Didn't know where to put this - N/A or FI/Nitrous section :smile:
I've been designing and fabricating a custom ITB build using a hacked-up OEM intake manifold with slim Jenvey 50mm SFS throttle bodies.
The problem with some of the aftermarket ITB setups I've seen (besides the price markup), is that the injectors have been angled such that they are injecting the fuel cone directly onto the opposite intake runner wall. Sure, at high mass flow rates into the runner, the fuel droplets are entrained and obviously make it into the cylinders, but this is not the ideal path and can be greatly improved
I didn't want to inject above and below the throttle blades (for complexity reasons, although for high RPM, injecting the fuel sufficiently far away from the intake valves is beneficial).
So, the following are the design goals:
1) I live in a cold climate, drive this car a lot, and want it to idle well so this uses an aftermarket idle air control valve and the ITB blade edges are custom coated for less-leak through
2) I want the TB's as close as possible to the intake valves
3) The TB's need to be angled correctly to optimize airflow and help direct it into the ~40 degree head intake angle, yet be capable of incorporating a special surprise later (not the nitrous)
4) The injectors need to be oriented correctly
5) Keep costs and fabrication down by using a hacked-up OEM intake manifold, which also happens to preserve the ideal injector placement for design goal #4 )
6) Design linkages for simplicity and reliability
7) Incorporate an innovative air filtration system and a progressive 150 HP shot of nitrous (I have a built engine http://www.nsxprime.com/forum/showthread.php/154927-Semi-DIY-Mild-Engine-Build-for-FI)
Image showing OEM intake manifold and heads with injector angle and runner angle (marked up courtesy of Greenberet):
View attachment 163026
Compare with the injector angle for the SOS/Hayward and Toda designs:
Now, some have correctly preserved the OEM injector placement. For example, the old Comptech builders and someone over in Japan:
So, in preparation, I completed yet another iteration in my exhaust lineup optimized for N/A flow and using a vacuum-actuated bypass valve instead of my boost-actuated vales with the old turbo setup (quiet mode, low-restriction loud mode, and zero drone with a 1/4 wave resonator and all titanium piping). Took it to get a baseline N/A dyno plot, got the titanium exhaust tip hot enough to blue naturally on the dyno, and then washed it in preparation for the winter overhaul....
Peak WHP was 297. It was previously over 310, but since then I've added the heavier '02+ wheels and the BBK :frown:
More to come!
View attachment 163032
Unfortunately this is as good of a wash as it gets these days
View attachment 163033
I've been designing and fabricating a custom ITB build using a hacked-up OEM intake manifold with slim Jenvey 50mm SFS throttle bodies.
The problem with some of the aftermarket ITB setups I've seen (besides the price markup), is that the injectors have been angled such that they are injecting the fuel cone directly onto the opposite intake runner wall. Sure, at high mass flow rates into the runner, the fuel droplets are entrained and obviously make it into the cylinders, but this is not the ideal path and can be greatly improved
I didn't want to inject above and below the throttle blades (for complexity reasons, although for high RPM, injecting the fuel sufficiently far away from the intake valves is beneficial).So, the following are the design goals:
1) I live in a cold climate, drive this car a lot, and want it to idle well so this uses an aftermarket idle air control valve and the ITB blade edges are custom coated for less-leak through
2) I want the TB's as close as possible to the intake valves
3) The TB's need to be angled correctly to optimize airflow and help direct it into the ~40 degree head intake angle, yet be capable of incorporating a special surprise later (not the nitrous)
4) The injectors need to be oriented correctly
5) Keep costs and fabrication down by using a hacked-up OEM intake manifold, which also happens to preserve the ideal injector placement for design goal #4 )
6) Design linkages for simplicity and reliability
7) Incorporate an innovative air filtration system and a progressive 150 HP shot of nitrous (I have a built engine http://www.nsxprime.com/forum/showthread.php/154927-Semi-DIY-Mild-Engine-Build-for-FI)
Image showing OEM intake manifold and heads with injector angle and runner angle (marked up courtesy of Greenberet):
View attachment 163026
Compare with the injector angle for the SOS/Hayward and Toda designs
:Now, some have correctly preserved the OEM injector placement. For example, the old Comptech builders and someone over in Japan:
So, in preparation, I completed yet another iteration in my exhaust lineup optimized for N/A flow and using a vacuum-actuated bypass valve instead of my boost-actuated vales with the old turbo setup (quiet mode, low-restriction loud mode, and zero drone with a 1/4 wave resonator and all titanium piping). Took it to get a baseline N/A dyno plot, got the titanium exhaust tip hot enough to blue naturally on the dyno, and then washed it in preparation for the winter overhaul....
Peak WHP was 297. It was previously over 310, but since then I've added the heavier '02+ wheels and the BBK :frown:
More to come!
View attachment 163032
Unfortunately this is as good of a wash as it gets these days
View attachment 163033
