MFJ

iTrader: (4)

Just trying to get my fueling sorted out before everything else gets here.

The Motor:
All Forged LS 347
LS6 Intake
PRC 225 heads
Big cam
42lb injectors
200-250 wet shot might shoot a 300 from time to time

The racetronix says it's good to 600 rwhp which on motor will be fine but spraying I'll be well over 600 rwhp.

Any suggestions?

HCI2000SS

iTrader: (2)

Didn't you make the same thread the other day?

MFJ

iTrader: (4)

In external I made one but got no answer on another fuel pump. After talking with a tuner yesterday he said I would need more pump than the racetronix since I'm pulling off the rail and also such a big wet shot of spray.

HCI2000SS

iTrader: (2)

Gotcha! Doesn't Racetronix make a bigger pump...like a 340 or something?

MFJ

iTrader: (4)

I thought so. they show for being for trucks but I guess they would work. I've seen threads of people doing dual walboro pumps which I really don't want that headache.

By the way, thanks for recommending going to the 42lb injectors the other day. That's exactly what my tuner said it would need. He wants to do an external fuel pump but I'd rather keep it in the tank if I could.

I just don't want to hit a 300 shot and go lean.

MFJ

iTrader: (4)

Granatelli has a 340lph in tank pump. The Racetronix 340 is only 255 lph, which is what I have now. Supposed to be good to 800 rwhp. So it should do the job. Luckily I cut an access panel when I did the Racetronix pump. Don't know anyone that's ever had one but I guess I'll give it a shot.

HCI2000SS

iTrader: (2)

Yes I did that access panel as well...makes life a lot easier lol. Now will that Granatelli pump work with your current hot wire kit or is that not needed with that pump at your power level?

MFJ

iTrader: (4)

It doesn't say. It just says 340 lph at 45 psi. Of course we run 58-60 psi. So honestly I don't know. I guess it wouldn't hurt to use my hotwire kit to ensure it works or I might burn up the pump. (Shrug) I'll have to call them I guess.

MFJ

iTrader: (4)

Granatelli said no. It's just a plug and play pump. No hotwire kit needed. Stock wiring.

HCI2000SS

iTrader: (2)

Cool! So you should be good to go then right?

Racetronix

iTrader: (2)

A few facts about the 99-02 fuel module.

1. A 340LPH pump draws more than twice the power of the factory pump well exceeding the factory harnesses' current carrying capacity. This will reduce pump performance by 20% or more. The fuel module's factory 150-series bulkhead connector is a common failure point even with the factory pump. This is why new Delphi modules use the 280-series bulkhead connector which handles twice the power. Our FPWK-017W wiring upgrade kit addresses all the shortcomings of the factory fuel pump harness. This change is covered in GM's tech bulletins.

2. The GMS pumps do not support the jet pump bucket filling system where the Racetronix system does. This can lead to fuel starvation under hard acceleration and cornering as well as long-term reliability issues during storage.

3. A properly wired 340LPH pump will overwhelm the factory return system / regulator with fuel volume. This will cause a major pressure rise at idle/part throttle, tuning issues, more power draw, heating of the fuel and premature pump failure from excessive head pressure. Our 255LPH based system already creates a smaller pressure rise of 2-4PSI. This is why so many people were taking out the brushes/armatures in 340LPH pumps when they first came out and still do to this day.

Bigger is NOT always better. Parts have to be engineered to work in unison to provide proper performance and reliability.

These are the three primary reasons we have not released our RXP34x version of our F99 system yet as it must be bundled with the proper wiring and plumbing solutions.

This topic has been covered many times on this forum and others for over 12 years. A simple search will dig up all sorts of great technical posts about this.

There will be many members who will get on here and brag about how little they spent or got away with not upgrading. The bottom line is that running a HP pump off of the factory wiring will cripple its performance and accelerate failure of the pump and the electrical system’s vulnerable components.

MFJ

iTrader: (4)

Well, I have been impressed with my Racetronix since I installed it. That's why I went to Racetronix website first looking for a bigger pump that can handle 700-750 hp . Do you offer one? Like I said I have the hotwire kit already on my 255. Or are you saying to just use my existing hotwire kit?

I don't want to rig up multiple pumps, make a bunch of crazy harnesses. I just want a pump that won't KILL my multi thousand dollar motor. The car is still a daily driver as well and I don't want to keep changing pumps.

Searching this site isn't the easiest thing to do either and some of the info I'vce read, I know to be wrong on some threads.

Racetronix

iTrader: (2)

Please contact our sales dept. to discuss your requirements.

Thank you.

MFJ

iTrader: (4)

No phone support and I hate typing. I don't really want to join a forum just to get technical advise, I just want to speak with a real person.

But this is straight from the Granatelli website.

Granatelli Motor Sports introduces a New Series of In-Line and In-Tank 340 liter per hour Electric Fuel Pumps. The all new “Granatelli Signature Series” line of pumps are high-output electric fuel pumps that fit the most popular EFI applications. Intended to mimic the original equipment compact, lightweight pump in size and shape, the similarities stop there. The Granatelli Signature Series Pumps can out flow the factory by as much as 100% without increasing current draw or stressing the factory wiring harnesses yet they still fit into many existing hanger assemblies.

Racetronix

iTrader: (2)

You can call one of our many dealers such as Texas Speed, WS6 Store, Hawk's Third Gen, Lingenfelter etc.

You have no problem typing on this forum and asking all sorts of questions. Most people work 9-5 and do not have time to call during business hours, dealing with busy lines etc. Our forum gives our customers 24/7 access to topics covered by 100's of posts as well as technical docs which can't be related over the phone. Our techs monitor our forum 24/7 and provide support after hours, weekends and holidays!!!

Post the flow vs. voltage vs. current graphs/charts of this GMS 340LPH pump. We are sure this technical data will tell a different story. GMS does not make a pump which has a jet-pump feed port. Most HP pumps share the same case size/design as the Walbro GSS34x-series pumps allowing them to physically fit identical applications but that does not imply that they properly support the technology in factory fuel pump modules. The factory pump is able to fry the F99 bulkhead connector so any HP pump is going to have the same problem or worse. Statements made in the ad above are vague at best and may be misleading to customers who do not have technical knowledge of fuel systems.

MFJ

iTrader: (4)

I'll call texas speed. Derek knows my setup. I don't have their flow numbers, I don't work for them. But if what they state is not true then it shouldn't be stated that way......and that's what I was told on the phone.

And no, I don't have a problem typing on this forum and asking questions. See that's what this forum is for....I've supported tons of sponsors of this site. You included. It takes 2 minutes for a phone conversation and about 30 mins for me to type something because I have to do it on my free time.
Your statement came off like you were being a smart ***. But I could have taken it the wrong way.