Yes, I like all these ideas. I don't know why I didn't just look into a vehicle that came stock with similar displacement and boost.

So the calculation per that website is accurate then. 51lb of injection minimum. The calculator is already at 80% IDC, so why should I run larger injectors than 51? That part I do not get.

 

thats drivetrain loss, not SC drag

the hp before the SC drag would not be a published number. the 270-300hp at the crank is already after the drag from the SC.

 

Honestly, if you only do about 300 to the wheels, you'd be just fine with 36-42 lb injectors. 42 lbs at the most. You can tune out the extra fuel and still have room to expand. You could also toss in a stock fuel pump from a car that has similar stats.

The walboro I used is @ 80 PSI so I'm not sure how that would affect your Jeep.

 

WHP is not to be used in fuel management calculations ever. Especially when considering forced induction. Catastrophic engine damage could occur. Don't ever use WHP to determine injector size. Especially in a Jeep with a 23% drivetrain loss.

300WHP would mean I have a serious chunk of unaccounted for HP in the engine in my calculation.

 

Your calculations seem pretty good. However don't add theoretical hp to the equasion to determine your objectors size because of the hp consumed by the sc.
That is why the bsfc is lower with a sc engine. Stick with the .55 and figure from there.
I have a chart that came with a set of injectors I had years ago, it was a flow chart based on pressure.
I'll have to find it but if I remember correctly they flowed 760cc@45 psi 830@65 and something like 980@100.
Not that it has to do with this but on a my 4 cylinder I ran them at almost 80 psi full boost and they were almost 90%dc.

 

If you find that I'd like to see a picture of it.

 

Im looking for it. I was on their site to see if they had the info also and found this calculator
http://www.deatschwerks.com/fuel-calculators/
This is a great company for injectors also, and their prices are unreal.
I have to go through my tool box to see if I have the paperwork.

 

found one. not mine but still a good chart, actually probably the injector you would use.

 

I calculate 20% drivetrain loss on all automatics, regardless of setup. 25% for 4WD on top of that.

I can use WHP to calculate it just because I know how much to put into the motor with that loss already accounted for.

 

So the IDC's.... is what i'm seeing on witchhunter the dynamic or static at 80%?

 

I found this article, which I have read before and forgot about years ago, on boosting a stroker engine to make record high HP and Tq numbers. It made 693 HP with 777lbs of torque running 30 lbs of boost on a stock head with larger valves at 100% IDC. It was bored .060 over like mine.

48lb injectors. Seems like witchunter is over-killing.. ? They didn't even have a proper tune on it when they initially made 570 HP without a tune. Tuned it made 693/777.

I did the math at 90% IDC for 450 HP and got 45.8lb injectors for a 43.5 PSI. For my 49 PSI pump I would need 40lbs to make 450 HP at 90% IDC.

Why is 80% IDC recommended? They ran 100% IDC with 30 lbs of boost on a turbo. I'm going to be using less than 5 PSI (not using the 5.5PSI pulley provided). I don't see the danger in 90% IDC, but then again I don't quite understand it yet.

Where can I get thicker headgaskets? I read and found that .045 is stock and is what I have. Per my stroker build I should be at 9.7 right now. Every .010 added to the gasket will reduce compression .2. So if I could get one at .065 I would be at 9.3. One at .075 would put me at 9.1.

What is a good combination of compression for 5.5 PSI of boost?

Edit: Link to the "Insane Inline II" : http://www.jpmagazine.com/techarticl...t_2/index.html

 

I recalculated for 85% IDC and got just over 42 lbs. I'm going to use 42 lb injectors for my setup. Any disagreements there? The SC setup comes with 400cc (38 lb) injectors for the stock 4.0.

I should be fine with the 42's.

 

Ford 4.6 Mustang running a Whipple (TwinScrew) supercharger with a magnificent intercooler. It's cramming more, and cooler, air into the cylinders with smaller fuel pump and injectors.
http://whipplesuperchargers.com/product.asp?ProdID=1208

415 HP, 6 PSI, and 34lb injectors. Almost an exact replica of my displacement and boost, but a smaller fuel pump AND smaller injectors. Having a hard time finding what the fuel rail pressure is.

 

Remember that a turbo is much more efficient.
Running very high duty cycle is not good for an injector, although I believe .you can get better atomization at higher dc, its not good for any long term use.
It's been a while but I believe it causes premature ointment wear and can cause an injector failure.

 

What's ointment wear?