s63tu Ported Throttle Body

[allmotor_2000]

I had just finished developing a ported TB solution for the s63tu - won't be able to try it, may offer it for sale.

As you may be aware the s63tu has the worst TB design ever... plastic throttle plate that is welded into the shaft. Unlike traditional throttle bodies, it is quite difficult to upgrade.
The stock plates get eaten up over time (for meth users... its quite quick actually) and results in poor idle, cold start misfires etc. I replaced 2 sets in 4000 miles....

This is a ported solution (3.5mm over stock per TB) with a custom machined shaft and throttle plate.

Should provide some meaningful gains (for somebody else... )

[bm5bullit]

Nice work. Please pm me with details. Thanks.

[WickedBMW]

I’m interested.

Also, any updates on you aftermarket diff mount.

[allmotor_2000]

Originally Posted by WickedBMW

I’m interested.

Also, any updates on you aftermarket diff mount.

It’s $1000ea. I have one set. Can make more...

Diff mount is ready - couldn’t do the last test fit so looking for a friends M5to try out.

[edysinger]

It will definitely flow more but it will be interesting how the ECU reacts to a change like that to the throttle body.

[allmotor_2000]

ECU won’t care as long as long as the stop, emergency air and open positions are the same.

[Used2be]

Originally Posted by allmotor_2000

ECU won’t care as long as long as the stop, emergency air and open positions are the same.

If people who just modify their intakes are having induction related problems, how is it that a ported throttle body will be tolerated by the sensors in the otherwise stock intake tract without difficulty? Was the .138" overbore done for more airflow or to make building and installing the more durable throttle plate possible? Both probably? Please don't get too technical with your answer, my understanding of this is limited!

[allmotor_2000]

The MAF is well before the turbo - the TB is AFTER the IC... the only sensor after the TB is the IAT sensor on the manifold. The TB is AFTER the intercooler itself. Putting the CSF cooler (30%) larger didn't throw any codes.

The over-bore is for flow - could have put a metal plate with stock bore but what's the point?

[Sales@RKautowerks]

Originally Posted by allmotor_2000

The MAF is well before the turbo - the TB is AFTER the IC... the only sensor after the TB is the IAT sensor on the manifold. The TB is AFTER the intercooler itself. Putting the CSF cooler (30%) larger didn't throw any codes.

It's still possible you may need a recalibration, but i almost want to say you can get away with it because of how the car is calculating the density, but the OEM engineering background wants to disagree heavily. The maf is reading the volumetric airflow, the car then has a feedback loop involving the wastegate duty cycle, the map sensor before the throttle body, and the map sensor post throttle body. The angle of the throttle body controls the mass flow into the system. If the wastegate %, map sensor output, and then angle of throttle don't all fall in a certain threshold, i can see it throwing an code.

The coolers have nothing of involvement in this discussion, you could completely remove them and it wouldn't matter. The sensor post cooler is calculating the density of air in the system, the post TB map is calculating mass flow based off what the throttle body should be allowing to enter.

If the TB angle is 50%, boost is 22psi, the car is putting X amount of air into the system because the TB is controlling it. Now you increased the size of the TB, the car has noway to calculate this because the mass flow equation was done originally using the maf, no recalculation was done afterwards to adjust.

So now 50% throttle is 55%, boost is still 22psi(according to map sensors), but more air is being introduced and the vehicle has no idea why. The ECU
was calibrated to talk to the maf and they're disagreeing now with the tables.

If i were to bet, i would say you need a recalibration for the throttle body because the system is part of a feedback loop involving other sensors.


-R

[Used2be]

Originally Posted by allmotor_2000

The MAF is well before the turbo - the TB is AFTER the IC... the only sensor after the TB is the IAT sensor on the manifold. The TB is AFTER the intercooler itself. Putting the CSF cooler (30%) larger didn't throw any codes.

The over-bore is for flow - could have put a metal plate with stock bore but what's the point?

The larger throttle body is for more flow, so even if the MAF is upstream, won't the system flow more air and upset the tables for the MAF? Or, with the stock intake perhaps the airflow won't increase even with the larger throttle body?

In the engine manual it mentions the throttle body "has a flow optimized connection" to the intake manifold. To maximize the benefit of the larger TB, would modifying the manifold be warranted, or even required?

Just posted and saw RK's much more educated response. I'll leave it to you two to discuss, thank you both.

[allmotor_2000]

What are u talking about re flow at the second MAP?

The post TB sensor is a MAP... not MAF. It calculates pressure and temperature. Nothing related to flow. The TB is a flow meter (not sensor) you are right there.

