When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
I'm sitting here thinking. We need to upgrade the fuel system on my sons booted silverado because he wants to run e85. We aren't going too far with boost, maybe 14-15 psi. (theres numerous reasons I'm limiting the boost and those reasons are non negotiable....one is because kid with a heavy foot). Anyhoo... I was thinking, just for now, I could run a 225ish pump for cruising around and then a secondary 525 pump on two switches (redundant) that activates at 1-2psi. This is how I have it in my car, works great but I do have a return system. I can't help but think why would this not work on a dead head system? 80lb injectors isn't gonna take it too far anyways. What you guys think?
2004 silverado Z71, 5.3, richard cam. 80lb dekas, 340 in take aem pump currently. Huron speed kit, 7875 vs racing turbo.
(I know I know....I should run 1" feed line and 3/4" return and 500lb injectors etc etc....but I'm not wanting to do all that right now....so cheap and easy is what I'm wanting.....but is it ever cheap and easy? nah)
None of them are a dead head system. They just have the return in the tank or as part of the filter assy. Believe most trucks are “in tank style" returns. You can setup an aftermarket regulator in the rear and utilize all the OEM fuel supplies and rails no prob. Or use the factory return setup, but you won’t have rising rate pressure with boost. I've done several aftermarket regulators in the back with 1 line going to the front. Works well.
I’d keep it simple and run one pump. Single 525 in tank would prob be fine, but I'm not sure how far ti will go.
1 AEM 400 inline pump alone will make 600ish WHP assuming 13.4v or higher. I’d keep it simple and run one pump. They can also be run in tank if you prefer. Much better pump than the walbros IMO. They flow more at boosted EFI pressures @ less amps. I’d run a set of decapped stock injectors if you’re on a budget. My decaps flowed about 80lbs at 60psi base. Made 560/600 at 11-12psi without an IC on a super mild 5.3 with 241 heads. Had voltage issues so I had to stop there. But I'm sure it would have made 600whp if it had steady voltage on a single aem400 w 80's.
None of them are a dead head system. They just have the return in the tank or as part of the filter assy. Believe most trucks are “in tank style" returns. You can setup an aftermarket regulator in the rear and utilize all the OEM fuel supplies and rails no prob. Or use the factory return setup, but you won’t have rising rate pressure with boost. I've done several aftermarket regulators in the back with 1 line going to the front. Works well.
I’d keep it simple and run one pump. Single 525 in tank would prob be fine, but I'm not sure how far ti will go.
1 AEM 400 inline pump alone will make 600ish WHP assuming 13.4v or higher. I’d keep it simple and run one pump. They can also be run in tank if you prefer. Much better pump than the walbros IMO. They flow more at boosted EFI pressures @ less amps. I’d run a set of decapped stock injectors if you’re on a budget. My decaps flowed about 80lbs at 60psi base. Made 560/600 at 11-12psi without an IC on a super mild 5.3 with 241 heads. Had voltage issues so I had to stop there. But I'm sure it would have made 600whp if it had steady voltage on a single aem400 w 80's.
good info. Currently I have an AEM 340 in tank, 80lb dekas. I guess maybe just see how far it can go now? I know I need to upgrade the power to the pump and that should help. It’s running off factory wiring which I know won’t last long, I know this because the wiring failed in my gto with an aeromotive 340.
I don’t have a problem adding a secondary pump, I kind of prefer that. Works well in my car.
Might also consider an inline pump run in series as a “booster”. You can run fuel through them with the pump off and trigger the booster pump with a boost switch or similar. Easier than dropping the tank and paralleling pumps. Have to tune around the pressure spike, but thats not super difficult. Would also make injector flow more and combat the non-rising rate FP issue.
i dont know what year your truck is , i tried this on my 08 silverado it had a fpcm (fuel pump control module) and had nothing but trouble . burned up pumps huge spikes/dips in pressure. finally i just went home made wiring and a return setup. if you have a fpcm at least hot wire the pump/pumps. just my experience anyway.
Might also consider an inline pump run in series as a “booster”. You can run fuel through them with the pump off and trigger the booster pump with a boost switch or similar. Easier than dropping the tank and paralleling pumps. Have to tune around the pressure spike, but thats not super difficult. Would also make injector flow more and combat the non-rising rate FP issue.
not worried bout dropping the tank. He just did a frame swap (smashed a tree and bent the frame) and the bed is unbolted. I just like how my 255 primary and 525 secondary pump work
i dont know what year your truck is , i tried this on my 08 silverado it had a fpcm (fuel pump control module) and had nothing but trouble . burned up pumps huge spikes/dips in pressure. finally i just went home made wiring and a return setup. if you have a fpcm at least hot wire the pump/pumps. just my experience anyway.
It's a 2004. I plan on running a silcone sleeved high quality 10ga power wire to the secondary, and downgrading the primary from the 340 to a 255 or something like that.
OK so 2004 I believe those had a standard bucket fill with an internal regulator in the hat, correct? Those internal regulators get completely overloaded in a hurry and your fuel pressure won't be stable with larger pumps even if they are staged with a hobbs. Personally I'd be tempted to just run a single Walbro 450 in the bucket and just deal with the higher pressures at idle/cruise if you are against running a return setup. Also upgrade your wiring and just use the factory wire as a trigger for a heavy current relay. I would not run a 525 constant duty.
