I've only run it one night at New England Dragway.. (3 runs)

All 3 runs were high 2.4 60 foot times (I just can't get off the line without spinning like crazy. Even dumping the clutch at 1500 rpms and getting into it after the car has started moving will light the tires)

The 3 runs were:

14.2 @ 102.5
14.3 @ 101.9
14.2 @ 102.4

My car has Khumos from the previous owner..I think they are the culprit. I really think this car should run a 13.5


Thoughts?

get some new tires, or just put drag radials on the back when you're at the track. You should also be executing a burnout (obviously) before staging to warm the rubber before you make your run.

If the tires are getting a little old they will dry out some and traction decreases.
I'm thinking of getting some MT ET Street drag radials gust for track use.

Oh BTW Kumhos on mine got me to 13.1 / 1/4 down here on a 100 degree 95% humidity day. Did you warm them up real good? Got to clean the dirty rubber off.

See if you can get ahold of a set of 16" rims cause I can tell you those 17" WS6 rims are some heavy pieces.

When I ran my 97 with the stock 16's I could get into the 13's but when I put on my 17" WS6 rims for some reason the best I can do is like 14.1.

ya. 17's have more surface area, so they look better, but you'll cover more ground in less time with 16s.

If you can get the 60' times to around a 2 you can loose 3-4 tenths on the other end,putting you around a 13.7-8. You mph show 13 second abilities.My mph is only a little more and I ran a best of 13.48. It's all in that first 100 feet.

well, I wouldn't be dumping the clutch you are always going to spin, you need to get off easy and then nail it!

I read your mods list and when my car was in that type of mod form I ran in the 13.5 range.

what suncoast hood do you have? I have the predator ram air from suncoast.

Doug

It's the Firehawk type.. lower profile.

I pick up my car from the body shop today after the TA nose conversion.. I'll post pics tomorrow.

I'm looking into lighter rims.. Best I've found so far is a Konig 17x9 5 spoke that weighs 21.6 pounds.. Costs about $169 per rim.. still looking at maybe moving to a 16", but I really like having 275's all around and I really doubt there is a lightweight 9 inch wide 16 inch rim out there... (hard enough to find a 17x9 that isn't almost 30 pounds)

Kev

Wow Sue, I'm surprised that your times went down...how much heavier are those 17" WS6 wheels? I would think for our cars that the extra weight plus the extra width would decrease the traction problem, which would decrease the 60' time and drop those ETs. Interesting! I'll have to think about how much difference wheel weight can make on ET..maybe work out an angular momentum problem.

I personally wouldn't trade back down to the 16s...tire selection is worse and the biggest you can get is the 255 drag radial. I used to spin my 16s like crazy, but after I put on the 17s, the car felt a lot grippier and more consistent. Man I wish we had a decent 1/4 mile track around here to confirm my SOTP impressions. I'd take both sets of wheels (my 17" ZR1's and the stock 16s that I have) and try it for myself.

Anyone else tried it?

I'm not sure what the weight difference between the stock 5 spoke 16s and the WS6 17s are cause I've never weighed them (might do that sometime this week just to find out since I'm putting my 16s on for the winter) but I do know that when I swap rims that when I carry the 16s to the car and the 17s to where I store them that there is a noticable difference in the weight. I can carry the 16s with no problem at all at about waist level with one hand while the 17s I can barely get to waist level using two hands. I'm short too (5'3") so that might make a difference with that. But my husband also says that the 17s weight more then the 16s too so it isn't just me.

Oh I believe you...my ZR1's with 275s are a bit heavier than the stock 16s with 245s. Like I said, I would have thought that the extra weight would have contributed to improved traction.

You're looking at added unsprung weight which has a lot to do with accelleration. Heavier and wider wheels are not usually better. Now, lighter and wider is much better. However, you'll notice a bigger difference with the weight. It takes more power to get a heavier wheel to turn than it does a lighter one. Try rolling the different rims and see how much effort difference there is (or just ask Sue). Reducing the weight of the wheels and tires allows more power to be put down (although overpowering will still burn them up!!) instead of being used to gather momentum on those wheels. If you had two identially prepped cars but one has a lighter wheel/tire combo, he'll win every time. Just my .02, but I put lightweight aluminum wheels on a Nissan Sentra (I know...but I was young and it was cheap transportation) and could definitely tell a difference, especially running against other stock Sentra's. Try it and you'll see, your times will go down with lighter (not necessarily smaller) whells and tires.

Try warming them up good.
Went to the track this evening and really warmed up the Kumhos
I forgot my skull cap cause I was just going to watch then decided to make a run even tho I knew I wouldnt be able to make another with out the helmet.

got a 1.943 - 60'
13.00 flat 1/4 mile
at 107.17mph
my RT was a pitiful 0.164

Wish I could have made another run - I want in those 12's
They wouldnt let me run again

Thats an excellent time! I wish my car ran that good.It will eventually

Your not too far from it now!

Nothin' a little cam wouldnt fix. Looks like you have most everything else you need!

I agree with you to a point, but you also recognize that burning them up isn't a good thing either, which our cars are prone to do. You said that if you have 2 identical cars and one has a lighter wheel/tire combo then the guy with the lighter wheel/tire combo will win every time. But if he can't get that power to the ground because the wheels are too light and just spin...no way he'll ever win! And in this case, it's not just lighter versus heavier, it's lighter and skinnier versus heavier and wider so there are other issues as well. Now lighter and wider...I'll agree for the rear that's probably the best solution! Of course, the lightest and skinniest wheels you can get on the front and still maintain control will also help.

