[Mike@SolerPerformanceLLC]

There is a much debated problem w/ the throttle response of the LT1/LT4 engines, manual or auto, the issue has been described in this and other forums (Corvette, Camaro, CTS-V, Trucks, SUV’s), just to mention a few descriptions:

- Throttle Lag
- Delayed response
- Car feeling heavy or not nimble
- Difficulty climbing hills at low/moderate throttle
- Uncertainty when passing other cars or unpredictable response at low/moderate throttle
- Stumble when shifting on manual transmissions

You name it, this has been my issue w/ my Corvette 7 since test driving at the dealership. I've tried a Throttle controller, AFM disabler, ECM Tuning, and arguably the three most talked about ported throttle bodies (PTB) out there. I have also combined some of the above w/ some success but still not enough. One just needs to hop into almost any other comparable car to feel they respond better.

After spending so much time/money, I decided to take it upon myself to find out, I also have all the equipment needed at work (measuring, testing, simulating, machining etc.)

Long story short; it is the throttle body. Between idle (~5 degree throttle) to ~30 deg throttle angle the amount of mass air flow (which is proportional to power) puts our cars at a weigh to power ratio similar to that of trucks and SUV’s, both in terms of absolute value and rate of change. Not to be confused w/ the weight to power ratio that is usually published, which is calculated at WOT, above 35 deg throttle angle our engines shine. It is on the part throttle range (idle to 30 deg) that the issue exists.

I’m not going to speculate on the reasons, but I can tell you that our throttle body p/n 12678223 or 12620263 is used in many GM vehicles and that such throttle response helps w/ fuel economy. That helps to keep parts cost low and meet EPA requirements for the fleet. However, I do not think one size fits all and that a high performance car needs to sacrifice performance for economy.

The throttle controller and the tune improve response by making the throttle plate move faster between the 5-30 deg range. Faster, but it still needs to go through a tortuous path for the air flow, and the manifold pressure doesn’t recover as fast. It is a transient process, and it is from the intake manifold where the pistons suck the air from. Notice that this is not true throttle response, it is just tricking the ECM into thinking you have pushed the accelerator pedal harder. The actual throttle response is the same, only physical changes to the throttle can make for a true throttle response.

The existing aftermarket ported throttle bodies also helped, they do change the throttle physically, but their effect only starts to take place at about 25 deg in what I thought was the best one of them. Definitely a step in the right direction, but I noticed they were not optimized and that more could be extracted from them, that is a throttle body that can increase the absolute value and rate of change of mass air flow right from idle and up to 35 degrees to achieve the same weight to power ratio (in that range) of similar high performance cars that feel nimble and fun to drive at part throttle.

Another long story short, I reversed engineered 10ea OEM throttle bodies, 3ea aftermarket ported throttle bodies, and a benchmark (competing car maker model) OEM throttle body. Optimized/modified the OEM throttle body to meet the benchmark throttle response as well as the goal stated above.

Our modified throttle bodies (MTB) are made (CNC machined) from a brand new OEM throttle body, flow and engine tested. Our design has been fully vetted by Corvette 7, Camaro 6, CTS-V owners, fully and openly tested by Corvette Forum members mainly. Driven in different conditions/modes for a few thousands of miles now at extreme temperatures and altitudes.

See pics below for more insight into what I’m talking about…and most importantly what do you think? All comments welcome.
Please visit us at : SolerEngineering.com

Thanks,

[DenverTaco07]

very cool, I'm impressed, but i'm not an engineer so that's probably not saying much.

I assume no tune required?

[Mike@SolerPerformanceLLC]

Thanks, DenverTaco07. Correct, no tune required. Installation instructions attached for a Corvette 7. Very similar for a Camaro 6.

[z28pat]

Does the throttle response issue have anything to do with this being a throttle by wire setup instead of a physical connection between pedal and throttle body?
And also ,
Would this void the warranty ?

[biker2k]

id love to hear real world dyno results

and not for nothing
this is how you do a product launch not like some unnamed cold air intakes!

[cellsafemode]

warranty voiding technically can only occur on products/modifications that can be proven to be the cause of the warranty work needed.

