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I wouldn't want to attempt to beat a McLaren from a roll in anything, they are absolute beasts bone stock, I still wouldn't want one.
Once they release a C8 with the C8Z engine and AWD I will be in line.
Yeah they trap 145-148 .. from what I am seeing the Erays are not really pulling that much harder off the line vs Z on the street or the track.. 911 turbos are dig monsters
I wouldn't want to attempt to beat a McLaren from a roll in anything, they are absolute beasts bone stock, I still wouldn't want one.
Once they release a C8 with the C8Z engine and AWD I will be in line.
They’re a missle in a straight line, that’s why I was happy run within a tenth of a second on a 3.1 mile road course recently…
I don't have a horse in the race on this, just a data guy following the debate for fun. This definitely points out a disparity in the two measurement systems. How do we know what the truth is for the situation (it may be neither the dragy or the PDR)? Does this need to be done on a drag strip with a beam-based timing system, then compared to Dragy and the in-vehicle metrics?
With all of the debate on here about one vs the other, I'd think there'd be appetite for a video of this for someone with access to a dragy and a C8 with the latest version of the PDR.
I don't have a horse in the race on this, just a data guy following the debate for fun. This definitely points out a disparity in the two measurement systems. How do we know what the truth is for the situation (it may be neither the dragy or the PDR)? Does this need to be done on a drag strip with a beam-based timing system, then compared to Dragy and the in-vehicle metrics?
With all of the debate on here about one vs the other, I'd think there'd be appetite for a video of this for someone with access to a dragy and a C8 with the latest version of the PDR.
The Dragy has shown consistent data to a dragstrip timer, many people have run at the strip with the Dragy on and the results are always less than 0.1 difference in the 1/4 mile.
0-60 times off by 0.5 between the PDR and Dragy show a huge flaw in the in car PDR.
Remember, Chevy wants to sell cars, taking your buddy out and showing him 2.x sec 0-60s is much more impressive than 3.x second 0-60s.
I don't have a horse in the race on this, just a data guy following the debate for fun. This definitely points out a disparity in the two measurement systems. How do we know what the truth is for the situation (it may be neither the dragy or the PDR)? Does this need to be done on a drag strip with a beam-based timing system, then compared to Dragy and the in-vehicle metrics?
With all of the debate on here about one vs the other, I'd think there'd be appetite for a video of this for someone with access to a dragy and a C8 with the latest version of the PDR.
Hmm, I started this thread and don’t give a crap about which is accurate! Don't care if GM system is "right" just making comparisons. Second, no one knows how the dash 0 to 60 test on my E-Ray is run. May have nothing to do with the PDR! GM switched from other sensors to a matrix of accelerometers to operate the MRC a few years ago. Local to use those. They sense movement in all directions. Operate at very high speeds. Very accurate. Perhaps that is what is used.
They may add a rollout- don’t care, it’s comparative numbers I evaluate not posting values for the Gunness Book Of Records.
Don't have a horse in what is the perfectly accurate data! Thread gets hijacked into unrelated augments that I don't care about- so beit! Perhaps at the BASH someone can ask what the 0 to 60 mph test on the right side of the E-Ray dash is based on. I'm comparing what I do, outside temp, with passenger etc and the numbers achieved.
The Dragy has shown consistent data to a dragstrip timer, many people have run at the strip with the Dragy on and the results are always less than 0.1 difference in the 1/4 mile.
0-60 times off by 0.5 between the PDR and Dragy show a huge flaw in the in car PDR.
Remember, Chevy wants to sell cars, taking your buddy out and showing him 2.x sec 0-60s is much more impressive than 3.x second 0-60s.
Correct. The dragy has been verified for years. Most of the professional racers and teams use it.
Hmm, I started this thread and don’t give a crap about which is accurate! Don't care if GM system is "right" just making comparisons. Second, no one knows how the dash 0 to 60 test on my E-Ray is run. May have nothing to do with the PDR! GM switched from other sensors to a matrix of accelerometers to operate the MRC a few years ago. Local to use those. They sense movement in all directions. Operate at very high speeds. Very accurate. Perhaps that is what is used.
