WHPLASH

I was just wondering what some of you have done with porting the intake/throttle body. Any dyno numbers? Any companies out there offering this?

Thanks!!!

Kracka

I plan to do both. Soler is the gold standard as far as TB porting goes, but plenty of other perform the work as well (C7 & C8 share identical TBs, along with some trucks). Intake manifold porting is done by Wilson and SoCal Porting, plus one other company I know nothing about. Soler + SoCal is my planned combo.

WHPLASH

Thanks Kracka!!! That is some good information.

Z0Sick6

Mamo Ported TB just came in. He is well known in the porting world for Corvettes and Camaros. I had his on my C7 Z06 and most threads of reviews comparing PTBs on C7 Z06s touted his as the best.

Billy20

I’ll 2nd Soler Performance!! Their customer service is 2nd to NONE

Snowblind2.0

I saw 10-15 hp on my ported combo. The c8 throttle body is the same as the c7 and the Camaro6 so their are plenty of used ones on the market too if you want to save a buck. I hear good things from Katech, Pray Performance, Tick, and Soler. GPI sells a ported combo and can also get you a larger LT5 95mm tb (with adapter) if you feel that may free up more power...I haven't seen any evidence that it does though. ​​​​​

I ported my own IM and bought a used Pray ported tb for $130 outright.
Edit; forgot about Mamo. As was said, near the top also !

HeadTurner

I have the Ported TB from Soler... it is a very nicely ported and they have great customer service 👍🏼.
I also had my Intake Ported by Lethal Performance here in San Antonio.
I should be taking it back to the Dyno in a couple weeks to confirm results but seat of the pants, mid to top range has improved.

HeadTurner

This is the Soler TB

TexasMark

I am curious - why would GM have not already chosen an already optimally sized throttle body for the stock C8 engine?
I can see the need for a larger throttle body if other performance mods are made at the same time (forced induction, air filter, exhaust).

c5racr1

Because Corvette team has to use available parts before they can request specific parts be made. And TB and hubs can be used from shared platforms. As well as a lot of other parts come from the GM parts bin. Always have.....
the c8 is different but has a lot of shared parts with Cadillac and Camaro platforms, a lot!

Kracka

Agreed. Parts bin because it's "good enough" but as we know "good enough" is never the best. This throttle body was originally used on the Chevy/GMC trucks then found its way onto the C7, gen6 Camaro, and now C8. Just like with air filters, OE has a different set of priorities than the aftermarket.

Hib Halverson

The throttle body on the LT2 is the same 87-mm TB used on the L86 truck engine, the LT1 and the LT4.

I disagree that Soler is the "gold standard" in ported TBs. I've looked at all of them and I prefer the Mamo V2 for 87-mm TBs.

Here are some pics comparing the Soler to the Mamo. Judge for yourself which might flow more air.


Soler Engineering ported 87-mm throttle body.


The Mamo Motorsports 87 is truly ported, then polished and it has the milled throttle shaft with countersunk fasteners

The OE TB flows about 900 CFM, the Mamofied 87-mm unit flows about 1100 CFM.

Mike@SolerEngr

Hib, great job with the pictures, we do not have the luck of getting a comparison like this very often despite your verdict. We do have many customers that have had at least another brand before, no pictures or comparisons, but they kept ours.

A few comments though;

That is our "V1" for the LT1, it should be compared to the other existing LT1 versions at the time, in terms of both pictures and airflow. At that time we were flowing 10% above the closest competitor, which was not the one being brought up here by the way.

If you send us the serial number on the back we can tell you how old it is.

The picture of our V1 LT1 is, unfortunately, hiding one of the most important features, the shaftless high-pressure side of the blade, that can limit a fair judgment quite a bit on an already unfair comparison.

The OEM flows ~970 SCFM at 20.4 inH20, that is correct. There seems to be consensus about this value among those who have tested this throttle body in a flow bench, except for one vendor reporting ~900 CFM. We have also tested throttle bodies advertised as flowing 1000 CFM, resulting in 970 SCFM just like the OEM. Meaning, do not take the face value of what you are told, let alone judging for yourself over a comparison of choices that don't exist anymore.

​​
Despite that, our retired V1 still flows 1123 SCFM. So we could still stand the comparison. Our “V2” like in the picture of post #8 by Headturner, flows 1170 SCFM. Our next release will beat that, soon to enter production. To compare our products, you have to get our latest as we don’t stop improving our products.

That’s only regarding WOT, at partial throttle, our advantage is even greater.

If you send us any throttle body (not ours) we’ll tell you how much they really flow and add at least 50 SCFM at WOT without changing anything visibly. Do you have a way to test them?

