Bias Ply or regular street radial?

[G-man]

Hey,

I was wondering which tire would produce better grip for acceleration/street.

I seen 15" wide bias ply tires with that hot rod looking tread pattern zigzag or something, and thrn you got hoosier and MT producing a street radial as well in the same size.

Hence I am wondering

[XH29N0G]

The biggest difference for straight line grip is probably related to the rubber compound that is used.  I do not know what the different compounds are on different street tires.  FWIW I have been told at the strip that drag radials can hit harder and break things on stick cars than wrinkle wall slicks so there may also be other differences. For street tires,

[HPP]

The rubber compounds are only part of the formula. The carcass the tread wraps around is a bigger factor in the formula.

Bias plys are more forgiving and are a good tire to learn traction control techniques with because their grip is very linear and they are audibly going to tell you were they are in the grip cycle. They loose traction gradually and will regain it gradually so they will allow a driver to  easily control traction. However, their construction also produces a very narrow window of alignment range that they will tolerate before they start showing unusual wear. This means they cannot use very aggressive alignment angles to produce good handling. In wider widths they also tramline, or hunt grooves in the pavement, to an extreme degree that will require  constant adjustment and driver vigilence and in some instances cannot be  adequately controlled with  even slightly worn suspension components.

Radials are the opposite in all regards. They can produce higher total grip but will loose traction more suddenly. They roll easier but will need their speed reduced signifiganctly to regain traction once its lost. They tolerate much wider alignment angles and can use much more aggressive angles for alignment which will produce better road manners.

[INTMD8]

I've used them all on the street. My preference by far is MT drag radial.  Years ago ran 9.7 @149mph on 17's, manual trans. They work awesome.

[71_Charger_R/T]

I'll say this. My repro Good Year Polyglas GT bias ply's sure hook better on dry asphalt than any of the radials I've run on the car! (Including 50 series BFG TA's)
And the look can't be beat on these old cars! But yes, they certainly follow the cracks in the road a lot more than a radial!

[c00nhunterjoe]

The biggest difference for straight line grip is probably related to the rubber compound that is used.  I do not know what the different compounds are on different street tires.  FWIW I have been told at the strip that drag radials can hit harder and break things on stick cars than wrinkle wall slicks so there may also be other differences. For street tires,

Thats backwards. Stick cars dont like radials. The bias slicks are better on stick cars. Radials on the same car are worth about a 1 mph increase in track speed.

On a street driven car, radials are the way to go simply by a stability standpoint.

[G-man]

Hey and thanks.

When you mention stability... you saying the bias ply generally if you let the steering wheel go the car will drift with contours of the road more than the radial... ?

So essentialy:

Radial - more grip than bias. Can put more power to the ground than you can a bias.
Radial - Goes straight (generally speaking - minor corrections required in steering wheel) even if road is all over the place

Bias Ply - Wont lose traction instantly like radial, more forgiving here but at the cost of not being able to put as much power down.
Bias Ply - generally makes the driver have to constantly correct direction of car via steering wheel because it goes with the road much more so than a radial.



If that is correct, then essentially unless I want the look of a bias... there is no point to getting them.

While on the subject, who produces a slick tire for the street?

I been reading that hoosiers ultimately give the best traction over MT but hoosier only make a race tire not usable on street while MT have soft tire compounds usable on the street.

Wasn't sure if thats pretty much all there is then... a MT.

What brought that to mind is that I remembered a guy with a 70 challenger, he had about 800 HP in his car, pure street car, doesn't go drag racing... but... he always said for the street fun/grip when he runs into people that wanna give it a go off the light.. hes always prepared with his MT 275x10.5-15 while a regular street radial, even 15" wide will
never grip with 800HP.

So for a powerful car like that, wanting to hook on street... you need a street tire made out of slick compound.

Elaboration on this and is MT all there is?

[c00nhunterjoe]

The grip is based on the compound in the rubber. A 275/60 bfg radial ta does not compare to a mickey thompson 275/60 drag radial.

Bias street tires such as the goodyear polyglas repros are junk in my opinion for a driven car. They ride awful and you are constantly fighting them, or any bias repro factory tire. If you want a modern tire for a street driven vehicle then something like the bfg radial ta, cooper cobra, and hoosier makes a street tire as well.

