13 replies to this topic

[neglectedtorana]

Hi All,

 

Although there won't be any racing activities for a while with lock down getting more serious I am considering tyre options for my next outing whenever it may be.

 

When I took my car to the track for drag racing I had to be fairly gentle leaving the start line with street tyres to avoid wheel spin. I know drag radials would be better but would semi slicks be an improvement?

 

I have 16" wheels on the car and a few spare wheels to match so would like to match whichever tyre to wheels that match the car. Hoosier make drag radials in my size but at $420 a tyre it seems like a lot of money for an occasional outing.

At a previous event I tried the motor khana course and think it was more fun than drag racing and my street tyres held up pretty well.

 

Will I get good grip using a semi slick for drag racing?

I have found some Falken RT615K semi slicks at a clearance price and am wondering if they would be ok for drag racing, I think they would probably be good for the motor khana and have good online reviews from all sorts of car types mostly in the USA.

 

Any thoughts or knowledge on using semi slicks would be appreciated?

 

Cheers, Tom

[gtrboyy]

Depends on manual or auto...the diff...whether want to drive to track & back home or trailer.

 

For a manual especially if it's high powered a slick is more forgiving & less likely to shock or break parts where an auto will work fine with drag radials if setup correctly.Downside is need crossply up front for slick yet not needed for drag radials.

 

If it's multi-purpose like driving events semi slicks are ok I guess...depends on what car is set up for etc.

[hanra]

What is the science behind requiring a cross ply on the front with a drag slick. I’ve always wondered about that.

[Dr Terry]

AFAIK many drag slicks have a cross ply construction. If you're run cross ply rears, you must run cross ply fronts.

ANDRA introduced this rule during the 80s after several crashes apparently caused by the wrong mix of tyres.

I believe some states have rule for street cars.

Dr Terry

[Oversteer]

Semi slicks don't work at the drags anywhere near a drag radial, may be an improvement over a poor road tire(not a good one), different of heat profile, track to drag.

 

Drag radials are grip city, only issue is not enough power to leave the line/spin them a bit to get out of the hole on power/not bog.

 

Drag slicks(not semi slicks...not the same type of tyre at all) have No sidewall, so lateral control is abismal, its the way they ripple and give the controls the power being applied, so to control that you need a front tire with the same grip/give to balance.

Edited by Oversteer, 18 July 2021 - 09:38 PM.

[ozyozyozy]

Semi slicks for drag racing are no good, they will provide only marginally more grip than stockies, the sidewalls are too stiff, require a decent burnout to generate heat. Can also have issues with axle tramp using them.
Best semi slicks to use are yokohama 050, then prob hankooks, kumho’s.

[gtrboyy]

Apparently the cars wander & sway like crazy if drag slicks on back & radials on front....obviously the faster the car the more dangerous it becomes to correct or over-correct steering.

 

Don't think you can mix it nowadays although might have been ok for cars 12secs or slower back in the day.

 

Most go drag radials drive to track & drive home rather than 2 sets of wheel if using drag slicks & suitable front runners

Edited by gtrboyy, 18 July 2021 - 10:03 PM.

[rexy]

When I was young and impoverished I used to run G60 McCreary (now American Racer) dirt track tyres on the rear with radials up front. Phenomenal grip on the street but very difficult to drive in an on and off throttle situation like most street driving is. Perfectly stable in a straight line under full throttle but once you backed off the rear end would move around quire a bit. Very easy to get turned around as the rear of the car started to steer the front.

 

Had a near miss which was the end of that combo for me. Started using the MT ET Street tyres as soon as they appeared. They are the best of the drag radials. Pump them up properly and they corner pretty good too.

 

Rags in front of radials ok, rags behind radials very dangerous.

[neglectedtorana]

Interesting reading, I didn't expect semi slicks to be the answer to a tyre that can do it all.

Will have to consider how many trips to the 1/4 justify drag radials or if I am to try and find more motor khana events and just accept less traction for the 1/4

 

Just on the topic of drag racing I thought this was amasing with under 2L of engine

 

https://www.facebook...495055650835391

[Dr Terry]

Rags in front of radials ok, rags behind radials very dangerous.

 

It seems funny to hear the use of the word "rags" when referring only to cross ply tyres.

 

These days most (if not all) radial tyres have steel belts, but during the 60s & 70s they were all textile radials.

 

Textile = rag, so to me a "rag" tyre could also refer to an older style radial tyre.

 

That's why I call them cross ply or radial ply tyres.

 

Dr Terry

[lawn bowls]

or maybe try to buy a secondhand set of tyes of your choice for the back of your car that have about half wear still left in them,if money is a problem just my opinion.

[rexy]

Rags always meant cross plies in the context of what we were using them for. Textile radials were never part of the equation. 

[Redslur]

Drag radials are the go on anything up to around 450hp from my experience. I have driven 11 second cars from Canberra to Sydney on drag radials, run several 11 second passes then drive home. That car had 450hp. I then took another 550hp torry up I owned and ran it using the same drag radials and it spun them up too much and only managed an 11.4. I then came back with a full slick and ran 10.9. So horses for course I guess.

[Westside Performance]

Never used a semi slick tyre, but I used drag radials for 1/4 mile runs and they stick like glue to a hot track but its a tyre for straight line use only. Wheelspin kills your ET and makes you look like an amateur so I would bite the bullet and have an appropriate tyre for your next quarter mile test run.