Looking for Fuel Pump giudance for mid 10's

[Firechaser]

I originally purchased the Hotwire kit w/ the 340 Walbro pump from Racetronix (didn't install yet) with the intentions of just adding some goodies to the existing motor......Well...that's all gone, now I'm building a stout motor and I am wondering if I can use this kit along w/ maybe a Magnafuel pump in-line to help w/ the fuel or do i need to go a totally different route? i've seen the twin in-tank kits but if I can keep what I have and just "piggyback" w/ an inline pump too I would rather do that. Thanks for any insight.

 

[Beamer]

Firechaser,

You will se a very recent post on the exact same subject here, http://www.turbobuick.com/forums/general-turbo-buick-tech/312073-fuel-pump-mid-10-sec-car.html

You will see opinions of both angles here. One says that 10.70's with 75# injectors are maxed at 100% duty cycle, that must have been a very bad tune or no alky added. If you are running alky, you can use dual nozzles and easily obtain mid 10's with a proper tune and of course, appropriate goodies to the powertrain. The single most important bit of knowledge of our cars, no matter what power levels you are looking for, is the tune of your combination. Running lean is a very bad idea, and WILL damage componants. The extent is depandant upon how bad the tune is and parts in your combination.

The hotwire is a must for any modified combination above stock. As for the Walbro, that is your choice if it is safe enough for your comfort level. There are many that have run mid 10's and some into the 9's with a single Walbro pump. They are basically proven as a nice upgrade from stock. We also have somewhat "upgraded" choices such as the Denso pump out there that requires modifications for use in our cars. Not extreme, but some time to use them. They have better specifications at least over the Walbro pumps.

You will find that you can spend an unlimited amount of money on your car if possible. You can go with a double pumper setup, but alky will get you further in my opinion!

Mike

 

[Firechaser]

I've read that post in it's entirety before posting this thread and agree their are many different opinions. I've taken the piggy-back approach on modded diesel trucks in the past and it has worked fine and was wondering if anyone had tried the approach on the Buicks and what the outcome was. I've also read the Walbro's may last or not last and believed an inline pump added would be insurance as well as more sustained pressure under load. As for Alky, that is a given for me at least.....so basically if the piggyback setup doesn't work I would just sell my current unused kit and just go w/ an external probably versus using the walbro and a smaller inline pump as a helper pump.

 

[johnplogii]

I have a Red Armstrong double pumper, not exactly sure what pumps he uses. On one occasion my second pump didn't come on & I ran 9.95 at 135 or 136mph on one pump only. The fuel pressure did drop at the end of the run & the xfi is what saved my motor by adding a bunch of fuel. I do not run alky. Mid tens is not a problem with my particular pump, but who's to say yours flows the same? Just be careful & keep an eye on things closely.

 

[Beamer]

I am pretty sure that the double pumpers that Red sells uses a Walbro 340M pump. Not the standard Walbro pump that is commonly used to replace the stock pumps, and especially the 169 pump that had failures some 1 1/2 years ago. They seem to be more reliable.

As for what you need to do... You only need to run 1 Walbro for mid 10's. A great recommendation would be to replace it yearly or so, to have ease of mind about a $125 pump. You can feel better by using a Denso pump that has not had the history that the Walbro have had. You could feel good also with a double pumper. There is also several high end pumps that are used by the big boys if you want to feel safer yet.

As for the additional inline pump with the in tank unit... I do not know much about those and if they help or hurt in our applications.

Good luck and enjoy your ride !

Mike