I don't know.

Apparently cars built at different times may have a little different tolerance for running without sensors. You'll probably just have to try your car out to see what happens with no sensors in the back.

My experience is that, if you just swap out the rear tires to ones with no sensors but still have sensors in the front, you will immediately get notified of "xx psi" in the rears probably followed by "Limit Speed to 55" (the so-called "limp mode"). I was able to go as fast as I wanted to, but I wasn't driving aggressively. I believe I've read that if the G-load and yaw rate sensors detect forces over a certain amount that the car will reduce engine power on you.

If you have NO sensors at all (NO sensors in ANY wheels - all 4 wheels do not have any sensors, or they're not registered), that's when the one hour thingy comes into play. In that case, when you have gone for approximately one hour you'll get the "Service Tire Monitor" message followed by "limit speed to 55". You can just clear the messages from the DIC and keep driving for as much gas as you have in the tank. However.....if AH was off or you were in Comp mode, AH will automatically come back on and you can't turn it off again until you shut down the engine, restart, clear messages - then you can restart, clear any messages, and should be able to turn AH off or go into Comp mode again for another hour.

So....I think you can drive to the track 75 miles. You'll get "xx psi" almost immediately after you start driving, probably followed by the "limit speed to 55", but should be able to clear the DIC messages and drive as fast as you want to. But, DennisNJ says he has had the car shut down on launch at the strip - probably because of G-loads, and the car pulls power to keep you from going too fast on what may be flat tires. Again, you'll just have to try it in your car to see.

Bob

 

Thank You, This Is What I'm Looking For..

 

I realized what happened to me on my test drive. It took me less than an hour to drive the 50 miles to the track (going the long way on country roads with my girl driving leisurely and doing the limit below 50 mph) and not flooring it. Getting there, I shut it off for a bit. I went driving around for another 45 minutes and shut it off. I then went back home and stopped at the grocery store. Again, less than an hour. Then drove around town some more and went home. So no messages and no problems. Ditto with GlennHL. His drive to work is less than a half hour each way and he lives less than 2 miles from the strip. Naturally we all turn off the car while waiting in line at the strip. We also all at least disable TC and some even disable TC and AH at the strip.

After reading BEZ06 posts today, I put the BFG's back on and went on the freeway doing 70 mph. About 5 minutes doing 70 I got one and only one DIC message saying "Traction Active". It put me into "limp mode" where I could not power downshift, use the paddles etc. I then hit the TC button and happily got "traction control off". Everything went back to normal, I could power downshift, floor it, paddle shift etc. etc. Got off the freeway, turned back on TC, tried to floor it, could not do it and got the "traction active" message again. Hit the button, turned off TC and back in business once again. I never have got a "XX PSI" message, "Service Tire Monitor" message or "Limit Speed" message. In fact, it still read 29 psi from the oem tires (when bringing up the rear tires readout in the DIC) with the BFG's still on the car.

So the solution is when you put your drag radials on (at least for my 2007 car), you got to keep traction control OFF or TC and AH off from the get go. That keeps the computer from being able to turn "traction active" on. Oh, my tires pressure were 25 lbs for today's run. Next time I'll drop them to 20 and see what happens.

 

i turn ah and tc off every time i start the car and drove for a month purposely avoiding the sensors, for a month no problem until i hit the throttle hard and the traction was great

 

I went out again one more time and this time I turned off TC (only) prior to pulling out the garage. Went on the freeway, no messages, no limp, no nothing except everything was normal even power downshifting, flooring it and hitting 110 mph. Tires pressures were at 21, a bit slippery () but that doesnt matter since there are no rear tire sensors. The minute you hit that button, "traction active" comes back on, but you can still press the button once again go back to TC Off, Comp Mode, or TC and AH Off.

 

I pulled mine,( stock wheels) and put some hi polished on with new sensors. After 20 miles , dic says service tire sensors, no limp mode period. After a few days I figure'd out my dealer resets them for free
and have 3 more times. Each time I change wheels

 

Dennis will probably agree with our other premier forum drag racer, Ranger, who says you should never turn off the AH for straight line drag racing.

When you're going straight the AH will never activate no matter how much wheel spinning or straight line acceleration you have.

The AH will activate when the tail end starts to go sideways, and it can activate and stop small problems from developing into big problems before you can even sense what is happening. When the azz end starts sliding you want all the help you can get to keep out of the wall or the other guy's lane.

So, you can turn off TC when drag racing, but leave AH on.

Bob

 

I know that, I personally keep TC OFF only. Though some peope do keep TC and AH off, not smart IMO. Though I do believe Dennis recommends keeping TC and AH OFF when doing heat-up burnouts on the drag radials prior to staging.

 

Thank you so much for testing/retesting these theories/ideas, it should help us figure this all out.

 

Yes I do believe that he does that, as do I.

 

You know, there is that option for you and me doing Dennis's TPS cannister mod. Now that I got my BFG's mounted (which btw-stick out 5/16" beyond the fender with the C5 Z06 wheels-maybe should have gone Wagon Wheels), I dont feel like re-mounting/balancing them with sensors. Sensors are $110 shipped from Fred Beans and a Bartec programmer is about $140.

