Bypassing the top speed limiter

4.2 V8 32v Naturally Aspirated - 414 bhp
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TaPaKaH
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Bypassing the top speed limiter

Post by TaPaKaH » Fri May 18, 2018 9:06 pm

Hi guys,

It turns out that my B7 RS4 has an electronic speed limiter at 270 kph.
The limiter kicks in in both 5th and 6th gears at ~7900 and ~6900 rpm, respectively.
Car will just abruptly stop accelerating, although going downhill you can nudge ~275-ish (and uphill it won't do more than 265-ish).

I've been trying to find a way around it without spending a few hundred to have it removed by a tuner.
Double-tapping the gas pedal (technique mentioned on some online boards) did not help. Neither did accelerating in 5th gear and shifting into 6th.

I found out that there is software like Lemmiwinks and UniSettings (both look very similar) that allows to program the speed limiter offset.
However, the el-cheapo OBD2 cable that I bought on eBay (ELM327, Prolific PL2303 controller inside) wouldn't work with either. (Nor would it work with VAG-COM, but it did with ScanMaster-ELM)
Trying to set up the OBD2 connection with UniSettings, I see that the software expects a cable with FTDI controller. However, looking at eBay I see that all FTDI-based (FT232RL or CH340T) OBD2 cables do not officially support the B7 generation of A4/RS4 and would therefore be useless.

Hence the question: Did any of you have any experience of removing the speed limiter "at home" / on the cheap?

Thank you in advance!

Seattle-squash
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Re: Bypassing the top speed limiter

Post by Seattle-squash » Sat May 19, 2018 3:10 am

Just get a tune, and sounds like you like to go fast and this way a bit faster even and no more limiter, win-win!


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TaPaKaH
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Re: Bypassing the top speed limiter

Post by TaPaKaH » Sun May 20, 2018 12:12 pm

That's what I've done in the end. Turns out that there isn't much life beyond the speed limiter. Vmax is around 290-292 kph and it takes ages to get there.
https://youtu.be/RXVRfsg6Hso

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Ian_C
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Re: Bypassing the top speed limiter

Post by Ian_C » Sun May 20, 2018 1:34 pm

Nice night run!! Did you selotape your mobile phone to your forehead haha :thumb:
B5 B6 B7 B9

Seattle-squash
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Bypassing the top speed limiter

Post by Seattle-squash » Mon May 21, 2018 5:23 am

Ian_C wrote:Nice night run!! Did you selotape your mobile phone to your forehead haha :thumb:
^ This cracked me up!!!

However, maybe with a tune you get close to the 300kph territory. Now, take it easy and I want in no way contribute to your new speed records on public roads. However, your car is still pretty quick car in comparison.

Just talk to the Koenigsegg’s crew, and borrow their airstrip for a day, throw on their carbon wheels, pray for the wind in your back, and see ya! Image






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Covkiller
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Re: Bypassing the top speed limiter

Post by Covkiller » Mon May 21, 2018 6:54 am

Image
RS4 B7, Mugello Blue, K&W V3 & HR ARBs, set up by Centre Gravity, Milltek Valved Non Res & cat bypass pipes, BMC air filter, braided hoses, DOT 5.1, Terraclean, MRC Full Carbon Clean, MRC remap 448PS 477NM, 20" S7 alloys with 4mm spacers & Hawke spigots 66.6 > 57.1, AP Racing front discs. Sold Sept 2019. Now rocking an F80 M3

DavidRS4
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Re: Bypassing the top speed limiter

Post by DavidRS4 » Mon May 21, 2018 6:53 pm

:bowdown:
B7 RS4 Saloon, Phantom Black, Forge Oil Cooler Kit, 20 x 10.5j Vossens, Carbon Front Splitter, KW V3 Coilovers, Adjustable Front Arms, 20mm Spacers, Revolution Carbon Air Box, Rear 4 Pot Porsche Brake Conversion, Stud & Nut Kit, Milltek Non Res Non Valved Exhaust, RS6 Gloss Black Grill, Slightly Tinted Windows, JH Motorsports Stage 3R Clutch & Lightweight Flywheel, Robnic Braided Clutch Line. JH Motorsports Lightweight Grooved F & R Rotors with Braided Hoses and Hawk Pads

TaPaKaH
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Re: Bypassing the top speed limiter

Post by TaPaKaH » Mon May 21, 2018 11:48 pm

I remember seeing a quoted top speed of 301 for the saloon and 298 for the estate version (which I have) so I thought that with a chip tune 300 should be doable.
Oh well, speeds north of 250 are hardly ever practical with the B7 RS4 anyway. Fuel consumption is ludicrous (according to my calculations, is around 45L/100km near top speed, which means that the full tank is gone in half an hour) and due to traffic you can rarely reach them even on unrestricted autobahn.

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Covkiller
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Re: Bypassing the top speed limiter

Post by Covkiller » Fri May 25, 2018 11:07 pm

It does 193mph on the clock, but it needs a long clear run to get up to that speed and very difficult holding your phone and taking a photo. I don't recommend anyone doing this.
RS4 B7, Mugello Blue, K&W V3 & HR ARBs, set up by Centre Gravity, Milltek Valved Non Res & cat bypass pipes, BMC air filter, braided hoses, DOT 5.1, Terraclean, MRC Full Carbon Clean, MRC remap 448PS 477NM, 20" S7 alloys with 4mm spacers & Hawke spigots 66.6 > 57.1, AP Racing front discs. Sold Sept 2019. Now rocking an F80 M3

Softishman
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Re: Bypassing the top speed limiter

Post by Softishman » Sat May 26, 2018 8:45 am

Supercharger = problem solved 😎
@softishman on IG
Check out my RS4 there!

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