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turbo cbr 1000
oadamo - 12/12/07 at 09:13 PM

hi ive got a carb version.has anyone on here done a turbo conversion on one of these. did you lower the compression if so how. and how much boost are you running.
thanks adam

TimC - 12/12/07 at 09:42 PM

jambojeef and moorron have both done this. Don't believe they have dropped the cr.

jambojeef - 12/12/07 at 10:12 PM

Thats right Tim,

Not lowered the CR on my engine running 7psi of boost.

Boost and CR are just 2 factors in quite a complicated scenario though. Id recommend "Forced Induction Performance Tuning" by Graham Bell or if you want to look at some pretty pictures "Motorcycle Turbocharging, Supercharging, & Nitrous Oxide" by Joe Haile. I keep the latter in the bog!

Geoff

oadamo - 12/12/07 at 10:33 PM

quote:
Originally posted by jambojeef
Thats right Tim,

Not lowered the CR on my engine running 7psi of boost.

Boost and CR are just 2 factors in quite a complicated scenario though. Id recommend "Forced Induction Performance Tuning" by Graham Bell or if you want to look at some pretty pictures "Motorcycle Turbocharging, Supercharging, & Nitrous Oxide" by Joe Haile. I keep the latter in the bog!

Geoff


hi jambojeef how did you go about setting up the carbs after you had done it.
adam

jambojeef - 12/12/07 at 11:24 PM

Hi Adam,

Still in the process of doing it. Need to get xmas out the way then get me an LC1 with RPM attachment to log some data then take it from there.

It works well power wise on standard jets with a very noticeable power increase once boost builds and a smooth transaction throughout the rev range once boosting from about 4500rpm onwards but it could be detonating all over the place and I havent even balanced the carbs yet.

Waiting until I can get the aforementioned wideband kit and some decent weather then get tuning - im guessing it wont be far off though on standard jets - may need the needles lowering or jets changing for smaller ones even.

Ive noticed a slight stutter when crossing over from vacuum to boost - will perhaps sort an air priority valve or tweak the dump valve to allow air to bypass the turbo until the boost builds.

However you'll be pleased to know that running a blow through carbed turbo set up ts more tunable than you might think. My plan next winter is go proper EFI with 'squirt or VEMS which should be ultimately the most tuneable option and safer for the engine in the long term and hopefully more driveable.

Geoff