and I understand the need for the PT job. Owning and running vettes is a full time experience 
Engine Drag Control Active????
Thread Starter
Safety Car
Joined: Dec 2004
Posts: 4,477
Likes: 2
From: Boca Raton, FL
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14
The difference between STOCK REAR size and his reported REAR size is 1.07%. He claimed STOCK FRONT size so there won't be a difference.
The Active Handling, Traction Control (and Engine Drag Control?) depends on STOCK front to rear stagger. You can run any wheel/tire size Front to Rear that fits in the wheel wells if you maintain the stock stagger.
The STOCK Front to Rear stagger is 4.25%.
The Active Handling, Traction Control (and Engine Drag Control?) depends on STOCK front to rear stagger. You can run any wheel/tire size Front to Rear that fits in the wheel wells if you maintain the stock stagger.
The STOCK Front to Rear stagger is 4.25%.
Le Mans Master
Joined: Aug 2004
Posts: 5,259
Likes: 16
From: Monroe Township New Jersey
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14-'15-'16
St. Jude donor in memory of jpee '14
If the sizes given in your original post were correct;
245/40/18R and 345/30/19R
Then your tire sizes shouldn't be causing a problem. You are stock diameter on the front and only 1.07% larger on the Rear.
Try this calculator;
http://www.1010tires.com/TireSizeCal...?action=submit
245/40/18R and 345/30/19R
Then your tire sizes shouldn't be causing a problem. You are stock diameter on the front and only 1.07% larger on the Rear.
Try this calculator;
http://www.1010tires.com/TireSizeCal...?action=submit
We installed Z06 fenders with the same size tires (245/40/18R stock goodyears and 345/30/19R pilot sports) on my son Joeys 07 without any issues. The car is a daily driver and he has over 3,000 miles since we installed the kit & tires. There has to be something else causing the problem.
Tech Contributor
Joined: Jul 2002
Posts: 14,950
Likes: 264
From: St. Louis, MO
St. Jude Donor '08
Excellent website haljensen!
Jeff, I recalculated the numbers too, your rears are .29 inches taller than stock, which causes your front/rear ratio (stagger) to be 1.056 vs. 1.044 stock, which is only 1.1%. FYI stock C6 Z06 stagger is 1.043 stock.
Tread Sidewall Rim Ht in inches Stagger
Stock
245 40 18 25.71"
285 35 19 26.85" 1.044
Current
245 40 18 25.71"
345 30 19 27.14" 1.056
Diff in rears - diff in stagger 0.29" 0.011 = 1.1%
Optimal with new rears
255 40 18 26.03
345 30 19 27.14 1.043
Pilot sports are made in 255/40/18.
But I have to agree with the poster above, now that I took the time to run the numbers, this .29", 1.1% difference doesn't seem like a lot.
Can you readily replicate the problem? If you can find a spot where it does it, then borrow Craig's stock tires and try to replicate it with his. That's what I would do before I bought more tires.
There's also an excellent white paper on drag control in this thread that might help you find a spot to replicate it.
http://forums.corvetteforum.com/show...t=drag+control
Jeff, I recalculated the numbers too, your rears are .29 inches taller than stock, which causes your front/rear ratio (stagger) to be 1.056 vs. 1.044 stock, which is only 1.1%. FYI stock C6 Z06 stagger is 1.043 stock.
Tread Sidewall Rim Ht in inches Stagger
Stock
245 40 18 25.71"
285 35 19 26.85" 1.044
Current
245 40 18 25.71"
345 30 19 27.14" 1.056
Diff in rears - diff in stagger 0.29" 0.011 = 1.1%
Optimal with new rears
255 40 18 26.03
345 30 19 27.14 1.043
Pilot sports are made in 255/40/18.
But I have to agree with the poster above, now that I took the time to run the numbers, this .29", 1.1% difference doesn't seem like a lot.
Can you readily replicate the problem? If you can find a spot where it does it, then borrow Craig's stock tires and try to replicate it with his. That's what I would do before I bought more tires.
There's also an excellent white paper on drag control in this thread that might help you find a spot to replicate it.
http://forums.corvetteforum.com/show...t=drag+control
Thread Starter
Safety Car
Joined: Dec 2004
Posts: 4,477
Likes: 2
From: Boca Raton, FL
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14
Glad to hear it is not the tires, just saved about $500. As to running Craig's tires, I was running OEM front and rear while waiting for the new rims and did not have any DIC reading.
Now, this might sound silly and maybe I'm just looking for ways to "cure" this DIC notice. But, I took the car to Roger's yesterday for an oil change, both regular oil and supercharger oil, and had them clean and oil the SC filter. I have not seen the DIC notice since.
This might be happenstance or maybe I've purposely stopped looking at the DIC
, I'll need to see what happens in the next few days.BTW, the folks at Horsepower were equally confused, and you know that doesn't happen easily.
Oh well, let's see what happens.
Jeff
Last edited by schilitj; Jun 2, 2007 at 09:55 AM.
Race Director
Joined: Mar 2005
Posts: 10,399
Likes: 26
From: Austin Texas
Terminology dates me. The first time I heard it used was oval track stock cars where one side wheels/tires were larger than the other side to "help" the car turn. As used for the 'Vette it's the the smaller front tire diameter vs. the larger rear tire diameter.
Thread Starter
Safety Car
Joined: Dec 2004
Posts: 4,477
Likes: 2
From: Boca Raton, FL
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14
Race Director
Joined: Mar 2005
Posts: 10,399
Likes: 26
From: Austin Texas
I'll be 65 in July. SS and K-Mart retirement $$ already trickling in. May have to get a part time job to afford future mods.
Thread Starter
Safety Car
Joined: Dec 2004
Posts: 4,477
Likes: 2
From: Boca Raton, FL
St. Jude Donor '05-'06-'07-'08-'09-'10-'11-'12-'13-'14
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