With each bank individually controlled by separate throttle bodies would you want separate monitoring of the air to compensate the fuel on that bank.

Theoretically you don't want more power (air n fuel) on one side rather then the other but this is how cylinder shut down on the v8's work.

I can see the benefits of having a maf on each side because both servos may not respond to voltage and such exactly the same so you may have to tune or sync them up other ways.

Speed density is usually the easiest to tune for most people but doesn't mean it's the best air metering technology.

I'm sure you guys have a handle on this but just sharing my .02cents

 

OS,

I may have described this incorrectly. There are six 48 mm throttle bodies. One TB for each cylinder. There will be two servo motors. Each servo motor controls one bank (3 TB's) of TB's. The servo motors are controlled by a Link motronics (that interfaces with a modified Porsche ECU) as the Porsche ECU is not capable of controlling more than one servo motor or dual injectors. We could have had a lot of linkage and one servo motor with a big return spring, however we didn't like the pressure of the spring or the room required for the linkage.

You are correct about the air in fuel theory and it is in fact more than theory. The banks isolated by themselves would be close but not perfect. If you look at this pic you will note a balancing tube between the two banks. This feature makes the air pressure balanced or "perfect" so to speak.


Here is a different approach using the same balancing idea with six TB's. We tried to improve by eliminating the heat sink material along with the certain negative areas inherent with the type of design.

 

still watching...keep it up chad, getting close!

 

The information and testing continues to arrive. Our goal and reality will not meet. The goal was to make as much HP and torque as possible, (something that was leaps ahead of anything currently out there) while at the same time providing responsiveness in the same league as the HP and torque.

The mega hp, in excess of 1500 hp is there with GT42R size turbo's. The response is not. The lag is not acceptable for anything but straight line and high speeds. The engine max's out the GT35R's with excellent response. The reality is, depending on the impeller used just over 1200 to just over 1300 hp is the maximum power these turbo's are capable of providing under our build. We easily max out these turbo's at a realitively medium boost. I do not see any way to utilize larger turbo's short of future advancements in the variable vane turbo's design.

With our fuel, air and engine management capability along with the build of the motor we will be in a position to take advantage of possible future turbo improvements. However for now we will proceed with the GT35R turbo with an 86 mm wheel.

More later.

 

Now are you talking brother, looking forward to the dyno day. For the love of Jesus man let's see this completed before X-mas of this year already.

 

Hi Art, have not heard from you for awhile ........ how is your mom doing?

There isn't a lack of wheels. KA will be done soon and there will be no lack of local challenges waiting to be the first to best her. It will be fun and interesting.

What makes this build complicated is the GT3 pointer high lift cams, multiple TB's w/ dual servo motors, dual staged injectors nitrous and non Porsche ABS system. The Porsche ECU doesn't have provisions for these type of things. If it was a race car it would be easy, but there are too many street options the ECU controls to just get rid of it. We are currently working on the wiring harness and schematics.

 

might be worth neil giving justin nenni at tuning concepts or titan a call as they have both ventured down the standalone path before. may not have done all what you are doing but surely might save neil a little trouble

 

Thanks OS for the help. Currently we are not at any impasse. It is very entailed, and Neil wants everything down on paper (as in drawings and schematics) and for Todd K to agree to his responsibilities as to the areas of his expertise.

It comes down to a very complete review prior to proceeding with placing the motor into the car.

Sorry about deleting the update. It had a piece of information that was not suppose to be released. It will be before the car's performance numbers are released.

 

Ok ......... the motor is done and it won't be too terribly long before it is in the car and tuned.

Now we are going to turn our attention to a different part of the car. It has bothered me for a long time that the 996tt can produce 1200 to 1300 hp with turbo's like the GT35R and yet the response isn't the greatest and so much of the power is un usable because it isn't being hooked up to the road. In other words ........ so much power is being wasted.

We believe the stroker along with the new intake plenum and multiple throttle bodies have answered the response question, however it just isn't possible for the rear wheels to hook up the developed power to the road. Upper gears yes, lower gears ....... no.

What is needed is a system that can transfer somewhere between 400-500 hp and it's relate torque to the front wheels and all the while contribute to great handling.

We do not have the system yet, but it is about to be developed and these cars are about to enter a new realm of performance.

 

The more we look into traction options, the more we find that is available. Currently looking into Drexler and Xtrac drivetrain components for front LSD as well as a part replacement for the viscus coupling.

In addition we are looking into launch control, gear boost anti lag and gear dependent boost systems.

More as we progress and make final decisions.

 

With launch control, KA could be a Veyron killer.

 

The hp and torque this motor achieves with so little boost is frightening. I believe most challenges would be over before the opponent even begins to make boost.

The achilles heel will be this instantaneous power in the lower rpm range will do no good if it can't be connected to the road. The first four gears will be worthless if the rear tires are spinning. Depending on the gear everything above 400-800 hp can be a waste with rwd on these cars. The stock awd front dif and viscous won't handle more than fifty foot pounds of torque. This is why we will be replacing these parts. Currently, depending on the gear being used ........ hp/torque is being wasted. We require parts that will plant a minimum of 300 to 400 hp/torque up front while maintaining handling.

Currently we are not familiar with the other engine management systems that can be utilized.

We are doing a crash course as to what is available and works.

We really want to see all the developed power being utilized in a positive manner. We are not going to attempt to reinvent the wheel here.

 

well if you don't need your front wheel drive, I need a front set of axels

 

Update:

We are still looking at differentials. It appears Drexler Motorsports in Germany can build an electronic differential that can handle our power requirements (max. 600 hp to the front wheels) . It will allow us to do away with the viscous coupling ........ the differential would be controlled by our EMS.

Looking into launch control, gear boost anti lag and gear dependent boost systems, we decided to incorporate launch control and the gear dependent boost system.

We will not incorporate the gear boost anti lag system because it destroys turbos in short order. What occurs is the turbo's spool up off throttle by the engine management system automatically adding fuel to keep the turbo's spooled. This is very detrimental to the turbo ........ some of you guys would probably like the show. What would occur off throttle between gears is a six to eight foot ball of flames coming out the exhaust. Seriously 6-8 feet of flames ........ no way.

 

Yeah, the rally car racing world uses it, but they replace stuff daily in those motors. Dumping raw fuel into your exhaust manifold is destructive to a 40k engine. Ferrari had their own system for a while which seemed better. It used a bypass valve from the intake manifold to the exhaust manifold. When you let off the gas the bypass valve open and compressed air from the intake was let into the exhaust system, and with the combination of slightly retarded timing for excess fuel, ignition occurred and bam boost. The difference was that instead of retarding timing 20-40 degrees they could do it far less, basically just enough for excess fuel to mix with the new air. Much safer but I am sure it still took it's toll on the system. Another way was to add an extra fuel injector to the exhaust pre-turbine to get the same effect without retarding timing. all of these are bad for the engine, turbos, cats. I had another idea but who knows if it will ever work.

I guess if you have a 5k motor it's no big deal to do this stuff.