None of the dot approved drag radials are actually approved for street use. Read any of their sites. They have the bare minimum work done to get a dot number for the race categories that demand a dot tire. Now, that said, many many people run them on the street, including myself, without issue. They are worthless in rain, just pull over and wait. They are meant for max traction in a "legal" tire. They work great and wear out fast but thats the tradeoff for traction.

So in conclusion, if this a street cruiser with a motor, stick with the bfg or coopers. If you want straight line performance and will never see a wet road, get the drag radials. If its a track car, put slicks on it. As far as brands like hoosier and mickey thompson- it comes down to what you want. They are all about the same for traction given you buy the same rubber compound.

[Mefirst]

If it was me Id buy a set of M/T Radials (ET Street S/S Tires #3453) if you want better traction, but still mostly use your car on the street. These tires are a bit of a compromise, but they do work really well though the track prep has to be more or less perfect for them to hook/stick.

Dragracing..

A radial (slick) tire is often faster BUT the track prep needs to be really good for radials to work. Also the adjustment of the chassis is different running on radials. The tires needs to be planted hard against the track surface. You need to run an upgraded suspension setup, so no SS springs and old tech stuff like that.. You need DA shocks and Cal-Tracs, better yet Ladder bars or 4-Link setup to really get a car to hook on radials.

Biasply Slicks on the other hand are more forgiving if the track prep is not the best. But you have to run them with less air pressure, to little and riding the top end feels quite gnarly. The chassis needs a more soft/progressive adjustment, you cant hit the tire to hard, if you do, it will "kill" the sidewalls and bounce/shake. A true Slick tire should/would work better with an old stock type S/S spring and NA shock setup...

To get a car to hook is more than just running an X type/brand tire, the chassis tune is the most important part.

/Tom

Ps... About getting a tire to hook on the street. The same principal as at the track. The tire needs heat to work (well and glue if on a prepped track). Even if you run soft slicks on the street and do street light to street light racing you have to heat up the tires to get the tires to hook. Cold slicks dont hook that well...

[XH29N0G]

The biggest difference for straight line grip is probably related to the rubber compound that is used.  I do not know what the different compounds are on different street tires.  FWIW I have been told at the strip that drag radials can hit harder and break things on stick cars than wrinkle wall slicks so there may also be other differences. For street tires,

Thats backwards. Stick cars dont like radials. The bias slicks are better on stick cars. Radials on the same car are worth about a 1 mph increase in track speed.

On a street driven car, radials are the way to go simply by a stability standpoint.

C00nhunter, Sorry that isn't what I meant to imply.  I was told that bias would be better and that the drag radials would not forgive and also would break things as a result.  

HPP:  I knew none of the stuff you mentioned and appreciate the clarifications.  My experience was limited to changing from BFG T/A's to smaller MT ET-street radials with a softer compound and it made a night and day difference with traction, that was why I mentioned the rubber compound.

[Mefirst]

Manual trans cars can be run on radial slicks just as on biasply slicks. The thing is as always the chassis tune... most seem to prefer slicks because its easier to set up the chassis...

[HPP]

HPP:  I knew none of the stuff you mentioned and appreciate the clarifications.  My experience was limited to changing from BFG T/A's to smaller MT ET-street radials with a softer compound and it made a night and day difference with traction, that was why I mentioned the rubber compound.

No problemo. I was running oval tracks at the time the local guys were swapping from bias plies to radial, so I had more of a handling perspective on it. That first roundy-round season after the track changed the spec tire to a radial, it was very interesting to watch formerly fast cars suddenly sliding around because they  hadn't figured out the differences in set up and driving style. The bias plys were great for stab and steer driving. The radials required you actually finesse the car.

I also spent a couple of years drag racing with a change from bias-ply to radial as well, but I was in only a 400 horse car using leaf springs and running 12s, so the changes for me were not as dramatic as some of these guys with experience in single digit e.t.  racers.

But yes, the compound is also a factor in it all, but not the only part of the equation along with  tire construction  and suspension settings.

[G-man]

Im guessing the MT Et streets are slicks with grooves in them? Vs the standard street tire radial that lasts 25,000 miles.?