There is no recalibration needed and the DME can compensate for the additional flow per TB angle in the various factory maps.

The larger IC also allows more flow... why wouldn’t that affect the MAF? It doesn’t.

[allmotor_2000]

Originally Posted by Used2be

The larger throttle body is for more flow, so even if the MAF is upstream, won't the system flow more air and upset the tables for the MAF? Or, with the stock intake perhaps the airflow won't increase even with the larger throttle body?

In the engine manual it mentions the throttle body "has a flow optimized connection" to the intake manifold. To maximize the benefit of the larger TB, would modifying the manifold be warranted, or even required?

Just posted and saw RK's much more educated response. I'll leave it to you two to discuss, thank you both.

Yes - the TB is angled. It’s not overbored the same amount on both sides. It’s tapered.

The diameter across the TB at the shaft is smaller than the intake manifold.

End of the day let the test data speak for itself. Ideally I would have that before posting anything but at this point only have data showing it doesn’t throw codes or anything like that.

[Sales@RKautowerks]

Originally Posted by allmotor_2000

What are u talking about?

The post TB sensor is a MAP... not MAF. It calculates pressure and temperature. Nothing related to flow.

There is no recalibration needed.

The larger IC also allows more flow... why wouldn’t that affect the MAF? It doesn’t.

A map sensor can calculate the mass airflow because it speaks to the maf sensor, they are homies in this system, the conservation of mass says so. https://en.wikipedia.org/wiki/Conservation_of_mass


Maf sensor is measuring airflow into the engine

Maf = Mdot = rho(density) * V(velocity) * A(area).

Area is known, 3.5"

rho is known, 1 atmosphere (or pretty damn close, i believe there's a Barometric pressure sensor on the vehicle)

Velocity is not known, it is calculated using the sensor. This calibration is done on a bench dyno with a secondary sensor to complete the mass flow equation.

Now you know your Mdot into the system before the turbo, which will always be the same after the turbo. This is fundamental engineering, Mdot in is Mdot out.

This Mdot is introduced into the turbo which compresses the air

Turbo now changes the fluid density so your rho has changed in the mass flow equation.

Fluid goes across the cooler, giving up temperature and recovering density some more.

Now we get to the map sensor, this map sensor measures the temperature and pressure of the system, the area in that location is not relevant at this moment because the area will not change the temperature or the density.

This information is then fed back into the ECU, which now controls the wastegate, the wastegate is electronically controlled, it actuates duty cycle to hold the density constant, based off the Mdot being introduced at the MAF.

Now we get to the throttle body, this is a known area again. Throttle body controls the amount of air going into the engine.

The vehicle needs to know HOW MUCH mass flow goes into the engine.

Mdot_engine = RHO(new density provided by map sensor) * V(dyno calcuted and known based off RPM) * A(area of the throttle body)

The Mdot is back calculated now on a dyno to establish at each angle of throttle you are introducing X+y amount of air. This helps the vehicle establish the mass flow into the engine, so yes the map sensor does not calculate mass air flow directly, but it completes the equation necessary to figure out how much air the throttle body lets into the engine.

So you see why the area of the throttle body is very important in all this and why you would have to know the area. Your statement that there is nothing related to flow could not be any more wrong. The TB area has everything to do with relationship to flow.

So once again, the only significance the intercooler has is the temperature and density of the air. The intercooler does not speak to any of the sensors and is not part of any calculation. If you measure Mdot at the intercooler, yes it would change because i changed the area when i designed them. But that area is irrelevant to the vehicle to establish how much is going into the system.

-R

[allmotor_2000]

With all this science and math you have put up, why is that your intake doesn’t make any more power than a stock box with a K&N?

This thread is about the TB.

I am not arguing the TB doesn’t change flow. All I said is the DME can tolerate it.

[MrPowell]

This is why a simple Speed Density setup is sooo much easier to control LOL! On my Syvecs all that matters about the TB is the voltage linearization as far as 0-100% (I run a C6 Corvette 90mm TB on my 996TT). The MAP (behind TB) and IAT sensor (pre-TB) dictate the main portion of the fueling calculations. Well even in that scenario the IAT is an adder function because it's use to advance or retard timing/fueling depending on air temperature.

[allmotor_2000]

Originally Posted by MrPowell

This is why a simple Speed Density setup is sooo much easier to control LOL! On my Syvecs all that matters about the TB is the voltage linearization as far as 0-100% (I run a C6 Corvette 90mm TB on my 996TT). The MAP (behind TB) and IAT sensor (pre-TB) dictate the main portion of the fueling calculations. Well even in that scenario the IAT is an adder function because it's use to advance or retard timing/fueling depending on air temperature.

