A race bmw 316, m10, s14, m20, turbo, na, its been the lot!

[Graham]

Re: A race bmw 316, m10, s14, m20, turbo, na, its been the lot!

ive been pondering what to do with the front spoiler, after it was damaged i had repaired it with fibreglass, but its looking pretty secondhand.
i could of easily bought a new one but in the end opted not to, instead fit an OE bumper skin its lighter, cheaper wont shatter if knocked and easy to attach with a few bolts, and will probably stay attached if knocked. in circuit racing you want panels reasonably well attached, bodywork hanging off is likely to get you black flagged and ruin your race.

as the bumper skin is lighter than the old spoiler and ive saved a bit of weight doing away with its mounts i gave thought to giving the center section a bit of reinforcement, partly to help it stay attached and partly a bit more protection for the rad and oil cooler.





i also used the opportunity to upgrade the webbing front towing strap to a pair of wire straps, although the old strap seemed plenty strong enough, it wasnt really blue book compliant. Finally i got the corner weight scales out again, all the recent work has paid off, the cars down another 10kg to 918kg, heavy by escort standards, but not bad given an iron blocked straight six up front, best bit is the nose of the car is actually 20kg lighter, so we are back to 55/45 weight distribution with a near empty tank and me on board. i really need to put myself on a diet now, as i now make up 10% of the cars all up weight!

[Graham]

Re: A race bmw 316, m10, s14, m20, turbo, na, its been the lot!

a hidden benefit of moving the extinguisher, battery, wiring etc is the inside of the car looks tidier, looking tidy does not give a performance advantage, but i know as a scrut myself if a car looks tidy i dont look as hard for stuff wrong! just need to clean the floor now!



when i bought the car it had short stubby dtm look mirrors, which i replaced with standard E30 ones, the reason being one was damaged and reward visibility was rubbish, having not raced for a long while i was more concerned with rearward visibility than go faster mirrors. last year experimenting with ducting air into the cabin i was stunned as to how much air pressure built up just under the mirrors, so i have bought some cheap extended dtm type mirrors, i should still have decent rearward visibility and they are certainly a lot more slippery shape, half the weight of the OE ones too.



lastly for the moment ive bought a new screen, a preformed polycarbonate one, its half the weight of the glass one, plus i dont need the screen rubber which saves another 2kg weight. it cost a small fortune, but if it out lasts 4 glass screens it will of paid for itself. i used to use poly screens before, i used to cut them out myself, but being cut from a flat sheet they never fitted great and had to be screwed in, which probably didnt help with wet weather condensation problems i used to have.

[Graham]

Re: A race bmw 316, m10, s14, m20, turbo, na, its been the lot!

rear toe is about 2mm in so its there or there abouts. i really dont want to do anything to unsettle the rear end, sideways might be good in a drift car, and a loose rear is great for changing direction with a rally car on gravel, but its slow on a race track

[robt100]

Re: A race bmw 316, m10, s14, m20, turbo, na, its been the lot!

at least its going the right way, the toe out should help the ackermann for slower corners, what is the rear toe looking like?
Yeah, softer damping might help, though you then dont want to go too soft and end up having the initial bite but then loosing more front end.

[Graham]

Re: A race bmw 316, m10, s14, m20, turbo, na, its been the lot!

ride height wise the car is now level, rather than arse end up like it was, corner weighing it shows its taken a bit of weight off the front which should help. geometry wise the alloy arms are exactly the same as steel, i had changed the front toe to give it some toe out, that has helped sharpen the steering but down nothing for low speed, lap time wise the car is considerably faster than it used to be, so it going in the right direction, slow speed turn in is its weakest point now, probably not helped by the stiffer front ARB, i plan to back off the front damping, what it probably wants is less rebound, but the shocks are single adjustable only, so will just have to try

[robt100]

Re: A race bmw 316, m10, s14, m20, turbo, na, its been the lot!

