PollyMobiles Rebuild

[pollyp]

Afraid so.
I always corner weight on cold tyre pressures more consistent and easier to monitor

yep balanced on cold tyres set to warm 3bar pressure, then after initial drive when they're actually warm I reduce the pressures back to the 3bar they were balanced for

 

[h701micra]

I set the cold pressure on each axle and leave them. Getting them warm and resetting relies on them reaching the same operating temperature each time

After I corner weight the car I use tyre pressure to alter handling characteristics. Higher pressure giving higher operating temps and less forgiving ride. Lower temps run colder and generally more forgiving.
Then to alter contact patches.. Cross weights

Can't be giving away all my tricks though

 

[pollyp]

toyos labelled 3bars max so keeping it below that when warm or hot.
these soft side walled t1r need alot of pressure to retain stiffness but I dont want to risk an overpressure blowout on track.

I thought higher pressure reduces the contact patch but increases sidewall height & lateral tyre stiffness, reducing the amount of sidewall deformation/rubber bending, which reduces amount of heat generated?

http://www.autospeed.com/cms/A_108915/article.html

was thinking of measuring the inner/mid/outer tyre temps of each after each track run with me micro meat probe to identify if that tyre is under/over inflated or require camber adjustment

 

[h701micra]

That's the key element here is the contact patch
If getting max grip was just a case of increasing tyre pressure to max why do we need suspension?
You're at a much higher chance of a blowout running max pressure as there's less give than in a lower pressured tyre so your suspension has to be spot on at absorbing bumps to stop the car bring skittish. Although I'd say it already will be as your car simply doesn't weigh enough to justify such a high pressure being as the tyre is designed to work with 400kg+ corner weights. Once warm you'll find it feels lighter on the steering and stiffer but chances are your using 50% of the tread

Camber, caster are tricky to call. 1 deg negative camber has the same effect as 1 deg toe out on tyre temps. So you have to compromise as always

I've always gone by the rule of its easier to heat up something that is under more pressure.

Just sharing my experience here

That website suggests contact patch is not related to grip to which I disagree.. correct forces applied etc a larger contact patch will give better traction/grip than a smaller contact patch

 

[pollyp]

new set of predator pads arrived

took it to the garage and noticed on me shelf 3 diamond black boxes.
one was the wrong set of pads I was once sent,
one was the old set of rear pads,
but then one was a fresh set of predator FT pads?!

went "ohh for fook sa..ohh cmon" like dara in this clip



that's what I get for not checking first. least I'll have enough for the next few trackdays

meanwhile, since swapping the front tyres, the steering begins to drift right in the morning or going home. turns out the FR has a slow puncture so another thing to fix

 

[pollyp]

sprayed some detergent onto the wheel to locate the leak and hey presto, it's leaking loads from around the old valve. few more quid to replace that valve suppose

also test fitted the set of wheels that'll be run on the track initially:
avon/bridgest at rear and toyo at front
FR 6.75
RR 4.0
RL 2.5
FL 4.5mm

pulls to the left even after deflating the RH to 2.7bar
if the track was dry, I may swap the tyres left to right so the thicker RH tyres are worn down more.

 

[h701micra]

Just to clarify you've had the wheels aligned after corner weighting?

 

[pollyp]

Yep

 

[h701micra]

Have you had it back up on the scales since?

 

[pollyp]

Have you had it back up on the scales since?

not since I changed the front wheels to fix the drifting left.
I'm currently making a set of scale pad levellers so I can quickly and accurately level the scales rather than just stack bits of wood/tiles
then rebalance her

 

[h701micra]

not since I changed the front wheels to fix the drifting left.
I'm currently making a set of scale pad levellers so I can quickly and accurately level the scales rather than just stack bits of wood/tiles
then rebalance her

Ah I see
Wheels won't affect it at least as it's unsprung weight

 

[pollyp]

tday went to b&q to buy some square tubes n sheet panels.
when I quickly estimated the design of the scale leveller and amount of material and total cost of bits according to their site, almost had a heart attack as it reached over £200 to make! (although still cheaper than the proper £450 levellers on demontweeks )
was thinking of ordering it £30 cheaper online but need to make it this weekend so will have to suck the price.

