Cupra R airflow

[Wilko]

Phil, DPJ
Your engines are 4 stroke, so each piston only sucks in air each consecutive rev.
You need to divide your cc by 2, times by revs per sec, and then times by 1.15/1000 (realistic density of air at the temps we're talking.
so 1781/2 x 6320/60 x 1.15/1000 = 107.9g/sec at 100% VE and atmospheric pressure at the intake manifold.

So yours is 2.1 times this as you're running 1.1 bar ish at that point, so would be 226 at 100% VE so if you're at 200ish, you're at 88% VE.

At those sorts of revs, and 1.4 bar of boost, I'm seeing 245g/s with IHI, 258g/s being 100%VE, so I'm at 95%VE, but have Ported big port head, cams etc.

VE is simply can you get the full volume of the cylinders filled with air at the correct density.

Here's a great calculator to play with. Helps to sus out some of the bull power claims at peoples suposed boost levels.
http://not2fast.wryday.com/turbo/glossary/turbo_calc.shtml

Compression ratio effects cylinder pressures and burn rate, and higher compression makes more power, as long as you're within the knock limits of the fuel that you're using.

 

[DPJ]

Phil, DPJ
Your engines are 4 stroke, so each piston only sucks in air each consecutive rev.

It didn't take you long to spot my howler

Here's a great calculator to play with. Helps to sus out some of the bull power claims at peoples suposed boost levels.
http://not2fast.wryday.com/turbo/glossary/turbo_calc.shtml

Fascinating calculator. Cheers!

 

[Feel]

So to convert to metric, 1gram of air per sec would generate approximately 1.256 to 1.389 bhp.

Which averages to 1.3225

Or, to put it another way multiply g/sec by about 1.31 (on an LCR) gives BHP. Which is where we started

 

[ibizacupra]

Phil, DPJ
Your engines are 4 stroke, so each piston only sucks in air each consecutive rev.
You need to divide your cc by 2, times by revs per sec, and then times by 1.15/1000 (realistic density of air at the temps we're talking.
so 1781/2 x 6320/60 x 1.15/1000 = 107.9g/sec at 100% VE and atmospheric pressure at the intake manifold.

So yours is 2.1 times this as you're running 1.1 bar ish at that point, so would be 226 at 100% VE so if you're at 200ish, you're at 88% VE.

At those sorts of revs, and 1.4 bar of boost, I'm seeing 245g/s with IHI, 258g/s being 100%VE, so I'm at 95%VE, but have Ported big port head, cams etc.

VE is simply can you get the full volume of the cylinders filled with air at the correct density.

Here's a great calculator to play with. Helps to sus out some of the bull power claims at peoples suposed boost levels.
http://not2fast.wryday.com/turbo/glossary/turbo_calc.shtml

Compression ratio effects cylinder pressures and burn rate, and higher compression makes more power, as long as you're within the knock limits of the fuel that you're using.

you running cams John?

 

[J@mes]

this thead has started to go over my head!

 

[Wilko]

you running cams John?

Yep
Eurospec 268/260's
Made no difference yet, as I'm limited by max turbo flow, but there's a plan afoot.

 

[Feel]

 

[ibizacupra]

Yep
Eurospec 268/260's
Made no difference yet, as I'm limited by max turbo flow, but there's a plan afoot.

hehe

you cant help yourself John


kinda aggressive cams those for turbo motor. you checked valve lift for spring coil bind?

Got my catcams ready to drop in after I have dyno'd the new intake manifold step 2 mod.

What you planning turbo wise John? (pm if you like)

 

[Wilko]

hehe

you cant help yourself John


kinda aggressive cams those for turbo motor. you checked valve lift for spring coil bind?

Got my catcams ready to drop in after I have dyno'd the new intake manifold step 2 mod.

What you planning turbo wise John? (pm if you like)

They're a straight schrick copy, and they're only in as I got them for next to nout.
The specs if they're right put them miles away on the intake and at 0.26 mm from coil bind on the exhausts. They were run in a VVT motor before mine for a few K miles with no problems, but previous user didn't like the loss of mid range. I can always swap them for something less agressive later.

Turbo wise, I'm going for something to minimise turbine back pressure to help make use of the cams. Not going as silly as you, but it should spool as quick as the IHI and hold 1.6-1.7 to the limiter, vs 1.1 for the IHI. Subaru fitment, so nothing too radical.

 

[ibizacupra]

getting it to fit on the Js mani and DP?
TD05H turbine?

(fishing)

 

[WileEcoyote]

The CR is 9.5:1 on the AMK,APY and BAM engine, Bore is 81mm and Stroke 86.4mm, well thats what the Audi service manual says it is.

Interstingly, the Leon CR book that came with my AMK LCR says differently.

I'll fish it out when i get home

 

[VIKINGODIN]

I 175G/S at 7000rpm in second gear and a cheap stage 1 remap.is that normal or is maf crap?

 

[rsmith]

Jebus, thread resurrection or what, 175g/s, depends on what your running car wise and 2nd gear is not a good gear to log, there is not enough load, 3rd preferably 4th.

 

[VIKINGODIN]

Jebus, thread resurrection or what, 175g/s, depends on what your running car wise and 2nd gear is not a good gear to log, there is not enough load, 3rd preferably 4th.

Done another run an managed 209g/s in 3rd gear redline,is that good?whats this equation everyon uses to calculate horse power? maf reading times 1.31 or times 0.8 or summat?,also its a 210bhp cupra r remapped expecting around 250 with forge TIP and 007p valve and pipercross panel filter and standard ko4 turbo if thats what you mean by running?thanks

 

[ibizacupra]

209/0.8=261estimated