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I am a ZR1 owner and had the chance to drive a 7 speed Z06, what is with the bog or hesitation off idle? I've heard other new Z's doing the same. I really liked it other than the stumble off idle and what seemed like less low rpm power.
Mainly in the tune because most people that buy these cars can't possibly drive them safely without such handicaps. For me a ported throttle body helped the issue somewhat. I have an M7. Some people say a CAI helps as well. True fix, I'm told, is a tune. This is why I've been considering a Diablo tune. The throttle hesitation is the only thing that irks me about the car. Also, FWIW people will say the Vitesse fixes it...it doesn't.
Mainly in the tune because most people that buy these cars can't possibly drive them safely without such handicaps. For me a ported throttle body helped the issue somewhat. I have an M7. Some people say a CAI helps as well. True fix, I'm told, is a tune. This is why I've been considering a Diablo tune. The throttle hesitation is the only thing that irks me about the car. Also, FWIW people will say the Vitesse fixes it...it doesn't.
Why would GM tune a hesitation into the car? It actually seems more dangerous vs better throttle response.
Just picked up a 17' Z06 (A8) and I noticed this on the freeway. Yesterday on the freeway I slowed down to around 62 mph from 75 mph and I pressed the throttle very little and it felt weird. Felt like it was in 8th gear at really low rpm and it took a sec for it to start going. I've read a few threads that have said this is normal. My brother drove the car and he noticed it as well. Anybody know what's up?
Last edited by SharkgrayVetteZ06; 10-27-2016 at 01:01 PM.
People talk about the loads of torque, all the way across the RPM band, and all the horsepower off the C7 Z06, and they post up dyno graphs to prove it.
But, those dyno graphs are with the engine under WOT and under boost from the supercharger.
Low RPM and partial throttle is what people are seeing when they ease away from a stop sign, or give it a little gas on the highway to speed up. Under those conditions the engine is not in boost and is nothing more than a normally aspirated engine. The bypass valve is open and the rotors are spinning but not moving any air under pressure. The incoming air passes through the throttle body, through the bypass valve, through the intercooler bricks(which also offers some restriction to the airflow) directly to the intake valves.
The LT4 only has 10:1 CR, vs the 11.5:1 CR of the LT1 or the 11.0:1 of the C6 Z06 etc. At low RPM the lower CR make the engine is less responsive and less efficient, when not in boost.
The gas mileage figures you see are based on normal part throttle driving and not at WOT and under boost in the case of the LT4. The lower CR is the reason the highway gas mileage is lower for the LT4 vs the LT1 or the LS7. The LT4 is not as efficient under those low RPM, part throttle, no boost, driving conditions.
People talk about the loads of torque, all the way across the RPM band, and all the horsepower off the C7 Z06, and they post up dyno graphs to prove it.
But, those dyno graphs are with the engine under WOT and under boost from the supercharger
Low RPM and partial throttle is what people are seeing when they ease away from a stop sign, or give it a little gas on the highway to speed up. Under those conditions the engine is not in boost and is nothing more than a normally aspirated engine. The bypass valve is open and the rotors are spinning but not moving any air under pressure. The incoming air passes through the throttle body, through the bypass valve, through the intercooler bricks(which also offers some restriction to the airflow) directly to the intake valves.
The LT4 only has 10:1 CR, vs the 11.5:1 CR of the LT1 or the 11.0:1 of the C6 Z06 etc. At low RPM the lower CR make the engine is less responsive and less efficient, when not in boost.
The gas mileage figures you see are based on normal part throttle driving and not at WOT and under boost in the case of the LT4. The lower CR is the reason the highway gas mileage is lower for the LT4 vs the LT1 or the LS7. The LT4 is not as efficient under those low RPM, part throttle, no boost, driving conditions.
That has nothing to do with throttle hesitation, the ZR1 only has 9:1 compression with no stumble off of idle, it's definitely in the factory calibrations, but why is my question. It border lines on dangerous because the car almost feels like it's going to stall because it doesn't respond off idle.
Mine doesn't stumble. Take it to the dealer (or whoever owns the one you drove should take it in, I guess).
You're claiming it has lag so bad it's border-line dangerous, which I'm pretty sure means something is wrong somewhere. Unless this is just another "C6 owner trolling C7 owners", but I'll give the benefit of the doubt up front!
Also, the amount of low RPM power always exceeds available traction in my car, so if you're finding it slow, it must be hooking up, which it likely shouldn't be. Particularly with MPSS, there's no way I can keep mine planted in 1st. Wish I could, but I wound up with drag radials instead due to it.
Mine doesn't stumble. Take it to the dealer (or whoever owns the one you drove should take it in, I guess).