These pictures are best suited for the comparison, but even so, do not judge just by the looks.



WOT, Inlet



WOT, Outlet



Low-Pressure side, Dimpled



Part Throttle, Slotted in flow direction through idle TP.



Home.


Thanks,

Hib Halverson

The image source used "SolerV2" in the file name, hence my assumption. If it's in error, it could be because I don't fully understand the differences between all the TB porters' "V1", "V2", "V3", etc.

The throttle body to which I was comparing the Soler TB is a Mamo Motorsports 87-mm "V2" that is sold for both the LT1/2/4 engines, as well as the L86/L87 in trucks.

That information is not available to me.

Sorry. There was no attempt to mislead. That was the only image I had at the time I first posted. Here is another I've acquired since.



I appreciate that advice.

In my opinion, a comparison to your latest, 91-mm throttle body wouldn't be that credible because of the four-millimeter increase in the size of the throttle plate used in the TB pictured above.

I do not. I'd have to rely on others with the proper flow bench.

I will try to keep that in mind, going forward. If I can't find a legitimate flow bench locally, I just might take you up on that

My interest in posting to this thread was not to disparage Soler Engineering throttle bodies, rather, it was to disagree with the statement made earlier that Soler TBs are "..the gold standard..." Clearly the product works well, but the gold standard in ported throttle bodies? I'm not sure I agree.

Let's talk about air flow in general just for a bit.

Take Gen 4 or Gen 5 V8 heads...consider the intake port just above the valve pocket and the pocket, itself. Engineers who design those parts of intake ports, based on CFD studies and other types of air flow analysis, do all sorts of things in the interests of creating swirl and tumble–both different forms of turbulence–in the cylinder charge which remains after the intake valve closes and just before the spark comes. They do this by messing with CSA, shape, direction of the port near the valve as well as the contour of the protruding valve guide above the backside of the intake valve. They'll, also, place bumps, ridges or even wing-like devices in the air flow to create that swirl and tumble in the air flow as it passes the intake valve opening which improves homogeneity of the air/fuel charge going into the cylinder so, when the spark comes, that charge ignites quickly, the flame front burns evenly away from the plug and burns with as least emissions as possible while putting maximum pressure on the piston at just the right time to enable the engine to produce the highest torque level possible.

Now, upstream of valve, like...in the first part of the intake port in the head, in the manifold intake port, in the throttle body and in the tube, duct or pipe that connects the TB to the air filter assembly, turbulence is far less desirable. You want the flow through those to be as laminar as possible because, in those spaces, turbulence degrades air flow.

What does this have to do with ported throttle bodies?

Well, when you have a throttle body with button-head fasteners holding the throttle plate or you have teeth, bumps, ridges or other protuberances in the TB's inside diameter sticking out in the airflow going through by them you get obstruction and turbulence and, IMO, that makes air flow through the throttle body less efficient.

I think ported throttle bodies with shafts CND'ed flat but supporting both sides of the throttle plate, countersunk fasteners holding the plate and an inside diameter which is smooth as possible would be closer to a "gold standard"...if there was such a thing in the throttle body market.

I've researched throttle bodies ported by Soler, Katech and Mamo Motorsports. Based on 1) my experience using a 95-mm Mamo on my LT5 and 2) looking at imagery of all the 87s, right now, I'm partial to Mamo's 87-mm TBs.

TexasMark

Interesting data. So the throttle body affects air flow at only one segment of the entire air path (affecting flow rate and turbulence, good or bad).

It seems to me that the system as a whole needs to be performance tested after making each change to the air flow; Experiment and iterate until an optimal solution is found.
And when you think you are done, iterate again using a performance air filter (and so on).

Given the chaotic nature of air flow and turbulence, a feature in one throttle body body (such as dimples) might improve perf for one engine design, might decrease perf in another.
I wonder if this throttle body was specifically developed, tuned and optimized for the C8's LT2 engine architecture...?

And if a goal is to truly optimize air flow, should we choose a tested, optimal combination of air filter, throttle body and intake manifold, all at once?

Wilson Manifolds Ported LT2 Intake Manifold

Hib Halverson

In a perfect world, that's how the intake system should be tested. The problem is that, in practice, that's not how a lot of people view it nor how the various parts are designed. Conventional wisdom is the throttle body is a separate entity from the intake system between the throttle body inlet to air filter intake.

Highly unlikely considering it was designed in early 2010s for light truck engines. Corvette and Camaro "piggybacked" on the development and used it in their platforms

Mike@SolerEngr

Thanks, Hib. I'm very glad you understand the little details so well; Why? Because then, and only after you have “all the information*”, maybe you can reassess your verdict. If not, fine too, as long as you have “all the information*” at hand.

