best 16" tire size for my 308

Maybe so, but my car handles A LOT better with the even larger aftermarket anti-sway bars I put on from www.SanerPerfFab.com

 

I think I'll try a semi-symmetric experiment:
Put a pair of Kumo Supra 712 220|50-16s for the front & see how it handles with the best of the 220|55-390s on the rear. Probably try different tire pressures & camber, maybe switch the 390s to the front, to see how the understeer behaves.

Probably better make my 1st tries in a big parking lot.

Will decide on rear tires based on what I find out.

 

In looking at all past threads to date concerning tire sizes you really need to look at specific data for your choice tire. Tire Racks website is by far the best place to start for seeing current data on tires. They have so much data compared to other sources. Once you select a tire and select "Specs" the current size of tire your looking at comes up and includes all the same specs for all the tire sizes available for that tire type. All the sizes can be found in the range we use 205/55,225/50,245/45 and 245/50 16's listed on one page for easy comparison. It varies greatly with each type tire and manufacturer. One thing to note is the weight of each tire. It varies greatly and the range is 20-30 per tire. This could mean up to 40lbs per car depending on the tire you choose. Thats a big differance for racing....lbs=hp.

Using the info on Tire Racks website I see the top rated tire in the Ultra High Summer Performance category was the Avon M500's. That being said they are on the high side for weight at 28-30lbs per tire yet some others like the Toyo T1-R's are only 21-22lbs per tire. That being said has anyone tried the Toyo's? From all of the reviews using BMW's they have received high marks. Does anyone have experience with the Toyo's on Ferrari's?

 

Verell,

Don't have my cars close anymore, but will look for you. Both with stock suspensions, I have both setups in 16".....

One set is 8" all, IIRC, one set is 7" front 8" rears, and whatever size I have on the yellow car is max, as the inside of the tire JUST chaffs the liner if you get airborne over railroad tracks...........

I'll find my notes, or take trip out to the ranch to look.. (in the barn there, for now). I have the 16's off the blue car, still here in the garage....

bbl.............

 

Well I made it back from the Crescent Classic in one piece.
And the Fuzion ZRI tires I installed on my 308 performed as well as any of the higher priced street tires I have used in the past.
I put them through a pretty good workout of WOT down the straights,
very tight twisties, and wide sweepers, and never had a traction problem.

The only problem I encountered was my fault,
as I entered a turn too hot and caught the driver side fender lip on the tire.
I had my 308 sitting very low, which was fine for normal driving,
but just too low for playing with modern cars at full speed.
So a few turns on the adjusters to raise the front end up a little and all was well.
In retrospect, the Eibach springs I installed, 325lb front 275lb rear,
are fine for normal driving conditions, or with the car raised a little higher, but with the car as low as I like it,
I think 400lb front and 350lb rear would have been a better choice for playing with modern fast cars in the twisties.

 

I can't believe it, my order for Kumo Supra 712s was cancelled by Sullivan tire - seems they're out of production & NLA!

Strange tho, tire rack shows them in stock.

 

Hi all, for those of you who don't know me, I'm Scott Major. The SCCA /COMSCC/ NEQ/ CCS/ FUSA instructor that went out with Verell at NHIS. I race motorcycles currently. I previously campaigned a 1986 ITS Spec RX-7 in SCCA, COMSCC, EMRA and other series on the east coast for 7 years.

A few things to consider with the 308 in stock form. It is has a light front end and is prone to understeer. It has well under 300 HP and has a relatively short wheel base with a wide track and mid engine with a good centralized weight distribution.

Looking at the less than 300 HP, and weight distribution factors it is my opinion that with a *close to stock* alignment, there is no need to put 245's on the back of the car. Doing this, you provide more grip to the rear of the car versus the front. Thus inducing understeer which is multiplied by the fact that while the weight is distributed well it lends itself to the rear of the car. Less weight and grip up front = understeer.

Putting symetric tires on all 4 corners will allow for a neutral set up with a *close to stock* alignment. When aggresively driving the car the front will grip a little less than the rear giving us that comfortable, controlable understeer we as a society have been taught to deal with in a slide situation. As throttle is applied through our apex or slightly post apex, the car will begin to transition to a mild oversteer or a neutral drift. All 4 tires sliding and rotating at the same rate with minimal steering correction. This set up provides the ability to steer the car with the rear wheels.

(close to stock) I have discussed this with Verell off line about slight camber and caster changes he may want to make with the new rubber. Providing a flat contact patch, quick(er) turn in and minimal out of the norm tire wear.

Where the 300+Hp comes into play. Looking at the 308 QV it has somewhere between 235 -245 HP And prolly just under 200lb Ft of twist depending on which dyno you look at. It uses the power effectively but is not a real monster when it comes to breaking the back end loose from throttle enduced oversteer. Therefore the need to have additional grip in the rear is not required. I call it a finesse chassis set up versus a muscle chassis set up. If you give me a race prepped cobra with 400 HP. Yes, I want 315's in the rear with 275's up front. Or we'll say a 512TR. 245's up front.. 295's in the rear. Why, cause it has a ton of torque and 428HP. It will roast the tires out of a corner when laterally loaded. Hell, it'll do it when not loaded in any direction.

The 308 in stock form will find its fastest way around a road course by holding a higher corner speed and using what power it has up high in the rev range. Its a graceful, gliding car versus a point and shoot car that wallows into a corner (by comparison) and muscles its way out of the corner with gobs of HP and torque. The awesome thing about most Ferraris is that they have combined the best of both worlds in most cases. The 355, F40, etc are all examples of this.

