Another 888 tyre pressure thread

[Space Cadet]

I've searched through all the past threads and truthfully there is so much conflicting advice and the Toyo guide itself is a bit vague - I know it lists a range of pressures per weight of car, but is this for front or rears, or both???

I've a set of new 888's 195/50/15's on my stripped out PH1 172.

The tyres have been filled with Nitrogen, so for the time being there won't be too much hot-cold difference.

I would really appreciate some advice as what to set them at for road use and what to change to (if necessary) for when on the track.

Thanks.

 

[The Boosh!]

http://www.cliosport.net/forum/showthread.php?537705-R888-Set-up-Info ?

 

[jenic]

I asked a guy on here what to set mine to who had some, he said 27psi all the time, i rolled with that and am happy on road and track. I did experiment a bit at Oulton (ranged from 25-29psi cold) and found 27psi cold all round was what I liked.

 

[Fred@BTM]

sod the the nitrogen, i doubt they've been purge filled so you've wasted your time anyway

road 28psi all round

track 26rear 23 front (targeting 30psi hot all round)

but to be honest there is no set answer, its whatever suits you

 

[Keith185]

^Agree with Fred, he knows what he's on about

I run cold pressure of Front 27, Rear 25 again aiming for approx 30psi hot all round.

Start with approx these pressure and tweek from there as you feel.

 

[chrispy.clio]

I dont know if you want to do this, but when on track just put somthin like 26-27 all round. Do a few laps (car might not handle that great) come in and get straigh out and get a tyre pressure reader with a deflater button. The tyres will be read pretty high readings (more so at the front) anyway let all the tyres down to 30psi. and you should have a good balance.

Then go out again and get a little quicker then come in after a few more laps and check them again and lower to 30psi if needed.

 

[chrispy.clio]

^Agree with Fred, he knows what he's on about

I run cold pressure of Front 27, Rear 25 again aiming for approx 30psi hot all round.

Start with approx these pressure and tweek from there as you feel.

27 in the front and 25 in the rear?

Do you mean the other way round?

 

[BoroGTI]

27 in the front and 25 in the rear?

Do you mean the other way round?

No he's got it the right way round, always gonna have slightly more in the front

 

[chrispy.clio]

No he's got it the right way round, always gonna have slightly more in the front

No you dont.

I think your wrong actually.

 

[Tony Hunter]

Fronts will always get hotter so you need to start with less in them.

 

[Fred@BTM]

Fronts will always get hotter so you need to start with less in them.

CORRECT

i run 23 front 26 rear (COLD) this usually bring me upto around 30psi HOT

 

[nevsrevs]

I run as above around 23 in the front checked after every session on track and gets me to 30 every time!

 

[Space Cadet]

Thanks guys – much appreciated, so I’ll aim for 30 both front and rear when hot then.

(The wheels and tyres were brand new and were inflated with nitrogen free of charge, wouldn’t have gone for it normally but for the time being hopefully they’ll have a little less cold-hot difference than normal air.)

I had to start of with a pressure, cold and on the road, James at JMS suggested 29 front and rear to allow for 1 or 2 PSI increase, I can always let a couple out when on track - which will hopefully be end of November now when the car is eventually finished.

 

[Fred@BTM]

you'll get way more than 1 or 2 psi rise when hot!

the nitrogen won't make f-all difference as its not 100% its the same as putting normal air in

 

[Space Cadet]

Thanks Fred

I’m already familiar with pressure rises on track tyres filled with normal air so will obviously keep an eye on them. If the Nitrogen helps then it helps, if it doesn’t it doesn’t.

 

[Fred@BTM]

it won't becuase they haven't been purged (ie you vaccum the air fully out on the tyre first then add nitrogen) so the tyre is already full of norml air anyway before adding nitrogen

its a gimic anyway, most people used dried air these days

 

[Space Cadet]

I bought the wheels & tyres from the motorsport section at Demon Tweaks as they actually did the best deal and already had the tyres in stock. They mentioned that the tyres would be filled with nitrogen I and don’t know for certain that they didn’t vacuum out the air before hand. To be truthful I’m not expecting anything and therefore won’t be disappointed. I’m used to checking the pressures every time I come in so will see then.

