E30 318i: Noisy exhaust gets a bung / silencer

My E30 has a 4" straight-through Japanese tuner style exhaust back-box fitted, which to the say least is LOUD. In fact, it's one of the loudest I've heard on any car, including a Subaru turbo I had with a de-cat pipe. I figured the centre-box had also been removed from the E30, given the noise level, but find it is still there under the car and looks to have been replaced not too long ago, so I guess the only reason for the volume from this 1.8 litre 4-banger is because it never had a catalytic converter from the factory and is subject to no emission controls that bind (and quieten) modern cars. This E30 is 1988, so must have been right at the end of this phenomena.

While the loud pipe might be fun on a jaunt, working on the engine at home I find myself needing to start and idle the car constantly for testing and this is where the noise causes a problem, mainly with my neighbours and passers-by. They tolerated it for a couple of weeks, but with a few running problems that are still being ironed out and the car unable to move to another location I decided to try and mute it a bit. 

I had two options. Buy a more sociable back-box or get a silencing 'bung' for the current one. I'm not best pleased with look of the Jap-style straight-cut end pipe, I mean I like them but don't feel it suits the boxy E30 and though I'm down with car style juxtapositions all DAY, this isn't the one I would have chosen, so first looked for a replacement. New stock items are not expensive, but too much for this project, so second hand was the way, with twin 'sports' style spurious back boxes and used OEM items going for between £50 and £100. I was tempted by a nice twin square pipe from a German tuner, but the seller had no idea how loud it was and at £55, I still deemed it too pricey at this uncertain stage in the project. People at work fit ‘bungs’ to their motorbikes so I thought this was budget way to reduce the burble by a few dB.

DOES IT WORK?

Yes and no. It certainly takes the edge off the noise level, that ‘crack’ has gone, but it’s still one loud exhaust. The info says it reduces sound levels by up to 15 decibels and I have adjusted to the quietest, most restrictive setting, but without a dB meter I can’t really say if it is that much. In my opinion it’s not to that great an extent but it is somewhat quieter. 

Don’t expect the exhaust to sound as quiet as a stock back box with baffle plates. I suppose you’re never going to get a quiet exhaust tone and still enjoy the slight increase in power a straight-through pipe gives, so as ever there is a compromise, but it has certainly done the trick for me of making the car less anti-social when tuning it in my driveway! Who knows, when I get the E30 out and about over the summer the bung may well be coming back out.

E60 Audio: New Amp sound cut-off issues.

This is common with BMW stock sound-systems. Something to do with taking an audio-feed from the rear speakers causes the entire sound-system to stop audio altogether. This happens in E39 and E46 models, but they can be reset straightaway with the ignition. The E60 and other iDrive models need a 16-minute cool down before audio can be restarted and this just won't do.
The problem did not occur in my E39 using an Alpine V12 1kW amp, only with a cheaper 'Toxic Audio' 1kW amp I was given at some point. This has its own volume control and the Alpine is just too loud, but with the long cut-out in the E60 I may simply have to revert back to it and turn bass all the way down on the head-unit. Having said that, there's no guarantee the Alpine will not still cut out audio and I have now found similar cases from people who have bought brand-new, good quality amps, so it looks like that rules out a fault with the Toxic. Worse still, my stereo suffered the audio cut out this week while the amp was plugged in to the speakers but not even turned on [no remote-signal], so this would back up my original fears that the cut-out is to do with too much current being drawn through the rear speaker cables, causing the head-unit to shut down all audio until the system is reset [fully powered-off and back on].

Here is a thread about it on bmw5.co.uk , I cannot say if the power of the amp versus the subs has anything to do with it though - http://forum.bmw5.co.uk/topic/83362-new-sub-woofer-issues-with-audio-cutting-out/

** UPDATE:

After fitting the Alpine V12 amp I have not had any sound cut off issues, just as it was in the E39, but it is still way too loud and overpowering the system, even with bass turned all the way down on the head-unit / iDrive.

To finally get this Alpine amp in balance with the stock system I've bought a crossover-box off eBay, which is a slight extra power-drain, but at least it has a Gain control for each channel so I can turn the subs down and the bass on the stock speakers back to normal. It also cuts out the high frequencies and lets only the low ones through for the subs, though I'm not sure if this will do a great deal for sound quality. I cover fitting that in THIS POST.

