simon's learning what to do with the polo thread

[simon k]

just capturing Sam's tyre speel for when it gets buried in his thread...

Yeah if its just circuit then you cant beat A050 or from Gary has said the Dunlop Direzza DZ03G are a goodn too. Theres the Hankook Z221 (I think) but not sure if they have 15's. I reckon 205/50/15 mediums would be the go but running 195/55/15 on the back and the 205/50's on the front would work great too if that's all you can scrounge up will work great too.
If you were to use a street semi rather than a full r spec then the best would be the yoko AD08R($) or Federal RSRR/Nitto NT01 (which is affordable). You can find Toyo R888R's for pretty cheap on ebay sometimes but they seem to be mostly in 195/50/15, haven't seen too many 205's for a good price.
Best bet would be to keep hunting for r specs on gumtree being careful of the sidewall build dates to make sure you get something reasonably fresh, but the top street semis will go pretty hard too.

[simon k]

with Sam's encouragement I have some nicer tyres... 2x R888R in good condition and 2x A050 with a little life left. Hopefully they last me a few sprint days

[sambb]

You wont believe how noisy they are when you first put them on. Feathered edges on the tread cuts, pickup and such a stiff carcass... they sound like all your wheel bearings have gone at once. Then when you get going on them you wont believe how hard you can lean on them and how quiet the car is ie no tyre squeal, just grip!

[simon k]

I put them on today, and yes, very noisy! also grippy, very grippy, should be fun on the track

My road tyres are 205/55/16 RE003, and I'd done the maths on how much bigger would be than standard 205/45/16 when I put them on, and yep, they're big, straight away there was noticeable loss of acceleration due to the taller gearing... but the speedo is dead accurate, 110 on the speedo is exactly 110 on the satnav

Before I went down the 15" wheel I did the maths on how much smaller they'd be with 205/55/15 and was OK with that, but then found that only 205/50/15s were available, so did the maths on that... Not until I put the wheels side by side did I really see how much difference there is! They're tiny!



I bought some cheapo rattle cans of white paint and gave them a few coats. I like white wheels...



There's a LOT of clearance between the tyres and the guards. I can easily drop the backend a 20mm or more down the track, when the RE003s are worn out I'll go to something smaller and longer wearing

[sambb]

They should rip through the gears compared to what you've been running on the street then! I'll be very curious to see which you prefer at the front (A050 old vs R888R newish) but either way they'll be great on the track especially once you get some proper temp into them. Yep they are grippier at street speeds but when they are properly hot on the track you'll be giggling to yourself.

[simon k]

sounds good!

Here's a picture of my coilover converted bilstein, I had the wheel off so I took a picture...



I had a look at how we can mount the sway bar link off the bottom suspension arm. A bit of angle on top of the arm poking out towards the front of the car would do the job. It'd need a fairly substantial sandwich plate underneath and probably some spacers to stop it from crushing the arm

Here's a completely useless picture

[sambb]

I forgot how beefy the shaft is on those B8's. Yeah the pic and what you said makes sense. I wonder if you could just seam weld a reinforcement strip along the front edge of the control arm, flush with the top edge of the arm and the pinched edge, and literally just tap directly into it for a short 90 degree offset drop link.
Was under there last night putting a spanner on everything and giving it the once over now that a few events are starting back up and found a shagged tie rod inner that i'll have to get onto. Looks doable to me.

[Sydneykid]

I forgot how beefy the shaft is on those B8's.

Inverted shock, so it's not actually a "shaft" but the shock body itself. The "shaft" is inside the strut tube. Makes for much reduced bending of the strut unit as a whole, so it retain the alignment settings. Plus avoids most of the stiction that MacStruts suffer badly from. I would never use anything else but an inverted shock on a strut car.

Cheers
Gary

[sambb]

yeah i'll be going 2 way bilsteins next time 'round for that reason.

[simon k]

I forgot how beefy the shaft is on those B8's. Yeah the pic and what you said makes sense. I wonder if you could just seam weld a reinforcement strip along the front edge of the control arm, flush with the top edge of the arm and the pinched edge, and literally just tap directly into it for a short 90 degree offset drop link.
Was under there last night putting a spanner on everything and giving it the once over now that a few events are starting back up and found a shagged tie rod inner that i'll have to get onto. Looks doable to me.

like this?



or you may mean to rotate it 90° to have the rod drop into a hole with a nut underneath

[sambb]

No I was thinking take your channel and run it along the front edge of the control arm ie encase the length of the leading edge. Then where the drop link will bolt onto the control arm you could have another layer of channel to reinforce that location moreand allow you to tap directly into the leading edge for the drop link. It didn't look to me that you need the extension/protrusion out from the control arm. Dropping vertically down from the FARB looked like it would fall against the control arms front to me, but I'm probably off on that.

[Sydneykid]

If you can use something like, say, a Subaru a step around (C shaped) rear swaybar link that should enable you to have the bracket on the lower control arm.


The standard Subaru ones are plastic, so not so good for big swaybars



Spherical bearing style




Bush Style

Cheers
Gary

[simon k]

it's not so much that the link needs to get around anything, it's that the end of the swaybar is a fair way forward of the LCA. The leading edge of the LCA only *just* ahead of the driveshaft

the photo I took really is useless.... need to get under there with some a weetbix box and do a proper CAD model (Cardboard Aided Design)

[Sydneykid]

Although it's desirable, it's not necessary to have the swaybar link dead vertical. After all the OE one isn't. If you can run a straight link at say 30 degrees to vertical that would be fine. I was just looking at the C shaped link as possibly being necessary to clear the drive shaft when the wheel is turned.

Cheers
Gary

[simon k]

I was gifted a set of soft Nitto NT01s last night, he even gave them a fresh coat of tyre softener... I now have more tyres than I need, they take up a lot of space compared to mini tyres

What sort of hot pressure should I be aiming for with tyres like A050, R888R and NT01? I was using 30psi with the RE003, but no science behind why I picked that