Project: RS2 ABY

[Dan]

Bigger turbos make the same power with less boost, thus 1.9 bar does no
equal X HP, it is turbo dependent.

Possibly a stupid question, but how does this work?

Surely x bar in the inlet manifold is just x bar, no matter where it came from?

I know that if the engine is ported to increase flow, you can make more power with less pressure -- since the reason for the drop in pressure is that more air is being supplied, but more of it is flowing though -- but with the same engine, how does said engine care about the size of the turbo, beyond what boost pressure it's getting pushed into it?

[djh]

as I understand it

smaller turbo making x power at 1.5 bar boost flat out

bigger turbo making same power at 1 bar of boost not even breaking into a sweat.

[Rocco]

Colder air?

[EspenW]

Yes, colder air and (much) lower backpressure.

[driftin jo]

The smaller turbo makes less power due to overall flow, a small turbo running 2 bar
for instance may make 500hp but a bigger one could make 500hp at only 1.7 bar, this is because there is much less restriction to exhaust flow from the bigger turbos turbine.
Think of a power in terms of pressure differential between inlet pressure and exhaust pressure.

Put simply, as above,

Mostly down to much lower back pressure and yes the bigger turbo will have
lower charge temps for a given boost pressure, lower temps equal more air mass thus more fuel can be burned.

[Dan]

Aha. That makes sense. Thanks guys.

[Sonic]

The car is undergoing some final prep for it's ring trip next weekend... Will has done a brilliant job of replacing and cleaning up some parts - now with new wishbones and solid subframe bushes.



The brake carriers also required a little maintenance.

[Jamo]

What cams have you got in there Sonic? You need to do a spec sheet

[Sonic]

What cams have you got in there Sonic? You need to do a spec sheet

I think i'd find that handy as well, there has been so much done to this car that i regularly forget things, particularly when it's out of sight, out of mind.

It's running ABY inlet and RS2 exhaust... i'm aware 7A would be better, but i had the RS2 cam from when i was intending to go RS2 spec with turbo, and figured i should use it.

[Jamo]

I dont subscribe 7A is better, all cam combos have a trade off think RS2 with a KKK turbo variant is the best fit

[Sonic]

Apparently 7A would give more upper-end without any noticeable decrease low-end by removing the rs2 cam.

[Sonic]

Rear subframe done as well, just having ARB brackets made.

[BorisShakhov]

The car is undergoing some final prep for it's ring trip next weekend... Will has done a brilliant job of replacing and cleaning up some parts - now with new wishbones and solid subframe bushes.



The brake carriers also required a little maintenance.

Is it 8,8 strength bolts on the carriers?

[prj]

Apparently 7A would give more upper-end without any noticeable decrease low-end by removing the rs2 cam.

No.

[Sonic]

No.

Must have got lost in translation then

What was it that you meant with 7A cams?