Low profile tires on Slicers, is it ok?

[ALWyzBrknSHO]

I was wondering, is it ok to put low profile tires on slicers? I know it will screw up the speedo and all, but I was wondering if it'd be ok to o say put 225/45/16's on a slicer? Think it'd be kinda cool for the acceleration benefits, but not sure if it'd make the car too low or anything (which I doubt).

 

[Porkchop]

I know it will throw your speedo, but by much I don't know. There was a website out there that did the calulations to that respect but I don't remember it, maybe another member knows it.

The one thing that you will definitly sacrafice is your ride quality, you will get a rougher ride with 45's. I don't know if you have any suspension mods ... like koni/intrax, or tokiko/eibach but you will have a crap load of wheel gap because I think 55's were stock.

 

[ALWyzBrknSHO]

Actually stock size is 215/60/16, so yea it'd throw it off quite a bit, but I dont mind that, this would be for more of a fun thing, and I dont have any suspension mods.

 

[AutoSHO]

From a looks standpoint, it will be hideous...

 

[Chris Benvie]

AutoSHO:
From a looks standpoint, it will be hideous...

what he said

 

[ALWyzBrknSHO]

Dont care about the looks all that much.

 

[Shoaz]

Should work fine. Bondurant's place used to keep 205/55R16s on some of their SHOs (at the least, Bob's SHO #1 had 205/55s on last time I was down there.) The Bondurant SHOs always had slicers.

That can help for track car to increase torque everywhere at the expense of top end. If you never hit top end at your fave tracks, then it's a nice trick.

 

[keli]

AutoSHO:
From a looks standpoint, it will be hideous...

For real. Say hello to even more wheel gap If you don't have suspension mods/aftermarket wheels, why are you going low-pro? I'm just curious. You won't notice that much more "acceleration benefit", just a rougher ride, less treadwear, and more people staring and thinking wtf...

 

[TimboSHO]

I have 225/45-16s on my slicers because i got a good deal on them. I don't have any suspention mods, and yes, there is considerable wheel gap, but it's not that hideous. But that way i have room to move if i lower it in the future as well....

 

[GR8WYT]

Here's the specs, including the speedo error:

My understanding was that, in general, you did not want to go below 97% of the original diameter to preserve speedo accuracy, but more importantly, not confuse the ABS computer.

 

[Shoaz]

Smaller tires won't confuse the ABS if you do the same thing to all four corners. The ABS may get confused if you only put small (or large) tires on one end and not the other, but otherwise it has no way of knowing (or caring) about the tire diameter.

 

[yamahaSHO]

GR8WYT:
but more importantly, not confuse the ABS computer.

Why would it confuse ABS... Shouldn't it just be looking for a locking tire/brake... I would think all it is looking for is when you stop the wheel from spinning when you are moving.

 

[AutoSHO]

You'd be surprised... when we went to bigger tires on our Dodge truck (all 4, same size) it made the ABS much less likely to engage (Rear wheel ABS only). We aren't sure why, though... Doesn't make sense. But, I'm just pointing out that it can happen.

 

[RickieFrat]

AutoSHO:
You'd be surprised... when we went to bigger tires on our Dodge truck (all 4, same size) it made the ABS much less likely to engage (Rear wheel ABS only). We aren't sure why, though... Doesn't make sense. But, I'm just pointing out that it can happen.

When you place bigger tires on something that has a computer hooked up to it for a small size tire, it makes the computer think the tire is doing less work. Think of this, on a stock tire that we'll say takes 100' to stop from 65mph / will take longer on a bigger size tire due to the roll out lenght. Thus making the ABS think that the tire is not in any danger so the ABS will not react in time unless the tire is locked up causing damage to the ABS system itself.

pcorn

Thats why in drag racing you will see some cars having tall rear tires. It makes the car seem faster than what it is. A taller tire will make the car faster.

Now here is something else to wreck your brain. A guy might have 16" tires with 65 series side wall. The next guy can have 18" tires with 45 series side wall. Place both rims and tires next to one another and they will have the same height.

Keep this in mind. You placing a low profile tire on a stock rim will only make the engine work harder and get less gas miles. You will also be going slower than the speedo is saying. When I had 17" on my SHO with low pros I noticed the setup was lower than my stock setup when I placed them next to each other. The car was lower and it handled great ..... But the engine was doing tooo much work and gas miles droped. doh

<small>[ December 06, 2003, 01:45 AM: Message edited by: RickieFrat ]</small>

 

[Shoaz]

RickieFrat:

AutoSHO:
You'd be surprised... when we went to bigger tires on our Dodge truck (all 4, same size) it made the ABS much less likely to engage (Rear wheel ABS only). We aren't sure why, though... Doesn't make sense. But, I'm just pointing out that it can happen.

When you place bigger tires on something that has a computer hooked up to it for a small size tire, it makes the computer think the tire is doing less work. Think of this, on a stock tire that we'll say takes 100' to stop from 65mph / will take longer on a bigger size tire due to the roll out lenght. Thus making the ABS think that the tire is not in any danger so the ABS will not react in time unless the tire is locked up causing damage to the ABS system itself. pcorn

The ABS sensors sense wheel rotation rate only, not torque, so how could the system tell what size tire is on the vehicle?

 

[RickieFrat]

By the rotation of the wheel and the grove that passes it. The bigger the tire .... the slower it will turn. Vise versa for a smaller tire.

When my 17" was installed, my ABS would sometimes kick on when I went over a hard bump (RI ain't that big .... if you hit one bump, you hit the same one tomarrow). It never did it with my stock rims. shrug

 

[AutoSHO]

*brain hurts*

Smaller tire = shorter gear ratio = more mechanicaol advantage = easier for the engine to accelerate the car = engine turns faster at a given speed.

Larger tire = taller (numerically smaller) gear ratio = less mechanical advantage = harder to get the car moving, more wear on clutch = slower engine speed vs. vehicle speed = better fuel economy on the highway

 

[GR8WYT]

Here's a quote from http://ca.autos.yahoo.com/maintain/tire_matching_rules2.html

On cars and trucks that have antilock brakes (ABS) equipped cars and trucks, most vehicle manufacturers say replacement tires should be the same size as the originals. This is necessary because the diameter of the tire affects how the wheel speed sensors read, which in turn affect the operation of the ABS (and traction control) system. Changing to a larger or smaller diameter tire, or installing different sized tires front and rear can upset the operation of the ABS system. This may create braking problems and/or cause the ABS warning light to come on (which means the system is deactivated).

 

[Shoman594]

Kevin,
Do you have a link for where to get that program ?
Thanks

 

[GR8WYT]

Shoman594:
Kevin,
Do you have a link for where to get that program ?
Thanks

The program is several years old and is freeware. I can email it to you since I can no longer find the version I am using. There is a newer version at http://cat.cc/cat_se.htm , but I don't like it as much.

To the Moderator: Is there a preferred method for file sharing on the forum here?