A.R. Shale Targa

Considering a winter upgrade and just wonderin' at what point I'll
need to address the injector sizing in order to not run lean.
So how much power have people made before they upgrade ????
FWIW I do about 90% freeway driving..minimal around town stuff..and
the occasional blast down the dragstrip just to verify performance #s.
Lastly are LS2 injectors an easy swap or are adapters needed ????

WKMCD

The best thing if you're doing a H/C upgrade is to pickup a set of Ford Red Tops. They are about 36lb on our fuel rails. I ran them with me 460RW H/C 346 build and they worked fine.

printmanjackson

you need to tell us what you have done or going to do with the engine so it will give us an idea about the HP you are going to have.

I think at @ 415-425hp those will pretty much top out.

A.R. Shale Targa

Current set-up is the original 346 short block (#s say LS6)..EPS 218/226
117 ls +3..small I know but wanted a stock idle and a broad powerband
Lift is .595/.598..LS2 chain..self modded oil pump (only 23,000 miles)
I did 4 hrs. total work on the original 241 heads..rocker bump gone and
bowl blending..also gasket matched the EX and streamlined the guide.
These were flowed at 246/200 with LS6 hollow valves lapped in on the
GM valvejob. Lunati dual gold valvesprings and surfaced .030 for 62.5cc
Stock LS6 intake, DIY TB, stock bellow and air box with K&N filter.
The car was tuned at Speed Inc. at 365/344 with BBK shorty headers
bolted to the factory 4 cat headpipe and Corsa axleback. Car ran 12.29
@ 116.7 on MT DRs in this condition. I upgraded to XS Power LTs with
3" hi-flos but never retuned and ran 11.87 @ 119.85. Purely guessing 2b
around 380 ish rwhp....3400 race weight at 2000 DA.
I've recently acquired some 243s from an 03 Z and would like to send
them to TEA for a quick port job and spring package....since I doubt I'd
gain much just by throwing them on since my comp. is now @ 10.75:1
I want the engine bay to look stock and unmolested save for the
headers..so no CAI or FAST manifold..I'd like to gain approx. 25-30 rwhp
and perhaps pickup 3-4 mph in the quarter without affecting the pure
drivability of this thing. I can lug it 900-1000 without issues and it gets
between 30-33 miles per gallon highway with the M6/3.42 combo.
Thanks for your help !!!!!

A.R. Shale Targa

This will probably be my best bet to keep the duty cycle down since a
retune will need to be done anyways. I don't expect to be anywhere
near that power number since my cam is a baby stick. What is the deal
with the 03s getting a mid-year fuel pump change ??? Aparrently after
a certain vin # they received like the LS2 style pump/pickup...just
curious since mine was a late production 03.

tblu92

Industry standard is to not exceed 80% duty cycles---However it is not a hard wall---You can run it over 80% as long as you don't run it too long and give the injectors a chance to cool off----
On my 98 with apprx 400 RWHP and stock 28# injectors-- it will go as high as 92% on a drag pass --only briefly in 3rd gear (A4) No issues as they can cool down between runs--
Autocrossing or road racing could create an injector to overheat and fail
Going to larger injectors than needed can create low RPM ( around town) and idle issues.
The pulses sometimes can't get small enough for that small fuel demand

A.R. Shale Targa

Great info ^^^^^^ Thanks alot sir !!!!

CTD

If you decide to go with the SVO Red tops, I've a low mileage set that I'm no longer using. Also the correct data would go with them in HPT format.

Shameless I know....just sayin

A.R. Shale Targa

...I'll keep that in mind sir ^^^^^^^

RonSSNova

When I was data logging IDC while drag racing, my LS2 (33lb/hr) injectors showed 92% duty cycle @ 6600 rpm. I would imagine this would change slightly with AF ratio.
So those red tops would work well.
I'm an A4 and go 122+ in the 1/4.

LS2 are shorter, so some sort of spacer is needed. The connector also requires an adapter. They fit my FAST 102 w/o a spacer.

Ron