They may add a rollout- don’t care, it’s comparative numbers I evaluate not posting values for the Gunness Book Of Records.
Don't have a horse in what is the perfectly accurate data! Thread gets hijacked into unrelated augments that I don't care about- so beit! Perhaps at the BASH someone can ask what the 0 to 60 mph test on the right side of the E-Ray dash is based on. I'm comparing what I do, outside temp, with passenger etc and the numbers achieved.
If it’s inconsistent how can you compare results? PDR has had glitches on lap times where it’s off by seconds, people who are consistent drivers realize this and don’t just believe it because the car said it happened.
If it’s inconsistent how can you compare results? PDR has had glitches on lap times where it’s off by seconds, people who are consistent drivers realize this and don’t just believe it because the car said it happened.
I'll say it one MORE time you nor I have any idea if the test to the right of the center dash anything has to do with the PDR. That test was NOT on my 2020 C8 Z51. It may well use the matrix of accelerometers GM switched to for MRC input a few years ago.
So until GM says what the accuracy is or isn't I'll use it.
SIDEBAR Heck I have been drag racing since 1959. Then it was my seat of the pants accelerometer that controlled my left foot slipping the clutch. Had to do the same on my friends 1967 435 hp 427 Vette! No didn't need an instrument!
Even my current Street Rod, with its set back 8.2 liter engine, 53% of its 3000 lb static weight on the 16.5 inch section width tires ONLY has postreaction in the Currie 9" Ford dif. I have the adjustable 4 bar link rear set with an instant center a foot or more in front of the car so get lots or rear weight transfer at launch. The adjustable height rear coilovers set for equal TIRE load at launch. But if one tire losses traction have <1/2 second to lift or you're in a ditch. Yep seat of paints accelerometer is what I use!
Spent several months fie tuning the 850 Holley. That required an Oxygen sensor in the Sanderson Log Tube header collector. Had to block the power valve and use jet expansions for the rear with proper jest. Also found had to add two 50 CC accelerator pumps front and back of the 850 double pumper. BUT had to select the proper accelerator pump cam for quick large volume squirt BUT did not dump the fill 50 CCs.
Yep, Holley has 8 different accelerator pump cams with various ramps to control the amount and timing of fuel. had to use jet's jet extensions for the rear bowl and accelerator pump squirters that had to be evaluated to eliminate slight hesitation. Was fun to finally getting it right. Used my G-Tech Pro accelerometer 23 years ago to accomplish the task. Now it mostly goes to Car Shows! Have several pages on my website with how set Holley's that get may visits from old timers who still use carbs!
I'll say it one MORE time you nor I have any idea if the test to the right of the center dash anything has to do with the PDR. That test was NOT on my 2020 C8 Z51. It may well use the matrix of accelerometers GM switched to for MRC input a few years ago.
So until GM says what the accuracy is or isn't I'll use it.
SIDEBAR Heck I have been drag racing since 1959. Then it was my seat of the pants accelerometer that controlled my left foot slipping the clutch. Had to do the same on my friends 1967 435 hp 427 Vette! No didn't need an instrument!
Even my current Street Rod, with its set back 8.2 liter engine, 53% of its 3000 lb static weight on the 16.5 inch section width tires ONLY has postreaction in the Currie 9" Ford dif. I have the adjustable 4 bar link rear set with an instant center a foot or more in front of the car so get lots or rear weight transfer at launch. The adjustable height rear coilovers set for equal TIRE load at launch. But if one tire losses traction have <1/2 second to lift or you're in a ditch. Yep seat of paints accelerometer is what I use!
