Xcel

Is the LSD 3.15 ratio and still available?

The head in my M50B25 cracked so I'm looking at a replacement (with or without valvetrain). (deleted my last post due to it being redundant)

Seems pretty normal to me, I haven't noticed revs hanging and the clutch grabs pretty firmly. The gearbox has taken a bit of getting used to though, you can't throw it between gears quickly like some cars due to how notchy it is. 1st/3rd and 2nd/4th are quite close together laterally so it's quite easy to go from 1st to 4th by accident, not sure if it's the short shift kit or just how the gearbox is designed. I have to make sure I don't select reverse when going for first too haha.

Haven't been posting progress but the car is now a manual and I've been driving it around like that for 2 weeks now. It's been a headache, the competition clutch was riveted the wrong way so the clutch disc was rubbing against the guide bush and making an awful squealing noise. Easy fix with a grinder but we were having trouble bleeding the hydraulics and then the clutch pedal wouldn't keep pressure. Had to replace the master cylinder with a brand new one which solved that problem. The only issue remaining is shuddering (clutch chatter) when slipping in first/reverse which is probably related to my clutch kit - avoid competition clutches in my opinion. I think it's time to put this project on hold so I can have a car that can actually be used and not spend a month on jack stands. I'll need a 3.15 LSD at some point though because the gearing is a bit short and fuel economy suffers at 100kph doing around 3600rpm. It's probably not the most interesting one to share on here anyway because my budget it pretty low. Here is a photo I took of it way up on the ranges anyway. Quite impressed that it got up the gravel road without issue despite being lowered and it's a lot of fun around the twisties.

If it's anything like my E36 then that's just how they design these cars. The rear of my car has a few cm more ground clearance than the front so it still has the rake but the tyres sit roughly the same as yours in the arches.

So we ended up making our own socket extension with some steel tube and finally got the automatic transmission out, but what a mission. The surprising thing was the weight difference between the two. The automatic is 95 kg including torque converter and ZF manual only 36 kg (excluding clutch and flywheel).

That sounds like a good idea actually, will have to give it a go in the morning.

Update: Designed door panels and got them cut out with a cnc plasma cutter on 1.6mm aluminium. It was a bit rough around the edges so I attacked it with grinding tools and a wire wheel. I've managed to install the door panels so that they fit well with some steel reinforcing around the handles to reduce flex. Going to cover them in black vinyl so they don't look so nasty. ATF was drained then exhaust, drive shaft, head shield, ATF cooler and lines have been removed. Engine is tilted back and we're trying to remove the bolts holding the transmission on. Currently our ratchet extensions are proving to be too flexible with the length required to clear the automatic transmission. Sprayed the bolts with CRC and will try them again tomorrow.

Lanzar Vibe 410

Ah I will try to find some cheaper Bridgestones, but the PS3's are on special currently ($239 ea). Yes the brakes will be getting replaced with a 330i conversion after the manual conversion is sorted.

Decided to replace my Lanzar Vibe amp with an RE Audio XT-800.4 gem I found on TradeMe. Not a huge upgrade in power but it's a better quality amp, looks nicer and doesn't seem to run as hot. I'm quite happy with how the suspension feels on the car despite it being a bit of a mix, but that's how it is sometimes when you're running to a budget. The wheels are rarely ever scrubbing on the arches or guards and it's still quite comfortable with much less body roll. Koni seem to be a great choice in shocks for the street. As you can see the arches now meet with the top of the tyres nicely. Next I will probably need to replace my rubber because they are snow tyres (what it came with for some reason). They don't provide the most direct road feel and wear down pretty quickly but don't seem to be nearly as dangerous to use in summer as most people say. I'm tempted to get some Michelin Pilot Sport 3 tyres from Hyper Drive.

Too expensive for what it's worth and it's always a gamble when buying springs. The Dobi Sport springs I have at the moment seem to ride fine and I'm happy with the ride height now that it's been lifted. Eventually I'll probably just replace the whole lot with decent coil overs when I'm ready to get it certed.

Head and headgasket appear to be fine but the coolant reservoir cracked so I got that replaced. Engine is running well again, just need to get the front lifted up a bit with 20mm spring packers.

Today I learnt the hard way about bleeding your cooling system properly with a BMW, it's a bit more complicated than adding it straight into the radiator like in my previous cars. The symptoms of air in the cooling system were confusing me, I thought I'd added too much coolant into the expansion tank but the system had hot spots, started boiling and forcing coolant out. Unfortunately it did get hot enough that the engine stalled and started leaking some oil so I'm getting the engine compression tested tomorrow to make sure the head gasket is still good.

Poor wheels, I'd rather park 1 foot from the curb than risk scratching mine. You've done a great job with them.