brought 5 x 25x25x2000mm square tubes, a 1000x500x1 sheet and 500x500 sheet for £135

for the 16 bolts and 32 nuts, wanted to use big m12 bolts to ensure it'll support the weight, found it cheaper at screwfix, 25 m12x150mm coach bolts with nuts included plus another box of nuts for £21

needed more weld rods.
used to just get pack of 50 x 1.6mm rods from welduk, but went to local toolstation and got a 5kg pack of 2mm rods for £14 and blimey was surprised to find it's more than I expected. gonna last for awhile

slowly refined the design to be as compact as possible so it just needs 3 square tube instead of 5 and can return £34 worth of tubes back

really should find myself a metal merchant

 

[l_jonez]

Wow that expensive. B&q etc are expensive for pretty much every thing. I get my steel from a local fabricator. Last lot was 7m of 40x40x3mm for £15.

 

[h701micra]

I thought I got my metal cheap

 

[Noddie]

Standard mild tube/box should be about £1.80/Kg
What you got Paul looks like ERW though so more like £3/Kg, you don't need ERW though I wouldn't have thought

 

[h701micra]

Standard mild tube/box should be about £1.80/Kg

I was quoted £46 for 18metres of 25x25x2.5 for nissanubarus tunnel. I though that was pretty good

 

[Noddie]

I was quoted £46 for 18metres of 25x25x2.5 for nissanubarus tunnel. I though that was pretty good

I make that about 31.6Kg so £1.45/Kg

 

[h701micra]

I make that about 31.6Kg so £1.45/Kg

That's nerdy and cool all at once

 

[pollyp]

tis what I get for not finding a good local metal merchant when I need it quickly..
BQ is the only convenient local place I know that supplies various tubes n sheets.

I'd usually order online in advance for much lower prices.

 

[pollyp]

marked the cuts along the tubes

all tubes cut and filed

clamped the pieces onto a flat block to ensure all the frames are level and square

frames all tacked

finish welding the frame joints

drilled the 10mm holes

don't have a 12mm drill for the thread so tapped it to m12

fit the nuts to the coach bolts

screw the bolts onto the frame

tacked in place

welded

after welding the nuts, the thread will be slightly stiff from distortion so I remove the bolts and retap the threads to realign it

4 scale levellers made, just need to cut and weld the plates onto them to finish

and this is how they'll be stored within the platform scales box

 

[Enuo]

marked the cuts along the tubes

View attachment 27354

all tubes cut and filed

View attachment 27355

clamped the pieces onto a flat block to ensure all the frames are level and square

View attachment 27356

frames all tacked

View attachment 27357

finish welding the frame joints

View attachment 27358

drilled the 10mm holes

View attachment 27359

don't have a 12mm drill for the thread so tapped it to m12

View attachment 27360

fit the nuts to the coach bolts

View attachment 27361

screw the bolts onto the frame

View attachment 27362

tacked in place

View attachment 27363

welded

View attachment 27364

after welding the nuts, the thread will be slightly stiff from distortion so I remove the bolts and retap the threads to realign it

View attachment 27365

4 scale levellers made, just need to cut and weld the plates onto them to finish

View attachment 27366

and this is how they'll be stored within the platform scales box

View attachment 27367

Invest in a 12mm drill bit... and a 10,2mm drill bit to go with that M12 tap

 

[pollyp]

Invest in a 12mm drill bit... and a 10,2mm drill bit to go with that M12 tap

not essential nor worth it yet cos I rarely use m12 tbh.
this is a one off and just tapping the hole upto m12 does the trick

 

[Enuo]

not essential nor worth it yet cos I rarely use m12 tbh.
this is a one off and just tapping the hole upto m12 does the trick

Still bad engineering practice... although on thin metal you can get away with it...

 

[pollyp]

Still bad engineering practice... although on thin metal you can get away with it...

bad or not, it worked.
tapping the hole to a m12 actually helped keep the coach bolt snug n square straight whilst tacking the nuts in place.
if the holes were just 12mm holes, the bolts would've have a slight clearance to move about and end up becoming slightly wonky.

