Product Reviews

JHM Stage 3 Big Turbo Kit for the B7 Audi A4 2.0T


JHM has wrapped up development of their “Stage 3” big turbo kit for the B7 (2005.5-2008) Audi A4 2.0T and I got a chance to drive one of their shop cars, Dru’s 2006 Audi A4 Avant aka the JHMWGN, while they were in town for Big SoCal Euro and write an exclusive review of the kit before it hits the general public. This is the same car that recently put down a 12.5 quarter mile time at 111 mph with a full interior, stock B7 S4 catback, and street tires, making it the fastest B7 A4 known to-date (timeslip), so needless to say I was quite excited to check it out!


JHM is currently taking pre-orders on the kit, but for now they’ve dropped a lot of information on their product development thread on Audizine. It features an in-house assembled TD05H-R turbo and JHM tuning to provide a smooth delivery of power throughout the powerband, as well as all supporting mods you’ll need to get the turbo installed and running correctly like a tune and fueling. The kit runs on OEM S3 injectors and a JHM upgraded HPFP to handle fueling, and has a JHM 3″ Test Pipe and JHM 3” Downpipe-Y that mates up a stock or aftermarket B6-B7 S4 Cat-back exhaust. Dru’s car is also equipped with the JHM Large Core front mount intercooler and JHM lightweight flywheel and Stage 1 clutch combo, so while it has supporting mods to help the big turbo kit reach it’s potential, it’s not heavily or aggressively modified either. 


I drove and rode around in the car all morning and what was most impressive to me was the drivability of the kit – despite it being the fastest big turbo kit available for the B7 A4, it’s also one of the smoothest. The car felt very OEM-like and the powerband was really smooth – they did a great job tuning the car to maintain streetability. I’ve driven other big turbo A4s where the turbo hits like a freight train (and when you let off the gas, ditto), but this car was really smooth and predictable, which makes it great for a daily driver or track toy alike. Dru’s car actually uses a stock B7 S4 Cat-back exhaust and their street-oriented Stage 1 clutch with RS4 pressure plate, so it shifted and sounded like it could be OEM if it weren’t for the louder “blow-off” noise and the butt dyno registering something a lot more powerful than OEM.


Equally impressive to the drivability of the kit is the pricing – while the official product page and final pricing has yet to be released, they’re taking pre-orders and pricing can come in the $3-4k range depending on what mods you already have installed with discounts given if you already have a JHM tune, for instance. That’s a great bang for the buck, and any B7 owner can completely transform their car for about the same price as a decent set of wheels and tires…


Another nice advantage of this kit is that JHM supplies everything you need, and all of the parts are designed to work together – you can see the fully assembled kit above. While a lot of B7 owners have put together their own big turbo setups, a lot of them struggle with getting the right tune, dialing in the fueling, or mating it up to the best exhaust manifold – JHM takes all of the guesswork out of it, and their tuning is some of the best in the industry, making this kit hassle free to buy, install, and enjoy.


As followers of this blog know, I have many JHM parts installed on my car – I choose their parts for many reasons, but largely because they’re innovating and bringing new parts to the platform I can’t get elsewhere, and equally so because they test the CRAP out of the parts before releasing them, so they’re reliable and proven. While anyone can produce a part, JHM takes the extra time to do true R&D, install the parts on their own shop cars, then test the limits of those parts repeatedly in high-stress situations like the drag strip. For instance the 12.5 quarter mile time was achieved on Dru’s car on a tune more aggressive than what they plan to release to the public, because they wanted to test the limits of the stock internals to ensure their kit was safe and that owners would have nothing to worry about – not only did the engine not blow, but he was hard shifting at 7,000 RPMs and fully prepared to take the car home on a trailer if he had to…then a few days later he drove it 600 miles on the freeway to a car show like it was no big deal!


Dru’s avant and Jake’s sedan have both been testing this big turbo kit for quite some time with very positive results – fast time slips, great drivability, and a nice fit & finish too. I’d say I’m excited to see more of these kits on the road, but then I’ll need to get used to getting smoked by A4s which is not something I’m looking forward to, lol. Kudos to JHM on a well built kit, and thank you Dru for letting me drive and photograph your car!


If you’re interested in pre-ordering this kit or learning more about this car, contact Dru at JHM by emailing or giving them a ring at 209-968-0077.

Nick Roshon

Nick has been an Audi owner and fanatic for the last 10 years, and started Nick's Car Blog in 2009 to share DIYs and pictures of his A4. Currently he drives a 2012 Audi TT-RS, and has previously owned a B7 S4, B7 A4, and an 82 Audi Coupe (GT) LeMons race car. In his day job, Nick is a digital marketer and lives in San Diego, CA, USA.


  1. Typically your blogs are full of info and insight and I look forward to reading them. Your a4 big turbo blog told us almost nothing about the performance gains of the big turbo a4 build. Did I miss something?

  2. Sorry to disappoint Daniel, this was written before the kit was widely released and I couldn’t get it on a dyno. There’s a huge performance gain, I just can’t quantify it.

  3. Thanks for the continued reviews. The piece regarding JHM’s reliability helped make my decision. Excellent blog by the way, I have stopped by on multiple occasion. You are always informative.

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