OK so 2004 I believe those had a standard bucket fill with an internal regulator in the hat, correct? Those internal regulators get completely overloaded in a hurry and your fuel pressure won't be stable with larger pumps even if they are staged with a hobbs. Personally I'd be tempted to just run a single Walbro 450 in the bucket and just deal with the higher pressures at idle/cruise if you are against running a return setup. Also upgrade your wiring and just use the factory wire as a trigger for a heavy current relay. I would not run a 525 constant duty.
I think so, its been a year or so since I pulled it apart and changed the pump. Now that i think of it, it has a regulator inside of the bucket.
OK so 2004 I believe those had a standard bucket fill with an internal regulator in the hat, correct? Those internal regulators get completely overloaded in a hurry and your fuel pressure won't be stable with larger pumps even if they are staged with a hobbs. Personally I'd be tempted to just run a single Walbro 450 in the bucket and just deal with the higher pressures at idle/cruise if you are against running a return setup. Also upgrade your wiring and just use the factory wire as a trigger for a heavy current relay. I would not run a 525 constant duty.
o I agree, I never intend on running a 525 constant duty. For sure. Just on a Hobbs switch and the boost controller output as a redundant.
honestly with what he has now, the wire should be upgraded. If I go bigger it definitely will be upgraded.
can you maybe elaborate more on the flex setup? Like what sensor. How to tie it in to the computer. Did you tune it?
*8a runs from pumps to t under truck
*t splits to dual 8an into back of fuel rails
*6a from front of rails to regulator side ports
*botton bott(return) has 6an that runs to flex fuel sensor from there back to tank with 10 micron filter under the truck.
* yes my truck is tuned but its on holley terminator x but it can be done on factory computer, I had this same fuel system before I went holley
Parts list
*huron speed dual 525 pump assembly $850, I didnt buy the plug n play harness its an additional $250
*amazon flex fuel sensor $56
*evil energy 6an braided ptfe kit $120
*evil energy 8an braided ptfe kit $120
$ 8an splitter amazon $14
$ amazon 10 micron filter $35
$ regulator was on truck when I bought it but you can find a decent one for not to much
*8a runs from pumps to t under truck
*t splits to dual 8an into back of fuel rails
*6a from front of rails to regulator side ports
*botton bott(return) has 6an that runs to flex fuel sensor from there back to tank with 10 micron filter under the truck.
* yes my truck is tuned but its on holley terminator x but it can be done on factory computer, I had this same fuel system before I went holley
Parts list
*huron speed dual 525 pump assembly $850, I didnt buy the plug n play harness its an additional $250
*amazon flex fuel sensor $56
*evil energy 6an braided ptfe kit $120
*evil energy 8an braided ptfe kit $120
$ 8an splitter amazon $14
$ amazon 10 micron filter $35
$ regulator was on truck when I bought it but you can find a decent one for not to much
can you maybe elaborate more on the flex setup? Like what sensor. How to tie it in to the computer. Did you tune it?
Just run a 2002 Tahoe OS to enable flex or you have to know somebody who can populate the relevant tables in your OS so that it functions properly. HP Tuners does not have all of the tables defined in the editor but people have created XDFs for many operating systems to do so.
Just run a 2002 Tahoe OS to enable flex or you have to know somebody who can populate the relevant tables in your OS so that it functions properly. HP Tuners does not have all of the tables defined in the editor but people have created XDFs for many operating systems to do so.
On my GTO I mounted the flex fuel sensor in a bypass style holder. Not sure what the sensor itself is capable of flowing, but in the bypass mount it allows full flow through my -10 size feed line. The sensor just looked like it would eventually be a bottleneck otherwise.
no, the second pump only comes on when I get into boost. holley controls the signal. Honestly holley was one of the best investments I put into the truck but if you dont want to go that route you can put the second pump on a Hobbs switch. That's how I had it before holley.
Generally, you don’t want to run a flex sensor on a return line. The return flow isn’t always constant and can cause varying content readings. I had this issue initially. Was close to maxing out my fuel system and it wasn’t returning a steady flow of fuel. Unfortunately, in this case it causes false higher ethanol readings which can really mess up the tune. Esp if you change timing based on ethanol content. I ended up running a surge tank and putting the flex sensor inline with the low pressure “fill pump” that keeps the surge topped off. Worked great from that point on.
Surge tanks are a great cheap option I don’t see a lot of. Lets you basically keep a factory tank and oem pump and all oem sensors and fillers w very little modification. Mounted 2 AEM400 pumps ($150 each) my regulator/flex sensor/pressure sensor/filter etc all on the surge tank in the trunk with a single -8 line to factory rails up front. Bit of an octopus in the trunk, but cleaned things up in the engine bay a ton. 1/3rd the cost of the twin 525 setup above and pumps more fuel. I use the "evil energy" push lock fittings and hose on amazon.
6 Common C5 Corvette Failures and What's Involved In Repairing Them
Slideshow: From wobbling harmonic balancers to failed EBCMs, these are the issues that define long-term C5 ownership and what repairs typically involve.
Retro Modern Bandit Pontiac Trans AM Comes With Burt Reynolds' Autograph
Slideshow: A modern Camaro transformed into a retro icon, this limited-run "Bandit" build blends nostalgia with brute force in a way few revivals manage.
Top 10 Greatest Cadillac V Series Performance Models Ever, Ranked
Slideshow: Cadillac didn't just crash the high-performance luxury vehicle party, it showed up loud, supercharged, and occasionally a little unhinged...
Coachbuilt N2A Anteros Is an LS2-Powered C6 Corvette In Italian Clothes
Slideshow: A one-off sports car that looks like a vintage Italian exotic-but hides a C6 Corvette underneath-just sold for the price of a new mid-engine Corvette.
525 PUMP and a dead head system 
