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Sundayjumper and his 316i

PostPosted: Thu Jun 07, 2018 10:52 am
by Sundayjumper
My car is arriving later today - bought blind from ebay - so I'm hoping I've not made a massive mistake here ! It's a W-reg 316i Compact. Ta-da:


Silver, black interior, sports pack, no sunroof. That's "my" spec !

Apologies for the following brain dump. Lots of possibilities and I need to work out the priorities. Keen to hear any & all suggestions.

I'm not going for a full-on rally build. I've been doing Autosolos in my other car but wanted something smaller & lighter instead that will also cope with some grass autotests and some winter fun events. The important thing here is that I need to stay in the "production" class. I can modify the engine, brakes, suspension, but I have to retain a full interior (different seats are OK, but removing them completely is a no-no), glass windows, factory body panels. If I don't stick to that I get moved to the "kit car / specials" category and would need to go all-out on the build to be competitive. Which I can't really afford right now.

So my plan is to lighten it as much as I can without falling foul of the rules. Any top tips there ? There must be a bunch of sound proofing I can lose while still keeping a "full interior" ? Simplify the wiring loom ? Hollow out the rear seat ??

The engine might need to be switched for a 318ti. I think that would be allowed. A 2.8 six-pot might be pushing my luck.

Brakes I assume will need some updating and I'd like a LSD but as far as I can see they're rocking horse poo and priced accordingly nowadays :(

Suspension, I nearly jumped in and bought the s/h Eibach springs that are on ebay atm but if I'm stripping some weight I don't know where the ride height is going to end up. Are there affordable coilovers that aren't rubbish ?

Interior I'll want a bucket seat, harness & bolt-in rear cage I think. No need for a full cage at this level.

At the wild end of possibilities, I love the wide-arch rally cars, but I don't have a handle on just how much work that involves. How is the wide track achieved ? Big spacers & offset wheels or is there a "proper" solution with modified suspension arms ? Lots of cutting / welding ?

Re: Sundayjumper and his 316i

PostPosted: Thu Jun 07, 2018 10:56 pm
by Sundayjumper
Do I just need to find a cheap 2.8 Z3 and transfer the entire running gear to my Compact, killing several birds with one stone ?

Re: Sundayjumper and his 316i

PostPosted: Wed Jun 13, 2018 12:38 pm
by Sundayjumper
I had a mini ebay spending spree at the weekend.

Cheapie coilovers (I've got a broken rear spring that needs replacing and I'm curious to see if £250 coilovers will put up with some autosolo / autotest abuse)
Spare set of wheels (wrongly listed as 15" when they're actually 16", £55 seemed good)
Rear strut brace (which will also act as reinforcement to the top mount)
Front bumper mesh to replace the slats (to make it look like an M3 :roll: )
US front number plate trim (because I'm secretly a bit chavvy :roll: )

And a 16ft Brian James trailer !

I'm holding off on buying other mechanical bits until I decide on the overall plan. Stripping a Z3 is the most appealing option right now but I need to sort some workshop space to avoid making my driveway look like the back end of a trailer park.

First job is to find out if there's anything actually wrong with the car and to get it through an MOT. My code reader will only access the engine ECU, not the airbag, ABS, etc, there were loads of DME faults logged, but to me they looked consistent with a general strop about flat battery at some point. All four coils, all four injectors, fuel pump, MAF and some others too. They can't ALL be faulty...... can they ?

Re: Sundayjumper and his 316i

PostPosted: Fri Jun 15, 2018 7:31 am
by Garry.M
Should be a fun build.
Being that age of 316ti, it should have discs on the rear which is good. I've a mate that bought a 4.1 lsd for his rally car build - which turned out to be a 168mm,,, so it might be up for sale. He might end up using it until he can get a 188mm
Ripping the interior out and using a hot air gun to remove the sound deadening will a bag weighing nearly 10kg! When the interior is out you could send your wiring loom to Chris Ransley of Cr Mtech in Shrewsbury. The std loom is 14-15kg!,,, he can strip it right back til it's 4.8-5kg and you'll still have electric windows, heater etc. Each door bar is the best part of 3kg. Removing rear wiper motor. (if you're allowed in the regs). Are you allowed to replace the passenger seat with a bucket seat?

Re: Sundayjumper and his 316i

PostPosted: Fri Jun 15, 2018 9:24 am
by Sundayjumper
"Ripping the interior out and using a hot air gun to remove the sound deadening will a bag weighing nearly 10kg!"

Just from the sound deadening ? Nice. I need to keep all the visible interior trim in place, but it'll be fine removing the hidden stuff from behind it. Same for under-bonnet and roof sound deadening.

Loom was already on my list of things to do, is there any online info about what can be removed ? I was going to take a trial-and-error approach, pick an item to remove and then follow its wires back down the car.

Rear wiper can definitely go, and I'm allowed to put a bucket seat in to replace the passenger seat.

Re: Sundayjumper and his 316i

PostPosted: Fri Jun 15, 2018 9:51 am
by Spac
If you can excuse my crappy handwriting, this is what came out of my '99 316i.

Re: Sundayjumper and his 316i

PostPosted: Fri Jun 15, 2018 10:39 am
by Sundayjumper
That’s handy, thanks !

What’s involved in removing the ABS stuff ? I wasn’t planning on going that far but it can go on the “one day” list along with the adjustable bias pedal box.

Re: Sundayjumper and his 316i

PostPosted: Fri Jun 15, 2018 12:04 pm
by Spac
I haven't done any ABS removal on the 318 yet. Just gotta remember to hit the DSC button before each run!

On the 318Ti, I removed the wheel sensors. Supposedly this can trigger a fault code that lowers the rev limiter to 5300rpm - my car didn't do it from the ABS delete, but some other fault did... :/ There is a work-around, but I can't vouch for its effectiveness.

Re: Sundayjumper and his 316i

PostPosted: Tue Jul 31, 2018 11:36 am
by Sundayjumper
Well, we have some extremely slow progress.

The driver's window wasn't working, seemed like it had just come off the runner, but one day due to me being dopey and forgetting about it, I absent-mindedly pressed the button and was rewarded with a nasty crunching noise from inside the door :oops:

Short story - s/h regulator from ebay for £20, easy job.

The car had a full set of warning lights on the dash, brake pads, ABS, ASC, airbag.

Brake pads - someone had left the osr sensor wiring loose so it had rubbed on the driveshaft and worn through :roll:

Airbag I was able to clear with a code reader.

The ABS & ASC warnings remain. The reported error is the return pump, a bit of Googling suggests it's probably dodgy electrics in the control module. So that's my next step although I quite like the idea of ditching the whole lot to keep the car as simple (reliable) as possible.