limits of returnless..or just go return??

[ctgreddy]

Over winter I'm gonna switch to e85 and wondering which way to go with my fuel system. Right now it's a stock setup with a bap and 60's. My goals are ~700whp so what do I need? I'm wondering if I can stay returnless and do dual aeromotive 340's with a stock hat, dual fpdm's and the lethal 8an feed line with stock rails and 80's. My only concern would be is the stock hat not going to work out for this setup? I have a feeling it would limit me both in flow capacity, but also in not being able to put big enough power wires to the pumps.

If I have to upgrade the hat then I'd think at that point I would just do a return style setup with the regulator in a dead head configuration. At that point I would just do walbro 465's, 8an feed/return going to the regualtro than to stock rails w/ 80's.

So what are the limits of the stock hat/returnless system and will I be past them?

 

[Nightmare302]

The stock hat will not work with this setup, even if you could magically make the pumps fit and wire them I wouldn't trust it. Fuel is one place you don't want to cut corners. I'd run dual AEM 320's -8 feed -6 return stock rails Fore F2i reg. I strongly prefer and recommend ID 1000's at that point but the 80's might make it. If you plan to go over 800-900rwhp then I'd step to aftermarket rails and 465's or a triple AEM setup (that way you don't have to do it all over again).

 

[GodStang]

So much easier to go return. I tried so many Returnless setups just refusing to convert. Spent tons of money and time. After 7 years went Return and the best my car has ever run.

 

[JeremyH]

Just save your self possible headaches and go return. 80's are too small. Go 1000cc. I had to stop at 760ish rwhp because I started maxing my 1000's. I run a Fore return setup and love it.

 

[ctgreddy]

Im getting conflicting responses on the 80's, some guys say they'll be fine for my goals others say there's no way. I'd love some ID's but dont know if they're worth it.

 

[cj428mach]

Im getting conflicting responses on the 80's, some guys say they'll be fine for my goals others say there's no way. I'd love some ID's but dont know if they're worth it.

Injector dynamics has an injector calculator on their website. When I looked at the ID1000's they were iffy on 20+ psi at the 39lb base pressure for e85 and 700rwhp. So I opted to bump them to 50psi base pressure and that should put them at 85% duty cycle. I believe the ID1000's are 98lb injectors vs the 80lb so many people run. Based off ID's calculator I don't know how 80's could ever work but there are plenty of people out there doing it.

 

[JeremyH]

Like mentioned boost level and base pressure play a large role in how far your injectors will get you. And remember there is no 100% duty cycle with injectors at around 90% duty cycle they becomes static and you will run lean pushing any further. I had sd 80's at 650rwhp and didn't feel comfortable running them past 700rwhp so I got the bosch racing 1000cc injectors they are the same as the id's for about half the cost. They are amazing as well, car idles and cruises like stock and I get better gas mileage than the 80's.

 

[01yellercobra]

The stock hat will not work with this setup, even if you could magically make the pumps fit and wire them I wouldn't trust it. Fuel is one place you don't want to cut corners. I'd run dual AEM 320's -8 feed -6 return stock rails Fore F2i reg. I strongly prefer and recommend ID 1000's at that point but the 80's might make it. If you plan to go over 800-900rwhp then I'd step to aftermarket rails and 465's or a triple AEM setup (that way you don't have to do it all over again).

Aren't the 340's the same size as the stock pumps? If so why wouldn't they fit?

 

[Nightmare302]

Aren't the 340's the same size as the stock pumps? If so why wouldn't they fit?

I would not call them the same size as they are different in the way they look. The 465's are much bigger. Secondly, trying to make the stock hat work is just asking for trouble, are you going to modify the hat to have a -8 out and -6 in? At the point of "making" the stock hat work you'd have so much time and money in something that would be at best ghetto rigged to work. I'll say it as I always do, if you don't have the 300 bucks to buy a return hat and do it right then you have zero business pushing that much hp in a car.

 

[01yellercobra]

I would not call them the same size as they are different in the way they look. The 465's are much bigger. Secondly, trying to make the stock hat work is just asking for trouble, are you going to modify the hat to have a -8 out and -6 in? At the point of "making" the stock hat work you'd have so much time and money in something that would be at best ghetto rigged to work. I'll say it as I always do, if you don't have the 300 bucks to buy a return hat and do it right then you have zero business pushing that much hp in a car.

I know the 465's are different. They need an aftermarket hat in order to be used. But the 340's have the same shape as the stock. They're a popular upgrade for the single pump guys. So they can't be much bigger.

 

[ctgreddy]

The 340's work in a stock hat. I just put a set of the aeromotive ones in a customers car. But that said I don't think 340's would be enough for e85 unless I used my bap with them as well.

Obviously if I had to rig up a 8an feed and a return on the stock hat that would be pointless and hack. My question is would a stock hat feed line and staying returnless work for the hp level or would it be too much of a restriction.

