FRiCK916

Ive got an 02 C5Z... I recently bought a Walbro 267 (450lph) pump to drop in my stock bucket. This was suggested to me by my old tuner, so I have this pump.

New tuner says this pump being so big will create drama with the stock returnless fuel system and wants me to go with a smaller pump. I've looked and feel like the lingenfelter bosch 350 lph is the only other option.

In anyone's experience here, is this info accurate? Should I stick with the 267 pump? Or buy the bosch 350lph...??

This is an NA combo that should be in the 600rw range and I'll be using bosch green 42/50lb injectors.


I know this isn't a blown combo, but I used to be and this is also where all the C5 knowledge lies...

Thanks dudes

PEETYZ

I'll let others chime in on the larger drop in options. I will say I supported 570rwhp on LPE drop in (http://www.lingenfelter.com/product/...l#.VxeqYz_2ZD8 )and 60lb injectors alone on my P1SC initial setup.

Adding a racetronix harness (http://www.lingenfelter.com/product/...l#.Vxeq_z_2ZD8) will help and I highly suggest it if you don't have it.

If you can run a BAP that will increase the pump output significantly. You could even run your stock pump, BAP, and racetronix harness will support 600rwhp easy

slow ride

A rewired 255hp like the LPE pump should get you to 600whp NA no problems and be a direct fit. The big 450 will end up overrunning your regulator that is mounted in the fuel filter and cause you to run higher than base pressure at light load/idle. Remember a NA setup will run a little leaner than a boosted setup under full load ~12.8-13.0 AFR on gas so it would need less fuel overall. I made 500whp with a 100% stock fuel system and ford red tops, but that was pushing the injectors.

FRiCK916

My stock pump is a 255.. a harness will get me a little room, not much tho. This is a 11.75:1 430" motor, 385cfm LS7 heads, 243/259 cam and MSD/NW102, 7/8" headers... I'm guessing 600rw or maybe a tad more.

Is that bosch pump still too much to drop into the stock system??

slow ride

I've never tested the stock c5 pump or if the c5 z06 pump is any different nore have I seen solid test data on it. Not sure what racetronix and LPE sell for a 255/225 unless it's just a high pressure version of a stock pump. Those stock and aftermarket pumps do have the extra pickup on them to draw fuel from the bucket and the sock. I'd probably just rewire the stock pump and monitor fuel pressure.

jimbos'ss

I ran into issues with the 450 and the stock regulator. It overpowered it so badly that after a while it stuck up. I changed filters and a few other things until I finally gave up. After putting in the 97-98 fuel rail and return line, I've had no issues.

FRiCK916

Come to find out the stock pump is 255 @ 43psi... the lpe/racetronix pumps are 255 @ 60psi. So I'm thinking the little better pump with the racetronix harness should get me there.ive got the Bosch green giants... they're a 50lb injector @ 58psi.

BLOWNBLUEZ06@RKT Performance

I don't have time to get into it in complete detail, but the 267 won't work in your bucket unless you cut the entire bottom out of it. It's not just about fitment, but also about function. I wouldn't hesitate to run the 267. Your stock fuel system isn't returnless. It's just that the regulator and return aren't up front, they're in the filter.

If you run that pump and mod the bucket the way that it needs to be, I would caution you on running your tank low on fuel because it won't allow it to get as low as stock before it dies.

FRiCK916

I'm aware of the fitment issue as well as function, I'm honestly kind of lost, as I've never seen a C5 pump with my eyes or held one. Is this even an "upgrade" for an 02 C5Z?

http://www.racetronix.biz/itemdesc.a...2D005A&eq=&Tp=

All I need is something that will support 600(ish)rw.. NA. The simpler, the better.

silver408z

I have seen where people post that they are running the racetronix pump and hotwire kit to mid 600s NA. The racetronix also allows you to add a boost a pump too. I think those have gotten to 700 NA.

The problem might be that that the doing the pump, wire and boost a pump might over powering the stock fuel regulator and return. You might be at the point where you have to do a true fuel system and not just upgrade stuff.

FRiCK916

Nice. The more I dig, the more I think that pump and a harness will be ok.

HardcoreABN

I will never run a BAP again, had one fail and almost cost myself an engine.

FWIW, I just went and converted to a return-style fuel system and put a walbro 450 in the tank. I'm currently working on a custom pump hanger that will allow 2 or 3 pumps (including the 450) for those of us with early style tanks.

C5 Pete

Fwiw, I'm running a Walbro 255 with a Hotwire kit and BAP on my NA 427 that makes about 700fwhp. Stock filter/regulator. E85. 80lb FIC injectors 74%dc at 7600rpm.

Good luck with your project!

slow ride

To me and others I have spoken to they appear to be the same damn thing Either that or the stock pump is like the 190lph version. I wish someone actually flowed these both. I suppose I could flow my old stock pump.

blackdak318

Let me know what you wind up doing and how it works. I am in pretty much your same situation and trying to research the best/easiest option. I am a complete noob to the C5 fuel system so I'm looking for a drop in install. New motor is a 12.2:1 440" LS7 that made 590 rwhp in the last set up. I currently have 42# injectors as well but am concerned about them being maxed out or too stressed around that HP level.

Turbo-Geist

I think everyone would agree that the fuel system is not the place to experiment with less is more. If you want an easy golden recipe for 600rw in a C5 using gasoline, I would go with a Racetronix 255 in tank, hot wire harness, BAP, and rail mounted regulator with a return line. This is a plug and play setup.

If you are feeling a little more creative, you could go with one of the larger pumps and modify the bucket and wiring for the pump. This would allow you to get away from the BAP and provide additional headroom.

FRiCK916

Not really wanting to experiment either. Just wanting to know the simplest route to take. I don't want an aux fuel system with an 044 pump ect. I was wanting to run the most reliable and simple system I can. From what I've been reading and hearing from people it seems as though the lpe 255 and harness could do it. Was thinking of doing a rail mounted return off my test port while mounting the regulator on the firewall and using a 97-98 fuel filter... I get a little lost with all the fittings ect that are needed. I suppose I could go back and use A&A's fuel system instructions to see what lines need to go where out back. Unless someone got a nice little parts list and guide?? Lol

I really appreciate all the posts, that's what this is for, thanks dudes.

FRiCK916

Also, after more reading I have come to the conclusion the bosch 42's (~50@58) won't be enough. Gonna step into some LS9 injectors (56@58).. with some EV1 to EV6 adapters.

HardcoreABN

The most reliable would be a walbro 450 in tank. voltage boosters and aux pumps are band aids.

blackdak318

I would recommend doing more research on the LS9 injectors. There can be issues with LS9 injectors as the LS9/ZR1 use a variable fuel pressure system that can cause problems in non ZR1/LS9 cars. In addition to the fuel pressure issue the LS9 injectors have a spray pattern set up for boost that is not ideal for N/A. Not saying it is impossible and there aren't people who have used them no issue, but there are things to think about when it comes to tuning and potential issues with those injectors.