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View Full Version : Emergency - Fuel Pump Installation Concern


SuperG
03-30-2006, 04:31 PM
I dropped my Cobra off at a well known and recommended shop here in Houston to have the Walbro 255 lph fuel pump installed. This pump will replace the stock fuel pump and the T-Rex, which came with the Vortech kit. The T-Rex has failed, that is why I bought the Walbro.

However, the shop is recommending to keep the inline booster pump...that they are concerned the Walbro is not sufficient by itself.

The recommendations I received on this board and another ALL say the Walbro is sufficient...does anyone differ from that opinion?

As further information to consider...the Vortech installation contains nothing outside of the kit, like a smaller pulley or larger injectors...therefore, I expect the maximum Hp to be in the neighborhood of 400 Hp.

Thanks for the help!

ausie
03-31-2006, 06:29 AM
I cannot relate to the fuel supply for what would be efficient for the application, but I can reply on a related part, fuel pump driver circtuit (not sure the actual term). When changing from the stock pump to a higher capacity pump, the electronic driver circtuit needs to be updated as well since the older units prior to the 03 cobra cannot handle the increase in current.

SuperG
03-31-2006, 07:40 AM
I cannot relate to the fuel supply for what would be efficient for the application, but I can reply on a related part, fuel pump driver circtuit (not sure the actual term). When changing from the stock pump to a higher capacity pump, the electronic driver circtuit needs to be updated as well since the older units prior to the 03 cobra cannot handle the increase in current.
I had not considered that, nor had I heard that before, but it makes sense. I am hoping the increased draw is within appropriate tolerance, then I won't have to make any changes. In addition, the T-Rex will be removed, so no more draw from that.

ausie
04-01-2006, 03:08 AM
I believe there was an article in 5.0 mustang (january 11, 2005) "focus on Fuel" . The article was for a returnless fuel system uppgrade using a dual focus pumps. (255lph each). There was a small statement to replace the fuel pump driver module to handle the current otherwise it would become overloaded. The fuel pump driver module will alter the voltage to the pump(s) in response to change in fuel pressure. Perhaps the fuel pressure sensor is getting the wrong message with the in-line pump.

When I thought the article was in MM&FF, I came across many with the T-rex and the Vortec as well as Paxton. Perhpaps they may help or possible indicate some of the trouble spots. The fuel pump driver module may not be the issue as long as the current of the pump is below 30 amps (will be limited to the stock fuel pump current draw). I now would doubt the fuel pump driver module is the problem, just that it could possibly be part of it.

Not sure if the T-rex needs to have well regulated voltage (fixed at a specified value so that it will not change like it does in the Tank pump. Also there may be a recommended change of the fuel pressure regulator. Never really dove that deep into the fuel systems all that much. I would probably see what some articles may bring to the surface. The tech's suggestion may be the right one. Perhaps an insurance policy to prevent fuel pressure pulsations if the tank pump goes into limp mode.

SuperG
04-01-2006, 07:57 AM
Thanks...I'll look for that as my cruise control and clock crapped out while driving from the shop!

tcrews
04-03-2006, 08:53 PM
I cannot relate to the fuel supply for what would be efficient for the application, but I can reply on a related part, fuel pump driver circtuit (not sure the actual term). When changing from the stock pump to a higher capacity pump, the electronic driver circtuit needs to be updated as well since the older units prior to the 03 cobra cannot handle the increase in current.This isn't an issue with the '96 or '97 Cobras, only '98 and up.

tcrews
04-03-2006, 08:56 PM
I dropped my Cobra off at a well known and recommended shop here in Houston to have the Walbro 255 lph fuel pump installed. This pump will replace the stock fuel pump and the T-Rex, which came with the Vortech kit. The T-Rex has failed, that is why I bought the Walbro.

However, the shop is recommending to keep the inline booster pump...that they are concerned the Walbro is not sufficient by itself.

The recommendations I received on this board and another ALL say the Walbro is sufficient...does anyone differ from that opinion?

As further information to consider...the Vortech installation contains nothing outside of the kit, like a smaller pulley or larger injectors...therefore, I expect the maximum Hp to be in the neighborhood of 400 Hp.

Thanks for the help!Personally....I ran a 255 Walbro and the T-rex inline on my '97 Cobra...when it was basically stock and a stock Vortech. The 255 pump "may" supply enough but I liked having the assurance of enough fuel under boost. I remember with the stock intank pump the T-rex howled like a banshee, once I swapped to the 255 intank it was almost dead silent.