Need some Advice on fueling

[fairlady2jz]

Hello everyone, I'm looking for some specific advise on fueling for my 04 cobra roller build and it's related to the factory 39lb injectors, just hear me out lol.

I've read a bit and I'm aware of the 39lb injectors maxing out around 500 to 550 rwhp which that's my goal on 93.

My dilema is do I stay with returnless to do a BAP with ford gt pumps and the 39lbs or should I do a return style (which I have most of the parts) with twin 465 pumps -8 feed and -6 return?

Would doing the return style keep me safer due to the added fuel volume?

Would having the base fuel rail pressure let's say at 50lbs be an issue for the cobra 39lbs on the return style since typically they are set lower and ramped up with the pwm on the return less style?

BTW setup is a built teskid with jp flat top pistons, h beam rods, arp hardware, kellog crank, 9 thread heads fully done with home porting and stock cams. Eaton is stage 4 ported by stiegemeier with a 2.79 upper and a 4 or 6 lb lower.

 

[LS WUT]

@FleeMan @04sleeper @2003RedfireVert @03' White Snake

 

[LS WUT]

Hello everyone, I'm looking for some specific advise on fueling for my 04 cobra roller build and it's related to the factory 39lb injectors, just hear me out lol.

I've read a bit and I'm aware of the 39lb injectors maxing out around 500 to 550 rwhp which that's my goal on 93.

My dilema is do I stay with returnless to do a BAP with ford gt pumps and the 39lbs or should I do a return style (which I have most of the parts) with twin 465 pumps -8 feed and -6 return?

Would doing the return style keep me safer due to the added fuel volume?

Would having the base fuel rail pressure let's say at 50lbs be an issue for the cobra 39lbs on the return style since typically they are set lower and ramped up with the pwm on the return less style?

BTW setup is a built teskid with jp flat top pistons, h beam rods, arp hardware, kellog crank, 9 thread heads fully done with home porting and stock cams. Eaton is stage 4 ported by stiegemeier with a 2.79 upper and a 4 or 6 lb lower.

Tagged some guys who can give you some knowledge.

 

[2003RedfireVert]

There was thread last week on this.

Honestly, if you have to ask this question the my personal advice is to go return. We all know you won’t stay with the Eaton. We all know you will want E85 (until our government bans it along with the freedom to breathe).

I was in a very similar situation. I bought a modified FPDM, I already had a BAP, I already had 39lbs enlarged to 55lbs…I had a ported Eaton…I ended buying a Kenne Bell. Instead of trying to make the returnless work I went straight to Fores website and I bought a $2k return setup. I only regret going with 80lb injectors…I should have gone with bigger injectors.

My setup is a 2.8 KB, E85, Fore duel 465s, FC3 controller, -8/-8, 80lbs injectors. Close to 700wh…I already want more…only took me a year .

Do it right the first time.

 

[fairlady2jz]

There was thread last week on this.

Honestly, if you have to ask this question the my personal advice is to go return. We all know you won’t stay with the Eaton. We all know you will want E85 (until our government bans it along with the freedom to breathe).

I was in a very similar situation. I bought a modified FPDM, I already had a BAP, I already had 39lbs enlarged to 55lbs…I had a ported Eaton…I ended buying a Kenne Bell. Instead of trying to make the returnless work I went straight to Fores website and I bought a $2k return setup. I only regret going with 80lb injectors…I should have gone with bigger injectors.

My setup is a 2.8 KB, E85, Fore duel 465s, FC3 controller, -8/-8, 80lbs injectors. Close to 700wh…I already want more…only took me a year .

Do it right the first time.

Thanks for the reply, much appreciated. For sure I'll be going for more down the line lol but my focus now is just seeing what would be more capable/safer given I want to use the 39lb injectors to reach my initial goal of 500 whp for the initial face of the build. I know for sure return style is the way to go for big power.

The returnless/return fuel system dilema derives more from my curiousity if it's ok to keep a higher basic fuel pressure with the return style since with the returnless you you can adjust pressure based of the pwm if im not mistaken.

BTW how can you tell if your 39lb injectors have been enlarged to 60 lbs? I pulled a set from a guys car which he wrecked a couple of years ago and he gave them to me for like $50 and the car was making about 620 whp on a vmp. He told me he had some company enlarge them but I can't remeber who it was.

 

[FleeMan]

You’ll be maxing out those injectors trying to get to 500. Never been a fan of BAP’s, just upgrade the fuel pumps now and have no worries there till about 600. If money isn’t an issue go return right now. If staying returnless, 60’s, pumps and a bigger mass air for you goals with the Eaton.

 

[Klaus]

This is an easy one. Go return. You already have the set up and it sounds like you know what you are doing to put it in yourself.

Especially since you have a built motor and can easily turn up the dial to have significantly more power. Do it now and not worry about it later.

You should be able to get your injectors flow tested to see where they are at. Personally I have never been one to **** around with injectors. If you do not know exactly what they flow or if they are old replace them.

