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I would like to run 28" slicks but to match those I should have 4.10s. Trouble is I don't think I will be completely happy with 255/50/17 rubber on the street as it is only 27".

So I would like to find something say 28" tall and wider than 255 but retain good performance ratings.

Sofar my searching has turned up sport truck tires and mostly 29".
 

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I would like to run 28" slicks but to match those I should have 4.10s. Trouble is I don't think I will be completely happy with 255/50/17 rubber on the street as it is only 27".

So I would like to find something say 28" tall and wider than 255 but retain good performance ratings.

Sofar my searching has turned up sport truck tires and mostly 29".
The problem is that as you go up in size, a 1" change in tire size changes your effective final drive ratio less.
27/26 = 1.038 or 3.8% greater
28/27 = 1.037 or 3.7% greater
29/28 = 1.035 or 3.5% greater
It's still doable though, but as you mentioned, it is harder to find tires meant for cars.

When I suggested that you start a new thread for this, I was focusing on the other part of what you said (and didn't bring into this thread).


Have actually considered swapping to 4.10s for spring and fall and 3.42-3.73 in summer. I do drive the car some in winter, but not that much. Kind of a handful.
There is a thing called a quick change rear end. It allows you to pull off the rear axle cover and swap two gears and change your rear end ratio. No adjustments/shimming is required. These tend to be very expensive and are for racing use only.

Another thought is an adaptation of the Ford 9" rear-end/axle. The big difference betweent the Ford 9" and our rear end is the ring and pinion gears are held on their own frame which is bolted into the axle nousing. If you had two of these frames set up in advance, you could very quickly change over to a new ratio. You could have 4.56 gear set with a spool or a locker for the strip and a 3.42/posi for regular use. It would not take long to the cdhangeover. You could already have a bin file built for each case and flash it in and go. I would think that someplace like Moser would make you the axle...
 

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Discussion Starter #3
You don't quite seem to understand how advanced a user I am.
In the last week I flashed my pcm at least 5 times making little tweeks.

I have put 3 different housings and 5 different sets of gears in the car myself.

I make the guys with aftermarket headed strokers make excuses for why my little 350 is faster :biggrin:. The answer being I make good choices instead of relying on marketing. Admitting mistakes instead of blindly standing by them helps a lot too.

If you know what you are doing and have previously set them up and saved shims swapping gears in a 10bolt is not that much worse than swapping a 9" center section. Either way the shafts get pulled the lube dumped. Biggest extra effort for the 10-bolt would be setting pinion preload.

Far as a quick change, I know worked on a dirt track car a couple seasons, but seeing as I sometimes put as much as 350+miles on this car in a DAY just to go racing late in the season, a racing rear is not the answer.

Tires are just a easy way to tweek final drive ratio. If I found tires just over 28" they should fit well and drop cruise rpms by about 100rpms with 4.10s.

Maybe I will just take a different approach and sound proof the trunk better to keep out exhaust noise and deal with the extra rpms.
 

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You don't quite seem to understand how advanced a user I am. In the last week I flashed my pcm at least 5 times making little tweeks... I have put 3 different housings and 5 different sets of gears in the car myself.
I will admit that I am not familiar with you or your capabilities. I mainly hang out on "that other forum" and know many of the people there.


If you know what you are doing and have previously set them up and saved shims swapping gears in a 10bolt is not that much worse than swapping a 9" center section. Either way the shafts get pulled the lube dumped. Biggest extra effort for the 10-bolt would be setting pinion preload.
I have not set up rear ends like ours with the pinion captive in the axle housing. I read lots of horror stories about shops that have set them wrong. I have swapped hogsheads with no problem.


Far as a quick change, I know worked on a dirt track car a couple seasons, but seeing as I sometimes put as much as 350+miles on this car in a DAY just to go racing late in the season, a racing rear is not the answer.
That was the jist of my comment... maybe not something that you like to put a lot of miles on and depend on for a daily driver.


Maybe I will just take a different approach and sound proof the trunk better to keep out exhaust noise and deal with the extra rpms.
If the rpms (and slightly lower fuel economy) aren't a concern, then this might be your best choice. I was considering the Ford axle approach for me with a 3.42/clutch-type posi (or gear-type LSD) for daily driving and and 3.73 or 4.10 gears with a locker for the occasional trips to the strip. The downside is the initial cost to set it up.

A related question, have you tried out 28" tall slicks? I think of drag racing in this way: Ideally, you want just enough tire to get you quickly off the line and not lose control on the shifts. The rest of time down the strip, a bigger tire is extra weight that you carrying and it slows you down. I understand the advantage of the larger footprint with the taller tire for traction, but you are paying a big price in weight; not just weight on the scale, but also rotational inertia (since most of the mass of the tire is on the outside and this is now farther out). You said that you only have a 350 (not a stroker), I would think that staying with a 27" or even 26" tire would still be your best bet unless you are really breaking loose on the shifts.

Let me know how the taller slicks work out for you.
 

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Discussion Starter #5
The car does low 1.6 60ft. times with 3400 stall and 3.73s :eek:. Basically it makes more torque and is more responsive than the average stroker due to good parts and planning.
The local track just sucks for prep, here the car usually only does 1.7s due to spin.

My best 60ft times all come a couple hours from home on a well prepped track. Looking to let tire take the place of track prep here at home.

Suspension is basic too due to being a true street car. Has handling shocks, stock upper arms. Again I want tires to make up for the chassis.

I am sure I could get it to hook on 26" tires, but would lose consistency and compromise streetability of suspension to do it.

Far as other forums, I go by 96capricemgr.
 

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Dwayne, I know hook wise, you're going to potentionally lose a little traction by going to a shorter tire, but most all performance tires for 17" rims are going to be in the 25.5 to 26" tall tires.(I'm assuming 17" since you stated 255/50/17s). I would think you have your own dedicated drag tires.

If you're going to put them on SS wheels, from what I've been observing 275/40/17s would be the best over 285s. I'm just not seeing a full contact patch out back (well I'll admit I haven't done a huge smokey burnout to check) with the 285s even at 36psi.

Matt
 

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Discussion Starter #7
I have 15x10 MT drag rims for the track. 12.5lbs apiece :eek: I found someone clearancing them a while back, saved over $110 apiece vs. what Summit wanted :biggrin:.


What I was hoping for was a taller street tire to partially offset the gearing I should use with the tall track tire.

Maybe I should just use the 27x11.50 QTPs but screw them to the rim so I can go low with the pressure and hook that way.
 
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