All of that being said, looking at a Daily driver, stock, 308 that see's the track a few times a year. 225/50's front and rear are plenty of tire for the 308 at a good price point and readily available. They will provide consistent, useable grip that lends itself to the chassis of a stock 308.

Let the flaming begin.

 

Great comments Scott. I agree with what you have said. One point you left out is WIDE TIRES ARE COOL.

I know form is supposed to follow function, but I like the look. I have yet to track my car (hopefully some day), but aggressive driving on the streets at 7/10ths or 8/10ths the understeer only rears its ugly head occasionly. My experience is much more limited than yours. I've had a few days of karting and autocrossed a couple of times.

I want a well handling car that looks good too. I guess it all depends on your experience and priorities. I'm sure most people reach their personal limits before they reach the cars limits.

Thanks for the input.

Henry

 

Today I bought the Fuzion ZRi's in 225/60 & 245/45 16's. Installed for less than $400 OTD. I wanted the Toyo's but couldn't justify that cost right now. This set will have to do. I decided on the 245/45's instead of the 245/50 because this tires contact area was 8.6 inches instead of 7.9 inches. Other types of tires from other Manufactures could and will differ. So I went with the one with more contact area. Both Tire Rack and Firestone's website confirmed the size. OD is smaller than the stock size of 225/50's in this tire (24.6 to 24.9) but I like the look of the wider tires and I can't tell the differance just looking at the car that the fronts are lower in height than the rears. Time will tell if they handle good enough. In the rain is the ? right now. I'll post with an update after the first drive in the wet. Any way these are much better than the old rubber (96) that was on the car until now.

 

Dave,

Glad to hear you made it back safe

I'll have my Avon's (215/55 & 245/50) installed in a couple of weeks. I'll post an "expert" review too.

Henry

 

LOL!

I can also tell you -- despite Scott's comments -- that since I changed my tires to 245/45's on the rear and 225/50's on the front of my QV, I am able to take the corners my favorite track (which I've been running for over 10 years) much faster and at higher g's before the car starts to slide. That's with all else being equal (same tire model, same amount of wear, no other changes in the car). And then I put 5/8" spacers on the rear (mostly cosmetics to fill out the wheel well)!! As the saying goes, "Wider is Better".

 

Mike,

Where'd you get the spacers? How much were they?

 

The rear spacers are HR brand, hub-centric, $110 per pair (plus bolts of course). Click Here: http://snipurl.com/1z054

Hill Engineering also makes spacers that you can buy through Daniel at www.RicambiAmerica.com

 

Damn Mike, could you get back to people a little sooner?!

 

A year here, a year there, time flies when you're having fun!

 

Pretty sure I am going with Kumho Ecsta SPT's again for new tires this Spring as I went with them on the 348SS before I sold it and was very pleased. Have also had them on my DD M3 (although right now that car is riding on Mich Pilot Sport A/S).

The only dilemma I am really having is whether to stay with stock size up front (205/55) or go to 215/55's while staying with the stock size 225/50's in the rear.

I drive enthusiastically at times, but this car will never see a track (83 308QV by the way) and my primary concern up front is raising the front up by going with the 215's. Will the additional height be noticable and will the gains in front end grip be worth straying from stock sizes?

This car already sits level, but during acceleration squats to the rear fairly noticably (although I guess stiffer springs in the rear may be in order to overcome that issue) but just looking for some input on what fronts I should get if any of you out there care to throw in your .02

MB

 

Matt, it might be worth considering 225/55s in the rear - I put that dimension on my QV wheels on my 308 it looks and feels pretty good. Takes a few revs off on the highway (which I appreciate) and helps ensure a nice comfortable ride. It also proportions the profile view of the front and rear tires nicely.

 

Thats what i did and I think i could have gone 450 400 like MKE did. It rides nice with softer settings on the QA1s on the street.

 

What were the original 16" tires that came on an '83?

 

It is just getting more and more difficult finding HP tires in anything other than a 17" wheel or larger. A frustration to be sure!

Ciao,
George

 

Indeed, and Cliffbeer, I have 225 on the rears right now, I thought that was the stock size rear for the 16" rims, is it not? The challenge is finding tires that are actually made in that size that is also made in the 205 Fronts...any side profile pics of your car you can send me?

It is getting harder to find 16" tires...I used to think that finding 17" were getting harder to find for my DD M3, but now finding 16's is even more difficult than that!

MB

 

Hi Matt, what I was meaning to say is that I put 225s with 55 series rubber on the rear rather than the stock 225 50 series. In other words, a slightly taller side wall profile with the 55 series rubber than the 50 series. This tends to a) fill out the wheel well a bit more, b) take a few revs off when cruising on the highway, and c) keep the ride nice and soft, all of which I was hoping for...

 

Copy Cliff, and sorry I took so long to get back to you here. I will take a look at Tire Rack and see if they have that size for the rear.

What I really want to do is get a wee bit more rubber on the road without sacrificing the overall stance of the car at rest. What you are saying should do that, so I will take a look.

Thanks,
MB

 

Go with 245/50 on rear and 225/55 on front, if you can find them, it will give you the same diameter on both the front and the back. The sizes available today are far different from what was available several years ago. It sucks to have 16" rims today and still want the top performance tires.

 

You got that right. I have 17's on my daily E36M3 and even that is getting challenging...