Exaust bottoming out

4.2 V8 32v Naturally Aspirated - 414 bhp
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Myth
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Exaust bottoming out

Post by Myth » Thu Jul 25, 2019 4:02 pm

Hi I've had this car a while now and when I bought it the suspension was very low, I couldn't get it on my drive without a piece of wood because the exaust catching. I had the suspension raised to nearly the full height but I'm still struggling to the point that I caught it on a speed hump and it nearly parted at the joint behind the cat. It's a Milltek exaust and the suspension was replaced 3 years ago says in the repair sheet, springs shocks with coil overs replaced and set to 40mm lower as supplied by owner. Any ideas or fixes you guys can suggest?

Myth
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Re: Exaust bottoming out

Post by Myth » Thu Jul 25, 2019 4:29 pm

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B7saloon think its the cat that's catching, it was the clip on the joint but turned it to the side .

MrRSB7
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Re: Exaust bottoming out

Post by MrRSB7 » Thu Jul 25, 2019 10:49 pm

3EC31F55-4E2F-4B52-ABB9-151AB2E25168.png

Mine is really low

But it only bottoms out on the flexy exhaust pipes, they only bottom out occasionally fast over speed bumps etc
2006 2-tone merlin purple , decat delete, res delete, x-pipe and rear back box delete......rs5 alloys.. silver brake callipers

coffey555
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Re: Exaust bottoming out

Post by coffey555 » Thu Jul 25, 2019 11:35 pm

What coilover kit is fitted? KW V3 is 15mm lower at the front, 10mm lower at the rear over SS suspension.

The rear looks around the same height my car was until very recently when I raised the rear ride height.

SS+ is 10mm lower allround than the SS so on full height the KW V3 is only 5mm lower than SS+.

My flexi pipes are scuffed as they are the lowest part of the car.

All you can do is fit a coilover kit with less drop or return to standard SS or SS+ springs and fit Koni dampers.
Misano Red RS4 B7 Avant

Myth
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Re: Exaust bottoming out

Post by Myth » Fri Jul 26, 2019 7:26 pm

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The after market suspension was fitted by a previous owner. I dont know what make it is or even if it's a good make or a cheap one here's a pic of it maybe somone could identify it for me.

coffey555
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Re: Exaust bottoming out

Post by coffey555 » Fri Jul 26, 2019 7:52 pm

You have KW V1 or V3 coilovers installed, same manufacturer as the ones fitted to my car. They are one of the better coilover kits on the market.

Both V1 and V3 setups have the same range of height adjustment.

I would take it do a good local indie and ask them to raise the ride height followed by a full geometry alignment. At full height it will be 15mm lower front and 10mm lower rear than standard SS setup. That should see you clearing most things on the road.

My flexi pipes would just catch on a speed bump near my house but since I raised up the rear it no longer does it, front height was untouched.
Misano Red RS4 B7 Avant

Myth
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Re: Exaust bottoming out

Post by Myth » Fri Jul 26, 2019 9:01 pm

Thanks for help coffey.

jordanbutters
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Re: Exaust bottoming out

Post by jordanbutters » Sat Jul 27, 2019 10:04 pm

I'm on KW V3s too and 275s (so slightly lower profile) and had the same issue – my flexi joints between precat and cat were shredded to pieces because they're the lowest part of the exhaust by far. I've just fitted fresh downpipes with the precats deleted and on these the flexi part was added nearer the top of the downpipe, rather than at the lowest point – it's probably gained me 2cm+ exhaust clearance. Worth looking at doing if you're going for custom downpipes at some point.

coffey555
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Re: Exaust bottoming out

Post by coffey555 » Sun Jul 28, 2019 2:07 pm

Now that is a great idea! Might get that done myself so I can lower the car again.

Have you noticed a difference in sound since you gutted the pre-cats? I have already deleted my centre resonators so am worried it might be a little bit raspy without the pre-cats.
Misano Red RS4 B7 Avant

jordanbutters
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Re: Exaust bottoming out

Post by jordanbutters » Mon Jul 29, 2019 11:13 am

coffey555 wrote:
Sun Jul 28, 2019 2:07 pm
Now that is a great idea! Might get that done myself so I can lower the car again.

Have you noticed a difference in sound since you gutted the pre-cats? I have already deleted my centre resonators so am worried it might be a little bit raspy without the pre-cats.
I went from stock system with valves disconnected to pre-cat delete and x-pipe centre box delete so it's hard to say just how much the precat delete alone changed the sound. In my eyes (ears?) it's perfect now – it's not boomy past 2000rpm at all, burbles nicely and there's a nice rasp at WOT at the top end, but very little rasp unless you're revving it out. The burbles on lift off and downshift are more pronounced too, especially when the exhaust is hot. It's got just the right amount of character without being boomy.

jordanbutters
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Re: Exaust bottoming out

Post by jordanbutters » Tue Jul 30, 2019 12:02 am

coffey555 wrote:
Sun Jul 28, 2019 2:07 pm
Now that is a great idea! Might get that done myself so I can lower the car again.

Have you noticed a difference in sound since you gutted the pre-cats? I have already deleted my centre resonators so am worried it might be a little bit raspy without the pre-cats.
Here's a little video so you can hear it - https://www.dropbox.com/s/d74yxlmigp7hy ... M.MOV?dl=0

coffey555
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Re: Exaust bottoming out

Post by coffey555 » Thu Aug 01, 2019 2:41 pm

Thanks for posting that. Sounds good!

I am running pretty much the same setup, valves always open with straight pipes instead of x-pipe.

I briefly ran a Scorpion non-res exhaust that had an x-pipe and for whatever reason, it killed the V8 burble and the drone was absolutely horrendous! Sounded crap as well..... luckily it was second hand so shifted it on for not much less than I paid for it.

How you liking the car with the adjustable front 034 arms on it? I found it had a positive effect on the steering and tyre wear.
Misano Red RS4 B7 Avant

jordanbutters
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Re: Exaust bottoming out

Post by jordanbutters » Thu Aug 08, 2019 7:57 am

I’ve only had the top front 034 arms done for now as the OEM lower arms were done a few years ago - I’m probably going to go for 034 lowers soon though. At that point I’ll have pretty much completed the 034 catalogue 😂

coffey555
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Re: Exaust bottoming out

Post by coffey555 » Sat Aug 10, 2019 2:20 pm

They do lower arms as well? I have only ever seen their adjustable top arms. I will have a look to see what needs doing when I swap the subframes out..... :roll:
Misano Red RS4 B7 Avant

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