However, dealers and even OEM's will fight you and say the warranty is voided even though legally they aren't allowed to. You'll then have to pay for a lawyer to fight them.

So the short answer is always, if you care about the warranty being voided, dont do it. Stick to stock. Or you know, just stop caring about the warranty and do what you want.

[Mike@SolerPerformanceLLC]

Originally Posted by z28pat

Does the throttle response issue have anything to do with this being a throttle by wire setup instead of a physical connection between pedal and throttle body?
And also ,
Would this void the warranty ?

It is a compounded problem, mechanical, electrical/control, we took care of the mechanical part of it, which is the most influential one and rules over the electronic control.

Voiding the warranty is easily and completely under your control. It is widely considered a non-warranty buster Mod for that reason.

[Mike@SolerPerformanceLLC]

Originally Posted by biker2k

id love to hear real world dyno results

and not for nothing
this is how you do a product launch not like some unnamed cold air intakes!

Coming soon, biker2k. That is at WOT. At part throttle, where we spend 99% of our driving time, we have plenty of data, some of it posted above.

At WOT, you know how inaccurate chassis dynos can be, but we'll run back to back dynos and see what we get.

Some numbers we could give right now is that your effective bore diameter goes from 87 mm (stock) to 91 mm (with mod). Our inlet/outlet design make flow much more efficient, polished to reduce skin friction, even the screws are completely out of the way. All these will show up at WOT we expect an easy 10-20+ HP gain.

Some Corvettes have taken our TB's to the track, and just the smoothness and predictability makes them track worthy.

Thanks,

[Umbriel]

What about on a cammed Procharged car? Would it be worth the switch since the Procharger is cramming air into the motor?

[Mike@SolerPerformanceLLC]

Originally Posted by Umbriel

What about on a cammed Procharged car? Would it be worth the switch since the Procharger is cramming air into the motor?

You have a lot to win and nothing to lose by trying. In your case, it is more of a guesswork and patience game. Given your setup, we'll start you with an LT4 TB, if it doesn't work we'll take it down a notch and send you another one, and so on up to 4 configurations you can try with all shipping both ways paid by us, until we hit the maximum airflow your current setup is happy with. Most cases like yours end up working the 1st time, a few the 2nd time, and very rarely the 3rd time. All our heavily Mod customers have ended up pleased when they hang on to this plan.

We could certainly send one configuration that will work the 1st time and that still outperforms the competition, but that wouldn't be optimum for your setup and that is not our promise, but could consider if you don't feel like installing a couple of times.

Update: Just looked at our records, we have 4 Procharger and 3 A&A (very similar blower) customers. All Corvettes 7's (LT1) So, we have a pretty good idea of what will work for you.

[Mountain]

Originally Posted by Mike@SolerPerformanceLLC

There is a much debated problem w/ the throttle response of the LT1/LT4 engines, manual or auto, the issue has been described in this and other forums (Corvette, Camaro, CTS-V, Trucks, SUV’s), just to mention a few descriptions:

- Throttle Lag
- Delayed response
- Car feeling heavy or not nimble
- Difficulty climbing hills at low/moderate throttle
- Uncertainty when passing other cars or unpredictable response at low/moderate throttle
- Stumble when shifting on manual transmissions

You name it, this has been my issue w/ my Corvette 7 since test driving at the dealership. I've tried a Throttle controller, AFM disabler, ECM Tuning, and arguably the three most talked about ported throttle bodies (PTB) out there. I have also combined some of the above w/ some success but still not enough. One just needs to hop into almost any other comparable car to feel they respond better.

After spending so much time/money, I decided to take it upon myself to find out, I also have all the equipment needed at work (measuring, testing, simulating, machining etc.)

Long story short; it is the throttle body. Between idle (~5 degree throttle) to ~30 deg throttle angle the amount of mass air flow (which is proportional to power) puts our cars at a weigh to power ratio similar to that of trucks and SUV’s, both in terms of absolute value and rate of change. Not to be confused w/ the weight to power ratio that is usually published, which is calculated at WOT, above 35 deg throttle angle our engines shine. It is on the part throttle range (idle to 30 deg) that the issue exists.

