Quote:
Originally Posted by RidiCat69
Ahhh....very nice. Kind of an air to air fan myself, now, but that's only because I have an 04 cobra as a daily driver....can you say hear soak with manifold mounted intercooler?! Your water to air mounted elsewhere than my factory bumper mount on my cobra is prolly far more efficient. Different but well done!
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I may be reading your post wrong but just want to make sure you know your 04 Cobra is Air to Water intercooled. You have a charge air cooler under your supercharger and a pump that that circulates the hot coolant down through the tiny radiator in your lower bumper to cool it..
This is Air to Air....
Sorry to throw a S/C pic in a Turbo thread.... the next build is getting a TT Coyote.
And as E-Rod said above... IMHO 8.5 is too low for a street driven turbo motor. With that low of compression it would be a slug till the boost kicked in. I run 8.8:1 in most of the S/C stuff I do but belt driven is constantly forcing boost down the TB... with a street driven turbo setup you would run more along the low-mid 9's or even as high as 10:1 if you wanted to be really snappy and then Turbo from there. You get a solid driving street car before the boost and it just gets better. With regards to driveability and seat of the pants feel- compression ratio vs Turbo and pipe sizing is more critical than it is on S/C applications. Yes, it is true that the lower compression and higher boost will give you bigger peak numbers but unless this is a racecar your sacrifice in driveability won't be worth it. Why do you think the F&F crowd likes backing their turbos with NOS? Turbo is too big and the static CR is low so it will make big hp once you get spinning but the drivability sucks... its a pig off the line so spraying NOS through the impeller artificially spools the turbo faster than the exhaust will. Since most of the stuff you will see on this site is decent cubic inch American V8 we make enough torque to get away with more than a 4-6 banger import but you've still got to look at the big picture of how you want to drive this car. Another way to compensate is with sequential tubos... one small to spool off the line and a larger one to take over at higher flow like the 90's Supra Turbos. Or like the 6.0 turbo diesel crowd had... a variable geometry turbo that changes the housing size by RPM...acts like a small turbo at low RPM and then opens up as the RPM increases.
Another good point previously mentioned is the quality of your internals. Your stock short block should hold together under moderate boost and moderate use but if you start getting greedy and want to turn up the boost you should invest in a solid bottom end before it grenades on you.
Turbos do add complexity. Turbos are IMHO more complex to setup and tune than a S/C application but not undoable (you spend your time in plumbing rather than driving belts) But after doing the last 6 supercharged, intercooled, EFI big block motors I'm excited to do a couple turbo applications for the drivability factor... A 1000+ hp blown motor drives like that all the time... a 1000+ hp Turbo motor can be driven like a regular car when you aren't in the boost. If you are worried about IAT, definitely intercool or look at a rear mounted turbo system like STS.
Brian Hobaugh SCCA National Tour June 2014
First Hemi 'Cuda Convertible Ever Built
Short clips: Goodguys Pleasanton autocross and pit videos
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