Big HP guys running slicks, I need your advice...
07-04-2007, 08:24 PM
#16
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What size are the slicks? Basically the goal is generally to have the footprint width equal the rim width. I have 15" x 10" rims and a 10" foot print. On the Mickey thompson website there is a range of rim widths for their tire sizes. I suspect you maybe mismatched. Forget ET and MPH and focu on the sixty foot time. You should be sub 1.5 easily with that hp in a normal environment. I think if you get the sixty foot ironed out the other shift points will likely fall into line as well.
You will not know about the rest of the suspension until you hook up. One problem at a time.
You will not know about the rest of the suspension until you hook up. One problem at a time.
I agree, his 1.8 60fts are weak for the amount of HP he is making, they should be down in the low 1.5s, or 1.4s (a gain of 3 to 4 tenths in the 60ft alone). And as I mentioned previously, slicks on 15" rims with more side-wall are far superior to the low-profile slicks on 16" rims.
WD
07-05-2007, 08:30 AM
#18
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Off the top of my head, I don't know the exact size of the tires. I just know they are the Mickey Thompson ET streets mounted on the salad shooter rims. I'll go out to my shed later today and get the exact size for everyone.
Again, I am sure you guys are right, and I already know I could better my times with a smaller rim, and bigger slick. But thats NOT what I am looking to do here. I simply want to get the best out of what I CURRENTLY have.
BTW, the front tires are Nitto 555R's (275/35ZR18) at between 30-33 psi.
Again, I am sure you guys are right, and I already know I could better my times with a smaller rim, and bigger slick. But thats NOT what I am looking to do here. I simply want to get the best out of what I CURRENTLY have.
BTW, the front tires are Nitto 555R's (275/35ZR18) at between 30-33 psi.
Last edited by CALL911; 07-05-2007 at 08:40 AM.
07-05-2007, 12:42 PM
#19
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Alright, I just checked the tire size of my Mickey Thompson E/T Streets. They are 26X10.50 - 16CT
BTW, the video of the track runs is currently being uploaded. Once the server has completed uploading it, I'll post it up.
BTW, the video of the track runs is currently being uploaded. Once the server has completed uploading it, I'll post it up.
07-05-2007, 12:46 PM
#20
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Off the top of my head, I don't know the exact size of the tires. I just know they are the Mickey Thompson ET streets mounted on the salad shooter rims. I'll go out to my shed later today and get the exact size for everyone.
Again, I am sure you guys are right, and I already know I could better my times with a smaller rim, and bigger slick. But thats NOT what I am looking to do here. I simply want to get the best out of what I CURRENTLY have.
BTW, the front tires are Nitto 555R's (275/35ZR18) at between 30-33 psi.
Again, I am sure you guys are right, and I already know I could better my times with a smaller rim, and bigger slick. But thats NOT what I am looking to do here. I simply want to get the best out of what I CURRENTLY have.
BTW, the front tires are Nitto 555R's (275/35ZR18) at between 30-33 psi.
Pumping the fronts to 44 psi will help with the top end sashey.
07-05-2007, 12:56 PM
#21
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Well, on another pass I made later in the night, I spent a few more seconds heating the tires up, and when I dropped the clutch at 4200-4300 RPM it bogged the motor because it bit so hard! But then after 1st gear got back up to the upper RPM's and I shifted into 2nd, the car started sliding sideways again and I got out of it.
07-05-2007, 01:17 PM
#22
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Here's the video. As you can see, once the car is moving, it is difficult for me to keep it straight as the back end floats side to side. The first run I was able to stay in it to get a decent pass. The next run (and pretty much the rest of the runs that day) the back got a little too far out for me to feel comfortable to stay on the gas. The video made the sliding and floating look more tame than how it actually feels in the car. Is this normal for slicks? Do I just need to get used to this? Or is there a way with running different tire pressure or something (possibly better track prep) that will help the floating out?
Click here to see Video
Click here to see Video
07-05-2007, 02:20 PM
#24
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A couple of the earlier posters have already beaten me to the punch on this one, but, you are running one of the worst front/rear tire combos for "floating and top end sway", (as you refer to it), that you possibly could. 
You're attempting to run 16 psi of air in a bias ply 26x10.50x16 rear tire....(with 600+ RWHP I might add)....and 275/35/18 radial tires up front. 