E21 316: Taller springs for MOT.

Well my MOT, the UK roadworthiness test, has come round and the E21 is just too low to get into my local testing station, let alone up onto the ramps. This is where height-adjustble coilovers would be worth their £650, as even if I can get the car onto the ramps, an attempt to raise the wheels off the ground will cause the short springs to become loose in the pans. The solution to this problem is still cheaper than coilovers - shortened strut-inserts from this post at ~£400, but I'll still have to find somewhere with ramps low enough to take her.

Seems to me the easiest and cheapest overall solution is to just swap longer springs in for the test and put the chopped ones back on later. Seems like quite a lot of effort just for a 30-minute inspection, but that's motoring in the UK, we're at the mercy of the MOT and it sees more cool cars off our overcrowded roads than insurance write-offs ever would.

Slight length difference. The red SPAX was a -40mm too.

A nice set of yellow APEX -40mm springs set me back just £80 from eBay. They are a lot longer than I remember though, which heralded me finally buying some spring-compressors, £17.99 and bringing the grand total of this years test to a ton before I've even had it inspected... not good.

Fitting the rear springs was a doddle, but the fronts threw up a few problems. Getting the cut spring off was easy enough, but even under compression the longer one was never going to fit in the space available. After damaging my newly filled wheel-arch and bursting one of my strut-inserts - nightmare - I started looking for a better guide on replacing springs and find out if it can ever be done with the strut and brake-line still attached, but one doesn't seem to exist - a good validation for this and other blogs! I did, however, find a Youtube video of some guys fitting H&R springs without removing the shock, which did give some clues from about 3min30 onwards:

PROCESS:

Rear Springs - 

1. Follow the steps in THIS POST to remove and re-fit the rear shock-absorbers, swapping the cut-spring for the new ones, obviously.

Front Springs [without removing strut, steering or brake-line] -

1. Raise the car and remove the corresponding front wheel. [It makes life easier to drop the front on axle-stands and remove both wheels, doing both springs together.]

2. Undo the top-nut from the shock-absorber, located on the suspension turret under the bonnet, using a 19mm wrench and 8mm open-end spanner at the top of the strut-insert to stop it from rotating.

3. Disconnect the brake-pad sensor wire by simply pulling it apart at the join behind the disc and sliding the rubber-mount free of the bracket.

4. Remove the earth-lead from the strut by undoing the bolt with a 10mm wrench.

5. Remove the bracket holding the brake-line to the strut using a 10mm wrench and open-end spanner. [This is essential to free the brake-line enough for it to tilt forward without having to remove the hose and drain the brakes. Without freeing the bracket, the brake-line will be stretched to breaking.]

** If the spring is still under compression without the weight of the car on it, use spring-compressors to hold it short enough to loosen the top spring-pan away from the turret.

*** The strut can be tilted out far easier with the track-rods unbolted, using a 17mm wrench and moved out of the way, but mine wasn't budging easily and there is enough room if you can push the steering-arm down enough.

6. Remove the four nuts holding the anti-roll bar brackets to the sub-frame using a 17mm wrench and open-end spanner. The anti-roll bar should drop down and remove tension from the two struts.

7. Tilt the shock-absorber strut out of the wheel-arch, remove the top spring-pan and spring.

8. Drop the new spring onto the bottom pan and reverse the above steps, using spring compressors if necessary.

Wheel-arch gap a little more prominent. Was it really that much before?!

E21 316: E30 Sports Seats - fitted.

MJNewbs from eBay got back in touch and we finally negotiated a low enough price for the seats. The fronts are in great nick, only a slight fray to the driver's back-rest, but the rear seat back-rest has a few tear that I'll address in a later post.

Thankfully, the E30 seat bases fit onto the inner stock mount, next to the trans. tunnel, on the E21 so they are already sited neatly in the centre and only require the outer mount to be lowered. Here's how I finally got them to an equal height.

The outer seat-mount was cut away about 1.5 inches height from the lowest point of the floor-pan and the top half completely removed from the sill. This leaves a large flat T-piece section onto which a length of '2by4' style wood-beam was placed that sits at the same height as the inner seat-mount, give or take 2mm.