Spent several months fie tuning the 850 Holley. That required an Oxygen sensor in the Sanderson Log Tube header collector. Had to block the power valve and use jet expansions for the rear with proper jest. Also found had to add two 50 CC accelerator pumps front and back of the 850 double pumper. BUT had to select the proper accelerator pump cam for quick large volume squirt BUT did not dump the fill 50 CCs.
Yep, Holley has 8 different accelerator pump cams with various ramps to control the amount and timing of fuel. had to use jet's jet extensions for the rear bowl and accelerator pump squirters that had to be evaluated to eliminate slight hesitation. Was fun to finally getting it right. Used my G-Tech Pro accelerometer 23 years ago to accomplish the task. Now it mostly goes to Car Shows! Have several pages on my website with how set Holley's that get may visits from old timers who still use carbs!
PDR or timer why do they not match? GM isn’t going to claim any accuracy, the lower it reads the better as someone already stated it’s not in their interest to be accurate. It’s like a spike in a dyno graph, that states an inflated number though shouldn’t be considered. Believe whatever you want, truth isn’t relevant these days. With your logic a Prius owner could say his on board timer says it did 0-60 in 1.9 and it should be believed unless Toyota says otherwise.
PDR or timer why do they not match? GM isn’t going to claim any accuracy, the lower it reads the better as someone already stated it’s not in their interest to be accurate. It’s like a spike in a dyno graph, that states an inflated number though shouldn’t be considered. Believe whatever you want, truth isn’t relevant these days. With your logic a Prius owner could say his on board timer says it did 0-60 in 1.9 and it should be believed unless Toyota says otherwise.
GM went to a matrix of accelerometers to control MRC from devices position sensors on the "A" frame (see pic below.) Perhaps that is what they are using on the "New To Me" 0 to 60 test on the right ride of the center dash. Was NOT on my 2020 C8 Z51. Does not need all the inputs used for the PDR. In fact GM may pay Cosworth for whatever they use for PDR? Have not even looked at my PDR output as am not close to reaching the 1.3 peak "g" I did with my 2020 C8 MRC! Know that from my seat of paints accelerometer! I'll gradually get there! As Mario Andretti said when someone asked if he is nervous when he takes turns at Indy at WOT. He said sure anyone would be a fool who doesn't. But I gradually increase speed and get my mind to understand it's safe!
One reason I did not get MRC with my 2014 C7 Z51 was the spindly sensors prone to damage that were used. This is one on the "A" Arms! Now they use a matrix of very accurate fast accelerometers for MRC. Provides input in all directions. They could easily use than for the "NEW TO ME" 0 to 60 test on the right of my E-Ray Dash! May be very repeatable even if they add roll-out etc. Good for what I am doing and very simple to use and get instant feedback! As I have said, NOT looking to submit the data to the Guinness Book of Records.
PS: Perhaps if you do not wish to understand the many Silent Majority who view Threads but don't or will not post will like the info. This thread is a good example. Probably ~25 of us Vocal Minority (like you and I) who have posted (multiple times.) There are ~3000 Silent Majority who viewed but didn't post (look at the Thread statistics.) Many won't post! At this month's Car's & Coffee there were >40 Vettes of the 400 cars. Have asked many if they view the Forum. Most said yes but won't post, too many negative foolish responses. Thankfully I'm not one! Get many PM's thanking me for posting!
GM went to a matrix of accelerometers to control MRC from devices position sensors on the "A" frame (see pic below.) Perhaps that is what they are using on the "New To Me" 0 to 60 test on the right ride of the center dash. Was NOT on my 2020 C8 Z51. Does not need all the inputs used for the PDR. In fact GM may pay Cosworth for whatever they use for PDR? Have not even looked at my PDR output as am not close to reaching the 1.3 peak "g" I did with my 2020 C8 MRC! Know that from my seat of paints accelerometer! I'll gradually get there! As Mario Andretti said when someone asked if he is nervous when he takes turns at Indy at WOT. He said sure anyone would be a fool who doesn't. But I gradually increase speed and get my mind to understand it's safe!
