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Discussion Starter #1
These arrived today! Very excited.

I had the car r/roaded last week and it produced 397bhp (115,000 mile car, standard apart from an X pipe).

I'll put the car back on the rollers post-fitment and report back, but I'd hope to see the claimed 25+ bhp increase....
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Yes! Thankfully not my job! :)
I assume 397 is the crank number. If these are good headers, you should see closer to 35 at the crank. Decatting should add a few more. I know the 100 cell SS cats added about 20 more at the crank (from memory).

31 at the wheels is what I saw with my SS headers many years ago. So using standard 15%, you should see about 35 from just the headers.

A tune will probably add a few more. Get a good readout of AFR's.

Regards,
Jerry
 

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Discussion Starter #5
I assume 397 is the crank number. If these are good headers, you should see closer to 35 at the crank. Decatting should add a few more. I know the 100 cell SS cats added about 20 more at the crank (from memory).

31 at the wheels is what I saw with my SS headers many years ago. So using standard 15%, you should see about 35 from just the headers.

A tune will probably add a few more. Get a good readout of AFR's.

Regards,
Jerry
Hi,

I appreciate the input. I'd be made up with those figures! Yes, 397 crank. I'll dig out the r/r print out...

Kind regards

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Discussion Starter #7
31 at the wheels is what I saw with my SS headers many years ago. So using standard 15%, you should see about 35 from just the headers.

Regards,
Jerry
How differently did it feel to drive? Was there a notable increase in exhaust noise / tone?

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Discussion Starter #9
I just installed SS headers with decat pipes, it's very loud.
Oh no, I hope not too loud for me?! This is my family daily.

It has the std back boxes (which I'll leave in place).

Is it a bearable volume inside the car when cruising?

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I just installed SS headers with decat pipes, it's very loud.
Did you change the H/X pipe? That is usually a cause of most of the noise increase. With stock H pipe and resonators in place, sound really shouldn't be that bad.

If too loud, you may want to add back some race cats (100 cell) to help. I doubt you would even feel any diminution in HP (if any--car was designed to run with some back pressure).

Regards,
JErry
 

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My catback is aftermarket, Becker. I'll be going back to stock catback to tame it.
It's not so loud in the car, but it's brutal outside, with a horrible rasp on decel.
The Becker catback was fine before the headers/decat pipes.
 

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Discussion Starter #13
Thanks for the input, all.

Headers and decats now installed, and thankfully (!) sounds really good: barely any noisier on cruise / normal driving, but has more of a bark to it on WOT, but not 'boy racer'.

The pick-up is vastly improved: it revs cleaner and with more urgency and just feels like it's properly breathing.

Really happy with it.

Will post up new r/r printouts next week :)

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I"m so envious....I really wanted to do headers on my M5. Never got around to it and then sold it. The noise factor was serious though....my old E63 AMG was unbearably loud and essentially ruined the car because I couldn't drive it like how I used to without making such a scene.

That being said, I thought my first M5 was fun enough with just a tune and CAI. The second one with 3.62 diff added to a tune and CAI was brilliant! I can only imagine the awesome of having another 30-35hp up top.
 

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Discussion Starter #15
Cheers, yes, I'm really happy with them. It's more than just trying to convince myself it's a better drive, but I guess the r/r next week will tell the full story.

The best way to describe it is like breathing on a cold day having eaten a packet of mints . It just feels sssooo much cleaner , the throttle response has become so much crisper and immediate.

There's just a little thin, tinny metallic rasp (kinda like a loose heat shield) at certain revs which I hope will quieten when it cokes up a little, but nothing to be disappointed by.

I'm surprised by the gains to be had with it being an N/A car: by now adding a tune and air filters, 450bhp should be easily breached which is plenty :)

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Ok feeling a bit envious over here now.

Gosh I'd love to have another M5 in the future, but I just don't trust them now with their age and I couldn't justify spending a small fortune on a low mileage minter when they're the same price as a low mileage E60 wagon. Arrggghhhh why did I open your thread this morning 🙉
 

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Discussion Starter #17
Ok feeling a bit envious over here now.

Gosh I'd love to have another M5 in the future, but I just don't trust them now with their age and I couldn't justify spending a small fortune on a low mileage minter when they're the same price as a low mileage E60 wagon. Arrggghhhh why did I open your thread this morning
Ha ha, oh, r.e running costs, I'm sure there will be occasions when it's parked up on the driveway going nowhere, awaiting me saving up some money to fix it when it goes wrong. But...I'd rather do that than drive a much new Toyota Corrola without having to worry about the maintenance costs...

Mine is on 115k miles. A clutch and timing chain...and rod bearings WILL need doing at some point (biiiggg money) but...it's just such a fantastic car that I'll have to suck it up when the time comes...

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Ok feeling a bit envious over here now.

Gosh I'd love to have another M5 in the future, but I just don't trust them now with their age and I couldn't justify spending a small fortune on a low mileage minter when they're the same price as a low mileage E60 wagon. Arrggghhhh why did I open your thread this morning 🙉
Don't fall into the trap that newer is always better. It is just newer!! And it may have more bells and whistles, which may or may not enhance your driving experience.

The driving experience between an E39 M5 and E60 M5 is very different. Stock to stock, the E60 does some things better than the E39. But on balance most folks/enthusiasts prefer the E39. That is borne out in current pricing.

Get what makes you happy.

Regards.
Jerry
 

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Don't fall into the trap that newer is always better. It is just newer!! And it may have more bells and whistles, which may or may not enhance your driving experience.

The driving experience between an E39 M5 and E60 M5 is very different. Stock to stock, the E60 does some things better than the E39. But on balance most folks/enthusiasts prefer the E39. That is borne out in current pricing.

Get what makes you happy.

Regards.
Jerry
Oh, totally I'm with you on that. Haha for that reason I wont buy an F10 or newer M5 because they're just not 'special' anymore. But the E60 is special in it's own right, 90% due to that incredible V10 motor. And having it as a wagon with my little daughter wiggling her feet behind me in her baby seat is a nice thought that I'd love to make happen one day.

I've had two E39 M5s. What scares me is that having built an S62 for a friend myself, I know just how expensive and how intensive an overhaul can be. Granted, the same can be said of an E60 M5, but I can get a very low mileage and relatively fresh E60 for around 20k here in the UK, whereas having to pay the same for a similar spec E39 variant would hurt, seeing as I'm used to paying 8-10k for a higher miler one that I could trust. I dunno maybe I'm just getting too cautious in my old age...I'm just too afraid to get another E39 again. I know...it makes no sense saying that and still wanting an E60....but nothing I do makes total sense. I'll just keep driving my Japanese turbo coupes for now until I can bear it no longer and pull the trigger on an E60 in the future.
 

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Discussion Starter #20
Hi all,

I did say I would post my Dyno findings.

On a (much) hotter day than pre-headers,, the car produced another +14whp, mainly all from 5200rpm to the redline. Not bad, but not as much as I'd hoped for.

However, I've spoken to a couple of established tuners and the consensus has been uniform: it now needs to be live mapped for that car in order to realise the full potentially of the headers, with these companies saying a further +20bhp should be well within reach, so it's booked in for a live map in a few weeks: I'll come back to you and post all Dyno graphs.

As an aside, I'm going to have 200 cel sport cats fitted as it smells a little too fumey for my liking with no cats, so the (v.nearly new s/s de-cat pipes) will be up for sale very shortly...



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