To strengthen the edge of the wood where the seat sits a piece of 2mm-thick angle-steel was screwed in place, clamping the wood to the remaining edge of the cut seat-mount. The M10 seat bolts run through the wood and are bolted to the floor-pan, so the wood only acts as a riser, not an anchor and the angle-steel helps to distribute any downward force on the wood, or twisting motion as the seat is adjusted.

I chose to bolt my seats directly through the floor-pan for strength and this leaves a gap under the base of the wood at the inside corners, which I stacked out with a nut and large washers. This gives the added benefit of the seats being bolted first to the wood, then through the floor-pan with the same bolt. The downside is the sealed floor-pan nuts will need removing should the seat need to come out in future. The alternative method, used by HSVTurbo in his build here, is to bolt the seats to a thicker metal bracket, then bolt the bracket through the wood and floor-pan. This way the seat can be removed from inside the car leaving the wood fixed in place, but I just don't feel this setup will be strong enough, even with the thicker metal bracket.

I used M10 nyloc-nuts with a dab of stud-lock inside and large-diameter [40mm] 'bumper' washers. A good blob of silicone-sealant was put between the washer and body, then round the outside of the seated nut. Finally, I coated them in a thick layer of Finnegan's WAXOYL Underbody Sealant, for protection obviously, but also to blend the shiny nuts and washers into the car's underside.

I still have the rear-seats, including the folding arm-rest, along with the door-cards/handles and rear trim-panels, so we'll have to see how much will fit after the MOT.

E21 316: Big job broke out - Time to do the N/S/R Wheel-Arch...

This is the first wheel-arch I pulled to fit the 16s and it's the only one now still needing a tidy-up, to say the least. I cut too much of the lip off trying to wedge some balloon-like 45% profile tyres and left it in a right mess. The newer 40% profile tyres fit perfectly and only needed minor cutting to the other arches, leaving this one miles from the rim and totally out of shape. The bit I cut off is the line used to form the arch on the rest, so this one was missing an edge to build the filler up to and totally sculpting the new arch-line by hand with hanging bits of mesh and filler was never going to happen. The easiest method would be a plastic arch cover, hiding the cut area completely and easily smoothed into the wing, but all four would have to match and the Group 2 ones are just too big to consider. It seems my only options are -

A. Buy a new pressed-steel wheel-arch from eBay for £25. Trim it, grind the wing away in the right shape, weld it in place, grind the welds down flat and smooth it all off. Only then could I pull the new arch-lip out and fill it to match the other three. [http://www.ebay.co.uk/itm/BMW-E21-316-323i-1977-1983-REAR-PASSENGER-SIDE-WHEEL-ARCH-NEW-CLEARANCE-PRICE-/190865619545?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item2c707a3a59]

B. Spot-weld the piece I cut off back into place and secure it with fibre-glass filler. Fill the lip to match the others and build up and re-shape the arch up to where it meets the wing almost.

No doubt B involves a lot less time and effort, but it's still going to be a lot of rubbing down.

The chewed up scrap of metal, good job I saved it. It didn't just slot back into position, there was quite a bit of grinding and filing.

I had wanted to tack-weld the metal on and fill the gaps with fibre-glass, but I couldn't get hold of one so masking-tape did the job. I caked on plenty of P40 fibre-glass filler in between the tape, waited for it to go off, removed the tape and filled in the gaps.

Well sealed behind with more P40. You can see the sliver of metal in position as the light shines through, showing just how much arch got cut off originally.

It was then ground down with a rotary-file on the drill, mainly inside so nothing rubs on the tyre, but a bit to give the lip some shape. All that's left now is the arduous task of filling all that arch.

E21 316: (Wheel) Arch-Nemesis Beaten! - tidied up with a bit of flare.

Been enjoying the car and weather too much over summer to neaten up the pulled wheel-arches, but thought I'd take some time off to finish them before the rain and gloom sets back in.

I bent the lip with a pair of grips into the smoothest arch I could and filled it flush with P38 to where the original outer lip was. This took quite a bit of building up.

Normally I'd give it a coat of zinc-primer for now and rub it down again, but for aesthetic value I went straight to red-primer and it's already lifted the look of the car.

More of the rear arches had to be cut away than the front, so this meant a smaller and slightly easier area to fill. The only remaining arch is the dreaded N/S rear one, which I hacked to death trying to install tyres that were too big, but it's a mammoth job alone and will have to wait.

