were back LOL throttle body zs

[Drew]

Originally Posted by Eddie

why would your drive train make more losses beause the engine is making more power, what changed in the gearbox?

torque, turning force that will generate friction/heat. the more torque you put in the more you will lose through friction/heat.

might only be a small bit but will never be the same bhp number or percentage between std and tuned.

Drew

[Quadcam24]

jay, yeah i was joking mate , 180 wheels would be 210-215.

Drew,....i would maybe agree on a small variance on a big turbo build were your throwing hundreds of extra bhp through the transmission, but at this level where the power difference is 5-10 bhp or so, it will make no difference at all.
When ross sc zs made 260 odd bhp it was still 229 at the wheels.
mine made 212 fly, 180 wheels at powerstation when i had my cams mapped in, so no extra losses.


edit, i hope no news, doesnt mean bad news, must be mapped twice over by now unless its got a problem again ?!?!

what air filter set up has it got ...cone in inner wing ?

[POMPSKI]

Thats one angry engine. I love it.

[Eddie]

Drew

Point taken, you could also factor in wear on gearbox components, diff, bearings, any kind of drag on the clutch, brake pad contact, worn wheel bearings, general wear and tear on the bottom end of the engine, tired ignition system, so many variables from the point the car leaves the factory.
Most dyno’s have compensation formula’s to allow for resistance and climatic conditions, the general rule would be to use the factory figures as a bench mark and work from this point. Always best to measure effort and find a torque curve to make rough calculation on other numbers.
Once we have wheel torque it’s a little easier to “guestimate” the potential crank HP, this you already know of course, main point being, rollers and even hub packs calculate best guess for crank figures, I don’t believe Thor calculate crank HP they just stick with hub power, that’s fairly close to WHP once they fudge in the compensations.
I will be very interested to see just how much power over stock WHP (144) Steve’s car will make, personally, I don’t think the peak numbers will be particularly high but it should have killer torque based on the other mods done to the car.
We shall see I guess,

[Quadcam24]

so many variables its never an exact science, you just have to trust that they are close and thats it........ but when youve seen 4 people sitting on a cars bonnet, because it was supposedly so powerfull it was wheel spinning on the rollers...despite having just 200ft lb, it does make you sceptical, especially when youve seen 600 bhp supras on the same rollers running fine, rflmao !

what makes you think it will have high torque ed?
personally i would expect lower torque because i know how bad the zs runs without vis and i struggle to believe all that lost torque can be recovered and then some more created just from mapping, why have the vis if it can be mapped out better without it ?
i would expect similar or maybe a nadge more torque higher up but less low down and mid range.
I have lots of modified zs roller graphs with wheels plots on, so will be interesting to compare torque when the graph is posted here.

[Eddie]

My feeling is the torque curve on the VIS enabled KV6 delivers the torque curve progressively, nice and smooth to avoid a massive dump of low down torque. Remove the VIS valves on stock ECU it will pull out timing and fuel to compensate for the change it see’s that’s quite a change it cannot adjust and pull the best performance from.
With standalone management and unimpeded airflow you can create the curve how you want, depending on how the engine is breathing in other areas such as head and valves and of course out of the exhaust manifold, good flow coupled with some scavenging and maybe some cam over lap if the build will allow then you can tune your torque curve with timing, both mechanical by adjusting the cams gear/s and in the ECU. If I remember well he runs JS Manifolds which are designed for midrange, not sure which cams but it won’t be 285’s with stock valve train so 270’s at best, these aren’t designed to make power above a certain rpm. With the DTA they can tune the AFR’s to where they need to be then build an ignition map, based on components used in the build the airbox will flow for sure but there will be other restrictions and this will limit the full potential. Open out the ports in the head and use the different valves and new profile it will flow a lot more air, add larger cams it’ll flow more again, change compression ratio of pistons you gain again and put cams and breathing mods to full use, it’s ok having the airbox but how much can the head digest?
Small exhaust manifold system with short primaries will be good for torque, map in some ignition in the low rpm range and see what it likes, I feel this is where Steve’s car will make killer torque over the VIS enable engine.

[Ritchy]

like the technical talk here just need snowy senior across here now

[Drew]

not the easiest to see, it got wet in the door pocket before i bought it!

steve's 200 v6. std manifold but the valves open, so short runners and large plenum with a single throttle body.



Drew

[MG6Turbo]

Nope nothing bads happend, just Thor busy at the min. Its on the dyno just not finished yet as Peter has other jobs on which took him off the dyno.

So hopefully Monday I should hear something.

Interesting read though of the points, but it is an unknown so it will be interesting to see what difference the box has made.

As for seeing what the heads can flow, we know the std heads can flow 260bhp without any fettling, so theres no reason the heads will be a restriction at this level of tune with the piper cams used.

Also the inlet and injectors have been changed, so everything that has been bolted to the heads is totally different now anyway.

G

[Jay-ZS+]

Cant wait to hear George, any idea of the volume of the airbox and the runner length. Been learning alot of theory around air flow and helmholtz resonance just wondered what rev range the runners are designed to produce peak power.

Have read that in theory the airbox should be between 1.5-2x the displacement of the engine, be interested to see how this works in practice.