If cruising only on the street slick tire... how many km/miles should they last?

[XH29N0G]

Yes.  They are not designed to for high mileage.  I have been told a few thousand.  I have 2-3 thousand on them.  They also have very different wet/dry behavior.  I have been caught in the rain twice and am not comfortable with them on wet pavement.  I assume there are differences in how they go around corners (comments from others appreciated), and have been careful not to test them - simply from lack of knowledge.

With the original set up, street tires were fine.  After my engine was rebuilt to the ~500 HP range rebuild the car would spin if I hit the gas below about 20-30 mph so 1st, and sometimes 2nd, was useless for me.  I swapped to 255 R15 MT ET Street Radials and have something that doesn't spin unless I want it to. This makes it more enjoyable for me to drive and also inspired me to take it 1/4 mile.

There must be tires that are more sticky than the BFG radial TAs but not drag radials.  I know there are drag radials that are reputed to be more street friendly than the MT ET Street radials (e.g, a number run Nitto).  I would be tempted to try a street tire that was better than the TA.

[Mike DC]

 
I find it frustrating how little attention is given to breakaway traits of modern tires for handling.  Seems like all anybody wants is skidpad G's.

I would be willing to sacrifice some overall grip if it meant the loss of traction came in a more predictable fashion closer to what bias-plys do. 

[c00nhunterjoe]

If it was me Id buy a set of M/T Radials (ET Street S/S Tires #3453) if you want better traction, but still mostly use your car on the street. These tires are a bit of a compromise, but they do work really well though the track prep has to be more or less perfect for them to hook/stick.

Dragracing..

A radial (slick) tire is often faster BUT the track prep needs to be really good for radials to work. Also the adjustment of the chassis is different running on radials. The tires needs to be planted hard against the track surface. You need to run an upgraded suspension setup, so no SS springs and old tech stuff like that.. You need DA shocks and Cal-Tracs, better yet Ladder bars or 4-Link setup to really get a car to hook on radials.

Biasply Slicks on the other hand are more forgiving if the track prep is not the best. But you have to run them with less air pressure, to little and riding the top end feels quite gnarly. The chassis needs a more soft/progressive adjustment, you cant hit the tire to hard, if you do, it will "kill" the sidewalls and bounce/shake. A true Slick tire should/would work better with an old stock type S/S spring and NA shock setup...

To get a car to hook is more than just running an X type/brand tire, the chassis tune is the most important part.

/Tom

Ps... About getting a tire to hook on the street. The same principal as at the track. The tire needs heat to work (well and glue if on a prepped track). Even if you run soft slicks on the street and do street light to street light racing you have to heat up the tires to get the tires to hook. Cold slicks dont hook that well...

Very well put. Even with a good chassis and under the best scenario, its hard to get a stick car to dead hook on a radial slick. I watch it every summer, almost every weekend. That said, i still ran drag radials on my stick car on the street. They still hook, they just dont dead hook. You have to work for it. No side stepping at 6500. You have to walk it out and work for it. They still hook enough to snap axle shafts.... lol. I went through 3 sets before upgrading to a dana.

Also, the tire he recommended is the new version of what i ran for years and i 2nd his statements about track use with them on top of my street statements.

[Mefirst]

I have not raced a manual transmission dragrace car, it would be interesting because it seems to be such a compleatly different animal than a auto trans ride. The auto trans is more progressive and the manual seems more "violent"...

-How do you setup the chassis/shocks on a manual car? I kinda figure on the whole it is somewhat the same as an auto trans car, but there must be some difference in the setup???

/Tom

[c00nhunterjoe]

I have not raced a manual transmission dragrace car, it would be interesting because it seems to be such a compleatly different animal than a auto trans ride. The auto trans is more progressive and the manual seems more "violent"...

-How do you setup the chassis/shocks on a manual car? I kinda figure on the whole it is somewhat the same as an auto trans car, but there must be some difference in the setup???

/Tom

Much more violent. Thats why radials are generally not used on conventional clutches. Everything has to be perfect as you pointed out prior.  Set up varies track to track and round to round. Depends on track prep, condition, weather. Etc. Something as simple as cloud cover vs full sun changes everything.

[birdsandbees]

Ordered 5 of these this morning.. yes I did...