I was looking for some stiffer suspension to reduce body roll and drop ride height a bit so I bought some Koni shocks off trademe which came prefitted with some unknown springs. http://www.trademe.co.nz/Browse/Listing.aspx?id=1013835489 They reckoned it would be a legal drop but it's put me at about 90mm clearance at the front so I'm looking at replacing the springs in them. I'd like it to be a bit lower than stock but not so low that it's scraping on the guards and failing WOF. I was considering getting H&R OE sport springs to match the springs in the rear since they are only meant to have a 1" drop not 2". Can anyone recommend these springs or another type? Thanks. While it looks nice at this height, it's not very practical.

I do have some FLAC but MP3's are just so much easier to get a hold of. To my ears 320kbps MP3's are pretty much indiscernible from lossless though, I'm sure some will disagree

At this stage I'm not worried about the box at all because it performs superbly, it's still punchy and others can attest to this. The main issues I'm finding in terms of sound quality is rattles in the car and quality of the music files that I'm playing. Perhaps a good reason to run sealed is that you won't generate nearly as many rattles with powerful low frequency bass. Anything below 192kbps compression tends to sound bad and can have muddy bass when played so loud and some artists have bass boosted their songs so it's far too overpowering. There is also a noticeable frequency response drop between 100hz and 250hz where my front speakers just can't keep up in the mid bass but I'm not too worried about this. I could dynamat the car but that would be adding weight and building a custom enclosure for the kick panels to get in larger mid drivers is not a priority for me.

It was for my sub in both graphs, I posted the driver parameters and a Qts of 0.4 is suitable for either ported or sealed enclosures so it's a fair comparison. I'm not sure what your scale is for the excursion, but in reality the sub is operating within it's 30mm xmax which means it's not "flopping around". Everywhere I've read seems to confirm that a subwoofer with a Qts of 0.4 should have a ported enclosure equal to it's Vas and the two calculators I used all provided results in the mid 20's so if anything I made my box slightly too small.

Not necessarily, ported enclosures are more efficient and go much lower so it's a bit of a waste to go sealed unless the sub is designed for it or you don't like low frequency bass. This is a comparison I did in WinISD with my box compared to a sealed enclosure with a Qtc of 0.71. The phase plot was identical down to 50hz and group delay identical down to 70hz, increasing by 2ms at 50hz so I don't think they would sound very different in terms of quality since anything below 40hz is reduced by my subsonic filter. The main difference is around twice the output through it's useful frequency range.

What are you using to model it? My enclosure is actually only 23.1L after re-measuring it. As far as I know the enclosure Q or Qtc of 0.707 was only for sealed enclosures whereas ported use an alignment e.g. SBB4, QB3 or SC4. Are you sure you're modelling a ported enclosure?

You might have the parameters of the new version of the Havoc but these are the ones I used: Fs: 30.9Hz Qms: 6.07 Qes: 0.43 Qts: 0.4 Mms: 238g Sd: 480cm^2 Vas: 26.1L Bl: 19.8 tesla meters Xmax: 30mm RMS: 1250W I tried a few different calculators with similar results including WinISD and they all suggested an enclosure roughly the same as the Vas with a ~1.4m port tuned to ~31hz and I think it works well, I wouldn't say it flops around at all. From my understanding it's stiff suspension helps control it in such a small enclosure. I have a low pass filter set up to prevent over-excursion below 30hz and then adjusted gains to make sure it doesn't exceed the Xmax since I have more power than it needs available. Whenever I simulated recommended boxes they ended up being too peaky which might be nice for SPL competitions but that's not really my thing.

Thanks, yeah I am pretty happy with it so far but of course it's not perfect for it's age. I'm becoming familiar with the BMW quirks like paying $30 for a locking nut adapter just to be able to get my wheels off for example haha. Gave it a coolant flush today and the fluid seemed pretty clear so that's probably a good sign at least. It's dropping small amounts of oil but not enough to be concerned about. Otherwise the main thing it needs at the moment are new door cards, but I'm getting some aluminium panels to go in there made at the moment.

So I thought I might make a post to keep updated what I've been working on with my car so far. I'm aiming for a car that is street worthy and that I can take to track days to have a bit of fun with it while keeping it to a budget. What it came with: Motorsport body kit 17" wheels with BMW badges on them Monroe rear shocks tinted windows Audio: Clarion DXZ835MP head unit JBL GTO509C component speakers RE Audio XT-800.4 4 channel amp (bridged) Ascendant Audio Havoc 12" in custom ported box Sound Magus DK1800 class D mono amp Suspension: H&R rear springs Koni front struts with Dobi sport springs To go in: M3 ZF gearbox with manual conversion Stainless clutch pivot pin Short shift kit Stage 2 Competition clutch and lightweight flywheel Original suspension: Koni struts/H&R springs installed It's feeling a tad low on the front, may need some different springs to raise it up ~20mm

I wouldn't know how reliable it would be, but I'm curious to see how this combination would work: turbo kit (with a better quality turbo/wastegate) chip/MAF/injectors cooling + exhaust