You're claiming it has lag so bad it's border-line dangerous, which I'm pretty sure means something is wrong somewhere. Unless this is just another "C6 owner trolling C7 owners", but I'll give the benefit of the doubt up front!
Also, the amount of low RPM power always exceeds available traction in my car, so if you're finding it slow, it must be hooking up, which it likely shouldn't be. Particularly with MPSS, there's no way I can keep mine planted in 1st. Wish I could, but I wound up with drag radials instead due to it.
Dave
Not trolling at all, I really liked the ride in tour mode (Z07) the ease of the clutch and transmission and loved the rev match, but right off idle initial throttle input causes a very noticeable lag or hesitation. I was watching a guy pick up his brand new Z06 vert and while the salesman was walking him through the car while it was running the guy would hit the gas and I could hear it stumble. (Off idle only) Plus I will say my ZR1 felt much stronger in the lower rpm's.
You must be comparing part-throttle to part-throttle then and you don't like the throttle mapping, but that's about all I can think of.
For all I know the throttle mapping was optimized to get the M7 to pass the EPA drive loop and avoid gas guzzler tax (that's my actual best guess).
Have you driven a ZR1? The person I know owns both and agrees with me, I'll leave it at that. Again this is not a slam to the Z06, I loved it, but the lag would drive me nuts and tuning it out would void the warranty I assume. I was wondering if people were finding a fix for the issue.
Have you driven a ZR1? The person I know owns both and agrees with me, I'll leave it at that. Again this is not a slam to the Z06, I loved it, but the lag would drive me nuts and tuning it out would void the warranty I assume. I was wondering if people were finding a fix for the issue.
You can leave it at that, but my car doesn't do it, so I'm not sure what your point is - this car has a problem or ALL new Zs have a problem?
Go drive one that doesn't do that, like mine. But not mine :-)
I was watching a guy pick up his brand new Z06 vert and while the salesman was walking him through the car while it was running the guy would hit the gas and I could hear it stumble. (Off idle only).
My M7 will hesitate when I attempt to free rev it in neutral, but I feel no hesitation when I'm driving it in gear. The Rev Match feature is able to rev the motor very quickly with a race car like sound when you downshift. IMO the neutral rev hesitation is a protection factor of the OEM tune. I've never driven a ZR1 so I can't comment on how the two cars compare.
Have you driven a ZR1? The person I know owns both and agrees with me, I'll leave it at that. Again this is not a slam to the Z06, I loved it, but the lag would drive me nuts and tuning it out would void the warranty I assume. I was wondering if people were finding a fix for the issue.
jcguy, you touched on a sensitive subject on this Forum. The "bog" or hesitation is definitely there on my M7, '016 Z06. I have noticed it considerably less in Sport mode than in Tour mode. And, you're correct, in Tour mode, it can be dangerous. It shouldn't be necessary to feed this beast all kinds of fuel to get it going when you're stopped on a hill and that's what you get in Tour mode, less in Sport mode, but it is still there. From all my hunting and talking with a few aftermarket manufacturers (like Vitesse), the action that cures this ill is a tune. Can't explain why GM has it designed this way on an OEM ECM, but they do and they just don't want to correct that issue. You do learn to live with it, though.
You can leave it at that, but my car doesn't do it, so I'm not sure what your point is - this car has a problem or ALL new Zs have a problem?
Go drive one that doesn't do that, like mine. But not mine :-)
Lol, Dave I definitely wouldn't drive yours, BUT it seems your car is in the minority here considering the other posts stating exactly the same thing I am. I was simply curious to see if GM had addressed this and if not what the reason was for setting it up that way.
My M7 will hesitate when I attempt to free rev it in neutral, but I feel no hesitation when I'm driving it in gear. The Rev Match feature is able to rev the motor very quickly with a race car like sound when you downshift. IMO the neutral rev hesitation is a protection factor of the OEM tune. I've never driven a ZR1 so I can't comment on how the two cars compare.
Good point, in a 7 speed I'm guessing it's more noticeable because of slipping the clutch to get moving.
Have you driven a ZR1? The person I know owns both and agrees with me, I'll leave it at that. Again this is not a slam to the Z06, I loved it, but the lag would drive me nuts and tuning it out would void the warranty I assume. I was wondering if people were finding a fix for the issue.
I have owned 2 C6Z's one stock and one I had built, stage 4 BTR cam, PRC heads, intake and exhaust. I have driven my friends ZR1 multiple times and it does not have the lag! I currently own a 16Z M7 and know exactly what you are talking about. I have taken my car back to the dealer twice for the hesitation when you are coming of the clutch from a stop, with no resolution from the dealer.
I know when you leave the exhaust in the auto mode and drive in the tour mode it is less noticeable.
Last edited by 04screamin; 10-27-2016 at 04:15 PM.
10-27-2016, 11:48 AM
Noticeable hesitation
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