One reason I did not get MRC with my 2014 C7 Z51 was the spindly sensors prone to damage that were used. This is one on the "A" Arms! Now they use a matrix of very accurate fast accelerometers for MRC. Provides input in all directions. They could easily use than for the "NEW TO ME" 0 to 60 test on the right of my E-Ray Dash! May be very repeatable even if they add roll-out etc. Good for what I am doing and very simple to use and get instant feedback! As I have said, NOT looking to submit the data to the Guinness Book of Records.
PS: Perhaps if you do not wish to understand the many Silent Majority who view Threads but don't or will not post will like the info. This thread is a good example. Probably ~25 of us Vocal Minority (like you and I) who have posted (multiple times.) There are ~3000 Silent Majority who viewed but didn't post (look at the Thread statistics.) Many won't post! At this month's Car's & Coffee there were >40 Vettes of the 400 cars. Have asked many if they view the Forum. Most said yes but won't post, too many negative foolish responses. Thankfully I'm not one! Get many PM's thanking me for posting!
Appreciate the detailed explanations, but trying to figure out which is more accurate your seat of the pants g-meter or the cars 0-60 timer?
Yep, as I mentioned, GM probably used rollout in their calculations. Why not that is what you read with magazine data!
Most magazines use a Vbox to calculate time with a 1 foot rollout. Quoting, "Car and Driver is now including a 1-foot rollout before starting the clock during acceleration testing." Using rollout can add 0.3 to 0.5 seconds.
Why wouldn't they, it is what the magazines are doing and what you see reported. As I said, if going for a Guinness World Record I get the folks who check speeds at Bonneville Salt Flats, the Southern California Timing Association. That is NOT what I’m doing or care. I’m making a comparison with various factors, Ambient Temp, Tire heating, launch type etc.
I did note in his tests the dash value was consistent. That is all I care about. As I have been doing, I'll continue to report future data with how measured and a Pic of the Dash on my Threads and Posts.
Bear said he will run tests as well and compare with his instrumentation. Look froward to seeing his results.
Yep, as I mentioned, GM probably used rollout in their calculations. Why not that is what you read with magazine data!
Most magazines use a Vbox to calculate time with a 1 foot rollout. Quoting, "Car and Driver is now including a 1-foot rollout before starting the clock during acceleration testing." Using rollout can add 0.3 to 0.5 seconds.
Why wouldn't they, it is what the magazines are doing and what you see reported. As I said, if going for a Guinness World Record I get the folks who check speeds at Bonneville Salt Flats, the Southern California Timing Association. That is NOT what I’m doing or care. I’m making a comparison with various factors, Ambient Temp, Tire heating, launch type etc.
I did note in his tests the dash value was consistent. That is all I care about. As I have been doing, I'll continue to report future data with how measured and a Pic of the Dash on my Threads and Posts.
Bear said he will run tests as well and compare with his instrumentation. Look froward to seeing his results.
Rollout is good for 0.2 to 0.3 and should land the E-ray in the 2.5-2.6 range on a great run.
0-60 in 2.1 on the street or track with the E-ray is not possible.
Also, the dash value is consistently wrong, mine always showed 2.8 on my C8 Z51, but my Dragy results contradicted that.
The Dragy has been proven to be accurate.
You seem to be an intelligent guy trying to justify what has been proved as a flawed in car timer.
Rollout is good for 0.2 to 0.3 and should land the E-ray in the 2.5-2.6 range on a great run.
0-60 in 2.1 on the street or track with the E-ray is not possible.
Also, the dash value is consistently wrong, mine always showed 2.8 on my C8 Z51, but my Dragy results contradicted that.
The Dragy has been proven to be accurate.
You seem to be an intelligent guy trying to justify what has been proved as a flawed in car timer.
Correct and the faster the car the rollout takes less time, so I’d say the E-Ray is 2 tenth lower end and his reference to over .3 must be talking about smog era cars of his younger years.
04-22-2024, 11:15 AM