 

[willis414]

I made 715rwhp on e85 and 667rwhp on 93 with the return less setup. Here's my list I ran it this way for two seasons with zero issues. Hope this helps you

2.9 whipple non crusher (20psi)
Twin GT pumps
Fore hat
kB boost a pump
Duel FPDM's
Power wire up grade
80lb bosh injectors
STOCK rails
STOCK fuel line
BA3000 air meter
2lb lower pulley
Kooks full length headers
3" exhaust
TR 6 plugs gaped @ 28

 

[Nightmare302]

I know the 465's are different. They need an aftermarket hat in order to be used. But the 340's have the same shape as the stock. They're a popular upgrade for the single pump guys. So they can't be much bigger.

The issue is not "making" them fit. The issue is that you have an unstable platform for your fuel pumps. Hacking up and modifying the factory fuel hat is just ASKING for something to fail. I also would not use the aero 340's and would exclusively stick with AEM or Walboro 465's. To add to this, to work return or returnless you will need a hat, power wire upgrade. Returnless you will need a BAP and dual fpdms, return you will need a return line and a regulator. I would put them close to each other in terms of cost with where you are starting out from with a little bit more cost leaning towards return style. However, the return style is much safer (removes the "lag" on shifts) and is considerably easier to tune.

 

[sonicblew]

another vote for return. where you are starting is the time to do a return. i was too far down the returnless path so i slapped in bosch 105 injectors and a BAP. All the other upgrades were there. it was way more cost effective for me. i know i will eventually do a return. I ran out of pump at 700rwhp. if you use a stock hat i can see it restricting it. if you try to save money and do the stock hat and it ends badly by leaning out you are way worse off. I'm a fan of do it right, do it once.

 

[sonicblew]

I made 715rwhp on e85 and 667rwhp on 93 with the return less setup. Here's my list I ran it this way for two seasons with zero issues. Hope this helps you

2.9 whipple non crusher (20psi) (21-22psi)
Twin GT pumps
Fore hat
kB boost a pump
Duel FPDM's
Power wire up grade
80lb bosh injectors (105 bosch)
STOCK rails (FORE rails)
STOCK fuel line (-8 feed)
BA3000 air meter (ba2400 w/diablosport MAF)
2lb lower pulley
Kooks full length headers (MAC LT)
3" exhaust (2.5" exhaust)
TR 6 plugs gaped @ 28

i notated my differences for the op
nice returnless setup! almost identical to mine. i ran out of pump at 700rwhp though. thought id get a little more out of it.

 

[GodStang]

770rwhp, Twin screw, E85, FRPP 80s and have plenty of room.

 

[03Steve]

Sig

 

[JeremyH]

770rwhp, Twin screw, E85, FRPP 80s and have plenty of room.

Even running a 60psi base pressure which I believe is the max recommended for those injectors, there is no way there is plenty of room at that level. It is a sharp cutoff, duty cycle may look ok 75-80% but add 1-2lbs of boost and boom your going lean now, its not that simple with corn.

 

[GodStang]

Even running a 60psi base pressure which I believe is the max recommended for those injectors, there is no way there is plenty of room at that level. It is a sharp cutoff, duty cycle may look ok 75-80% but add 1-2lbs of boost and boom your going lean now, its not that simple with corn.

Only at 55psi under full boost. I had the same argument with my tuner and I had ID2000 installed. I pulled the ID2000 to go with FRPP 80s per my turners recommendation. My tuner was correct. Pretty sure I could get another 100rwhp and still be safe with my setup. You would be surprised the number of people in the 800-900 still on 80s and e85. Now that being said if I do go to a bigger blower and looking for more power over 850 I would most likily go 105s or bigger. The Original Posters goal is 700rwhp on E85. That is more than safe on 80s.

 

[JeremyH]

I had 80's at 650rwhp on the old setup and gas mileage was horrible and drivebaility suffered with the 80's. I knew I was looking for 700hp+ and dont like to run my injectors on the edge so I went to the bosch 1000cc injectors and I'm much happier with the 1000's. My gas mileage is up around 6-7mpg and these injectos drive like stock. I would say 2000's were alot more overkill for your level in the first place. I started maxing out the 1000cc at around 21-20psi 800rwhp+ (wasnt able to a full pull as I went lean). I backed boost down to 16psi added some timing to get the power back. I run a boost referenced regulator and 40psi base pressure. I could push further with a higher base pressure but I like to keep it low and evenly balance the work between pumps and injectors.

I still wouldn't say that you have plenty of room left with 80's at 55psi with e85 at your power level. Especialy when adding boost. I would be careful with that, although the e85 will be much more forgiving when going lean. If you and your tuner are comfortable with it thats one thing, but just as you see guys making widely different numbers on different fuel systems I wouldnt blindly reccommend that statement to another setup. There nothing to be gained by going to small on the injectors but definetly room for issues.

When going north on 700rwhp on corn I will always reccommed at least 1000's especialy since they drive so damn good for a large injector. On my setup if I push past 800rwhp I will likely get 1300's or 1600's and keep fuel pressure where I have it, rather than upping pressure to push the injectors further and loosing some flow capability of my fuel system.