can 24pound injectors support a 350 motor and paxton supercharger 8psi,trickflow heads,hooker headers,comp cams 220/230 dur 510/510 lift at 114 lsa stock eprom or would it be better if i install 30 pound injector that i have also and a custom chip made also.I have been running the 24 pounders for 7 years now but poeple say i should be running 30 or 36 pounders.

 

not sure how to answer your qeustion but one bit of advice is run the lowest # injectors at the highest pressure you can, best fuel atomization that way.

 

Don't listen to this person.

 

Run the largest injector you can afford, with a 1:1 FPR, and set your injector pulsewidths as low as possible at idle and tune your fuel map accordingly.

I'm running 36# injectors on my setup, and they go static at about 5500rpm, so I get a fuel drop until shift. At full boost, I'm at about 65psi fuel pressure.


(they will be for sale soon btw, as I'm gonna try and get some 42s or 50s, or whatever I can afford. )

-- Joe

 

1st on the list for these. Let me know what you want for then when the time comes..

 

Did I mention they were flow checked and serial numbered by Cruzin performance 9 months ago ?

-- Joe

 

so should i remove the 24 pounders and install the 30 pounders.

 

Goto www.rceng.com, and use the calculator.

Boosted apps, no intercooler, high boost.. Lots of fuel.

Not everyone is running Traxions setup at .45 bsfc. My car uses a TON of fuel and only runs 119mph in the 1/4.

-- Joe

 

I would go a little higher then 42Ibs, mine are a little over 90% DC with a 11.5 AFR but thats with only 42-44Ibs fuel pressure.

 

What are you running for a regulator? I'm running one from a supercharged grand prix, so it has a 1:1 ratio under boost. I like the way OEM does stuff.

I'd be really curious how your setup worked with higher pressure.

Hows $58 working for you? I switched to $60 a few months ago. Its been GREAT!

 

I'am just running a adjustable stock type regulator, to tell you the truth I never did check my fuel pressure with the supercharger on, I'am assuming it would keep the same setting as naturally aspirated. Tell me more about this grand prix regulator, what does the 1:1 ratio under boost mean?

The $58 is working ok for me, I haven't had much time to tune it properly, I'am basically just running the stock setting with some changes in the AE, spark table and I messed with the boost multiplier to get a steady 11.5 AFR. I have a hunting idle that I need to work on but so far things have been ok. I've been meaning to try out the $60 that grumpy gave me but I figure I get it to run ok first with $58, but I got a question for you, was it any different when your first started running it compared to the $58?

 

In a nutshell… no. assuming that you’ve got things setup/tuned right you should be maxing out 36’s. I’d be looking for 42’s or larger.

The only way that smaller injectors would work correctly for you is if you’re running an FMU

No.

Put a set on a flowbench, you’ll see that the spray pattern doesn’t change much for most injectors once you exceed something in the 20 psi range. If you measure response time you’ll find that as pressure goes up response time drops dramatically, injectors have a tendancy to go non-linear at higher pressures making things difficult to tune.



Why? Any vacuum refrenced regulator (IE, stock one) will also.

What’s the deal with the $60 code? I haven’t even bothered getting rid of the 165 in my formula and have been tinkering with the 808 stuff and some blow through maf stuff with the E6

 

Yes, Stock. Thats why I said I like the OEM grand prix regulator. It has a higher rail pressure, and it sits at the end of the rail vs between them (like the tpi regulator).

$60 is great. 32k image, fully commented source code thanks to Bruce, a TC TDF for quick mods (which is a free donation from TC).
$60 is really easy to tune. Even Bruce's "stock" configuration is a great starting point for most folks.

Here's a snap of me last night, tinkering with my alky/water injection. I had to shift at around 5700 because the tires broke loose.

Main reason i'm showing you this, is so you can see how my 36# SVO injectors run out of fuel, and we're talkng 60-65psi fuel at full boost, with a 255lph walbro in-tank:

 

so can the 30 pounders and go for 42 pounders.