Turbo cam

[John Wallace]

That book on Amazon:

Fundamentals of Turbocharging

[RednGold86Z]

That book on Amazon:

Fundamentals of Turbocharging

I ordered one. I think it will arrive on Monday.

[Shag55]

We need to bring the post back and hear about your varios findings on the subject. As it just so happens I have a 2.1ltr Autocraft motor in the works. It will be set up for a unlimited street class mostly drag but the occasional street drive. This motor will be set up with a roller cam. I had my cam ground bye Clay Smith wi
On a 9310 billit and it's 264@.050 with .390 lift on 112lbc. I chose this profile as a base line. It's relatively easy on the valve train and should have a good stable vacuum to aid in Idleing. I have 1.5:1 rockers and have not chosen a set of Lifters, maybe Isky, morel or ? My max RPM will be around 8500. I havent chose a compression yet either, as the heads aren't done yet but they will have a chamber volume of 50-60cc so I can run a relatively tight deck .040-.060 and be in the 8-9.5:1 range. Let's hear some thoughts.

Shag L. SL-1racing

[SWR]

Just have to chime in on one thing... the typical "exhaust pressure is normally 3 times the boost pressure or else it's laggy".. hey guys, please get out of the late eighties. If you drop a "too big super peaky will-only-give-boost-at-99%-of-max-rpm"-sized (that description would be suitable for a typical race setup in 1988) turbine on it today using all the tricks including ball bearings you end up with a free flowing system, the backpressure just is not there at low rpm, the engine breathes and hence it's actually responsive, even off boost. And then you produce more exhaust to drive the turbo from just over tickover, and with the BB CHRA oil drag close to just 10% of a typical floating bearing the transient response is into the milliseconds. You have enough useable boost at most any rpm used for a normal street driven car. You do NOT need 50psi at tickover anyway, altough it's easy to build 20+ psi just free revving a wellbuilt 2-liter 450+hp engine of today using current turbo tech without antilag.

[bigmikespec]

Newie posting here! Spent a lot of time reading and the information is great here.

With regard to turbo cam sizing (still learning here) camshaft/overlap duration affects dynamic compression. Are guys here looking at the dynamic compression also and upping the static to make up the difference with going with long duration cams? Is that even the "right" thing to do in that situation?

FYI, my application is a Nissan RB26-DETT. Have not chosen turbochargers or camshafts for a 400-450kW package and do not want to until I find out more information.

[SWR]

Newie posting here! Spent a lot of time reading and the information is great here.

With regard to turbo cam sizing (still learning here) camshaft/overlap duration affects dynamic compression. Are guys here looking at the dynamic compression also and upping the static to make up the difference with going with long duration cams? Is that even the "right" thing to do in that situation?

FYI, my application is a Nissan RB26-DETT. Have not chosen turbochargers or camshafts for a 400-450kW package and do not want to until I find out more information.

What use? Race, drift, road, drag..?

[bigmikespec]

Road/race application, stock stroke (73.7mm), 87mm bore and dry sump.

[Red R Racing]

Road/race application, stock stroke (73.7mm), 87mm bore and dry sump.

stock says Ash...lol

Given that your local track is not a big power circuit but also not any low rpm hairpin corners id suggest the JUN 264deg 10.5mm items matched to one of our stage 2.5 heads if using twin low mount Garrett 2860 -5 units. your rpm range will not fall below the working range of this combo so response will be almost instant.

Couple that with a Getrag 6 speed a 4.3 GTS-4 final drive and a few less donuts at morning tea each day would have even N1GTR (Steve-o) in awe.

[bigmikespec]

It is not a big power track but that being said not the only place it will be driven.

I am speaking to a fabricator regarding single turbocharger manifold. Something that is properly designed, individual runner lengths (dividing each exhaust pulse) and twin scroll collector. Head porting, camshafts, turbocharger and exhaust manifold all need to work together.

So single is the go! Thinking about a Borg Warner S400SX with 1.00 A/R turbine housing with appropriate head porting and camshafts maybe 270°-280° with as much lift as I can get away with.

edit: the donuts will just get replaced with something else

[Splitter]

Most published details regarding turbocharging are quite deficient in depth and scope. For a truly in-depth examination of turbochargin I would recommend the following:
Turbocharging the Internal Combustion Engine. by Watson & Janota, Wiley 1982. The textbook is out of print but is available on EBay for a mere $750. It is considered the turbochargers bible by serious tuners. A difficult read but well worth the effort. And effort it is.

Update: This book is now selling for $113 on amazon.com