 

[03' White Snake]

Hello everyone, I'm looking for some specific advise on fueling for my 04 cobra roller build and it's related to the factory 39lb injectors, just hear me out lol.

I've read a bit and I'm aware of the 39lb injectors maxing out around 500 to 550 rwhp which that's my goal on 93.

My dilema is do I stay with returnless to do a BAP with ford gt pumps and the 39lbs or should I do a return style (which I have most of the parts) with twin 465 pumps -8 feed and -6 return?

Would doing the return style keep me safer due to the added fuel volume?

Would having the base fuel rail pressure let's say at 50lbs be an issue for the cobra 39lbs on the return style since typically they are set lower and ramped up with the pwm on the return less style?

BTW setup is a built teskid with jp flat top pistons, h beam rods, arp hardware, kellog crank, 9 thread heads fully done with home porting and stock cams. Eaton is stage 4 ported by stiegemeier with a 2.79 upper and a 4 or 6 lb lower.

With a built motor, you should be going big now on the fuel system, Dual 465's, -10 feed, -8 return, 1050X or even ID1300's. Now onto your post.

GT pumps do not like BAP's. They are tough to tune and will have drivability issues. GT pumps alone will support 600 RWHP returnless. Been there done that before going return style. You can always go 80's for now, sell them to upgrade to bigger injectors later. 60's and 80's are the same price (or were), and I never understand why people always recommend 60's over 80's. I made over 700 hp on 80's with a base pressure of 50 psi before upgrading injectors.

Flat top pistons.... This will be over 10.0 compression ratio. You will need to be on E85 full time with that high of CR.

 

[beefcake]

Hello everyone, I'm looking for some specific advise on fueling for my 04 cobra roller build and it's related to the factory 39lb injectors, just hear me out lol.

I've read a bit and I'm aware of the 39lb injectors maxing out around 500 to 550 rwhp which that's my goal on 93.

My dilema is do I stay with returnless to do a BAP with ford gt pumps and the 39lbs or should I do a return style (which I have most of the parts) with twin 465 pumps -8 feed and -6 return?

Would doing the return style keep me safer due to the added fuel volume?

Would having the base fuel rail pressure let's say at 50lbs be an issue for the cobra 39lbs on the return style since typically they are set lower and ramped up with the pwm on the return less style?

BTW setup is a built teskid with jp flat top pistons, h beam rods, arp hardware, kellog crank, 9 thread heads fully done with home porting and stock cams. Eaton is stage 4 ported by stiegemeier with a 2.79 upper and a 4 or 6 lb lower.

A full return system will always keep everything safer and the fuel flowing better

really comes down to your budget and goals. I mean most of the guys if you’re really wanting to push it, you could do a more inexpensive injector like an FIC 1000 and like a basic fore setup.

we have all those on sale right now.

Send me a DM and we can go over your goals. Your also welcome to call - 855-827-7223 , I take calls 8am to 10pm Seven Days a week. - www.beefcakeracing.com

 

[04sleeper]

Biggest issue with just a BAP is you are pushing 20+ year old fuel pumps. Not good IMO. Best would be to go full return and be done with it. Pumps become a maintenance item after a while. And 20 years for any pumps is pushing it.

39's will NOT get you 500 safely. Best to upgrade to 60's if 500-550 is your goal. If you think you might want to go larger blower later, then go 1050X's.

GT pumps are a great pump and are very easy to tune. They have no issues with Boost A Pumps either. There is some bad information on this thread. My old 04 has been running GT pumps and BAP since 2005. Still no issues today. If I owned the car today, I would have upgraded to a full return fuel system already, but shows GT pumps and BAP are fine and can live no problem for many years.

Don't even get me started on "Modified Injectors". Here's a great article if you would like to read on modifying injectors. Drillbits and Dipshits | Injector Dynamics

Just my $.02 from working on these cars/ tuning these cars since they came out.

 

[fairlady2jz]

With a built motor, you should be going big now on the fuel system, Dual 465's, -10 feed, -8 return, 1050X or even ID1300's. Now onto your post.

GT pumps do not like BAP's. They are tough to tune and will have drivability issues. GT pumps alone will support 600 RWHP returnless. Been there done that before going return style. You can always go 80's for now, sell them to upgrade to bigger injectors later. 60's and 80's are the same price (or were), and I never understand why people always recommend 60's over 80's. I made over 700 hp on 80's with a base pressure of 50 psi before upgrading injectors.

Flat top pistons.... This will be over 10.0 compression ratio. You will need to be on E85 full time with that high of CR.

That's my short block I did use the mmr multi layer gasket so not sure the effect on compression that has.

 

[fairlady2jz]

Biggest issue with just a BAP is you are pushing 20+ year old fuel pumps. Not good IMO. Best would be to go full return and be done with it. Pumps become a maintenance item after a while. And 20 years for any pumps is pushing it.

39's will NOT get you 500 safely. Best to upgrade to 60's if 500-550 is your goal. If you think you might want to go larger blower later, then go 1050X's.

