Help Choosing a Flame Tube

[daveyofave]

Hey guys

Jetspecs has outputted a value of 5.0 inches for my flame tube diameter. I was searching online and have found one 6.0 inches. What occurs when having a flame tube diameter higher or lower than what jetspecs calculates? Also, the pipe has a 16 gauge thickness, does that seem too thin? Maybe I should perform some rupture analysis? JK JK
Also I was wondering if anyone knows why the standard flame tube diameter is 3x the compressor inducer diameter. I emailed Mark Nye but he said Jetspec was created by someone else.
The turbo chosen may not have been the most optimum for thrust performance, but I think will be best for just having something that whines.

Exhaust Inlet (Turbo Manifold) Flange: Standard T3 Flange

Exhaust Outlet Flange: 4-Bolt Flange

Turbine Trim: 74.2

Turbine Inducer Diameter:  64.8mm

Turbine Exducer Diameter: 55.8mm

Turbine A/R: 0.82

Compressor Trim: 48.1

Compressor Inducer Diameter: 52.7mm

Compressor Exducer Diameter: 76mm

Compressor A/R: 0.6
Wastegate: w/o Wastegate
Turbo Type: Individual

Bearing: Journal Bearing

Cooling Type: Water + Oil


Thanks 

[racket]

Hi

As the guy who made up the numbers in Jetspecs I guess I should answer your questions, Jesse created the software .

3X inducer dia was made the rule of thumb for smaller turbos due to their lower pressure ratios and general poorer ability to be made into a GT , they also being the cheapest to purchase meant that guys generally didn't have the means to build with the required sophistication , so a generously proportioned flametube produced a greater chance of success .

If there is care put into the build then 3X inducer AREA for the flametube cross sectional AREA will suffice .

52.7mm inducer =2181 sq mms , X3= 6543 sq mms or a flametube ID of 92mm will be enough , so a 4"SStube inside a 6" outer tube would do the job .

Your turbo is small enough to be fueled by a 9kg-20 lb BBQ cylinder of propane , propane is a very forgiving fuel and burns fast , so its not necessary to have an oversized flametube .

Your turbo's comp/turb sizing should be OK , though your turb A/R might cause some problems with reaching full flow potential..............be careful of your turbine temperatures .

Cheers '
John