do i need front runners if using slicks?

[badnews]

With the private day coming up at WSID i have a couple of questions regarding tyres.

-my mate has a set of slicks and front runners on 15" chasers, on my VY series 1 clubsport, will these clear the brakes on the front and back???

-if the brakes are too big on the front, what are people using? i think i remember hearing of people using the 17" space savers to clear them... am i tripping out or do some people do that?? and if they do, do they use the tyres that come on the space savers from the factory???

-is it safe to run with my 20" rims on the front and hoosier 26x10s on the back? my mate said it scared the sh*t out of him runnin with 19's on the front and he wouldnt do it again.

any feedback to any of these questions would be much appreciated.

cheers

[Mungrel]

With the private day coming up at WSID i have a couple of questions regarding tyres.

-my mate has a set of slicks and front runners on 15" chasers, on my VY series 1 clubsport, will these clear the brakes on the front and back???


Unsure, i don't think so.



-if the brakes are too big on the front, what are people using? i think i remember hearing of people using the 17" space savers to clear them... am i tripping out or do some people do that?? and if they do, do they use the tyres that come on the space savers from the factory???


They sure do, although they use proper front runners made by Mickey Thompson / Hoosier etc. I believe they are a cross ply compound like the slicks.



-is it safe to run with my 20" rims on the front and hoosier 26x10s on the back? my mate said it scared the sh*t out of him runnin with 19's on the front and he wouldnt do it again.


The car gets a bit taily at over 110kmh, its very unsettling, specially with a concrete wall either side. Its not a good idea, i wouldn't recommend it. I ran mine down the road with my 19s wen i first got em. never again. i backed off in third cause i was all over the road :eek:! Putting the front runners on, makes a huge difference.

[ratter]

Drag slicks are cross plys, so you will need to run cross plys on the front another option is to run MT street radials, very sticky tyre when warm but are radial construction and they will come in 15, 16 and 17" rim sizes to clear big brakes on the rear

[DaveHAT]

In summary:

15s wont clear your clubsport brakes.
Slicks rear and street radial front = scarey and something to be avoided.

Options for drag friendly tyres on cars with larger brakes ...

Swap to standard Commodore brakes for drags then swap back afterwards.
17" E/T streets, RE55 or similar semi-comp tyres for the rear.


As said by Ratter, run slicks ron the rear ... you'd be adised to run crossply front runners otherwise it will walk all over the track.

19", 20" whatever rims/tyres are fine as long as you run a tyre like the Mickey Thompson ET streets or semi-comps on the rear.

Simple equation goes ...
radial tyre front ---> radial compound tyre rear (ET street and similar)
Slick crossply rear --> crossply front runner front.

A crossply tyre rear and radial tyre front will be a scarey ride much as your friend described to you.

[jsttry]

Last time I checked ANDRA rules state you are not allowed to mix tyres if going under 12.5sec

[Mungrel]

Last time I checked ANDRA rules state you are not allowed to mix tyres if going under 12.5sec

i ran low - mid 13s when i did it, that was scary enough, i'd hate to think what itd be like mid at mid 12s! :eek:

It was my understanding that you wouldn't get past scrutineering with mixed tires regardless of what time you run?

[badnews]

thanks for the info guys. so is there crossply front runners available that would fit on 17" space savers???

[Animal]

I am one of the guys who changes rear springs and rear brakes / rotors on the day to use the 15" rims on the rear,and I also use front runners.

A few of use have seen the reuslts of others using slicks without front runners. It is not worth the risk - ever !

[uncle]

I would just go the Et streets as I would guess your not realy putting out enough power to need slicks.
My thing runs 11.20 still on ETstreets with 300rwkw as well as many other cars so you know they work just fine.
As others have said slicks and normal wheels on the front=BAD.
Not realy worth your time doing it because they can knock you back in the pits if you try and run a "mixed set"

[gcr1234]

I've just got a set of MT streets on 15 X 7 chasers, do they need to be balanced?

[SS_Brute]

I just ran a set of 17" MT Street Radials on the weekend and with a 3.91 diff ration i found that my overall tyre diameter was too small. Peaked out 4th a good 30 metres before the line. But otherwise a great way to be lazy and clear big brakes!

[vyssbeast]

I would guess your not realy putting out enough power to need slicks.


GenTTR should be puttin out enough power :smilesandbanana:

[ratter]

I've just got a set of MT streets on 15 X 7 chasers, do they need to be balanced?

Yes they do


I just ran a set of 17" MT Street Radials on the weekend and with a 3.91 diff ration i found that my overall tyre diameter was too small. Peaked out 4th a good 30 metres before the line. But otherwise a great way to be lazy and clear big brakes!

Lift the rev limiter slightly

[Animal]

I just ran a set of 17" MT Street Radials on the weekend and with a 3.91 diff ration i found that my overall tyre diameter was too small. Peaked out 4th a good 30 metres before the line. But otherwise a great way to be lazy and clear big brakes!

Just about to do the same, the 17" rims with the street radials will clear most performance brakes. I have been told that the 17" MT's are on the money.

You will need to measure the rolling radius of the wheel with a noted tyre pressure before making any adjustments.


I've just got a set of MT streets on 15 X 7 chasers, do they need to be balanced?

You didn't by any chance get the set we had did you ? :)

[gcr1234]

no I got them from star performance at Five dock (and the rims from a tyre place $40 each).

havent had them on the car yet

[HSVREDSLED]

Can someone explain the technical reason why you need front runners with slicks? I understand what the result is, (taily over 110km/h etc) but what is the technical reason for this?

Why does it happen?

[Oztrack Tuning]

The different tyres types cause a very bad wobble.

Just get some ET fronts and draglites. They are worth the extra cash and they stay nice and straight even with radials on the rear., They suit slicks oir radials no problem. Plus the rules permit them. Its just the other way around slicks rear and radials front that is banned.

[jsttry]

I believe its something to do with the radial tyre being more responsive to steering input and the cross ply less so. The mix means that you're more likely to over correct and loose control.

[badnews]

ok, i was having a look around and i can only seem to find 17" front runners that are 22.0/2.5-17 the tyre on my space saver atm is 235/45/R17. does anyone know if these front runners will fit on this size rim???