GT pumps are a great pump and are very easy to tune. They have no issues with Boost A Pumps either. There is some bad information on this thread. My old 04 has been running GT pumps and BAP since 2005. Still no issues today. If I owned the car today, I would have upgraded to a full return fuel system already, but shows GT pumps and BAP are fine and can live no problem for many years.

Don't even get me started on "Modified Injectors". Here's a great article if you would like to read on modifying injectors. Drillbits and Dipshits | Injector Dynamics

Just my $.02 from working on these cars/ tuning these cars since they came out.

The reason I initially mentioned the GT pumps and bap is because I have that exact setup on my 03 sonic blue but with 60# dekas on 93 making about 620 whp and she works flawless till this day, knock on wood lol that being said makes sense to go with a bigger injector

 

[fairlady2jz]

To all those who have responded, thank you. You guys have pointed out the obvious.
I'm just gonna go return style with twin 465s and get 80lb dekas like that atleast I'll have the tuning flexibility between 93 and e85 to make 500 whp without running into any fuel issues. I'm lucky to have 4 pumps within a 3 Mile radius with e85 so it's definitely a no Brainer.

BTW for ecu I been leaning towards the ms3, not sure if you guys have any 02 cents on that either lol

 

[03' White Snake]

That's my short block I did use the mmr multi layer gasket so not sure the effect on compression that has.

Who spec'd your pistons? No valve reliefs? You better check PTV clearance very carefully when assembling and timing this motor. I'd be very careful if you ever go to aftermarket cams with higher valve lifts.

The multi layer gaskets have minimal effect on CR. Use a CR calculator and figure out where you will be.

https://www.summitracing.com/newsandevents/calcsandtools/compression-calculator

@04sleeper When I was stuck on staying returnless, I wanted to run Improved GT pumps with E85 and a BAP and my tuner told me not too, it will have drivability issues pumping that much fuel and modulating it returnless. Maybe not the same with 93, but I listen and stayed away from that option and went return style.

Also, What's your opinion on how much CR you can safely run on 93? I've been told 9.5 CR is about the limit with these cars computers, because they do not have all the safety and timing features of the new computers.

 

[fairlady2jz]

Who spec'd your pistons? No valve reliefs? You better check PTV clearance very carefully when assembling and timing this motor. I'd be very careful if you ever go to aftermarket cams with higher valve lifts.

The multi layer gaskets have minimal effect on CR. Use a CR calculator and figure out where you will be.

https://www.summitracing.com/newsandevents/calcsandtools/compression-calculator

@04sleeper When I was stuck on staying returnless, I wanted to run Improved GT pumps with E85 and a BAP and my tuner told me not too, it will have drivability issues pumping that much fuel and modulating it returnless. Maybe not the same with 93, but I listen and stayed away from that option and went return style.

Also, What's your opinion on how much CR you can safely run on 93? I've been told 9.5 CR is about the limit with these cars computers, because they do not have all the safety and timing features of the new computers.

I just had a bunch of parts leftover i gathered throughout a couple of years and decided to put it all together, so there really was no spec (planning of) the motor, kind of a Frankenstein lol but everything was machined and measured as a normal build would. So its not a big boy motor but according to builder should be capable of 1200 bhp which I'm not looking to go near anyway.

I don't even plan on doing aftermarket cams. My goal with this motor was to put these leftover parts together for a good working motor to mainly do a max effort eaton setup on a lightweight termi.

In my neck of the woods we got a very competitive max effort 500 to 600 whp fbo, gutted pool of cars that has constant action so this was mainly put together for that. Since eaton cars normally push 500s it should fit right in.

 

[04sleeper]

@04sleeper When I was stuck on staying returnless, I wanted to run Improved GT pumps with E85 and a BAP and my tuner told me not too, it will have drivability issues pumping that much fuel and modulating it returnless. Maybe not the same with 93, but I listen and stayed away from that option and went return style.

While I like the return setup better for many reasons, there are zero issues tuning them in a returnless system. I do my own tuning and have never had an issue doing them, and I have tuned hundreds of them over the years. Sounds like your tuner didn't know what he was doing.

 

[01yellercobra]

JMO, but skip the 80's and go 1050X's.

I have the MS3 and I'm really happy with it.

 

[2003RedfireVert]

JMO, but skip the 80's and go 1050X's.

Yep!

 

[fairlady2jz]

JMO, but skip the 80's and go 1050X's.

I have the MS3 and I'm really happy with it.

The ID 1050x's or 1300 will be down the line if i decide to go with big power. I already have some fic's 1000cc and also have a brand new set of siemen deka 80lbs. Either or should get me to my goal of 500 to 550 whp easily, might even switch to e85.

How long have you had the ms3 for? Any issues or bugs that had to be worked out?

 

[01yellercobra]

If you have the FIC's then I wouldn't even mess with the 80's. We're using FIC's in my son's car and they're nice. I had the 80's on a big bore set up and while they worked, they weren't as nice as the ID's and FIC's.

I had one of the first units. There were some issues with it and they ended up replacing it later on. I think at this point most, if not all, of the bugs have been worked out.