WARNING: RS4 + FULL EXHAUST ACCELERATION TESTING INSIDE

[sakimano]

Just wanted to protect those who are terrified of standard acceleration testing of V8 Audi RS4s from seeing something they might deem awful.

With that out of the way, I added JHM 2.75" HFC/catted downpipes and JHM 2.75" x-pipe resonated exhaust to my car in the fall. This Saturday, I finally got a chance to do some standardized acceleration testing, running my car from a dead stop and accelerating through 4 gears to a point 400 metres away. With clocks and everything. Yes, the dragstrip. Or the 1/4 mile.

My fastest stock time was 2 years ago in April when I went 12.75 @ 108.36. Density Altitude back then was pretty good, around a couple hundred feet. Saturday it was quite a bit warmer as the day wore on. When I ran my best time I believe it was around 500-700 feet. It would eventually hit 1600 feet.

Saturday when I went back with the full exhaust it was a bit warmer, but still decent at around 500-700 feet. I went alone because everyone was busy. I just wanted to go give the car a rip, and get some GoPro footage for JHM who are working on an RS4 video.

So...first pass was a shakedown, and I went 12.73 @ 108. So that was cool...faster than my all time best when I was just giving it a rip. My 60' time was 1.81 which is the best I'd ever done so that was promising.

My best ET and trap of the day was 12.53 @ 110.53. I rattled off about 8 different passes in the 12.5 to 12.6 range. I had a couple of 1.78-1.79 60' times in there as well which was nice.

As a rough estimate, if the car picked up 2 tenths and 2 MPH...and in reality could pick up 3 tenths and 3 MPH if the weather was as co-operative as it was when I set my stock record, that means the exhaust is giving me about 20-30 hp over stock. I think we have seen something similar from cars with this exhaust who have been on the dyno, so that makes sense.

Funniest part of this, to me, is that this time is faster than the fastest PES M90 supercharged RS4 time. i.e. a £9,000 supercharger kit that they sold dozens of to people in the UK/US/Europe....and I just had my exhaust. Fastest PES M90 RS4 1/4 mile (in great DA) - Kryptonik 12.65 @ 110.6 MPH (he also had full Milltek exhaust which is a virtual stock replica so not likely to add anything).

Timeslip below, and video of the fastest pass....vs a new E63 AMG S (these have AWD over here). It was looking good for the RS4 for a little while...I jumped out by about 4 tenths on reaction, and had a much better launch which allowed me to hold him off for a good 3/4 of the track but DAMN did he fly by lol. You can see his time (11.80) on the board from my GoPro. Always a sign your race has not gone well when you can see the other guy's time!

My mods
JHM 2.75" downpipes (with cats)
JHM 2.75" resonated catback
Everything else bone stock
last carbon clean ~1 year/15,000 miles ago
1/4 tank pump gas Petro Canada 94 octane (EUR 99 equivalent)

The RS4 sounds pretty awesome I have to say. That external microphone (AudioTechnica lavalier mic taped to the centre of my rear bumper) works a charm with the GoPro. Normal GoPro sound is useless.

[DavidRS4]

That does sound lovely!

[Gavla]

Good time that for a "relatively stock" RS4

What RPM did you launch at? What were the tyre pressures? It seemed to just grip and go... Great sound those JHM exhausts

[R1RS4]

Sounds the biz that

Might have to change my down pipes if I cannot remove the O2 sensors

Would love to fit the JHM 300 cell cats , 2.75 with the 2.5 reducers, look a well made piece of kit

A group buy would be better but still have not had a recent reply for a group buy on the oil cooler pipes

[sakimano]

Good time that for a "relatively stock" RS4

What RPM did you launch at? What were the tyre pressures? It seemed to just grip and go... Great sound those JHM exhausts

I was launching from around 3700-3800 RPM (I usually go from there).

Tire pressure was in the mid to low 30s. I actually was spinning the tires a bit more than I would like as the day wore on, but the early runs I made were all like the one in the video. Best 60' time of the day was 1.78 seconds. Then a 1.78, a 1.81 and a couple of 1.82, including the run in the video.

[sakimano]

Sounds the biz that

Might have to change my down pipes if I cannot remove the O2 sensors

Would love to fit the JHM 300 cell cats , 2.75 with the 2.5 reducers, look a well made piece of kit

A group buy would be better but still have not had a recent reply for a group buy on the oil cooler pipes

they ran a huge group buy where they sold dozens of exhaust systems last year so I'm not sure if they'll do another. Savings were nominal...maybe $200 or 300 on the full system so it's not a huge miss.

I believe they charge about $3000 USD for a full exhaust including HFCats. That's about what..1800 pounds? Of course shipping eats up quite a bit.

[adsgreen]

Timeslip below, and video of the fastest pass....vs a new E63 AMG S (these have AWD over here). It was looking good for the RS4 for a little while...I jumped out by about 4 tenths on reaction, and had a much better launch which allowed me to hold him off for a good 3/4 of the track but DAMN did he fly by lol. You can see his time (11.80) on the board from my GoPro. Always a sign your race has not gone well when you can see the other guy's time!

holy cow - didn't realise they were 585bhp, 590lb/ft and 4wd

sounds like there was some launch control on there too.

[sakimano]

Yes launch control. Although it wasn't awesome off the line. The rs4 was quicker to about 100 metres by about a tenth, but after that he just reeled me in.

[R1RS4]

Sounds the biz that

Might have to change my down pipes if I cannot remove the O2 sensors

Would love to fit the JHM 300 cell cats , 2.75 with the 2.5 reducers, look a well made piece of kit

A group buy would be better but still have not had a recent reply for a group buy on the oil cooler pipes

they ran a huge group buy where they sold dozens of exhaust systems last year so I'm not sure if they'll do another. Savings were nominal...maybe $200 or 300 on the full system so it's not a huge miss.

I believe they charge about $3000 USD for a full exhaust including HFCats. That's about what..1800 pounds? Of course shipping eats up quite a bit.

Hopefully I can just get away with a set of down pipes, stay with the cats and sensors, my cat back Milly is not in bad shape but the down pipes are very rusty, may loose all the sensors

The JHM down pipes alone are $1300 approx £785 on today's rate + shipping which is not too bad considering the Miltek price just over a grand,

I will know in a week or two as will take it to the stealers to remove my faulty sensor

Have you kept the 4 x o2 sensors ? With your JMH system?

[E14STO]

Nice vid.
E63 flying near then once he's up and running! - big thing as well
I guess then that a RWD would be even more rapid - once on the move.
I only thought they were 525ish.

RS sounds lovely though and great launch

[toyneg]

Need one of those external mics, my footage on the Go Pro is always ruined by poor audio - car sounds awesome, might give mine a run at santa pod this year see what it can do

[MartayMcFly]

Sounds nice... shame the Merc caught up.

[TonyHayers]

Wow, that's fast. Nice vid.

Have you got any other mods apart from exhaust on here?

[sakimano]

No other mods. Just exhaust

[sakimano]

Found an in car video of one of the passes against a hatchback Mazda something. This was a 12.62 @ 109.80

Gives you an idea of the sound inside the car. Nice, but not ignorant.