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CUSTOM / SPORTS EXHAUST OPTIONS

Posted: Mon Jul 24, 2017 4:25 am
by classicman
Hi

I have an RHD Alpina B10 3.5, and strangely enough, it has a stock exhaust. Its very quiet and I would like to go to something more sporty without it being deafening or have to live with cabin boom at cruising speeds. All the research I have done so far seems to point to Fritzsbits, although I have heard minor complaints of cabin boom.

FritzsBits claim an extra 45bhp on the Alpina using their full system including headers. Being RHD, I'm not convinced about the headers, but I can see the possibility of extra power and a sweeter sound with a tuned exhaust. 45bhp though, I'm not sure.

I've tried to look for postings on the forum, but have so far been unsuccessful, so here goes.

Has anyone done any back to back Dyno testing with a stock exhaust versus a Fritz or any other system. I'm looking for concrete evidence, not just hearsay if possible please. Just because it sounds more powerful, it doesn't always mean it is, LOL.

I'm looking forward to some responses. Thanks in advance.

Re: CUSTOM / SPORTS EXHAUST OPTIONS

Posted: Mon Jul 24, 2017 6:13 am
by baders
Welcome classicman. Sorry I cannot really help, but take that claim by Fritzbits with the largest grain of salt you can find. There's an Ebay guy that makes copies (I believe) for the M30.

You have some pictures of your car ? Love to see them !

Re: CUSTOM / SPORTS EXHAUST OPTIONS

Posted: Mon Jul 24, 2017 6:49 am
by classicman
Thanks Baders. Here are some photos in the interim.

Re: CUSTOM / SPORTS EXHAUST OPTIONS

Posted: Mon Jul 24, 2017 10:11 am
by SWAUS6
Hi Classicman,

Ive just purchased a set of these: http://www.ebay.com.au/itm/192211358374 for my 1986 Aust delivered CSI.

Haven't fitted 'em yet, being ceramic coated at the moment, so I cant help you with fitment details as yet. They look the goods and I had them recommended by GAZ M3 on a post a month or so ago - "RHD Exhaust decision down under" - its towards the bottom of this Engine-Mechanical-Electrical page.

Best of luck,

BTW, that's is a very cool and desirable E24 you have!

Nathan

Re: CUSTOM / SPORTS EXHAUST OPTIONS

Posted: Tue Jul 25, 2017 10:22 am
by SWAUS6
Meant to add my planned method to manage cabin boom/drone: I intend to try a system with no rear muffler, instead to have my local exhaust shop make me a replacement twin pipe set up, probably in 2 1/4 or 2 1/2 inch, with j pipes to remove the drone. Intend to make the J pipe length adjustable with slip fittings immediately after the J bends, so we can check the drone RPM, calculate the length of the J pipes, and then adjust their length after the slip fittings. Will post the results when its done.

Cheers

Re: CUSTOM / SPORTS EXHAUST OPTIONS

Posted: Tue Jul 25, 2017 11:18 am
by MrE
Gday classicman,

Fellow Canberran here - for what it's worth, a few years ago I needed to replace my exhaust (just the rear can, not the whole system), wasn't looking for extra power or anything, just an exhaust with a decent rumble to improve on the bland sound of the stock set-up. Went to Powatone in Fyshwick and they were very helpful, and were very happy to be working on something classic and cool like the 6er. This was about 5 years ago, back when they were on Collie Street - they've since moved to Barrier Street, not sure if its the same owners these days though..?

-Ellis

Re: CUSTOM / SPORTS EXHAUST OPTIONS

Posted: Fri Jul 28, 2017 5:54 am
by classicman
Thanks for the advice Ellis. I've used Fyshwick exhaust before as well (Notaris Motorsport).

I'm trying to get into the science of this though. Better sound = tick. Better sound + improved performance = double tick.

BTW, are you a member of the BMW Car Club in Canberra? We're trying to get more classics onboard.


MrE wrote:Gday classicman,

Fellow Canberran here - for what it's worth, a few years ago I needed to replace my exhaust (just the rear can, not the whole system), wasn't looking for extra power or anything, just an exhaust with a decent rumble to improve on the bland sound of the stock set-up. Went to Powatone in Fyshwick and they were very helpful, and were very happy to be working on something classic and cool like the 6er. This was about 5 years ago, back when they were on Collie Street - they've since moved to Barrier Street, not sure if its the same owners these days though..?

-Ellis

Re: CUSTOM / SPORTS EXHAUST OPTIONS

Posted: Fri Jul 28, 2017 8:14 am
by jps635
I've got a full fritz system as few others here have as well.

Quality is very good, fit is good and sound is good. As my car is lowered I found I had to shave some off the rear box to avoid scraping on the ground, plus the rear box hangs down a bit from an aesthetics perspective. (some photos on another post here some time ago). So now all good. However, horsepower claims ??? I think a bit more zing at higher revs but otherwise ???

Before doing this I had a custom system which had a single edelbrock muffler, 2 to 1, back to 2 again. Sounded awesome but was tiresome on long trips - too much drone, which you don't get with the fritz system.

To put the performance improvements in perspective from seat of pants barometer, I got a more noticeable increase in going to the 4 pintile 19lb "mustang" injectors (but could have just been that mine were original and in need of a clean or change).

However, as you have an Alpina, I would leave well alone in terms of trying to improve the performance, but by all means improve the sound. Note; they raced the group A's back in the day with a standard log manifold.

