Hypergear Turbochargers and High flow Services Development thread

[Lithium]

2 minutes ago, WR33KD said:

I asked this question a while ago about dyno sheets but with a tcf of 1 isn’t that engine power and with a tcf of 1.1 or higher wheel power?

i went through a low talk with a guy here in nz to get my 400kw sticker.

My tcf is set to 1.1 as I’m only 2wd and 1.2 for 4wd or am I only the wrong page or am I reading the wrong book

No, the complete opposite.  The torque and power numbers shown on a "flywheel" graph on a Dynapack are whatever was measured at the hubs x whatever the TCF is.  If the TCF is 1.0 then the number shown is the hub number times 1.0, or basically exactly the same as what was measured.

Your TCF of 1.1 means that it has multiplied what the dyno read by 1.1, so it's inflated what the dyno measured by 10% as an attempt to estimate what the engine is making.... that's why they'd used 1.2 for 4WD, as there will be more transmission loss so they inflate the measured number by 20% to try and make up for that.  I personally can't stand this practice, and only use "flywheel mode" as it allows you to correct the hub torque using the final drive and I'll just set TCF to 1.0 to make sure there is no inflation going on.   Hub dynos read high enough compared to others as it is

[Dose Pipe Sutututu]

12 minutes ago, Lithium said:

Hub dynos read high enough compared to others as it is

Then there's the whole 1000nm army too (when clearly RPM input is missing and derived torque isn't used).

 

[GTSBoy]

And the whole idea of TCF is a bullshit anyway.

We all generally work on the idea that a DD roller dyno will read about 75% of the engine power at the rollers. That is NOT lost in the transmission. Some of it is, but the bulk of it is lost at the rollers. There is tyre slip and deformation on any roller. A huge amount of energy is lost to friction. If you don't tie the car down hard then you lose more to slip. If you do tie it down real hard, you 'll lose less to slip, but lose some more to deformation of the tyre. (I would suggest that deformation is a much smaller proportion than slip though).

AWD rollers have the opportunity to lose more power at the rollers, because 2x the number of rollers. But....with the same amount of engine power, because the power is less at each roller, there will be much less slip at each roller. So AWD cars might lose a bit more power than a 2WD car, but they could also lose a little less. Probably lose more in big power applications and lose less in low power, but I'm just guessing.

The 2WD thing was then further confused by people saying that the losses in FWD transmissions are less than in RWD transmissions. Now, whether that is true or not is not really important, because most of the power "lost" is still lost at the tyre-roller interface, not in the transmission. So out of the 25% "loss" that we pretend is a constant for RWD cars, maybe only 5-10% of it is in the transmission. And if FWD cars are more efficient in the transmission, then you might only save 1% out of that. So the total losses should still be in the region of 25% for FWD cars too.

The real situation is certainly nothing like saying RWD cars lose 25%, FWD cars only lose 15-20% and AWD cars lose 30-35%. Because those statements simply cannot be true in general. It is close enough for RWDs on DD dynos. It might be a little different for RWDs on other roller dynos (due to calibration differences, roller diameter differences, roller surface texture differences, etc). It is definitely different on Amercian roller dynos, which have an input field in the software for "How much power did you want?" And I won't talk about inertia dynos because they suck.

Hub dynos are great because all the tyre-roller losses just go away. You measure power much more close to what the engine is capable of, less only that which is turned into heat in the drivetrain. And that number is nowhere near as big as people think it is. If it was, then a 500HP car would boil the oil in a typical diff in a single dyno pull. Certainly after a few repeated pulls. It doesn't happen, therefore the losses in the drivetrain are smaller than people think.

Edited May 15, 2020 by GTSBoy

[Lithium]

1 minute ago, Dose Pipe Sutututu said:

Then there's the whole 1000nm army too (when clearly RPM input is missing and derived torque isn't used).

 

Yeah that's what I was referring to with flywheel mode, that actually corrects the 1000+nm torque by dividing it by the final drive - you just have to leave TCF as 1.00 so it doesn't do other inflation

[WR33KD]

Cheers for that guys, my knowledge of dynos and tubing is next to zero hence why I pay the pros to do it as it goes way over my head.

