Is it possible to turbo a car with a 10.5:1 ratio?

 

anything is possible if you are willing to upgrade almost every art of the engine. a compression ratio to 10.5:1 is high as it is...addding turbo...you are gonna have to use racing fuel, octane 100 or more.

 

That is right, you'll need 8.5 to 1 to not detonate the engine on 93 octane pump gas.

 

Not true look at the turbo celica's and the turbo matrix. Tuning my friend tuning.(although i dont know how they did it)

 

and 9.5:1 in oder ones like mine...S4's are 9.3:1 Many run more than 1 bar of boost..that's 15 psi. People with big turbos on A4's are running up to 25 psi with stock internals at 9.3:1 Granted the block is pretty strong since it's a VW2.0 less bored to handle the turbo charging. There are some going the 2.0 liter route these days and in changin pistons they are brining compression down to about 8.5:1. These guys are all running bigger tubos as well. No good data yet on times or anything.

 

and 9.5:1 in oder ones like mine...S4's are 9.3:1 Many run more than 1 bar of boost..that's 15 psi. People with big turbos on A4's are running up to 25 psi with stock internals at 9.3:1 Granted the block is pretty strong since it's a VW2.0 less bored to handle the turbo charging. There are some going the 2.0 liter route these days and in changin pistons they are brining compression down to about 8.5:1. These guys are all running bigger tubos as well. No good data yet on times or anything.

 

1-bar is 14.2 dude and yes you can turbo at compression ratio's of 10.0:1....or more......Xs engineering turboed a 2zz-ge( With an 11.5:1 compression ratio no less) It is all right there in the july issue of sport compact car. You just cant run insane boost level's.:wow:

 

Yes.

 

10.5:1 CR with alum heads is on the edge of forced induction applicability on pump gas. Since you can't run high peak boost don't get centrifugal. Centrifugal blowers have a thin boost curve such that have to be making min. 8 psi peak to have anything worthwhile down in the mid-rpm band. But 8 psi is really not safe for the long term even when intercooled if you stick to 92/93 octane. The only solution for motors with such high compression is something no more than 4-5 psi nonintercooled and 6-7 psi intercooled. At this low boost level, for anything worthwhile you need a thick boost curve possible with appropriately sized turbos or a pos. displacement blower. With 4-5 psi nonintercooled I'm confident you can run 26-28 deg. total timing on pump 93, which is the bottom threshold of timing advance I like. With 6-7 psi intercooled, you an probably run 29-30 deg. total timing with 10.5:1 CR. The fact that you can run more timing w/an intercooler does not mean you can run even more boost and drop back to the 26 deg. total timing advance threshold I feel comfortable with.

 

So that's a yes? (lucid and coherent explanation).

 

well...first off sorry for the multipost...the software won't let me erase my original one.

Second 1 bar is actually 14.50377 psi at sea level and it varies with altitude

and yes you can run high boost with high compression, but it has to be well tuned and internals have to be up to the task. Also, is that car you mention a purpose built car or a daily driver? I assume it's street driven but it also has some internal upgrades to hold that boost right? How much boost are they running in that setup? what kind of power? I think the context of the tread is keeping the car reliable. I wouldn't try to run more than .5 bar in the TLS without some serious internal engine work...and torque converter upgrade. But you are right....it can be done...anything can be done.

On a side note...I wen to the drags for the first time last night...some serious stuff there. We were at NE Dragway in Epping NH. Ferizzo spanked my best time of 15.9@ 87 with a 2.3 60ft with his 15.2@93 Not sure about his 60ft times, He ran consistently between 15.2-15.4 all night. People claim low 15's to hi 14's on the audi board with 1.8's at 60 ft in their 1.8T's....but I obviously can't can't drive like that yet. Time to practice.

 

See the july issue of Sport Compact Car about the Turbo Matrix. It is a decent article.

 

I'll take a look

 

anything can be done with $$

i have seen a turbo intergra type R that blows the engine in just 2 months....and he just keep putting back on the engine...