Well this is a bit of a general interest question. I was just reading an article on a the Nizpro twin turbo F355 Spyder. Very impressive. Anyway apparently its runing the standard 11.5:1 compression ratio with 14 psi of boost making 450rwkw's (all on pump fuel). I have never heard of such high compression ratios being used on a blown car. Generally they are in the order of 8.0:1 to 8.5:1, then I remembered the saab prototype variable compression supercharged engine that can alter the ratio from between 8:1 and 14:1 depending on load. So clearly it is possible to use such high compression ratio's.

Now my question is if Nizpro which in my regard are one of the leaders in aftermarket turbo modifications in Australia deem a 11.5:1 compression ratio as suitable for a turbo and can make it produce good power, why cant this be achieved on a mini motor? The benefits to fuel economy would be quite substantial and less engine mods would be needed to convert to a turbo motor. I understand that having such a high compression ratio is not ideal for performance but as stated there are other benefits.

Interested to hear anyones thoughts.

Sorry about the long post.

EFI with a fully programable engine management computer with MAP, O2 and knock sensors will let you get away with a lot more boost by controlling the advance precisely.

Also Jap pump fuel is WAY better than ours (their std stuff is 98 RON ?).

Haven't seen this car - you got a link to it?

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Too many cars, and too little time.

It is an Australian car but yes it does 98 RON, the link is here http://autospeed.drive.com.au/cms/A_2699/article.html but im not sure if you will be able to see the full article as you have to be a member.

Even with knock sensors and the like that is an impressive effort for a boosted car, not that many n/a cars can run that level of compression. But I guess you would expect wonders if you spend 40k on a turbo kit, small change compared to the car price I guess.

Apart from the ability to automatically retard ignition timing through the engine managements "Knock sensor", & the quality of inlet charge (also determined buy the computer through numerous sensors) & the engine designed with a far better chamber cooling properties via well designed water galleries etc,,,a late model multi cam , multi valved (almost Hemi) combustion chamber is far better at combustion "Flame front control" than the old agricultural A series 5 port cyl head, By Far!!!

we`ve set up quite a few 20valved toyota engines with the 1800cc bottom end & the 1600cc ,20 valved top end & have them running at 11.5:1 with no pinging & on pump fuel, ,,even in the race cars...that said , we havn`t force fed the things (yet) so i can`t comment there, but i can`t see why a blown, late model multi cam/valved hemi chambered, engine, couildn`t have control over pinging with decent knock sensing computerised engine management system.

easy-peasy

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No offence intended here but--> anyone writing a book about minis 30 years ago may not have experienced such worn or stuffed-with components as we are finding these days.

You should put your heart & soul into everything you do.

OK, just read that article (yes, you do have to be an Autospeed subscriber )

That car is a MONSTER ! 320kph +

I love it, nothing touched on the car or engine except for the addition of the turbos, intercooler and the custom exhaust.
But I didn't get my lotto ticket today

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Too many cars, and too little time.