We have the 1000nm army guys over here and it gets me every time that my 400kw can beat there 500kw every time and the it’s hard to believe who’s telling the truth when it comes to power 

[Dose Pipe Sutututu]

5 minutes ago, WR33KD said:

We have the 1000nm army guys over here and it gets me every time that my 400kw can beat there 500kw every time and the it’s hard to believe who’s telling the truth when it comes to power 

It's the best isn't it when you come to play with less power, less everything and deliver piles of choppage

[Murray_Calavera]

10 minutes ago, WR33KD said:

Cheers for that guys, my knowledge of dynos and tubing is next to zero hence why I pay the pros to do it as it goes way over my head.

We have the 1000nm army guys over here and it gets me every time that my 400kw can beat there 500kw every time and the it’s hard to believe who’s telling the truth when it comes to power 

Yep, that's why I prefer to ask what size turbo and what their MPH is if they have taken it down the 1/4 mile. 

[dyl33]

what turbo would you recommend for a r33 gtst for a responsive 280-300kw street car on p98 fuel.

Easy bolt on and still use stock airbox and return flow cooler. 

 

 

 

[GTSBoy]

Depending on the cooler, you may struggle to get above 280rwkW anyway.

[Ben C34]

On 5/15/2020 at 5:15 PM, Murray_Calavera said:

Yep, that's why I prefer to ask what size turbo and what their MPH is if they have taken it down the 1/4 mile. 

I prefer to ask for a skid

[dyl33]

1 hour ago, GTSBoy said:

Depending on the cooler, you may struggle to get above 280rwkW anyway.

It's a blitz returnflow, I know they're not the best.

I'd be happy with 280kw but could always change the cooler at a later date.

[hypergear]

5 hours ago, dyl33 said:

what turbo would you recommend for a r33 gtst for a responsive 280-300kw street car on p98 fuel.

Easy bolt on and still use stock airbox and return flow cooler. 

ATR45SAT BB model internally gated is recommended. U will need a proper cooler kit for that power. I can supply PWR front mount coolers if anyone's interested. Thats the same one as I'm currently using on the test car. 

[dyl33]

Ok thanks Tao, what would you expect a atr45sat to make with a return flow cooler?

Do you have any pictures of one low mounted on a stock manifold?

Also how does the atr45sat compare to the G4 hiflows?

Thanks.

 

[hypergear]

I don't think u will see much more then 270rwkws with a Blitz return flow cooler. Fitment of it is on Video below. O nP98 fuel, Power wise G4 high flow maxed towards 300rwkws, while ATR45SAT maxed at 322rwkws.   

 

 

I'm placing an bulk order for PWR 600x300x79mm coolers at a discounted price. if any one wants them let me know. 

Edited May 19, 2020 by hypergear

[hypergear]

Alternatively you can use standard G3 profiled 21U high flow thats bolton to factory location with minimum fabrication work. Made 282rwkws on P98 fuel and 330rwkws on E85 internally gated, super responsive. 

Edited May 19, 2020 by hypergear

[dyl33]

Ok thanks tao, I want to stick with the return flow intercooler for now.

Whats different between the g3 and g4 hiflows?

How much fabrication is needed between the high flow and the atr45sat to install? I thought just a metal intake pipe?

If it will only make around 270kw with return flow do you still recommand the atr45sat?

 

 

Edited May 19, 2020 by dyl33

[hypergear]

G4 comes with one size bigger wheels.  roughly 25kws difference in power compare to the G3. Trying to push 270rwkws out of blitz return flow is like pushing 520rwkws out of stock cams. So yes to ATR45SAT. 

[dyl33]

Ok thanks mate.

[jrm]

I believe PWR do a return-flow intercooler for these cars too (PWR PWI2204 for R34 GTT, at least).

Does anyone know if these have the same restrictions as the Blitz, and other return-flows?

[GTSBoy]

With return flows you necessarily have a core with less height, by about the diameter of the return pipe. That means the core has that much less area for flow, will present a higher pressure drop.

The outlet on the return side tank is usually not ideal either. The flow has to turn through 180° in a short radius. Will always lead to a larger pressure drop than normal cross flow outlets.

For all that - it's what I've got and I would happily stick within the power limitations imposed by it, if having a return flow was something I wanted to keep doing. And for a street car, it's a pretty desirable thing. If you want to make more silly power levels, you have to start giving up on things that are nice to have (for installation ease, more stock look, etc) in favour of things that work better for the power.

Edited May 22, 2020 by GTSBoy