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So you're using a MAF...but only measuring air off one cylinder bank ?
Yes exactly! It's sort of like using the aftermarket intake pipes where some of them have a larger diameter in the MAF surface area to decrease restriction. So anyone who can do that can also set up this. Much easier than SD
Thanks . Yes, it has 8 butterflies. By having a lot longer runners than the factory intake, the torque is up quite a bit also! I'll post results next week.
Yes exactly! It's sort of like using the aftermarket intake pipes where some of them have a larger diameter in the MAF surface area to decrease restriction. So anyone who can do that can also set up this. Much easier than SD
SD is a doddle, so not really sure you could get much easier ! lol
Or for n/a builds with ITB's many just use TPS vs RPM as main load parameters. Although I presume you must still be using the factory ecu so may not have as many options
SD is a doddle, so not really sure you could get much easier ! lol
Or for n/a builds with ITB's many just use TPS vs RPM as main load parameters. Although I presume you must still be using the factory ecu so may not have as many options
Definitely a very nice setup though
Well, yes we are using the factory ECU and we used to run it on SD with our old airbox style and used a temperature sensor. The problem with speed density is that it takes a long time to fill in the matrix correctly at each load and RPM. Once the density in the air changes, which is sadly not just a function of temperature, the tune is a bit off. Also we use a total pressure intake up front, so once we go above a certain speed, air air supply changes to what is set into the SD table at a given RPM/throttle position. Therefore when we setup the car on the dyno, we were always lean once we drive a bit quicker on the street... The MAF corrects for all those effects!
So here are some preliminary dyno plots. We gained about 10-20 hp nearly everywhere, depending on RPM. However, compared to my old setup, which was in one of the images posted above, we lost 20-40 hp depending on RPM.
I did some CFD to resolve this issue, as the airboxes are actually better than the old design. It turns out that the hoses have 25% momentum (mass flow) loss compared to a straight pipe of equal diameter and length.
Therefore I will make a carbon filter box, similar to the old design and we should be back on the amazing gains we had previously. On the old run, the throttle was released around 6200 RPM as our rear seal blew that time, so that's why the dyno goes down drastically towards the end.
So I don't have results for you yet, but we have advanced quite far. Dyno results should be available in 2 weeks.
For whoever hasn't seen it on the CorvetteForum I'll post some pictures here as well. The filter box is now finally finished. As I mentioned previously, the bent hoses showed mass flow losses on the order of 25% in CFD simulations. The lambda data backed this up once the new filter box was installed yesterday as we were way too lean. The fuel flow had to be increased by up to 28%!!! We haven't been on the dyno yet, but we are expecting very good news due to this. The car felt a lot quicker right away, especially starting around 3800 RPM. Enjoy the photos.
So how much hp an torque in ft pounds did it make? I see something about 740nm which is like 540 ft pounds of tq.
That's with the old setup with the hoses. We haven't been on the dyno yet with the filter box as we only got an appointment the week after next. But what I know from our previous setup with a filter box is that it will be well over 800 Nm. I'll post the results as soon as I have them.
That is the most beautiful intake work I've personally ever seen.
Plans to bring it to market?
Thank you for the kind words . Let's put it this way, I know it is not a product that will go in batch like a simple carbon intake pipe with a filter on top. But, the tooling is obviously in place, so making more sets is just a question of demand. But I look at the setup more as a cool marketing tool that shows the company's expertise in aerodynamics, and that with our tools such as CFD and know-how we are able to 'engineer' the results instead of just getting there by intuition and trial-and-error. So there will be more to come for sure soon...
As far as this system, I am considering having the alternator relocation kit cast, even though it is mostly needed by the Corvette crowd. But it is a part that is currently not economical and does not add to the power output of the system. The entire system in general is attainable, but including the Harrop ITB, the price is about what a supercharger would cost. And most people care more about the power output than having an incredible NA setup.
07-17-2017, 01:23 PM
Carbon airboxes with the Harrop Hurricane on an LS7 
. Yes, it has 8 butterflies. By having a lot longer runners than the factory intake, the torque is up quite a bit also! I'll post results next week. 
. Let's put it this way, I know it is not a product that will go in batch like a simple carbon intake pipe with a filter on top. But, the tooling is obviously in place, so making more sets is just a question of demand. But I look at the setup more as a cool marketing tool that shows the company's expertise in aerodynamics, and that with our tools such as CFD and know-how we are able to 'engineer' the results instead of just getting there by intuition and trial-and-error. So there will be more to come for sure soon...