Higgs....I luv ya....but some of us are NOT ...liberals. lol "Some of US drink motor oil and take care of our diaper rash with white lithium and we love the smell of race gas in the morning." Well said.

 

Doesnt throwing an extremely modified throttle body do the same thing?


btw, Lets not tribe up and start throwing political labels around. I dont care what your politics or religion you are in my corvette hobby.

An interesting 3rd option would be this new throttle body PLUS tuning. Could we actually see improvement better than just one solution alone?

 

At some point the cup just overflows.

 

Good to see Higgs following this thread. The end result with the OP and Higgs involved should be worthwhile. By the way, Higgs is probably not trying to suggest everyone here is a liberal. Many posts here suggest the opposite.
The tune change being suggested (DD tables, Max. engine Tq., pedal vs. RPM) is a massive tool which can totally change how the ZO6 operates and seems to be set that way to keep old guys like me from getting into trouble off idle with unintended throttle input.
The throttle body designed long ago for a different vehicle, does not seem to have been designed to introduce a hesitation off idle, etc.
Maybe the OP and Higgs can give us the real answer.

 

The liberal comment was tongue in cheek of course.

I have a 103 TB and a whipple and without the proper tune adjustments it will still lag and roll open slowly so I don't know what that means.....

 

There are tunes introduced to accept new mods/changed hardware w/o having codes/issues. This type is not needed as long as the changes are within the limits of ECM compensation for Mfg variations, dirt, ice, normal wear ect. This type of tune is not needed w/ this modification.

The other type of tune may be used in combination w/ hardware changes, and I think this is the type that would apply here. There is something else other than the throttle geometry adding to the delay. Although the throttle geometry is the main cause.

Not pedal mapping, IMO. I personally tried a TC in combination w/ the modified TB and yes, it overflowed the cup. The car would spin tires and fishtail at will. One can certainly get used to it but, in a moment when accurate tip in is needed it may be too much, dangerous I’d say. It’s a matter of taste, skill, and risk tolerance. Not recommended.


As far as I know, before ETC, throttle bodies used to be of the straight bore type, which respond naturally fast (large rate of change of flow area vs. angle). They also had an idle control valve to take care of the meager air flow needed to idle. So, as soon as you pulled the cable the car would get moving w/o hesitation.

When ETC was introduced, MAF sensors were expensive, so they shaped the body as an S to be able to meter air w/ the blade and get rid of the idle control valve. But that shape introduced a delay or lack of responsiveness, the inventor himself said it in the patent application.

Today, ~30 years after the invention, sensors have become so cheap and ECM capabilities have evolved so much, that they don’t need the blade metering the air anymore, but the S shape TB found another application/benefit, that is, fuel economy. The worst specific fuel consumption happens when accelerating from a stop to cruising speed, and it is well known that the longer that process take the better your fuel economy is. S shaped TB’s are great for this. They can also use a less expensive (lower resolution) stepper motor to control the blade.

 

So if you go all the way to the premise that GM chose this part for price and gas mileage, does tuning around this tip in hesitation make the throttle too aggressive off idle for public consumption as defined by GM? GM could have tuned it that way.

 

Jim, tuning can help w/ the electronic part of the problem (whatever it is). There is a mechanical component of the issue, from 0 deg to 35 deg the blade edges barely separates from the body contour. Which is what I'm going for.

I'm sure GM/Delco could have made a much better (responsive) TB along w/ its corresponding factory tune for that purpose and specifically for the C7's. Tip in wouldn't be anymore dangerous than tip in on other comparable cars that feel right/responsive. I don't think it was done for safety, there is one more reason, look at the list our TB's p/n apply to:

...and I think there are still more models, still looking. I refuse to believe one TB fits all.

 

Test results here: https://www.corvetteforum.com/forums...post1598860139

 

Great stuff. Look forward to buying one of your TBs when the testing is done and you are fully set up.

 

I love how an innovative idea/thread turned into the typical debate of who is right.

From my VERY limited knowledge of the subject from research on forums/posts I have come to the conclusion that the problem lies in both areas. Hardware and software and we have the typical fight between engineers on hardware vs software. GM purposely tuned the C7 to be more subtle in throttle response simply bc the car is made for the masses. Of the 100k plus corvettes out there, only a small group of owners want it to be more aggressive, others are fine with the stock performance. If any company wants to sell something, they make if for the masses, not the select few. Think of a computer virus. Apple fan boys will tell you, Apples don't get viruses. That's not true, Apple computers make up about 15% of the environment as a result, if you were a hacker/virus coder, would you write a virus for 15% of the population or write a virus for 85% of the population? Which is going to give you the most return? We have a similar example here. A piece of software was written for the masses, not the few. Furthermore, when a manufacture creates a product they aren't going to create a product that can only be used on a small percentage of their vehicles, I am going to assume here that parts of this TB are in use across the GM line in some why or the other.

