Hey guys, I'm still a bit new at this fuel injection stuff. Can anyone give me an idea of whether or not 30# injectors would handle a 400 small block with 400ish HP? Or, as an alternative, point me to some articles or formulas so I can figure out what I need?

The motor's going in a 91Z with a superram, 700R4. Doubt it will ever go above 5500 rpm and certainly won't go above 6000 ever.

TIA!

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"Beware he who would deny you access to information, for in his heart, he dreams himself your master"

'84 Black Camaro ZZ4 M5 (V-6 in a former life) -- street beast
'91 Medium Blue Metallic Z28 A4 (UB-HSTRY's old ride) -- currently broken
'99 Navy Blue Metallic Firehawk #120 M6 (99.44% stock) -- daily driver

 

http://www.rceng.com/technical.htm

 

Hmmm. I have a chance to buy 30# injectors but running the calculations seem to suggest that's too small unless I boost the fuel pressure up to about 50psi.

Is that a problem? I know stock is 43-44ish. Would it be better to simply buy bigger injectors and not "band-aid" smaller ones with higher fuel pressure?

In particular, I'm looking at the 30# ford SVO injectors. I've done some quick calculations and come up with 32.5# as the rating @ 43.5 psi. Those look like they would be ideal. Anyone else have any suggestions?


[This message has been edited by 99Hawk120 (edited August 27, 2001).]

 

30# are fine to 400hp, unless you get into big time power adders like a large n2o shot or high psi. boost when the added fuel need will max out the injectors.

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1991 Z28 ZZ4 with LPE superram base, SLP runners, LPE 58mm T-body,Random Technology ramair,TES headers,24#svo injectors,ZEX nitrous,Walbro 255lph f-pump,Accel AFPR,Random Technology catback,!cats,and mutch more.

 

Yes, but the 30# accell injectors, or the 30# SVO injectors (about 32.5 at the same pressure the accell's are rated at).

 

I think go with the svo injectors.

 

That's what I was thinking. The SVO's give me a little bit of a safety margin that the accell 30#'s don't. I'm pretty sure I won't need bigger than the SVO 30's.

 

30s are plenty of injector to get you into the 11s. If you can get a good deal on them they'll definitely suit you just fine IMO. If you're buying new you might want to start bigger just because though since as a 400 you'll naturally be using more fuel at idle then a 350 at that power level which is the real limiting factor.

 

with that link, it recommends 31 lb injectors for your application...... 30lbs will do the job, and the fords seem to be underrated a bit as well like you calculated...the 30lb svo's are perfect for your application. A few things to keep in mind is that you can get away with running 50psi all the time no problem really assuming the fuel system is up to it.....that's what i run on my iroc with the blower and stock injectors. Willie manages with 19lb injectors on a 12.0 second car with the right modications.

 

IM using the SVO 30s on my 406 IM installing it in the car this week so I cant say how they work for sure. I did some research and from talking to others with similar combos the 26-30s are what they suggested for a N/A 406.

I know a guy running mid 11s with a N/A 406 using 30s.

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Black 90 IROC, L98, A4, 323 gear. SuperRamed 406 in the works!