Whisper

iTrader: (12)

So my car is at about 460 rwhp NA. I have already built most of a wet kit to eventually spray the car with a 100 wet shot. Everyone recommends the Racetrnoix 255 kit (http://texas-speed.com/p-4357-racetr...-assembly.aspx). However most people say this kit is maxed at around 600 rwhp and I would like a little room to grow so I'm only spending money on the fuel system once.

Is there a pump similar to the Racetronix kit that will work with the stock bucket and not need further expensive upgrades to get me another 50-100rwhp of leeway? If not, I will just purchase the Racetronix but I want to make sure there isn't another cost effective solution out there. From the searching I've done, it seems it quickly leads to hundreds of dollars of upgrading other parts of the stock system if you want anything more than the Racetronix kit.

stevieturbo

I'd think any of the 340's will pretty much be a like for like swap, and some bigger 400+ pumps

Obviously wiring etc needs to be up to the job of running these high current pumps.

Whisper

iTrader: (12)

Will these still work in the stock bucket? I've also heard about needing to upgrade the 'bulkhead' as well? I also don't know what upgrading the wiring would entail. I would be paying a shop to do the work for me.

Whisper

iTrader: (12)

Actually from what I am reading in threads like this one-
https://ls1tech.com/forums/fueling-i...l#post19201904

A generic pump wont work because of how the fuel system in these cars work. However I notice they keep saying 99-02. I have a 98 with the smaller metal tank so does it have the same setup to cause these issues? Bah, the more research I do the more questions I have.

Whisper

iTrader: (12)

Any consensus? Seems some say some 340 pumps will work, others say they wont and that the Racetronix 255 is the only one that will work with all of the stock hardware.

If I am interested in only having fuel delivery available for nitrous, would an external tank/pump be a better option?

MM98

iTrader: (13)

Im running a single Walbro 450 pump on my stock 98 hanger & wasn't hard to do. Like stevieturbo said, you MUST upgrade the factory wiring, which is easy too. Just get the racetronix hotwire kit & a roll of 12 or 14 gauge wire & splice into the power & ground from the racetronix relay to the pump. I just removed the factory wiring bulk head, added a grommet & ran the wire through & used copper rtv to seal it.

Whisper

iTrader: (12)

I am a complete newb when it comes to fueling so break this down for me- what do you mean by stock 98 hanger? Are you saying you used the stock bucket with the Walbro and just upgraded the wiring?

MM98

iTrader: (13)

The 98's don't have a plastic fuel bucket like the 99-02's, they have a metal hanger with the pump at the bottom. The factory pump is incased in some plactic if I remember right. I just pulled the old pump out & put the walbro in the same position as the original. The factory pass through connector is junk for these bigger pumps. I removed the clip holding it in & just re wired accordingly. Set up has been working great so far on E85.

Whisper

iTrader: (12)

Good info! Potentially super silly question- you can still remove the 98 pump using the trap door method right, where you cut just changes slightly?

Also, what all do I need to worry about upgrading for a better pump past just the wiring and factory bulkhead?

MM98

iTrader: (13)

Yes, you can do the trap door. I would just get the racetronix hotwire kit for the 98's & re wire from the pump to the hotwire kit. If you go with a 340 pump or bigger you more than likely will need to get an aftermarket fuel pressure regulator as the factory one cannot control flow of these bigger pumps.

Whisper

iTrader: (12)

Any opinion on a good regulator? Mighty Mouse has been very helpful through PM and recommended 1 of 2 pumps I will probably go with, either-

https://www.fuelinjectorconnection.c...bine-pump.html

https://www.fuelinjectorconnection.c...00274-e85.html

MM98

iTrader: (13)

I like my Aeromotive fpr.. Those pumps might be a lil overkill if you're not running e85, but wont hurt you as long as you do an aftermarket regulator. With the new fpr, you will have to add a fuel return line, so keep that in mind too.

Whisper

iTrader: (12)

Argh, whats the max I can get without having to worry about a regulator? Ive been pricing them and most run the same cost (or more) of a pump, and then the need to run an additional line.

Racetronix

iTrader: (2)

Our RFPK-001 is enough to support 550RWHP in most applications. Install the kit in a new module if possible and clean your tank. You should always monitor your fuel pressure with a new system / build / while tuning.

If you have regulation / volume issues the fuel pressure will dip considerably. At that point you can consider a front-mounted regulator and some lines. These are available in our web store at very affordable prices.

Whisper

iTrader: (12)

Thats the thing. I know I'm likely to get greedy with spraying the car and move from a 100 shot to a 150 shot, etc. So I'm looking to get a pump/setup that can handle that before I plan on even moving up.

Any opinion on whats the largest pump I can use without worrying about a regulator?

MM98

iTrader: (13)

I ran a Deatschwerks DW300 without issue when my car was N/A

Whisper

iTrader: (12)

So one more silly question since I'm clueless on fueling. If I also need a 'return' line for my 98 to use the regulator, where must this line run to and from?

And is it safe to say that a 340lph pump would probably be my limit for the stock regulator?

MM98

iTrader: (13)

The line would go from the regulator back to the tank. I removed all my evap stuff & modified the factory evap line for a return. Ive heard of a few cars trying to use the 340 pump on stock regulators & it wasn't up to the task. Some were seeing like 70-75psi at the rails with that pump & stock reg.

Racetronix

iTrader: (2)

Even with our 255LPH based pump you will see a pressure rise to apx. 63PSI @ idle/part throttle b/c of flow restrictions in the factory system. Installing a higher flowing pump only worsens this problem. Excessive fuel pressure swings make tuning more difficult and in some cases shorten pump life. This is why Racetronix, A/M and other pump manufacturers do not recommend the use of 300LPH+ pumps in many late-model fuel modules. This is why we have not released a 340LPH-based solution for 99-02 f-bodies since the module requires design alterations to work properly.

There are those who cut holes in their modules and disable the jet pump to install other HP pumps but obviously there is a trade-off doing this and it is not something we support.

Some people get away with running 300LPH+ pumps in the F99 module but generally this is b/c they do not upgrade the wiring properly so the pump has reduced performance in the 20%+ range which offers marginally better performance than a 255LPH based solution with proper wiring but with a high-risk of melting wiring and shortened pump life.

No matter how much the pump flows there will ALWAYS be a pressure drop in high HP cars b/c of the factory regulator's location / configuration in the module. For best performance and pressure stability the point of regulation must be at the fuel rail.

Our pump is the only one which properly supports the factory jet-pump in the factory module.

Please keep in mind that all the flow numbers that are being thrown around here are at 43.5PSI not 58PSI where your system operates.

You are not going to find a magic pump solution which will support much beyond the stated HP above and at the same time offer the pressure stability and reliability required. A properly designed fuel system should flow at least 20% more fuel than your motor will ever need as a safety margin.

If you go much beyond the 550RWHP mark you will have to consider something more than a simple fuel pump swap.

FYI ... Our RXP255-based FPA-001B fuel pump assemblies actual flow on average 275-285LPH which is typically better than the older Walbro-based units.

Whisper

iTrader: (12)

Would a BAP give me any more leeway than 550?