E21 316: Sculpting New Arches...

The car survived a trip with 3 people in and no scrubbing at all on the 16x9s, which I found very surprising, but still I figure the arches are good to finish off. I've neatened up the pulled lips and made a start to filling in and re-sculpting the shape of the wheel-arches, but progress has been slow and my intentions of selling the complete project this summer are looking unlikely. I spoke to the guy who did the re-spray for me originally and he said to get the arches as good as could be and pass it back over to him to smooth them off and repaint them without having to go over the whole car again. Great, though I can't keep hurling money at it, and with more to do over summer I've had less time to spend on the E21 and more time spent enjoying driving it on the new wheels for a few weekends in the sunshine like I intended, not just the odd trip to work. Oh and there is the matter of my daily driver needing MOT attention, but that's a different story.

Never the less, both the o/s arches have begun to take shape. Getting the lips off the bigger wheels and tyres was too extreme a job for my arch-rolling kit, so I had to pull them out with grips in the end. This meant a fair bit less grinding on the o/s rear wheel arch and none at all needed up front. The arch-lip needed to be low for as much tuck as possible, I don't like the cut-arch look, so I got the pulled out lip roughly in line with the slope of the arch and built it up flush with P38 filler. This is as close to the look of those European BBS'd E21s as I could figure, with a slight flare to the lip rather than the flat-edged look of the original arches. This is probably the easiest method of smoothing and saves on a bit of body-filler, enough of which is being used already.

I haven't touched the nearside arches yet, the main thing putting me off being the n/s rear one that was used to test fit those oversized Yokohama tyres and has suffered greatly from the spinning-disc. With the extra lip cut off the rigidity has been lost and the general shape of the arch has deformed, as well as more tyre being visible, about 10mm of tuck being lost. I guess my only options are to try and spot-weld the rough section of lip back on that was cut too far, which I still have, and rebuild the shape of the entire arch in filler, or buy a patterned-part wheel-arch off eBay for £25, cut out the current one, weld in the new one, smooth it off, pull the lip out and fill all that in. Well, there's no doubt the first method is cheaper and a lot less work, but this is a large area to be filling and smoothing and a wide margin for error, plus I don't even know if the bent arch will accept the bit I cut off without messing it up even further... watch this space!

E21 316: More Open Arch Surgery! Wheels finally on...

Got the grinder out again today and tackled the job I haven't been looking forward to - cutting away the other rear wheel-arch. Progress was quick and smooth for a change, I guess because I had an idea of what to do now, but I think the lower profile tyres played a part. If only I'd bought them first time round I wouldn't have had to butcher the n/s quite so much. A good notch had to come out at the bumper shut-lines as these were the main bits sitting on the tyre, but less of the outer lip had to be cut away and the arch looks a lot smoother than the last effort.

The main problem with scrubbing was coming from the inner skin of the arch and the best way to get that off was still to peel it back, cut wide flaps in the metal using tin-snips and work them with grips until they snap clear.

It's been quite a bit of effort and hacking away at the car was heartbreaking, but at last the super fat wheels are on and no scrubbing whatsoever. Now to see about neatening up those arches...

E21 316: Front wheels fitted - the easy part.

No fouling on the pulled arch-lip with these skinnier tyres, but the front valance was still just about catching so, with the arrival of the new spacers, I thought I'd get the fronts boxed off before starting the arduous task of the other rear arch. Sadly, my camber-plates have yet to arrive, I guess they must be stuck while Customs & Excise figure out what they are.

Thankfully, the amount of valance that needed cutting away on the n/s was only about 8mm and I didn't have to remove the bumper after all. I did my best to follow a natural curve, not sure if I took a little too much near the bottom. Interestingly, the o/s of the front valance didn't contact the new tyre at all and the fender does not extend past the bumper. I wonder if the n/s wing has been replaced at some point giving a slightly proud line. I matched up to that line when repairing the lower-valance last summer, so that would explain why it was catching the tyre too. Either way, the o/s/f arch required no grinding at all, so a little more pulling and the fronts will be ready for smoothing in.

I've also been driving round the last day or two with NASCAR style staggered wheels - 16s on the n/s and still 15s on the o/s. The car steers great to the right, but is a bit recalcitrant going hard left. I must find time to wrestle that other rear arch on Monday or it'll be like this for a while.