My question is why can't both views on the subject be right? We have several engineers that have tuned out the lag via software and several engineers that have manipulated hardware to get the same result. Without offending those that posted here, are the credentials of a tuner the same of a software engineer that has 10,000's of hours coding and writing the programs that go into our cars? Is the OPs knowledge on the same level of that of the engineer that also spent 10,000's of hours designing parts for fleets of vehicles? Simply, the answer is No. However that doesn't stop them from challenging status quo. Some people decide to over clock their CPU in a machine to gain better performance, others will go buy a different processor for their rig. Again, software vs hardware.

Personally, i think gemtech's arrogance was clearly present in is "lol" statement and started his post in a hostile tone because his knowledge is being threatened to some extent. Someone above made a great statement relating to the fact that on these forums its common/second nature to put other people down if we don't agree with them. That's part of the problem with this world. Especially when they can hide behind a screen, that is the definition of a troll vs a professional opinion.

Okay, I am off my soap box... OP, thank you for the time and effort you put into a redesign of hardware, sir. And a shout out the tuners out there as well that put in the effort to make cars what the owners want them to be via overwriting software.

I am close to pulling the trigger on a Mamo TB and this caught my eye, perhaps I will get both and post my thoughts about how the car "feels" to me. Because that is what is important, my opinion of what my car should feel like.

 

^^^^^ Couldn't agree more. Just a couple of comments.

For more than I love my C7, I have to say the response is slow even for "made-for-the-masses" standards. I don't think anyone would expect the feel of a 200-300 lb/hp weight to power ratio at part throttle. I used to get very puzzled every time I drove my wife's SUV and it felt more responsive than my relatively tiny more powerful C7. I think it was a mistake to push this engine(s) towards the 30 mpg threshold. IMO the designers played so close to the boundaries of what it could squeezed in efficiency that they went too far. Add to that; manufacturing variations, statistical tolerancing and the like. The result is that for some of us, the engine cannot/barely meet the road loads. Those w/ the "stumble" and the "hesitation" can attest to that, I can't believe they were intentionally introduced, they sound like problems to me, can't say I find finesse/subtlety on them.

I'll admit that I can't have the level of those actually making these. As I said before, seems like they had a different goal, and that is the edge we (those challenging the status quo) have. Had they attempted to make a more responsive TB (also taking safety in mind), I'd have no place here. We wouldn't even be talking about this.

Yes sir, tuners can do their part here too, please do.

Finally, hardware can exist w/o software, but not vise-versa. It is only after fixing the hardware that software can aspire to do something decent...don't really want to get more philosophical or the thread will go the wrong way.

Thank you!

 

Agreed, we would have never of moved away from a carbonated engine to a computer managed fuel system. :0)

 

All the best to you with this. The stock throttle response is sluggish. I tried a Vitesse but pulled it and put on a Mamo throttle body. Big improvement and not placebo despite what some may claim.

 

More test results/reviews here:

https://www.corvetteforum.com/forums...post1598860139

 

Sluggish and they (GM) know it. I took my car to the dealer for this and they said it is a normal characteristic, there is a TSB that says it plainly. I can't remember the exact words but it was something along the lines of " do not repair, this is the way it is supposed to be". So, maybe it was designed like that on purpose, a high-performance sports car w/ hesitation, amazing!

 

hesitation and understeering, in the name of public safety!

 

OEM tune has throttle body not opening to 100% until 3200rpm.. at least on the LT1 equipped models. Also as mentioned above, Spark, Driver demand etc etc. All can make this issue non-existent with a capable tuner.

 

There is a simple fact, from 0-30 deg (first 33% of throttle) the distance from the throttle blade edge to the throttle body contour defines an area that keeps the flow chocked, and the corresponding weight to power ratio in that range is about 200-300 lb/hp (feels very heavy). There is absolutely nothing a tune can do to erase this.

A tuner can make the blade jump from 0 to 30 deg in no time and skip this low flow region, but the manifold pressure won't recover at the same time and when it does you'll will be going straight to an area where the airflow is way too high w/o any type of transition. I don't think anyone would enjoy the jolt and the consequences for the drive-line, not to mention it will be dangerous/uncontrollable.

IMO, tuners should concentrate on the known issues within torque management. Like; the .7 s delay when rolling to stop then applying the throttle, or the .5 s of zero torque after coming to a hard stop on a A6/A8 and applying throttle. And still, you can't be too aggressive here as the A6/A8 need some time to complete the shifts.

 

We'll be launching our website this weekend!