DIY twin pumps on the quick and cheap
#1
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
I get questioned on my set up very often and it has been around a long time. I had the opportunity to do a set up for a friend and thought I would put together a 2008 version of my 2003 twin in tanks (98 tank). My original system still on my car today can be found HERE
1. Run a fresh fused power wire front to back on the car for the second pump.
![](http://fastrides.com/photos/mm/images/26303/425x319.aspx)
2. (Not shown) Select a relay location for the second pump. This car got one near the passenger kick panel; This location is roomy and close to whatever we choose to trigger the pump.
3. Get a nice clean ground for the second pump.
![](http://fastrides.com/photos/mm/images/26313/425x319.aspx)
4. Cut the hole (hole was all ready cut for me in this case) and snag out the sending unit. You could also drop the tank. (98's are a PITA)
![](http://fastrides.com/photos/mm/images/26305/425x319.aspx)
5. Assemble your Y block for the pumps. These parts are from a place that sounds like Foam D-poe
and total about $10. I have never liked the 'brass T' versions. something like this clearly has more appropriate geometry.
![](http://fastrides.com/photos/mm/images/26306/425x319.aspx)
6. Drill a hole and install a grommet; Run fresh power and ground wires through and once in place follow w/ some GOOP to seal.
![](http://fastrides.com/photos/mm/images/26308/425x319.aspx)
7. Install pumps, these are GSS340 255lph high pressure same as what is in my car purchased from NEW ERA for $98 each
8. Solder and heatshrink connections to the pumps
![](http://fastrides.com/photos/mm/images/26309/425x319.aspx)
9. Secure pumps to the bracket, use some hose between them to dampen vibration
10. Install the fuel injection rated 5/16 hose and secure with clamps. I prefer these type as the worm gear type can chew up the hose. I also put a dab of loctite on the threads for good measure.
![](http://fastrides.com/photos/mm/images/26310/319x425.aspx)
11. Prepare to install, make sure area is clean. I reccomend unhooking the level sensor from the bracket, dropping the pumps in first, then dipping the float into the tank and reinstalling the sensor to the bracket. Don't drop the little lock!
![](http://fastrides.com/photos/mm/images/26311/425x319.aspx)
12. When you have the pump socks over the ledge inside the tank everything should fall into place nicely. hook up the pumps and test em out! I cut the harness to remove from the car, use a good insulated connector to make the connections.
![](http://fastrides.com/photos/mm/images/26312/425x319.aspx)
This was a @ $250 mod in total.
With a larger pressure line and fuel rails these same two pumps can fuel 1200hp, are quiet as stock, dependable as stock, and you can run the tank down as low on Empty as stock.
As installed here, I expect it to handle 800hp comfortably.
Full size photos available HERE
1. Run a fresh fused power wire front to back on the car for the second pump.
2. (Not shown) Select a relay location for the second pump. This car got one near the passenger kick panel; This location is roomy and close to whatever we choose to trigger the pump.
3. Get a nice clean ground for the second pump.
4. Cut the hole (hole was all ready cut for me in this case) and snag out the sending unit. You could also drop the tank. (98's are a PITA)
5. Assemble your Y block for the pumps. These parts are from a place that sounds like Foam D-poe
![Winky](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_wink.gif)
6. Drill a hole and install a grommet; Run fresh power and ground wires through and once in place follow w/ some GOOP to seal.
7. Install pumps, these are GSS340 255lph high pressure same as what is in my car purchased from NEW ERA for $98 each
8. Solder and heatshrink connections to the pumps
9. Secure pumps to the bracket, use some hose between them to dampen vibration
10. Install the fuel injection rated 5/16 hose and secure with clamps. I prefer these type as the worm gear type can chew up the hose. I also put a dab of loctite on the threads for good measure.
11. Prepare to install, make sure area is clean. I reccomend unhooking the level sensor from the bracket, dropping the pumps in first, then dipping the float into the tank and reinstalling the sensor to the bracket. Don't drop the little lock!
12. When you have the pump socks over the ledge inside the tank everything should fall into place nicely. hook up the pumps and test em out! I cut the harness to remove from the car, use a good insulated connector to make the connections.
This was a @ $250 mod in total.
With a larger pressure line and fuel rails these same two pumps can fuel 1200hp, are quiet as stock, dependable as stock, and you can run the tank down as low on Empty as stock.
As installed here, I expect it to handle 800hp comfortably.
Full size photos available HERE
Last edited by MIGHTYMOUSE; 02-24-2012 at 03:48 PM. Reason: fix links
#2
11 Second Club
iTrader: (3)
Join Date: Jan 2008
Location: melbourne, florida
Posts: 220
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Very nice...I did the walbro 255 on my 98 and the location i was told to cut was way off on my car...but I have been seriously thinking about doing this as I am at the limits of the 255 already and havent even gotten heads or cam in the car.
#5
11 Second Club
iTrader: (16)
Join Date: May 2004
Location: MS
Posts: 2,223
Likes: 0
Received 0 Likes
on
0 Posts
![](https://ls1tech.com/forums/images/ranks/ls1tech10year.png)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Help me out on the wiring if you dont mind. On pic 3 I see there are a lot of wires cut. What do those go to?
Right now i have a single pump. If I wanted to add another is all I have to do it run a relay for the second one and have it turn on with a hobbs switch.. And then leave the other one hooked up to stock wiring?
Right now i have a single pump. If I wanted to add another is all I have to do it run a relay for the second one and have it turn on with a hobbs switch.. And then leave the other one hooked up to stock wiring?