 

[pollyp]

cut out 4 sheet panels

in position

tacked

abit rusty at first, the sheet was mostly burning away from the pool rather than joining and found out that it was cos the sheet was pushing away from the surface hence just melts away.
needed more tacks to hold it down

welding better and better

and figured out my method and rythm

4 levellers welded

how they look at their highest position with platform scales on top

and at their lowest position, the coach bolt threads missing the sides of the scale.
to be corner scaled later in the week

for those curious bout the fuel filter, I grinded the lip off

and this is what's inside, looks the same as oil & air filters

 

[Noddie]

Please also use axle stands or wheels or something if you are going to be under the car while its on those

 

[pollyp]

Please also use axle stands or wheels or something if you are going to be under the car while its on those

when I'm adjusting the springs during balancing on these scales/levellers, the corner that I'm accessing is gonna be jacked up or on axle stands anyway for removing the wheel to access the springs and unload the spring seat to make adjustments easier

 

[pollyp]

I have a feeling I should corner balance and realign with the mismatched bad tyres I have on at the mo so that when I run with them on the first track session, the suspension is balanced rather than all over the place and a handful.

once these bad tyres are all worn down, swap over to the good set of toyos, re corner balance and align the suspension to that set of tyres all over again at the track side. just hope it's not wet or pouring down

 

[pollyp]

dear god I hope the weather forcast ain't true, it may be freezing and raining on sunday :/

wondering if I should still go with the plan of wearing out these old odd tyres out (I imagine the handling & braking will be twitchy on uneven treads) before switching to the fresher toyos.

 

[h701micra]

Uneven tyres is the least of your worries... suspected snow and ice?
Hope you've a spare soft suspension setup handy

 

[pollyp]

Maybe I could try out the bad tyres initially, see if they're stable enough. If its too unstable then I'd have to swap to the good set and reconfigure.

Currently on the original softest setting 4/3kg f/r springs.

 

[h701micra]

Maybe I could try out the bad tyres initially, see if they're stable enough. If its too unstable then I'd have to swap to the good set and reconfigure.

Currently on the original softest setting 4/3kg f/r springs.

4kg/mm... is 224lb/in and 3kg/mm is 168lb/in springs. That's what I'd consider a medium setup. You could go up to 300lb/in max on the front and 250lb/in rear for track days.

The uneven tyres should run fine on springs that soft. Just be sure to turn the shocks down a touch reduce weight transfer so they ride the road smoother. This assuming a slippy track. Of course it depends how you like them setup

 

[pollyp]

as mentioned in ur thread, I tried stiffening the front coil at castle combe with 6kg/mm or 336lb/in but resulted in more exit power-understeer.
Its now currently on 4/3kg f/r and will test the damper settings from soft to hard.

can't affor or bothered to buy another stiffer rear spring yet unless it's really needed.
if only I could fit some suspension travel sensors and write a datalog program to rec it for detailed analysis.

 

[h701micra]

as mentioned in ur thread, I tried stiffening the front coil at castle combe with 6kg/mm or 336lb/in but resulted in more exit power-understeer.
Its now currently on 4/3kg f/r and will test the damper settings from soft to hard.

can't affor or bothered to buy another stiffer rear spring yet unless it's really needed.
if only I could fit some suspension travel sensors and write a datalog program to rec it for detailed analysis.

Good old 'pots'. They give back very complex raw data. And can somewhat be a minefield of information
Like so

That's 4 linear suspension potentiometers (only 2 on screen) with an evo4 data logger. On a leisurely daily drive on an apparent smooth road. Measuring damper speed, g-force lateral and longitudinal and height

I'd say above 300lb/in you experienced understeer, earlier braking and reduced turn in?
Increase preload on your rears to determine if a stiffer spring would be necessary

 

[pollyp]

Good old 'pots'. They give back very complex raw data. And can somewhat be a minefield of information
Like so
View attachment 27433
That's 4 linear suspension potentiometers (only 2 on screen) with an evo4 data logger. On a leisurely daily drive on an apparent smooth road. Measuring damper speed, g-force lateral and longitudinal and height

I'd say above 300lb/in you experienced understeer, earlier braking and reduced turn in?
Increase preload on your rears to determine if a stiffer spring would be necessary

ah interesting. something to research into implementing. soon perhaps if I could create a 3D visualiser to see what the suspension is actually doing at a specific time and position on the track.
tis abit like a detailed virtual action replay u see on Rfactor or gran turismo or racing games.

turn in is fine and I usually trail brake to further help it but its mid-exit where it was understeering.
increasing rear preload would just poke the rear higher up won't it?