As suggested above, if you change out those wide radial front tires for a pair of 4.5"/5" wide bias ply skinnies, I'd bet 95% of your "float and sway" would be gone. Conversely, a pair of MT 275/50/16 drag radials on the rear would also reduce float and sway considerably. I know you just purchased those rear bias ply slicks, but...... something's gotta give here. 
You're attempting to run 16 psi of air in a bias ply 26x10.50x16 rear tire....(with 600+ RWHP I might add)....and 275/35/18 radial tires up front. As suggested above, if you change out those wide radial front tires for a pair of 4.5"/5" wide bias ply skinnies, I'd bet 95% of your "float and sway" would be gone. Conversely, a pair of MT 275/50/16 drag radials on the rear would also reduce float and sway considerably. I know you just purchased those rear bias ply slicks, but...... something's gotta give here.
07-05-2007, 05:57 PM
#25
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Well, perhaps my setup is not ideal, but it is what it is. Like I have mentioned REPEATINGLY, I don't plan on changing the setup from where I am at, as it is idealy setup for what I mostly use it for (street use). I probably won't do skinnies up front either as I have very large aftermarket Baer brakes that most skinnies won't fit on anyway.
Is it possible if I raised the psi in the front tires that I would help the floating as mentioned by someone? Also, will a simple change in psi for the rears help as well?
Is it possible if I raised the psi in the front tires that I would help the floating as mentioned by someone? Also, will a simple change in psi for the rears help as well?
07-05-2007, 06:09 PM
#26
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raising the air won't do anything........
If your not willing to change anything than you will just need seat time.......make alot of passes.
Try not to wreck it......at that power level, its smart to have an ideal set-up to get you down the track
If your not willing to change anything than you will just need seat time.......make alot of passes.
Try not to wreck it......at that power level, its smart to have an ideal set-up to get you down the track
07-05-2007, 06:23 PM
#27
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lol, thats the #1 priority, not to wreck it. It's used and enjoyed as a street car too much for me to change it up. This was still only my second time to the track with that power level and the slicks, so perhaps more seat time will be the key.
07-05-2007, 06:33 PM
#28
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It is not really an air pressure problem. Air pressure and susp can mask the problem or lessen it, but the problem will still be there.
When you have stiff sidewalls on one half of the car and flexible ones on the other half it will cause instability. It happened to me any everyone I know that has run your identical setup. The swap to skinnies is like night and day.
I can see your problem though, as big brakes make skinnies near impossible. If the big brakes are more important than skinnies, your only real fix for the problem is to swap to drag radials in the back. Radials will likely be harder to hook for you, but they will fix the sway.
When you have stiff sidewalls on one half of the car and flexible ones on the other half it will cause instability. It happened to me any everyone I know that has run your identical setup. The swap to skinnies is like night and day.
I can see your problem though, as big brakes make skinnies near impossible. If the big brakes are more important than skinnies, your only real fix for the problem is to swap to drag radials in the back. Radials will likely be harder to hook for you, but they will fix the sway.
07-05-2007, 06:35 PM
#29
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At one time I was using ET Streets on salad shooters with 16" high performance radials on the front and had no stability issues. The last combo, before retiring the car from the strip, was a 15" slick on the rear and high performance 17" radials on the front. No stability problems with that combo either.
Rich
Rich
07-05-2007, 07:01 PM
#30
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I don't think your solution has anything to do with the front/rear tire combination. You're simply breaking-loose those small 26" ET Streets with the HP your car has. And you'll probably always be in the "danger zone" to some degree running those small 26" ETs at the track. And, you’ve pointed-out that is your wheel/slick preference and don’t plan to change.
For example; when I had a 12.40 car (cam and bolt-on's), I also ran 16" rims and the 26" ET Streets. Sometimes when I shifted to 2nd the ETs would break loose and the car would get a little scary.
However, now with a low 11 second car and the correct wheels and slicks, the car never gets loose.
WD
For example; when I had a 12.40 car (cam and bolt-on's), I also ran 16" rims and the 26" ET Streets. Sometimes when I shifted to 2nd the ETs would break loose and the car would get a little scary.
However, now with a low 11 second car and the correct wheels and slicks, the car never gets loose.
WD