#6
9 Second Club
iTrader: (2)
Join Date: Nov 2004
Location: Amarillo,TX
Posts: 1,205
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Ok MM so you have 2 255s in your car with a 8an feed line, rails and regulator(boost referenced)?Do you still run alky injection? I figured you would need more for the crap load of power you have! That makes me second guess the expensive aftermarket tank inline pump thing...
#7
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Ok MM so you have 2 255s in your car with a 8an feed line, rails and regulator(boost referenced)?Do you still run alky injection? I figured you would need more for the crap load of power you have! That makes me second guess the expensive aftermarket tank inline pump thing...
(By the way your Turbo should be ready to ship shortly
![Devil](https://ls1tech.com/forums/images/smilies/LS1Tech/gr_devil.gif)
Trending Topics
#8
TECH Resident
iTrader: (17)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
SO what happens to the fuel pump "bucket" that the stock fuel pump is enclosed in? I have a '99 with the plastic tank (so it might be different than yours) and i know my fuel pump was in a bucket when i swapped for the single walbro 255, does this twin pump setup require that you just "throw them in there" loose in the tank like that? I know its prob. a stupid question but hey it was buggin me and had to ask
![Icon Confused](https://ls1tech.com/forums/images/smilies2/icon_confused.gif)
#10
Closed Sponsor Account
iTrader: (3)
Join Date: Jun 2007
Location: Boca Raton
Posts: 235
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
and just to make this thread useful for every year f body here is what to do if you have a 99-02 car.
After step 8 add these quick steps in for your bucket:
Cut out the bottom and sides of the bucket:
![Name: PIC_0025.jpg
Views: 7251
Size: 50.1 KB](https://ls1tech.com/forums/attachments/fueling-injection/623304d1501364818-diy-twin-pumps-quick-cheap-pic_0025.jpg)
![Name: PIC_0024.jpg
Views: 7434
Size: 46.4 KB](https://ls1tech.com/forums/attachments/fueling-injection/623305d1501364818-diy-twin-pumps-quick-cheap-pic_0024.jpg)
Then place both pumps together and run -6an line from each pump to the stock barb fitting, in this case i used a T-fitting because a large Y block like MM used will not fit in the 99-02 bucket.
![Name: PIC_0026.jpg
Views: 8307
Size: 39.4 KB](https://ls1tech.com/forums/attachments/fueling-injection/623306d1501364818-diy-twin-pumps-quick-cheap-pic_0026.jpg)
![Name: PIC_0023.jpg
Views: 7508
Size: 51.6 KB](https://ls1tech.com/forums/attachments/fueling-injection/623307d1501364818-diy-twin-pumps-quick-cheap-pic_0023.jpg)
In the end the bucket should look close to this with the fuel pump filters not sticking all the way out of the bottom of the bucket, if they do the feeds will be directly against the floor of the tank and pick up debris and hinder flow:
After step 8 add these quick steps in for your bucket:
Cut out the bottom and sides of the bucket:
![Name: PIC_0025.jpg
Views: 7251
Size: 50.1 KB](https://ls1tech.com/forums/attachments/fueling-injection/623304d1501364818-diy-twin-pumps-quick-cheap-pic_0025.jpg)
![Name: PIC_0024.jpg
Views: 7434
Size: 46.4 KB](https://ls1tech.com/forums/attachments/fueling-injection/623305d1501364818-diy-twin-pumps-quick-cheap-pic_0024.jpg)
Then place both pumps together and run -6an line from each pump to the stock barb fitting, in this case i used a T-fitting because a large Y block like MM used will not fit in the 99-02 bucket.
![Name: PIC_0026.jpg
Views: 8307
Size: 39.4 KB](https://ls1tech.com/forums/attachments/fueling-injection/623306d1501364818-diy-twin-pumps-quick-cheap-pic_0026.jpg)
![Name: PIC_0023.jpg
Views: 7508
Size: 51.6 KB](https://ls1tech.com/forums/attachments/fueling-injection/623307d1501364818-diy-twin-pumps-quick-cheap-pic_0023.jpg)
In the end the bucket should look close to this with the fuel pump filters not sticking all the way out of the bottom of the bucket, if they do the feeds will be directly against the floor of the tank and pick up debris and hinder flow:
![Name: PIC_0022.jpg
Views: 7418
Size: 41.1 KB](https://ls1tech.com/forums/attachments/fueling-injection/623308d1501364818-diy-twin-pumps-quick-cheap-pic_0022.jpg)
#18
On The Tree
iTrader: (5)
Join Date: Oct 2006
Location: Pensacola
Posts: 198
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
Also, if you run 1 pump on a hobbs switch/or switched by nitrous activation, do you need to install any kind of check valve in the supply line of the 2nd pump? Didn't know if the main pump would pump backward through the 2nd pump...
Last edited by NSTY WS6; 02-03-2008 at 06:49 PM.
#20
FormerVendor
iTrader: (45)
![Default](https://ls1tech.com/forums/images/icons/icon1.gif)
So, is this saying that you need to run a hotwire kit to both of the pumps, and not just the 2nd one?
Also, if you run 1 pump on a hobbs switch/or switched by nitrous activation, do you need to install any kind of check valve in the supply line of the 2nd pump? Didn't know if the main pump would pump backward through the 2nd pump...
Also, if you run 1 pump on a hobbs switch/or switched by nitrous activation, do you need to install any kind of check valve in the supply line of the 2nd pump? Didn't know if the main pump would pump backward through the 2nd pump...
Some pumps HAVE to have a check valve to double up on; these do not. I know Aeromotive pump-based systems bleed down FAST; so I would imagine they may need one to double up and block the non-running pump