Graham, is it just on entry that you're having trouble in the slow corners, or does it feel slow/like there is some push mid corner too? That shot of the new alloy arms seems to show a lot of caster on the front, which might not be helping in the slow stuff. Is there a way to temporarily back it off to test?
Also, now you've sorted out the rear, what kind of ride height front to back are you running (roughly)?
Lastly, are the dampers adjustable in any way? There could be a few setup tweaks to help in the low speed stuff. Even a little more toe-out may help. Ok, its not weight saving, but it may help!

[Graham]

Re: A race bmw 316, m10, s14, m20, turbo, na, its been the lot!

Ah well - looks like all bases covered, you have a dinosaur with a tail happy, no grip rear end! Short of getting a 911, I can see any other changes you could make LOL!

TBH its not that tail happy given that it has 220lbft and 285bhp the main reason im trying to shift weight rearwards is to try and stop it understeering going into tight corners

the latest effort, ive moved the both battery and fire extinguisher back about two foot each



i also changed the fuel return pipe, the new one is slightly lighter but it wasnt for that reason, although the braided goodridge hose doesnt leak fuel it does leak fuel vapour, i heard numerous times they ooze vapour but never experienced it myself before.



a cabin stinking of fuel isnt an ideal way to start a race, and probably isnt helping with regards to me getting car sick!

[rallyrob]

Re: A race bmw 316, m10, s14, m20, turbo, na, its been the lot!

Ah well - looks like all bases covered, you have a dinosaur with a tail happy, no grip rear end! Short of getting a 911, I can see any other changes you could make LOL!

And a 911's not tail happy !!! Really...!

[katana]

Re: A race bmw 316, m10, s14, m20, turbo, na, its been the lot!

Ah well - looks like all bases covered, you have a dinosaur with a tail happy, no grip rear end! Short of getting a 911, I can see any other changes you could make LOL!

[Graham]

Re: A race bmw 316, m10, s14, m20, turbo, na, its been the lot!

I don't want to sound like granny and 'sucking eggs' but have you a 'race tank' or std BMW? Battery in the boot, any fluid containers (screen wash, overflow tanks etc) into the boot? Whilst you needed lights in your last outing - do you need lights by regulation? - few kg's there? Shame you can't swap out the big bimmer gearbox for a transaxle box - that'd be a nice weight change! Any Bimmer alloy engines worth a swap?

thanks for the suggestions. let me see.

screen wash bottle and anything to do with washers long gone , including any wiring, car has bare minimum wiring to make it work.
yes i have to have lights, id even gone as far as taking redundant bulbs out the clusters.

there are no alloy engines i can fit and still have a bodyshell/period correct engine. the only engine i could fit which would not cost me a bunch of power and improve weight distribution is an S14, the 4cyl m3 engine, yes id love another one, but these days they are starting to make BDA's look affordable, not only would i have to change the engine but also the gearbox, i could end up spending 30k for a small improvement in weight distribution. it would be similar to swapping a pinto for an all alloy BDG, great idea, but if i had that sort of money i would be racing something else!

fuel tank is an alloy escort one in the boot, with fuel pumps etc in spare wheel well.

[katana]

Re: A race bmw 316, m10, s14, m20, turbo, na, its been the lot!

I don't want to sound like granny and 'sucking eggs' but have you a 'race tank' or std BMW? Battery in the boot, any fluid containers (screen wash, overflow tanks etc) into the boot? Whilst you needed lights in your last outing - do you need lights by regulation? - few kg's there? Shame you can't swap out the big bimmer gearbox for a transaxle box - that'd be a nice weight change! Any Bimmer alloy engines worth a swap?

