I wanted to get some opinions or possibly first-hand experience from any of you guys who have run any of the Paxton SC kits (Comptech/Vortech/SOS). I've seen so many posts of people running low-ish PSI on these kits with the stock fuel pump... people in the 8-10 PSI range. I was wondering if running the stock fuel pump on one of the "Stage 1" setups with a 6-7 PSI pulley and the RRFPR is a possibility.

I'm not sure that it is because of the RRFPR... the Stage 1 kits depend on the RRFPR to raise the fuel pressure throughout the rev range, and I'm sure the stock fuel pump's flow drops as the pressure rises. Those guys running the stock fuel pump on 8-10 PSI are using standalone tuning options and the stock FPR so I assume their fuel pressures don't get as high as a Stage 1 kit using one of the RRFPR's.

The car has a wideband gauge and I have an inline fuel pressure gauge that I can plumb in... I'm considering trying it out with the stock fuel pump just to see if I can adjust the RRFPR and keep the AFR's in check while monitoring the base and max fuel pressures. I know that CT and SOS include the 255 as a standard in their Stage 1 kits which would suggest that a fuel pump upgrade is required, and I have a Whinebro 255 ready to swap in if it doesn't go well.

Just wondering what you guys thought on the topic and if anyone has tried it in the past successfully (or unsuccessfully).

 

I'm running the stock fuel pump at 7psi (304 rwhp/Paxton Novi 1000) but as I'm on a DBW AP2, my setup does not need an adjustable FPR or larger fuel pump (though I am running ID 1000cc injectors). I know that probably doesn't help you at all.

 

Yeah, the returnless AP2's are exempt from this conversation, lol.

 

I would recommend upgrading the pump. Look at the Fullblown 290lph pump for your goals. I have their 340lph pump and love it. Direct drop in replacement and dead quiet operation.

 

Junky, Arax, you guys in here? Any thoughts?

 

I have a returnless AP2

I think there's small hope it may work, but you're likely on the very edge. I personally wouldn't chance it if you're going to loose money on dyno-time to find out the system is lacking. On my MY06 the fuel pressure drops with RPM, not sure how pre-returnless behaves; I'm assuming it would be similar (esp on a stock pump). You'll also likely run a high duty cycle just to keep up - all which would hurt your flow rates at higher RPMs.

You can improve your chances by running a dedicated heavy gauge wire to the pump to maintain voltage.

Another option is to increase the voltage at the pump to squeeze that extra volume out. Kenne Bell has a product called 'Boost-a-pump' if you're willing to make another purchase http://www.kennebell.net/KBWebsite/A...boostapump.htm

But like you said, all other Stage 1 KITs offer an aftermarket pump; presumably from their personal experience with the OEM unit?

 

Out of curiosity, why don't you want to run an aftermarket fuel pump? Granted the install is kind of a PITA, but it's relatively inexpensive and you already have one. I currently can't think of a reason or any real cons on why you shouldn't run one. It's not worth the risk.

 

Just wanted to avoid the Whinebro (and the install) if possible. Though I've got the fuel pump swap down to probably less than 30 minutes now. Its really not as bad as everyone makes it out to be... Just the first time sucks. Really just asking the question to spark the thought process of whether its possible to do safely.

We'll see if I'm in the mood to test it out Wednesday morning or not.

 

Well, my inline fuel pressure gauge didn't arrive in time, so I chickened out and just swapped the Whinebro in. So the world may never know....

Side note, the Whinebro really was not too whiney in this particular car. Stock wiring, even with the soft top tray still out of the car, even with less than a quarter tank of fuel. It surprised me.

 

In a few cases my pump became loud. Turned out that the fuel filler neck rubber/boot popped out of it's position opening up a 1/6 of an inch gap which allowed for noise to escape.

I can confirm Walboro is more loud than OEM. FullBlown340 is not.

But always check the side you cant see of the boot.

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