Standard Gti Head Flow Rate Cfm?

[Saveit 0]

Hi there,

 

Does someone know what the actual flow in cfm is for a standard 1.9 gti head? And what about the flow in cfm for the 306 xsi 8v (XU10J2)?

 

Stefan

[Saveit 0]

Nobody knows? Sandy, PeterT?

[Anthony 1,003]

Does someone know what the actual flow in cfm is for a standard 1.9 gti head? And what about the flow in cfm for the 306 xsi 8v (XU10J2)?

If it's a comparitive between the two that you're after then I've got flowbench results for a XU9 and XU10 head, but the actual CFM values are somewhat meaningless and can't be compared against results from a different flowbench.

[Saveit 0]

Hi anthony,

 

Yes i have the chart that you are talking about, but the thing that annoys me is why they chopped off the numbers on the y-axis of the chart. This means that you cant read the actual flow value and therefore cant compare it to nothing else. But if you say that 2 different flowbenches arent comparitive anyway, then it wont matter I just thought that you could compare the chart that you are talking about to other flow charts made on a 205 gti head for example.

[James_R 3]

From memory Gur Croft measured the head std at 88CFM jumps to mind

[petert 588]

From memory, a std. head flows approx. 150cfm @ 28in, and a big valve, well sorted head approx. 165cfm.

[James_R 3]

http://www.guy-croft.com/viewtopic.php?f=2&t=45

 

 

looks more like low 90's

[petert 588]

Croft flows at 10in., so you have to convert it to get an approximate value. The QEP qraph with the various heads on it is the best, even though the CFM is cut off. You can see quite clearly the differences between the standard and modified heads. It's when you compare the 8V modified 165cfm to 250+cfm for a standard Mi16 that realise what all the 16V hype is about!

Edited April 18, 2009 by petert

[Saveit 0]

Croft flows at 10in., so you have to convert it to get an approximate value. The QEP qraph with the various heads on it is the best, even though the CFM is cut off. You can see quite clearly the differences between the standard and modified heads. It's when you compare the 8V modified 165cfm to 250+cfm for a standard Mi16 that realise what all the 16V hype is about!

 

Hehe you are probably right, but i still fancy 8v over 16v any time. It just feels different. But Peter, how many bhp/nm can you pull from a 1.6 GTI 8v fully upgrated to highest specs with bikecarbs? And what do you charge for a fully developed 8v cylinder head (you can PM me if you like)?