compression ratio vs boost psi

**FastFwd** · 08-05-2009 10:48 AM

Originally Posted by delsol9000rpms

FastFwd that 268kw on 16psi was did on race fuel.

Definately believable.

Check the first post on this page.

http://www.ozhonda.com/forum/showthr...=111075&page=8

As ive said before i believe that someone can make 268kw on a stock block but running 16psi for anything but a "2 minute cross your fingures hope nothing die's Dyno run" is unbelievable. it would last less than 5 mins on a track.

**Sexc86** · 08-05-2009 04:29 PM

Originally Posted by lookingforboost

as for motor blowing if you reach the breaking point of an engine component then dosent matter how good the tune is then it will fail eventually for example a D series head bottom end will take large amounts of boost but the connecting rods only withstand about 200-220 hp and they will fail at this point ..... hey luke :P

lol cmon mate i made thate point 2 pages back :P

**lookingforboost** · 08-05-2009 07:19 PM

Originally Posted by Sexc86

lol cmon mate i made thate point 2 pages back :P

to lazy to read that far back

**Blue** · 09-05-2009 11:23 PM

story of this thread...

**myztery** · 12-05-2009 05:32 PM

Originally Posted by Blue

story of this thread...

if its better for a high comp/low boost or low comp/high boost
it was an application towards my motor, to make the most of my motor, or any motor in that app....

so the thread was bought out there...into what degree is high comp???

**Blue** · 13-05-2009 08:57 AM

my comment more so was that ppl just repeat - cus theyre too lazy to read "that far back"

**woznaldo** · 21-06-2009 09:00 PM

It's probably worth mentioning what CR OEM turbo cars run for reference. I know that VAG 1.8T 20v engines ran 9:1 or 9.5:1 from the factory depending on what car it was going in but, that would obviously be the OEM compromise on a mass produced turbo engine between reliability and drivability.

These engines a capable of reasonable power on std internals 400bhp+

I've got 1988 Renault 5 GT Turbo running a std carb blow through set up. The engine design is getting on for 50 yrs old now and that runs a std CR of 7.9:1 on it's 8v OHV non crossflow head.

The difference between the VAG engine and my old skool Renault lump is the advances in EFI technology and it's control, predominantly, ignition timing. The obvious other differences in head design have little to with a reliable CR.

Food for thought