With his cannister idea, sticking those sensors in it and keeping it in the trunk compartment sounds like a good idea if my no sensor theories dont work in the long run..

 

You may need a forklift to get it up J/K
No seriously, thanks to this thread I don't have to make one of my own. I was going to ask a similar question about these sensors. Thanks again ~Chris

 

Yes I've thought about that option as well but I'm trying to avoid buying new sensors (or taking the ones out of my stock rears which I'll still be using when not racing) altogether, if I was going to spend the extra cash to buy them for the cannister mod I would likely just install them on my DR/rim set up and have them programmed.




Yeah that was one of the reasons why I avoided using the C5 Z06 rims (I actually had an OEM set of 4 that I'd used on my C4 and my Z28 but sold them years ago when I realized I was buying a C6 instead of a used C5 to put them on), they fit but aren't a perfect fit.
Rear wagon wheels or any rear C5 LS1 wheel (18x9.5 with a 65mm offset) fit very well but there are only a few DRs that fit well on them and the C5 fronts (17x8.5 with a 54 or 56mm offset) are good as well, they might even fit on the car better and not stick out but again are too narrow for any serious track duty because you can only fit a couple of different sized 17" DRs on there.
I'm using C5 fronts with a 275x40x17 and am hoping that 8.5" width (9" - 9.5" is ideal) isn't going to hurt me too bad.

 

FYI- Don't count on active handling saving you. I've had two instances in the past 5 months that it didn't work. The first one, going down a hill and making a very hard left, off camber turn, hit a bump and the *** end was in the air- I corrected before I hit down and saved myself a head on.

The second time- was just a few weeks ago- coming home- driving the speed limit- up shifting- and all of a sudden I'm sideway-I hit a spot of brine (put down for ice removal) if active handling came on its news to me- My *** told me I was in trouble and I had to recover.

All my cars have active handling - and on the others you can tell when it comes on. Nothing on the vette.

 

the first thing i do when i start the car is turn ah&tc off every time

 

The first thing I do when i start the car is leave ah&tc on every time (at least for street driving).

Street driving is not like driving on a track where oil dropped by another car, or dirt from somebody going off the track is seen by a corner worker who yellow flags his section until they clean up the track.

As has been stated, AH will not save you every time you hit crap in the roadway or your *** end starts going sideways, but when I'm taking an off ramp aggressively and some clunker has dumped oil or a gravel truck has dumped crap on the road, I'd like all the help I can get.

On the track, if you're trying to drift/power slide you can turn off AH and do what you want to do. But if you are driving a road course smoothly and maintaining max traction AH will rarely come on, especially if you're in Comp mode. If it does, you probably need it. Having it on may even teach you where you're driving is kind of ragged.

I agree that if you want to get more than 50% of the capability out of these cars that you need to know how to drive it with all the nannies off.

On the street you can't get 25% of what this car is capable of doing. I drive like a crazy maniac with his hair on fire, and I guarantee that I'm never able to get 20% out of my Z on the street (hell, I can't get 85% on the track!)

The Active Handling will NEVER activate during street driving unless you really need the help it might give you.

I've read the stories about people who end up going backwards down the opposite lane because AH "accidentally" came on. Butt.....I don't think there is ANY reason to turn off AH for street driving - even if you're Michael Schumacher. The only time I can think you might need AH off is if you're intentionally drifting the car.

Just my $.02, YMMV, and you can do whatever you need to do to feel good when driving your car.

Bob

 

There is a message that tells you if the active handling is on. Plus the system is nowhere as intrusive as the MBZ system, it allows you to slip a little before it kicks in.

 

hi Bob the reason i turn it off is because my car slide out at my own stupidity, i had the car about a year one night i left the hospital after seeing my son he was in an induced coma, i guess i wasn't thinking clear and stepped on it at a light as i went further into it it got sideways bad, i reacted straitened it out and that's were the problem began the ah took over after i corrected i was faster, now i had to correct for the ah then it for me. it got so violent i felt i had shaking baby syndrome, and got dizzy the g force back and fourth was on real i almost crashed into the cement center wall, this was all done after i let of the gas 20 times back and fourth finally right before i hit i floored it and cut the wheel to the right then gradually straightened it out. all i can say its like when abs brakes first came out people would pump and they just don't work like that. so i turn it off because i am better than ah, and i don't want to fight it again

 

AH (as well as TC and ABS) can be a very useful tool for those not fully in tune (and in some cases even those that are) with their cars but for those that had no trouble controlling their cars long before all these modern doodads and electronic gizmos (and some of the cars I'm referring to didn't even have the inherent abilities/benefits such as low center of gravity, high tech suspension, great tires etc. that a modern Corvette has) came into existence they really don't help all that much.
I drive my cars pretty hard yet NEVER get ABS to kick in unless I do it intentionally for fun while driving on a pure sheet of ice LOL.