I’m not going to speculate on the reasons, but I can tell you that our throttle body p/n 12678223 or 12620263 is used in many GM vehicles and that such throttle response helps w/ fuel economy. That helps to keep parts cost low and meet EPA requirements for the fleet. However, I do not think one size fits all and that a high performance car needs to sacrifice performance for economy...

...The existing aftermarket ported throttle bodies also helped, they do change the throttle physically, but their effect only starts to take place at about 25 deg in what I thought was the best one of them. Definitely a step in the right direction, but I noticed they were not optimized and that more could be extracted from them, that is a throttle body that can increase the absolute value and rate of change of mass air flow right from idle and up to 35 degrees to achieve the same weight to power ratio (in that range) of similar high performance cars that feel nimble and fun to drive at part throttle...


...Our modified throttle bodies (MTB) are made (CNC machined) from a brand new OEM throttle body, flow and engine tested. Our design has been fully vetted by Corvette 7, Camaro 6, CTS-V owners, fully and openly tested by Corvette Forum members mainly. Driven in different conditions/modes for a few thousands of miles now at extreme temperatures and altitudes.

See pics below for more insight into what I’m talking about…and most importantly what do you think? All comments welcome.
Please visit us at : SolerEngineering.com

Thanks,

This is something I believe Tony Mamo touched on before, and where you need to be very careful how you "port" the area very near the throttle blade first few degrees because you can get the ECM to throw a code.

One thing I want to point out/comment: about the ported throttle bodies out there and not starting to do anything until about 25-degrees - Are your comments in respect to the theoretical 0-degree point (fully vertical; like your example sketch/drawing) of the throttle blade or in respect to their true, as-built rest position (which is NOT completely vertical)? Reason being as this is important to keep in mind with what you have posted and the work you have done.

P.S. - Appreciate the write up and the work you and your company did.

[HDRDTD]

Do you make one for a 5th gen ZL1 with a LSA engine?

[Umbriel]

Originally Posted by Mike@SolerPerformanceLLC

You have a lot to win and nothing to lose by trying. In your case, it is more of a guesswork and patience game. Given your setup, we'll start you with an LT4 TB, if it doesn't work we'll take it down a notch and send you another one, and so on up to 4 configurations you can try with all shipping both ways paid by us, until we hit the maximum airflow your current setup is happy with. Most cases like yours end up working the 1st time, a few the 2nd time, and very rarely the 3rd time. All our heavily Mod customers have ended up pleased when they hang on to this plan.

We could certainly send one configuration that will work the 1st time and that still outperforms the competition, but that wouldn't be optimum for your setup and that is not our promise, but could consider if you don't feel like installing a couple of times.

Update: Just looked at our records, we have 4 Procharger and 3 A&A (very similar blower) customers. All Corvettes 7's (LT1) So, we have a pretty good idea of what will work for you.

Ok cool. I'm having my Procharger put on in a couple of weeks and I'll get in touch with you about it.

Sent from my SM-G955U using Tapatalk

[Mike@SolerPerformanceLLC]

Originally Posted by Mountain

This is something I believe Tony Mamo touched on before, and where you need to be very careful how you "port" the area very near the throttle blade first few degrees because you can get the ECM to throw a code.

One thing I want to point out/comment: about the ported throttle bodies out there and not starting to do anything until about 25-degrees - Are your comments in respect to the theoretical 0-degree point (fully vertical; like your example sketch/drawing) of the throttle blade or in respect to their true, as-built rest position (which is NOT completely vertical)? Reason being as this is important to keep in mind with what you have posted and the work you have done.

P.S. - Appreciate the write up and the work you and your company did.

Thank you, Mountain. You are absolutely correct and careful we are. This is the area that really makes the difference in response out of a stop, right off idle. Very sensitive dimensionally, uncontrollable by hand porting. We think this is one of the features that sets us apart, our ability to carefully work this area w/o upsetting the ECM.

Minimum flow does not occur at the physical zero degrees (vertical). It happens at about 1-2 degrees (This is the "zero" for results plotted).