 

[h701micra]

ah interesting. something to research into implementing. soon perhaps if I could create a 3D visualiser to see what the suspension is actually doing at a specific time and position on the track.
tis abit like a detailed virtual action replay u see on Rfactor or gran turismo or racing games.

turn in is fine and I usually trail brake to further help it but its mid-exit where it was understeering.
increasing rear preload would just poke the rear higher up won't it?

The pots give you that information in those series of graphs.
You need that, combined with a shock dyno graph, spring rate graph, roll bar torsion, tyre temp, tyre pressure and dynamic wheel alignment its alot of sensors some of which dont currently exist in our market for dynamic camber or toe angles. So maths and sciences applies using the above. But definitely something of use if you can design it

It would raise the height to a point as the shock would max out... you can lower the ride height however on your coilovers. Its a relatively simple process and difficult to explain.
The end goal being that you simulate the body movement that a stiffer spring would give

 

[pollyp]

lets rebalance the car with the bad tyres.
disconnected the swaybars

levelled the scales, much easier n faster with the new leveller frame.
1/2 fuel tank, washer bottle full, dumbell ballast on and tyre treads are
FR 6.75
RR 4.0
RL 2.5
FL 4.5mm

the loading and ride heights are

FR 283.9kg 102mm
RR 171.9kg 100mm
RL 179.3kg 100mm
FL 297.4kg 99mm

the FL/RR crossweight is highest.
either reduce the FL preload but ride height was already low,
remove the FL ballast but cba,
increase FR ballast but no room and cba

lets try swapping the thinner rear tyre to the RH

FR 285kg 100mm
RR 173.2kg 100mm
RL 177.2kg 98mm
FL 298kg 100mm

meh that'll do cos cba to move ballast or adjust the coils

wheels still straight

well I've decided that if it's raining at the track, I won't bother with attempting to balance/align the setup cos it will NOT be enjoyable to tinker in the soaking wet with no cover.
also it's taken me 2.5hrs to just balance and align the car, erm thats half the track morning and afternoon wasted setting up the rig, tweaking and reassembling the car rather than driving :/

the rear parcel shelf appears to have sagged over the yrs from the heavy speakers and began to rub/rattle against the boot annoyingly. thought of sticking rubber pads but won't work

here's the banana'd shelf against a straight bar

so I drilled a pair of holes

and screwed a square tube underneath to straighten n support it

clear

but in tradition of things going wrong before any important events, I noticed an unusual green pool of coolant on the floor?
the fins and hoses don't have any damage or leaks but the bottom end of the rad is wet with green coolant, huh where's it coming from?

coolant tank was running empty, took the rad cap off and its empty.
grabbed a bottle and it took almost 1L to fill it up! eh so tonight I might've been driven home with almost no coolant!? surprised it hasn't overheated.
after filling up, checked around and OMG I see it slowly trickling out from the lower section of the rad!

Ohh FFS what the H
there's no visible damage, could be cracked?

cos the trackday is on sunday, I'm gonna have to urgently order another k11 auto radiator aren't I?

 

[pollyp]

OK no time to wait, googled for a 1.3 automatic radiator.

there's this 33mm cored radiator from Kimber car parts for £37.96 but I think the thicker core will be too close for the turbo inlet
http://www.kimbercarparts.co.uk/Sin...HTEX-CO^RADD&gclid=COv91ryB_7sCFXMRtAodg1QA9Q

a new 1.3 auto rad in ebay for £32, doesn't state the thickness but looking at the lower section it might be a 28mm? if not then I'll have to do some tweaking
http://www.ebay.co.uk/itm/NISSAN-MI...arts_Vehicles_CarParts_SM&hash=item3a88f503c5

oh bugga the free postage estimates next week, too late.
the express £18 courier estimates friday, that's cutting it too close :/

need to ring local parts places immediately tmorrow if they have any thick auto rads

 

[pollyp]

K I highly doubt any local parts store will have a new 1.3 auto rad and the used ones in scrappys prob either abit beaten or a 16mm manual plus I won't have any time off work to visit scrappys.
ordered the one on ebay with £18 express delivery total £50 for estimated friday, fingers X it arrives in time

 

[h701micra]

Bit of bad luck your getting Paul. Hope all goes well

Looking at your balancing there. I'd say if you lowered the RR 2mm to match it would've been spot on

 

[pollyp]

went to dealers for 3 bottles of coolant and the fella I know said I can have em free so kind of em

also suggested try that metal epoxy putty stuff and gave a small piece. if it's just a small crack/hole and this stuff seals it, at least its a backup plan incase the new rad doesn't turn up in time.

indeed lowering the RR/FL or increasing the RL woulda balanced the CW but the rear springs a pita to adjust and was at the cba state.
the springs r more less setup for the good set of tyres so once I pop those on it'll be balanced.