I would’ve thought that even if the air hadn’t been purged, by the time you’ve stuck circa 30psi in a tyre you’ve put many times the initial volume of the tyre in with Nitrogen, so even if the percentage is 80% nitrogen I must see some benefit and say a 3psi increase rather than 6 psi on normal air.

This has gone off topic a bit.

 

[Fred@BTM]

haha indeed it has!

 

[Space Cadet]

While we’re off topic - I’ve since fitted my 2118’s with their ET 43 offset, and as thought the standard OZ’s must definitely also be 43’s. As per the other thread I’m now certain I must have a narrower front track than a PH2 172, but from the other post you were saying that it’s just the rear track that is different?

We can take this over to the other thread if you like.

 

[Fred@BTM]

sotck phs1 172 is ET43, phs 2 is ET48, so technically the phs 1 is 10mm wider than the phs2, but i don't remember the geo off hand

 

[Space Cadet]

With standard wheels I can understand that, but as we both now have the same wheels and with the same spacers and the same suspension & settings the only thing that could be giving the PH2 an increased overall track width must somehow be mechanically through different suspension or hub parts etc??

 

[EllD90]

The PH1 will have the wider track. The lower the ET number, the wider the offset.

 

[Space Cadet]

Thanks, I understand about different ET’s, but as mentioned above I’m suggesting that the PH1 must somehow mechanically have a narrower track without the wheels.

 

[Fred@BTM]

yes it probably is if you go off the basis of thats exactly what renault did 172-182, 172-172 cup etc

 

[Space Cadet]

The rear looks fine with the 5mm spacers, perhaps ill look into some 15mm or 20mm hub centric spacers for the front.

I’ll be able to increase the camber on the front as well if I do.

Now this thread has definitely gone off topic!!

 

[EllD90]

Apologies! What happened to the 200?

 

[Tony Hunter]

We have now got 30mm each side on the front,but then again we are running 4 1/2 deg neg camber.We also start on 19-20 psi in the front and end up with about 28-30 weather depending.

 

[Space Cadet]

The 200 was only ever a 2nd car and only ever got used once a month or when I took it on track. So I thought I would have some fun and ‘build’ a track specific car, save a few pennies and ultimately hopefully have a better car for the track.

So I sold the 200 and bought a 20,000 mile PH1 172, it’s mechanically perfect. Everything is now done apart from the seats, harnesses and steering wheel which have been order but just waiting to arrive.


Tony - Thanks re the spacers, I’m running -2 at the moment as with the 43s and 5mm spacers we only had about 10mm safety margin on the tyres rubbing the suspension.

I think -3 on the front would be good, so perhaps with some 20mm hub-centrics then I should be able to increase the camber.

For some reason one side at the rear is running -1.5, whereas the other is -1, perhaps its had a knock at some point. I was thinking increasing them to -2 each side like the Cup Racers what do you run?

 

[Fred@BTM]

difference in the rear will be down to the wheel bearing

 

[Space Cadet]

difference in the rear will be down to the wheel bearing

??

 

[Fred@BTM]

one is probably a bit worn, hence the difference

 

[Space Cadet]

Ah I see. Although as part of the track preparation it has new Renault OEM discs (and pads) on the rear which included NEW bearings, so theoretically the bearings should be perfect.

 

[Fred@BTM]

theorctically yes, but they never are! wouldn't worry about 0.5degrees its nothing

 

[Tony Hunter]

As Fred say's 0.5 deg is nothing,you could take them apart and put them back together again and it would read different.We run -3deg on rear.

 

[.Kev.]

We use Nitrogen on fighter jets, not fighter Clio's.

 

[Space Cadet]

Thanks, Ok, nothing to worry about then. Blimey -3 on the rear, I was thinking that -2 on the rear and -3 on the front was hardcore!

For the time being the car is still road registered and will have to travel the odd 100 miles to the track so want to still be drivable on the road.