[Graham]

Re: A race bmw 316, m10, s14, m20, turbo, na, its been the lot!

i did another couple jobs, one was to change the plastic wheel spigots for alloy ones, as i keep melting the plastic ones, even when its wet





also loctited the wheel studs in, they have a habit of unscrewing when the wheel nuts are undone, its not actually an issue they dont need to be tight in the hubs, i usually just twiddle them back in, but it did dawn on me that i often have pit crew who may not be switched on with regards to loose studs, and therefore possibility send me out on track in a car with studs barely screwed in





i didnt get any pictures, but i did a few other bits to the car, i found a few bits of weight to take out, although as usual they all took weight off the back of the car, i bolted the rear bumper directly to the body without what was left of its original attachments, that saved a couple more kilos and makes it less likely the bumper skin will fall or hang half off given a tap from the rear. i also tweeked the trailing arm mounts on the rear beam, something ive been wanting to do to try and get some of the excess camber out of the rear wheels, turned out pretty successful too, as i managed to drop an inch out the rear ride height and still end up with a degree less camber, a real result as normally that would of added a degree. i was hoping that dropping the rear ride height would help shift the weight bias rearward, it didnt as such, because the front/rear bias remained same as last time i corner weighted it, but thats actually a result, because other than the alloy front arms, all the weight ive taken out the car has come out the rear half, so its still 55/45




its always slightly tricky working out what the changes have done weight wise, simply because always has a different fuel level, that 938 at the last weighin was with around 25 litres of fuel on board, so the car with a low fuel load is getting closer to my goal of 900kgs, not bad for a car with an iron straight six in it, and the only non steel body panel is a grp bonnet,

[Graham]

Re: A race bmw 316, m10, s14, m20, turbo, na, its been the lot!

its been a while since ive touched the car, but the racing season is coming, so had to pull my finger out, and get some upgrades happening.

i didnt get a lot of seat time last year but its clear on the right day at the right circuit, the combination of me and the car have the pace to run well inside the top ten overall, which means ive been giving thought as to how to get on the podium.

i cant easily find more power, but i know from chasing Porsches and lotus sunbeams around various tracks what i need most is a car which will carry more speed in the tighter corners, which means taking weight out the car, and more importantly off the front. the trouble is most of my attempts to lighten the car whilst being successful are all taking weight off the back so doing nothing to help the car turn in better, and not something i can fix by just drilling a few more holes, so ive splashed a bit of cash. ive ordered a polycarbonate windscreen, and some alloy front arms.



so these have been changed for, these....




the alloy arms being half the weight of the steel ones

[Graham]

Re: A race bmw 316, m10, s14, m20, turbo, na, its been the lot!

its been a while since ive touched the car, but the racing season is coming, so had to pull my finger out, and get some upgrades happening.

i didnt get a lot of seat time last year but its clear on the right day at the right circuit, the combination of me and the car have the pace to run well inside the top ten overall, which means ive been giving thought as to how to get on the podium.

i cant easily find more power, but i know from chasing Porsches and lotus sunbeams around various tracks what i need most is a car which will carry more speed in the tighter corners, which means taking weight out the car, and more importantly off the front. the trouble is most of my attempts to lighten the car whilst being successful are all taking weight off the back so doing nothing to help the car turn in better, and not something i can fix by just drilling a few more holes, so ive splashed a bit of cash. ive ordered a polycarbonate windscreen, and some alloy front arms.



so these have been changed for, these....




the alloy arms being half the weight of the steel ones

[Graham]

Re: A race bmw 316, m10, s14, m20, turbo, na, its been the lot!

i did a night race too, that was tricky! i had tried the car around the industrial estate at work in the dark, but unfortunately its quite well lit so whilst the lighting seemed good it turned out not to be.

i had been told race circuits seem totally different in the dark, they were not wrong, Brand Hatch i could drive blind folded, but donnington, no chance i never really got the hang of it during they day due to the appalling weather, in the dark i was back to guessing where i was going again, and as it got darker with lighting which really didnt live up to the job.

it had stopped raining and hour or so prior to the night race, so a switched the uniroyal tyres for some softer sticker Kuhmo V700's but in reality i wasnt able to make use of them, my lap times on the dark wet track being slower than in the full wet but daylight conditions.

there was not a separate qualifying session for the dark, instead we were given a position based on our day time starting place, only this time i was even further back, in 39th place! come the race i finished 18th, so a lot further up the grid, however i suspect that was more down to me keeping it on the track rather than raw speed. there were a couple of safety car deployments which didnt help progress, i was just pleased not to of caused them and teh cars still running with no issues or damage

https://youtu.be/BxBiVXTvsuo

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