 

[SuperUno]

Did you make the wheel adaptors for measuring toe in/out?

 

[h701micra]

indeed lowering the RR/FL or increasing the RL woulda balanced the CW but the rear springs a pita to adjust and was at the cba state.
the springs r more less setup for the good set of tyres so once I pop those on it'll be balanced.

Looking at it again a compromise of both would be best
But as you say its setup for your fresh tyres
Depends if you're in a cba mood again

 

[pollyp]

Did you make the wheel adaptors for measuring toe in/out?

yep the laser aligner is for checking all the wheels r pointing dead straight

making the unidirectional swivel plate
http://micra.org.uk/threads/pollymobiles-rebuild.35251/page-73#post-564155

making the laser alignment blocks
http://micra.org.uk/threads/pollymobiles-rebuild.35251/page-73#post-564288

how the laser is calibrated
http://micra.org.uk/threads/pollymobiles-rebuild.35251/page-72#post-563183

illustration of alignment method
http://micra.org.uk/threads/pollymobiles-rebuild.35251/page-73#post-564358

and actually aligning the wheels
http://micra.org.uk/threads/pollymobiles-rebuild.35251/page-73#post-564575

 

[pollyp]

Looking at it again a compromise of both would be best
But as you say its setup for your fresh tyres
Depends if you're in a cba mood again

yeah its really just set up for the fresh tyres.
the mixed tyres are just for shake down of the engine and has to be worn down so don't care if it ain't balanced anyway. if it's too twitchy at high speed I just slow down a tad
and yeah when its cold n raining I cba to work with numb wet fingers, arms, clothes

 

[pollyp]

removed the rad

then the fan and Oh My, well there's ur problem eh oops

shifting and resting the fan shroud closer to the rad core to clear the turbo has allowed the vibrating shroud to nibble at the soft Alu over 2yrs until one of the deformed tube walls couldn't withstand the pressurised coolant and developed a pinhole the other night.

removed afew fins for better access

initially tried to solder it as a fast fix but nope doesn't adhere

so lets use this 2 part putty stuff

filled the gap and slightly hardened after few mins

to fix the main cause, we're gonna cut afew mm off the shroud lip

and now it fully clears the rad core which should eliminate the problem

started her up, no coolant bubbles, no immediate leak, drove around few miles and yay it's bone dry and fixed!
still gonna replace with the new rad when it arrives cos u really dont wanna run a weakened rad core on track

also noted that all the rattling, knocking noise I used to always hear has now vanished after reinforcing the parcel shelf so the cabin is now rattle free

 

[SuperUno]

yep the laser aligner is for checking all the wheels r pointing dead straight

making the unidirectional swivel plate
http://micra.org.uk/threads/pollymobiles-rebuild.35251/page-73#post-564155

making the laser alignment blocks
http://micra.org.uk/threads/pollymobiles-rebuild.35251/page-73#post-564288

how the laser is calibrated
http://micra.org.uk/threads/pollymobiles-rebuild.35251/page-72#post-563183

illustration of alignment method
http://micra.org.uk/threads/pollymobiles-rebuild.35251/page-73#post-564358

and actually aligning the wheels
http://micra.org.uk/threads/pollymobiles-rebuild.35251/page-73#post-564575

Thanks

 

[pollyp]

radiator arrived and wtf looks different to the ebay picture

first of all it's all a made in china cheapo painted black metal

although all the major fitting points are there it feels kinda poor quality imo
the bottom section doesn't appears to be exactly square to the core

the main importance is the core thickness has to be 26mm and this one measures only 18mm FFS

well that was a pointless purchase, certainly won't be using this cos it won't perform with the hotter turbo and is poorly made so gonna send it back
the mended rad is now holding up fine.

the catchcan mount was getting loose n rusty so removed it

and reinstalled it better with an alloy mount

test drive and the radiator is holding up fine and the cabin is now so quiet rattle-free

 

[SuperUno]

What is / does the catchcan do ?

 

[Enuo]

Connects to the engine breathers, so you collect the oil rather than burning it.