Re: CUSTOM / SPORTS EXHAUST OPTIONS

Posted: Sun Aug 20, 2017 1:45 am
by MrE
G'day classicman,
Any progress on the exhaust? These cars deserve a decent rumble.
No, not a member of any clubs, I'm a bit too lethargic these days. Many years ago I checked it out for a bit, but not for ages.
That said though, happy to catch up for a drive around town sometime if you feel like it, an easy run out to the Cotter & Tidbinbilla or somewhere like that.
No hurry, my car is unregistered & sitting patiently in the garage at the moment waiting for spring to get here, but keep it in mind. I'd sure be interested in checking out an E24 Alpina, Ive never really had a good look at one before, though I guess it was your car along with a reseda green 633 that were on display at the wheels car show earlier this year?

Re: CUSTOM / SPORTS EXHAUST OPTIONS

Posted: Mon Aug 21, 2017 11:21 am
by Bhart
I tried an Ireland Engineering cat-back exhaust but the construction was so poor that I ended up only using the rear muffler and had the shop put in straight pipe between the Cats and muffler. I am happy with the sound of the rear only. Just enough to be interesting but not annoying and with a bit of rumble off idle.

Here's a short video, going up through the gears...

https://vimeo.com/229186998?fref=gc

Re: CUSTOM / SPORTS EXHAUST OPTIONS

Posted: Mon Aug 21, 2017 10:26 pm
by bpoliakoff
Billy boat Tri Flow. Almost too nice to put on the car. Not cheap, but the best out there. You can google their site.

Re: CUSTOM / SPORTS EXHAUST OPTIONS

Posted: Wed Aug 23, 2017 1:36 am
by 86_6series
"I tried an Ireland Engineering cat-back exhaust but the construction was so poor"



In 2016 I put in the ss cat back from IE and found the quality to be very good for a Chinese manufacturer.

The sound is just right for me, no droning. Was $500 shipped to NY.

http://www.iemotorsport.com/bmw/E28-E24 ... tback.html

Re: CUSTOM / SPORTS EXHAUST OPTIONS

Posted: Sun Aug 27, 2017 10:56 pm
by Bhart
My experience with IE exhaust, as detailed earlier;

viewtopic.php?f=2&t=27196&p=196054#p195789

Re: CUSTOM / SPORTS EXHAUST OPTIONS

Posted: Tue Sep 05, 2017 8:00 pm
by GRNSHRK
classicman, not sure where you are regarding this project, and since you're "down under", not sure if USofA parts suppliers is also an option, but I do have an opinion regarding this quote from Bert [-(
Billy boat Tri Flow. Almost too nice to put on the car. Not cheap, but the best out there. You can Google their site.
I for one went this route years ago, and what then passed for a resonator was a pair of glass packs, which is what appears to be still the same, now :-&

I went through GREAT LENGTHS to reduce the horrific drone that came out of this exhaust and filled the cabin with vibrations that only a true resonator, which these cars need, can reduce/eliminate [-X

I'm not sure what Bert has put on his 6er during the restoration process, and to my knowledge, he has yet to fire her up :-k

Their website claims that they have the latest in "resonance control technology", personally I would opt for some recent personal experience before I plunked down my hard earn duckets again :-?

Just sayin' \:D/

:mrgreen:

Re: CUSTOM / SPORTS EXHAUST OPTIONS

Posted: Fri Sep 08, 2017 2:36 pm
by MrCouch
When i did my exhaust setup i went with IE headers to supersprint center and rear.

IE could not have fit worse, It was an absolute nightmare to get them to fit and install. I was severely disappointing with the construction of them as well not to mention their customer service is horrendous. Stay away

Re: CUSTOM / SPORTS EXHAUST OPTIONS

Posted: Thu Apr 05, 2018 6:08 am
by classicman
I have recently sold the Alpina with the stock exhaust on it and now have an M635CSi (M6).

I'm faced with the same problem though as the car has a crappy custom exhaust on it. OEM is NLA, so I'm probably going to go the Fritz route.

Re: CUSTOM / SPORTS EXHAUST OPTIONS

Posted: Thu Apr 05, 2018 12:51 pm
by brickwhite
just bought Super Sprint for my M635.

Re: CUSTOM / SPORTS EXHAUST OPTIONS

Posted: Fri Apr 27, 2018 9:52 pm
by sharkfan
I've just fitted a Fritz system to the standard downpipes and manifold on my early Series 2 635CSiA. AFAIK, the system is the same for all E24's from 628 to ///M.

When you call them you do have to put up with the silly bhp banter... "Don't you want the manifold and the extra 25bhp" ... then a "We fitted just the system to a standard 635CSi and got 20bhp extra on a before and after dyno"

My impressions are that its well constructed but definitely very boomy between 1000 and 2000rpm, after that its ok and just louder than standard BMW from inside the car but saying that, when I've been to a couple of meets the system on similar other cars sounds deep, moody and throaty.

In summary, I'm not raving about it, it's a good system, at a good price and very easy to fit on your own. As for how it sounds, that's purely subjective. IMHO my M635 sounds much better on its OEM system but the best BMW straight six sound I've had was a 3.8 M5 Touring. When it came to me it had a standard system but with a stainless Eisenmann back box, but after I replaced the rotted centre system with two straight through pipes to the back box it sounded fantastic - only the slightest boom at low revs but an absolute screamer once it got to 3k plus.

I would be tempted to try straight through pipes to a Supersprint or Fritz back box when it came to replacing my M635 exhaust in a few years.