Exactly - have swapped TB’s with larger ones on numerous platforms and haven’t had any issues.

[edysinger]

Originally Posted by allmotor_2000

ECU won’t care as long as long as the stop, emergency air and open positions are the same.

It's so much more than that, you have correlation algorithms going on in the ECU doing "sense" checks on the feedback of the sensors. The MAF and MAF calculated from MAP must agree within certain tolerance and you also have pedal to throttle area correlation checks for "unintended acceleration" of the vehicle as some examples.

I agree the ECU can tolerate the change as we've seen bigger turbos, ICs, etc allow more air into the engine. In this aspect, there was likely disassembly of the throttle body components which I said it will be interesting to see what happens.

[allmotor_2000]

Originally Posted by edysinger

It's so much more than that, you have correlation algorithms going on in the ECU doing "sense" checks on the feedback of the sensors. The MAF and MAF calculated from MAP must agree within certain tolerance and you also have pedal to throttle area correlation checks for "unintended acceleration" of the vehicle as some examples.

I agree the ECU can tolerate the change as we've seen bigger turbos, ICs, etc allow more air into the engine. In this aspect, there was likely disassembly of the throttle body components which I said it will be interesting to see what happens.

That’s correct - should rephrase as ECU can accommodate (vs not care). The position values will throw hard codes if not done correctly. The rest is a function of flow per throttle increment (angle which is mapped to a range in the DME tables) given everything else.

I haven’t tested across all WOT or partial throttle conditions yet. I had designed this to solve a specific issue related to deterioration of the plate. I would have just used it in my car and would never even have posted it, but given the circumstances I am posting this among many other things to follow.

[Sales@RKautowerks]

Originally Posted by allmotor_2000

With all this science and math you have put up, why is that your intake doesn’t make any more power than a stock box with a K&N?

This thread is about the TB.

I am not arguing the TB doesn’t change flow. All I said is the DME can tolerate it.

It's already been proven they make more than a stock box with K&N, by a variety of people. Our intakes work off pumping loss reduction when the AREA is not changed. You're changing the area of a calibration piece. What part are you not understanding in this?

-R

PS: saying the "ecu wont care" vs the "dme can tolerate it" are two completely different statements. But if your analysis is that it can tolerate it, i can buy that. I ran quick calcs and your change is like 6% in airflow. The dme will tolerate up to about 8-9% before the lambda sensors cap out.

[RPiM5]

So 100% Pure Methanol will disintegrate the throttle bodies quite badly but 50/50 not too bad, while just 100% Water Injection has no effect on the throttle bodies? Am I saying this correctly?

Why not just run 100% water Injection for daily driving applications with 50/50 or Pure Meth for specific racing events once or twice a year thus saving the throttle bodies from disintegration?

Although it would be interesting to see if there are any performance increases with a bigger bore throttle bodies.

I haven't dyno tested 100% Pure Meth on the S63tu platform before but I have tested 100% Water Injection for about a 25-30hp gain and 50/50 at about a 50-60hp gain. I'm guessing Pure Meth might be around 80-100hp gain? I'm not sure why anyone would need to drive around with Pure Meth when going to Ralph's to buy some almond milk.

I like using 100% distilled water for daily driving myself. Cleans the engine out too.

In any case this is a cool project. I'm always interested to see any potential verified gains from mods.

[Sales@RKautowerks]

Originally Posted by RPiM5

So 100% Pure Methanol will disintegrate the throttle bodies quite badly but 50/50 not too bad, while just 100% Water Injection has no effect on the throttle bodies? Am I saying this correctly?

Why not just run 100% water Injection for daily driving applications with 50/50 or Pure Meth for specific racing events once or twice a year thus saving the throttle bodies from disintegration?

Although it would be interesting to see if there are any performance increases with a bigger bore throttle bodies.

I haven't dyno tested 100% Pure Meth on the S63tu platform before but I have tested 100% Water Injection for about a 25-30hp gain and 50/50 at about a 50-60hp gain. I'm guessing Pure Meth might be around 80-100hp gain? I'm not sure why anyone would need to drive around with Pure Meth when going to Ralph's to buy some almond milk.

I like using 100% distilled water for daily driving myself. Cleans the engine out too.

In any case this is a cool project. I'm always interested to see any potential verified gains from mods.

Why not put a port after the throttle body, none of this is an issue at that point. You don't have a reverse thermal transfer at the cooler, no TB issue, done. 1/8th NPT tap is all you need and it can be easily reached. Put a little grease on the tap and you don't have to worry about shavings.

-R

[TheHouseWon]

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