Simple, and without having to judge by looks or reading what's next, our latest LT1/LT2/LT4 throttle bodies flow 1165+/-20 SCFM @ 20.4 inch H2O, or 1388 SCFM @ 28", or 830 SCFM @ 10" in case you need other points of reference. Worth noticing that we report SCFM at a given vacuum. CFM or ACFM without a reference pressure differential, temperature, and humidity are meaningless, and can't be compared.

In a perfect world, that'd be all we needed to say. There's no escape from it, reporting a range of SCFM at a given pressure differential, locks us in a box with no room for excuses. It is legally binding. You buy this TB from us today and you airflow test it, if the result is outside that specific range of standardized units, at a set reference pressure differential, then we are lying, and that's that. Or, we are telling you the truth, and that'll be that as well, regardless of how fluent the TB may look to you or someone else.

Unfortunately, since folks would likely have to make a decision without airflow testing parts, or necessarily trust what they are told, then, we understand that they will have to look at the parts and somehow believe they can do what we say. So, here we go.

* We'll go ahead and try to explain what's visible and should be clear to those in this business, we are going to omit what's not visible and what should be the task of those in the business to figure out. So, you won't have all the information after all, but certainly enough information to make an educated assessment.

1. Versions: We do not have versions for sale, we have a throttle body for the LT1/LT2 and another one for the LT4, this is our smallest throttle body for Corvettes and they are all modifications starting from the 87mm stock GM throttle body. We compete against ourselves introducing changes at a rate of about twice a year, we keep track of those changes internally of course, but the product keeps being the LT1/2 and LT4 throttle bodies. We do not like the marketing strategy of calling things the "Soler V1", the "Soler X", or the like...basically, there's the part number for your engine and you get the latest one when you order.

2. Flow: Before heading into the details, let's define the order of precedence of the primary contributors to flow, and also how they relate to throttle position, for we should not limit ourselves to WOT flow only, the flows are very different at low throttle and at wide-open throttle, not in magnitude only but the physics of the flow is literally reversed and defies common sense.

Primary contributors to higher flow under the same pressure differential, in order of influence, greatest to smallest.

a- Flow area and primary flow

b- Geometry and primary flow

c- Secondary flows

Throttle Positions: Let’s do a sweep of the throttle blade and define low as idle to 25%, partial as 25%-75%, and then jump to 100% (WOT), and see what happens at those points with the main flow contributors, then we’ll see the effect of our design features on those.

2.1. Idle to 25% TP

Refer to Figs. 1, 2, and 3.

At idle, you have to have idle airflow, and there’s nothing of interest there. Perhaps the only thing worth saying is, do not mess with idle airflow, so we didn’t.

In this region the flow is choked, it reaches the speed of sound, and the airflow physics goes against common sense. One can increase vacuum and nothing happens. But we could increase flow area and also increase mass flow by changing the local flow coefficient.

This is how we did it, these are the slots you see running down axially in our throttle bodies (unique to Soler), substantially increase flow area at this position, while the angle on the edge of the blade (unique to Soler) increases the flow coefficient of the “orifice” for any area. These two combined, also happen to form a converging-diverging nozzle for the flow to further accelerate after choking, one of the counterintuitive features of flow in this region.

These are the reason our TB’s ramp up very quickly out of a stop, right of idle, no stumbles on A8, no stalling on M7’s.

These features also exist at the outlet of the TB, also unique to Soler. None else reworks the outlet.

As you can see we covered all the bases, with more flow area, and also a more efficient geometry. Taken to the maximum the stock tune and the ECM can handle without setting a DTC.


Fig 1. Soler TB Model at 20% Throttle



Fig 2. Soler TB LT1/LT2, Axial Slots as seen from the inlet.



Fig 3. Soler Performance LT1/LT2 TB, axial slots as seen from the outlet. Reaching down to idle position. The dimpled pattern on the shaft is being tested, not available yet.


2.2. 25-75% TP

Refer to figures 4., 5., 6. and 7.

Here you start to transition to “power TP%” or flow. The OEM is radical in this sense going from one to the other very sharply. We modified it to make it as linear as possible, a smoother transition, more predictable, but also continuing the faster ramp-up we already established on 2.1.

We continued the slots but curved them around the transition area, again more area, better geometry, as much as it can be for the stock tune, and hardware capabilities.


Fig 4. Soler Geometry (blue) vs. OEM geometry Red. Models at 30% Throttle.


