I actually bought this book a few years ago when I began my interest in forced induction...but with school and little time the book grew legs and vanished...thanks to the likes of Spoolin and all the other F/I guys I've been on a mad search for this book and I'm glad to report it was under a 3 ft high pile (one of many) of car magazines.
This book kicks ass...I've only cracked open the first few pages but I'm learning so much...I had a basic understanding of turbocharging but theirs so much more to learn...I wasn't aware that small turbos create higher intake charge temps and produce more back pressure Vs larger turbos...
Is their a turbo size that is sort of middle ground between small and large...that produces nice middle and top end power with acceptable lag...this is probably one of those unanswerable questions.
Bell states that a good balance between low and high end power is achieved when sizing the turbo to produce boost at about 30% of the redline rpm...Spoolin whats your input on that...is their a turbo size/type that produces those results?
Man...I just know I'm going to have so many questions...lol
With Garrett turbos it is the T3 with a larger compressorblade like a 60trim. I have no idea about mitsu turbos. the best is probably the VATN turbo. I think Aerodyne or Aerocharger, I'm not sure on the name. They make the vairable vane turbo. It's probably the best type of turbo when it comes to efficiency.
Is their a turbo size that is sort of middle ground between small and large...that produces nice middle and top end power with acceptable lag...this is probably one of those unanswerable questions.
Actually there is an awnser to that question. Selecting the proper turbocharger for a paticular engine application. This can be determined by compressor maps and and the size of the engine (i.e. 2.0L) and the rpm range (i.e. 7000rpm for an MP3 or 9000rpm for an s2000) and the compression ratio also helps determine how much exhaust energy will be made. All of these factors play a key role in proper turbo selection.
I would say that maximum boost should be reached by 40% of the engines redline. This equates to about 2800rpm. That gives you a turbo with fairly decent spoolup and low heat generating(backpressure) characteristics. In this case a large t3 or mitsu 16g fit the bill. This is evident because Corky uses a t3 in his MP3 kits.
Then it comes down to personel preference, what will the car be used for ? auto X or dragracing. If it is the latter of the 2 then u have to sacrafice low end drivability and get a bigger and more efficient turbo like a t3/4. Not all boost is created equal. 8psi from a t3/4 will be much more potent than 8psi from a t25. My opinion is to use a t3 with 60 trim wheel(bigger than corkys kits) But there are ways to ofset a bigger turbo and make it spoolup faster.
Some of these things are turbos utilizing ballbearings vs bushings. Turbos that are balanced and blue printed are more efficient and need less thermal energy to get things going. Manifolds that are tubular harness exhaust energy better than a common log style manifold and will also drop a couple hundred rpm in spoolup time.
dont know if you answered his question, but you answered a few of mine! btw...i read in this months Sport Compact Car that they strapped a frickin centrifugal blower onto the Wings West mp3!!!!!!!
