. keith reed says:

    The tri y 4-1 argument has gone on for many years. Would a tri y system with 1 and 7/8 primaries have fared any different? I certainly would not change my tri y system on my ve ss to 4-1 based on your tests.

    • OzGarage says:

      Its hard to say without testing it directly. A large amount of the gain with the 1 7/8 4-1 is probably not so much due to the pipe diameter but rather the different, high quality and well designed collectors which allows for greater scavenging effect than the other sets.

  6. Bruce says:

    I have been thinking of putting a full KPM 3 inch system on my E3 Clubsport, do you think It would be better based on your tests to pay the extra and go 1 7/8 headers, have you heard or dealt with this system in person, if so what do you think of it ?
    I have only heard the sound of the KPM on the net so far.
    Your Video’s are excellent.
    Thanks in advance

    • OzGarage says:

      Hi Bruce,

      We have not dealt with the KPM system as we do our own exhaust system for VE and VT-VZ so I cannot make judgement on it. I might be worth your while to take a listen to our system as I think it’s the best I’ve heard (I may be biased though…). 1-7/8 headers are a great choice, I am unable to provide data in comparison to 1-3/4” headers on a standard LS3 but I would doubt there would be any down side, I would definitely option 1-7/8 headers if you’re looking to do engine work or perhaps add a supercharger to the vehicle.

      Matt – HPF

  7. matt says:

    I noticed you guys fit these exhaust’s without an ecu tune which i was told i needed to do if i wanted to put extractors on my VE SS, i currently run a twin 3inch system from the factory cats back would love too fit 1-7/8 extractors.

    fantastic show will be watching frequently :)

  8. jason says:

    well done boys great vid needs to be more like you guys

  9. Damo says:

    Great vid ”learnt more on this then i knew about exhausts all my life..well done boys..maybe the cai should have been fitted first.. ve hsv E1 owner

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