Still in this region but moving down to 60% TP, now we are at the end of the transition, and for those in this business it should be common knowledge that there’s a dip in the airflow vs. throttle position curve, this is why you’ll see a couple of pockets to each side of the body.


Fig 5. Soler TB Model at 60%, showing pockets (ports) to the left and right sides of the blade.


Fig 6. Soler TB, actual at 60% Throttle.

This is how we get rid of the 60% dip and keep the transitional linear trend going on. You can readily see how it exposes flow areas that were not available before (another Soler unique feature).

It is about this TP% that other effects start to enter the equation, let’s jump the shaftless high-pressure side (yet another Soler unique feature) which will be king at WOT, but it starts to take effect right here.



Fig 7. Soler Performance Model at 60% Throttle, the effect of half-shaft on the high-pressure side.

Notice how we removed the shaft from this side and that although the blade divides the flow areas equally, the flow on the high-pressure side of the blade facing the incoming flow will move more than half of the air. While behind the blade the flow has lower pressure, and whatever we do to the shaft is shaded by the blade, or meaningless in other words.

Turns out one doesn’t have to wait for the blade to reach 100% for the shaftless high-pressure side mod to show up. The high-pressure flow on this side won’t encounter the shaft as an obstacle and create turbulent secondary flow, and this also helps with the 60%TP dip, and will continue to help even more as we approach WOT.


2.3. WOT (100% Throttle)

Refer to figures 8. and 9.

Now everything we have done before will combine and create more flow area projected in the flow direction (not all areas are created equal, it is not about removing more material, if it is not visible when projected in the flow direction, it won't do any good). The blue contours represent the area gained vs. the OEM in the primary flow direction.


Figure 8. Soler Model at WOT, showing flow areas gained in the primary flow direction.


This greater area is aided by more efficient geometry to yield the largest WOT flow for this OEM size of TB. The sharp edges on the leading and trailing edges of the blade we created to make a nozzle at low throttle are now knife edges helping at WOT. So are the transitional slots from idle to 25% we created at partial throttle, the continuation of those slots from 25-40%, and the 60%TP ports, along with a tapered entry and the half-shaft.


Fig. 9. Soler Model WOT cross-section.

The rest of the work is common porting, rounding edges, and polishing to avoid detrimental secondary flows. This we all know about and that's the porting we have already seen for decades.

It is worth mentioning that all our work is done repeatably in CNC machines, verified with a Coordinate Measuring Machine (CMM), and validated with airflow bench tests.

3. Summary

Well, it flows from 1145-1185 SCFM at 20.4” H2O at WOT and this is why, that's 12.2% over the OEM. It also starts flowing more than the OEM off idle, and in every single throttle position after that. We have not measured a single throttle body of this size that flows more at any single throttle position...and we have measured many, more than once each.

As you see from the number of unique features, we do things differently around here which contrasts with the common ported throttle body we have grown accustomed to. When you think about boundary layer flow and secondary flows you might be inclined to think there might be a better throttle body, but please concentrate on the primary flow and features (the actual main drivers of flow) and if you find a tie, use secondary flows as a tie-breaker. I’m confident that won’t be necessary.

…and again, you might want to consider there are some other features (not visible) we cannot disclose yet. But we don’t think we’ll need to bring either that for an assessment.

The domed screws are indeed a small secondary drag, but they need to be there for structural purposes. Our throttle body is not perfect. We realize that twice a year.

Thanks, Hib. I see you are a technical writer; my guess is you’ll get to this sentence and hopefully we did not bore you. Anyway, this is something that needed to be done as we haven’t really explained much since we started a few years ago. I hope it is helpful for the whole community, especially those wanting to do this mod.

Kracka

Very informative! I loved the actual technical data presented. I'm excited to order another Soler TB, but at the same time will hold off until I'm ready to actually install it to make sure I get the latest & greatest revisions. I'll likely do like I did for my C7 and send in a brand new unit for modification rather than sending in a used core.

On that note, do you see any advantage to AFE's TB spacer or is that merely a snake oil product?

Hib Halverson

I try. Some might disagree.

[/QUOTE]
That's one comprehensive reply. Thanks for taking the time to key it in. I haven't read the whole thing, yet and it's time to get the BBQ fired-up for dinner.

I'll save it for when I get to work on Monday morning...after my first coffee.

Driver_WT

Thanks for the great explanation and diagrams Mike. Very helpful.

Any comment on Hib's concept of measuring the total impact of modifications from the air intake to the combustion chamber? (which I suppose running the car or engine on a dyno is probably easier than trying to develop a metric based on air flow only as I am assuming that turbulence and mixing within the cylinder are part of the whole power improvement equation).

Thanks for taking the time to educate us all.