Outer Limits 4x4 Board

does anyone know the intake and exhaust flow rates for the 1HZ? 07 model

i need the figures to calculate intake,intercooler,turbo,exhaust gemoetry

cheers

4.2L x 4000rpm = 4.2 x 2000 = 8400 liters/minute

1 cubic foot = 28.3 litres

8400/28.3 = 296cfm (cubic feet per minute)

that's at atmospheric aspiration. add 6.8% for every 1 psi boost.

eg at 13psi:

296 + 296 x (.068 x 13) = 558cfm.

you can fiddle the numbers for whatever boost you intend to run.

your a godsend!

How would i translate that to kg/sec

Also, whats the average intake air temp gain with a turbo?

Z()LTAN wrote:your a godsend!

How would i translate that to kg/sec

Also, whats the average intake air temp gain with a turbo?

dry air at sea level is about 1.2kg/cubic metre.

1 cubic metre is 1000 litres.

1 minute is 60 seconds.

so first convert litres/minute to litres/second - divide by 60:

eg 8400 litres/minute = 8400/60 l/sec = 140l/s

then convert litres/sec to cubic m/sec

eg 140l/s = 140/1000 cubic metres/sec = 0.14cubic m/s

then convert to kg/sec

eg 0.14cu m/sec = 0.14 x 1.2 kg/sec = 0.168kg/s

you can still add 6.8% for every 1 psi boost (or 100% per 1 bar of boost)

however, termperature increase results in a mass flow decrease.

intake air temperature gain is highly dependent on the turbo and other factors, it is best determined by experimenting, ie put a temperature probe before and after the turbo and measure it. alternatively, it can be derived/estimated from the compressor map if you have it. someone might have a rough degrees per psi rule of thumb, but if you select a turbo that will be close to its efficiency island near peak boost at 2/3 to 3/4 of redline, it won't be ridiculous.

sweet as mate

cheers for the effort u have put in your reply.

dumbdunce wrote:4.2L x 4000rpm = 4.2 x 2000 = 8400 liters/minute

1 cubic foot = 28.3 litres

8400/28.3 = 296cfm (cubic feet per minute)

that's at atmospheric aspiration. add 6.8% for every 1 psi boost.

eg at 13psi:

296 + 296 x (.068 x 13) = 558cfm.

you can fiddle the numbers for whatever boost you intend to run.

Normally with a 2 valve head you'll only get 80% to 60% cylinder fill rate (less as rev's rise) so you may want to de-rate those numbers a little.
The same applies with turbo, as although the pressure difference is increased, the air is "thicker" (denser) reducing it's flow.

Paul

me3@neuralfibre.com wrote:

dumbdunce wrote:4.2L x 4000rpm = 4.2 x 2000 = 8400 liters/minute

1 cubic foot = 28.3 litres

8400/28.3 = 296cfm (cubic feet per minute)

that's at atmospheric aspiration. add 6.8% for every 1 psi boost.

eg at 13psi:

296 + 296 x (.068 x 13) = 558cfm.

you can fiddle the numbers for whatever boost you intend to run.

Normally with a 2 valve head you'll only get 80% to 60% cylinder fill rate (less as rev's rise) so you may want to de-rate those numbers a little.
The same applies with turbo, as although the pressure difference is increased, the air is "thicker" (denser) reducing it's flow.

Paul

fair point, but why unnecessarily overcomplicate the issue. you're never going to size your intercooler etc for bang on what you think your engine really flows - you're always going to give yourself a reasonably generous margin for excess capacity. knock off 20% for volumetric losses and add 25% for safety, and wow, look where you end up. if you're adding an intercooler you want top performance; cutting the size of your plumbing and cooler to the bone achieve nothing.

This might help

http://www.turbofast.com.au/javacalc.html

And yeah - I was thinking compressor wheel trim etc, not something you want to oversize.

Intercooler and pipes - oversize all you want.
Although if you get really really really really big, it could take a while to fill. I wouldn't go larger than 12" diameter unless it was a ricer, then I suppose 24" diameter pipes to match the 24" rims and 24" exhaust tip would be OK.

Paul

cheers for those Java calcs Paul