Think of it this way for the rear...the heavier wheels take a lot more effort to begin to turn because it's fighting a larger rotational inertia(aiding traction), but once you get them spinning the heavier wheels have more momentum. Take your experiment...start the lighter wheels and the heavier wheels rolling. The heavier one will be more difficult to start rolling. Now try and stop them. Which one is more difficult to stop? Also, it will depend on where the weight is added. If it's added all the way out at the edge of the wheel, it will have a much larger effect on the rotational inertia and the total angular momentum than it would if it was more evenly distributed on the wheel.

I haven't had the time to sit down and do these calculations myself, but luckily I found someone that already did, and he used worse case scenario (all the weight at the edge of the wheel).

http://www.audiworld.com/tech/wheel13.shtml

If he's right, then the added rotational mass doesn't affect the acceleration of the car nearly as much as is commonly believed. I now recall that I heard someone say before the 1:10 rule in another forum (or maybe it was here?). 1 pound of rotational mass (on the wheel) increase is equivalent to 10 pounds of static mass (the rest of the car) increase. It's probably not a hard and fast number, because it depends heavily on where the mass is added along with some other factors(traction, weight distribution of the car, power range, transmission type, etc.). But according to his worst-case calculations, it's more like 1:2, and for our cars I would think the increase in traction for small additions of weight would outweigh the total increase in weight. There's a fine line for balancing these two issues so it's possible that if the WS6 wheels are a LOT heavier the added traction is negated by the increase in total accelerated weight. I'm curious to see if it's a 10 pound or more difference per wheel(WS6 versus stock 16s)...that's probably a bit too much.

One thing that I was thinking could have an effect is the added friction down the track due to the wider tires. This along with too much added weight might mean higher ETs. Again, it's a balance of gains versus losses. Fun stuff!

Sue, something I would love to try if I had a track is to first try it with just the 17s on all 4 corners, then put the 16s on just the front and try it again, then put 16s on all 4 corners and see the result. My guess would be that the best time would come with the 17s on the back and the 16s on the front, if traction is a problem with the 16s on the back, that is. Gotta compare apples to apples too. If it's 16" drag radials and 17" snow tires...all bets are off! Dang I wish I had a decent track close by!

Tell you what Dwain - here's an open invitation to you. If you ever get my way next year we'll go to the track and we can do just that! I've got 17s, 16s and a couple of 17s with nittos on them. Oh and the choice of track is yours - I've got two 1/4 mile tracks within an hour of me.

Good call Dakman...it's been a long time since I studied that stuff and was kinda shooting from the hip. Excellent article...now I'll have to start doing some figuring!!! Thanks for the info.

Don't I wish...I'm lucky if we take a trip out of the state every year! I might just have to drag my Formy to a city at least somewhere close by that has a decent track...I wonder if there are any family vacation spots around here that have a decent track?

Lots of family vacation spots by me - Six Flags, Grants Farm, the Arch, Forest Park/St. Louis Zoo, downtown St. Louis, Anheiser Busch, etc.

Now were talking!

Any coffee houses too?

Oh yea, got coffee houses too along what's called the U City Loop.

Sassy, Whats the U city loop?

sounds interesting

The U City Loop is short for University City Loop. It's a section of downtown St. Louis that is interesting to say the least. Lots of little shops, cafes, avant garde' places, little theaters, etc. Sort of a cleaned up version of Londons SoHo district or Greenwich Village in NYC.

Kewl
I'll have to stop and take a look next time I'm up

It's a cool place...been there a couple of times when we were up to see the Cards play. I'd highly recommend checking it out.

Ok, I finally got a chance to weight both my stock 97 T/A 5 spoke 16" rims and my 17" 02 WS6 rims. All I can say is there is quite a bit of difference weight wise between the two.

The stock 16's with 245/50ZR16's weigh just under 42lbs each for a total weight of all 4 being roughly 168lbs.

The WS6 17's with 275/40ZR17's weigh just over 55lbs each for a total wieght of all 4 being roughly 220lbs.

I know it doesn't seem like much of a difference but the WS6's are 13lbs heavier each, with the total difference between the two sizes being 52lbs. I knew there was a difference weight wise but I didn't think it was that much.

damn!
now I'll have to weigh my 18" C5 wheels just so I'll know

That's a substantial difference! I wouldn't have thought it was nearly that much either. May be time to put my rims on a diet!

Another reason your seeing a issue with accelaration with larger rims 16" to 17" is the fact that the 17" rims and tires are taller than the 16" rims and tires. A taller tire changes your effective gear ratio. So therefore the shorter tire gives you more gear and the taller tire takes some gear away so it changes your overall acceleration. Taller tire taller gear lower number numerically shorter tire shorter gear higher numerically.

Just my two cents worth, take it or leave it... I've got a '93 Formula, bone stock. Worse yet, it's an automatic. Funny thing about these cars though, they're all a little different. It's got 16 inch Kumhos (255/50s) and it's one of the quickest non-modified 'birds I've ever driven. Last time I hit the track the car had 80,000 miles and ran a 13.5....just feather it off the line and then stay on it and the auto won't even hurt you that much, the car's got so much torque it doesn't matter as long as you can get away clean.

Did you light them up in the water box. If so how long?

Yea I toasted them good
Since I have an A4 I put it in first and power brake all I want
plenty of smoke but not too much

as you can see in my sig I've been back
and have gotten into the 12's with the Kumho street tires

12.9

wonder what it would do with some ET street radials???