http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=2404910251&c ategory=33555

Is this what I should use if switching over to the newer C5 26# fuel injectors? I know our stock pumps won't support the higher pressure, so I was thinking of purchasing this setup. Any comments??

 

Now that ad has me totally confused.

I think you can just drop in Walbro fuel pump by itself (same model as advertised) and it bolts on fairly easily. Plus it should only cost about $125 or less for the pump and sock with wiring. I agree that higher voltage will provide more capacity from the pump but you are no where near the limit.

I've got a Walbro hi-flow pump that I dropped in and I'm flowing through 42lb/hr injectors without problem. 26# are no biggie and I bet the stock pump will be able to provide enough flow.

As a side note you may want to go to a better pump than stock if you think you'll be making over 350-360 HP. I've heard that a Walbro pump can flow almost 600HP worth of fuel before you start to worry.

Overall, save your money and drop in a Walbro 307 hi-flow pump by itself. Will take you about 45 minutes to do (if not less) and you won't worry about flow.

P.S. I'm surprised you went to 26# C5 injectors. You are aware that ford SVO injectors also drop in and stock injectors on the C4 vette are 22#'s for older Vettes 24#'s for newer C4's?


[Modified by XTwinTurbo, 10:22 AM 2/27/2003]

 

The larger injectors don't mean higher pressure, ususally larger injector are used to keep the fuel pressure down. The base Fuel pressure is what I think your talking about.

What are your future plan for mods? The moids list in you signature are no where near needing an upgraded FP (unless you old on is dying).

 

The stock pump will support what you're putting in, so you probably don't need a larger pump unless you suspect something is wrong with the stock one or as previous stated you're going to start making alot more hp.

Don't need the wiring harness. It will provide more flow because of the higher current it can deliver to the pump, but its over kill. According to Walbro, they have never had any problems running the stock harness.

If you're still concerned about the current draw, buy the Walbro 340. Its a higher pressure (over 50psi I believe) pump with an armature made by Walbro which uses less current than the 307.

Holley pumps are actually Walbro.

 

Okay, I guess I need to explain a few things so everyone gets the same vision as I. My near future plans include the installation of the LT4 Hotcam Kit and a set of ported and polished LT1 heads. Haven't decided yet on the shortie headers.
I wanted to replace the stock 140K+ mile injectors because I just think they are getting towards the end of their life.
I freely admit that I hadn't done my homework on the LS1 injectors before buying them on an Ebay auction. Read in a few other posts that their flow rates are based on higher base pressures than the stock version I have now.
I already installed the AFPR, but didn't install the injectors yet because of the aforementioned mismatch.
I've done some datalogging with Datamaster and it shows some leaning out under WOT conditions in the right hand side. (just learning this part). My knock counts are way too high in my opinion.
Also, experiencing an occasional tip-in hesitation. Nailing the throttle from a standing start will net me a stutter, backfire type noise out the exhaust. When the car upshifts at WOT it occurs then too. When the tranny downshifts to passin gear it will experience the same symptoms.
Fuel pressure is currently set at stock 39psi. Going to experiment more with this situation as well. Increasing FP to 42psi made matters much worse. This is with stock stuff, except AFPR.

 

Agree with dumping the 140K mile injectors, and if your pump has the same mileage on it as well its probably a good time to get rid of that also.

I don't know what pressures the LS1 injectors are rated at but the ones you have now I think are the same as the L98 and are rated at 43.5psi.

How did you adjust the fuel pressure?

 

You could get away with the stock fuel pump, but its probably wise to buy a new FP @140K. I would buy a walbro 307 (low pressure 255lph) unless you think about running forced induction at a later time. IMO, I don't think you need the wiring kit for your appliaction.

 

Unplugged the vacuum hose to the AFPR. Plug the vacuum hose so as not to leak, then turned the adjusting screw to get the desired psi on the guage. I have the Holley AFPR.

I think I read that the LS1/6 injectors require in excess of 50psi working pressures.

 

Goody

I'll say this up front - not sure what your pressures should be with the LT1 but this is what my L98 is set for.

At idle 34-35psi with vac connected, when disconnected 44psi. When I installed my afpr I increased the fp to 47psi with the vac disconnected. I'm using 23lb injectors with some intake mods.

39psi for you sounds low, but again I have no LT1 experience. When the vac is disconnected your simulating WOT so you pressure at partial vac must be in the mud. Did you check your pressures before installing the afpr?

dgoodhue

Both the 307 and 340 pumps are 255lph. The difference between them is that the 340 has a higher rated check valve so it can provide more pressure at rates over 50psi if your afpr is set that high. Otherwise it doesn't matter because the regulator will dump.


[Modified by 1MoorTym, 4:13 PM 2/27/2003]

 

Hmmm.. perhaps you should consider one of these? http://www.racetronix.com/Racetronix-C44-FPK.html

BTW... the standard C5 Bosch/Delphi injector is rated 28lb/hr @ 43.5PSI (300KPa)

Racetronix

 

Wow Jack, I swore when we spoke the LS6 Inj's were 28.8 Lb/hr at 58 PSI?

Also I followed up with a few other individuals who stated all the LS series Bosch Inj's ran in the 50+ PSI range from the factory??


BTW, I run the Racetronix/Walbro GSS340 pump W/ hotwire kit & LS6 28 LB/hour Inj's at 58 PSI using an Aeromotive AFPR to set the higher pressure & one of the Racetronix "hot-wire kits. Really great setup no problems & a very clean install/package.


[Modified by superlund, 7:48 PM 3/8/2003]

 

The late model Z06 injectors are smaller than the std. LS1 injectors. The std. LS1 injector delivers a nominal 28.5lb @ 300KPa (according to my flow tests)
At 400KPa (LS1 pressure) my flow tests produce a nominal 32lb rating.

A set of '02 LS6 injectors I have here produce a nominal 28lb reading at 400Kpa.

I will dig up some of my flow tests this coming week just to clarify.

You might want to read this thread as some of the experts seem to have trouble agreeing on this issue:
https://www.corvetteforum.com/forums...njector+rating

Jack :cool:
Racetronix


[Modified by Racetronix, 9:25 PM 3/8/2003]

 

Cool...you had me worried. I didn't know the standard LS1 injector was larger than the LS6 Z06 Inj? Whats up with that?

BTW, I can't get the link to work it's dead....


-Jim


[Modified by superlund, 8:52 PM 3/8/2003]