What king of temporary gauge do I need to measure Turbine Inlet Pressure (Drive Pressures)? I assume I can hook it right into EGT hole on manifold?

RJ

 

Standard boost gauge will do, I recommend it going to at least 60#. Also an air filter (standard motorbike inline fuel filter) will keep soot out. Be careful with the hardware to avoid melting off plastic parts.

AlpineRAM

 

Thanks, my concern is the temps. Boost gauge line looks like it will melt easily. Filter is good thought!

RJ

 

Yes, add on a piece of copper or steel tubing before the transition to the poly.

I use about 5 feet. Copper will be easy to bend around in a nice tight circle or curl to keep out ofthe way.

How is everything Alpine?

 

Thanks Don! Everything is well except for my T-stat and some electrical troubles on my truck.
Darned rodents!

Your injectors do perform really well, I've racked up some kms (like a bit over 100 000) on them now so I do feel confident in my judgement.
Smoke levels have not increased since installation, (controlled environment, smoke test done at same temp, alt, engine temp etc)
Seem to have a ground problem on my truck now, weirdest stuff happening.

I think I'll have to ask for some more sets of injectors soon everybody who goes for a spin with me wants "at least the same"

AlpineRAM

 

After two minor setbacks (kept blowing copper tubing out of the manifold hookup) got results. Other than the obvious fact that I'm over working my B-1 at 50 psi boost, anyone with more expirience have any observations or feedback?
BOOST............TURBINE INLET PRESSURE
10 psi............................0 psi
20 psi...........................15 psi
30 psi...........................20 psi
40 psi...........................40 psi
45 psi...........................45 psi
50 psi...........................65 psi

This turbo spools very quickly. Because of this fact I was suprised to see the relatively low ratios at lower boost...expected way over 1:1, not under?

RJ

 

Those are great numbers! It shows a super high efficiency of the turbine wheels design to flow a fluid even at high rotor speeds.

At 20 PSI your chart only shows 15 PSI of TIP. This is great and should in theory,add to fuel economy. I am impressed at the 65 during 50 PSI. I see much worse with the HX40 and the 35.

Stock camshafts with tight lobe centers should work well with the balance this turbo has.

I have a newer Mach 2 now that should exibit even lower TIP values per manifold boost. When I made the 500 HP with 20 PSI of manifold boost, I had 8 pounds of TIP. Many still dont believe it was/is possible. TIP is important...many are just learning this...many dont even know.

Great work Rowland.

 

Thanks for the input. Just the kind of info I was looking for!

Can you explain how injectors effect TIP...Having trouble wrapping my mind around the concept of same size injectors resulting in different TIP?

RJ

 

I was thinking that high drive pressures are contributing to my high EGT's. I can see 40-42psi on my stock charger, and anywhere from 1350-pegged on the EGT gauge.

If I ease it up to 95mph, keeping EGT's at 1200, the boost gauge sits at 35-36psi. Then I nail it, she jumps right to 1500+ and 40psi.

Am I close on the high drive pressures? I know I need a charger

Chris

 

^^^Dude! 1500+? Tis running a little warm dont you think? EGT's shouldn't go over 1250 really... Here refer to this:

https://www.dieseltruckresource.com/...n&onlynewfaq=1

 

Gassers will have the air and fuel as one mixture enter the combustion chamber when the intake valve is open and then it is ignited. The pressure is higher for shorter time periods and does not last as long during the power stroke. Diesels have the pressure applied longer to the piston in the power stroke.

As the fuel in a Diesel is injected later and later in the cycle the pressure is longer and longer in duration. As long as the temperature is high enough to combust or partially combust the diesel fuel, you can continue to inject fuel.

The benefit of the increased duration or longer injection times decreases as the piston gets further away from TDC. So, longer duration can and will raise cylinder pressure for a longer unit time and with that some additional power, but you also raise the level of unburned or partially burned fuel. The combustion process continues even though the exhaust valve is open and the charge is begining to leave the chamber. Portions of the late charge are still expanding, still creating pressure. Larger waves of pressure exit the exhaust valve and continue down the manifold to the turbine section. Back pressure or drive pressure rises do to this. So does the boost from a higher rotor speed.

So, some adjustment is available in the injector to combat this. Inject the fuel faster, mix it with air faster, and get the process over quickly before the piston begins to outrun the pressure rise from later combustion processes. Effectively cut off the late fuel ( in microseconds ) so you dont get a large late burn, increased soot levels, and higher drive pressure. Its a balancing act because drive pressure is what gets the turbo to quickly spool.

On average the VP 44 trucks will inject fuel over 20-40 crankshaft degrees. Perhaps longer on the higher box settings.

So: 60 seconds per minute / rpm = time of one revolution of crankshaft rotation

60 / 3000 rpm = .02 or 20 milliseconds at 3000 rpm.

That one rotation is 360 degrees. Lets say 40 degrees are available for injection and the sake of argument. This would be considered a long duration of constant fuel injection in most engines. That 40 degrees gives us .05 miliseconds of time per degree of rotation. Or 2.2 miliseconds of time for 40 degrees. This small unit time is even smaller as RPM goes up and/or the number of degrees fuel is injected is less.

With these small windows you can still tweak a positive change. I dont want to give away the secrets of how the fuel and air is mixed better, but the idea is to mix it fast and mix it as thouroughly as possible. Stock Bosch injectors do this fine at the injection quantites and durations in a stock engine. Once you step up anything in the way of intake manifold pressure ( boost ) time of injection ( with boxes ) or the quantity, again with boxes or larger injectors...those stock Bosch or honed Bosch injectors begin to get worse and worse at their job. Rightfully so...they were/are designed and optimized for a specific task. Emissions and stock power levels. Not performance. Certainly not double the HP of stock. Obviously not a triple either.

Honing, punching in larger or a higher number of holes, etc is not the answer. Some of the aftermarket injectors are nothing more than the stock design with more holes. Or the stock design with larger holes. LMAO!

Don~