who's right?!

[03sm3341]

Last night at our local car meet two buds of mine both having turbo cobra's had a debate over fuel systems. The first bud that owns a very well know silver turbo car on this site has a fully built returnless fuel system while the second has a semi built returnless fuel system. His car is yellow btw By semi built i mean twin gt's in stock hat (no) stage 2 fpdm, 80lbs injectors and stock rails. This is were the debate begains. Ill refer to them as silver and yellow

Yellow-I heard your cars doing a little over 700 rwhp
silver- yeah
Yellow- You know your pumps are on the ragged edge right
silver- what do you mean
Yellow my tuner said there only good to around 650. If one fails your motors gonna pop.
silver oh yeah is that right
me- I think your tuners an idiot theres plenty of guys running those pumps with out trouble. Hell kb says you can run a boost a pump with there blowers and stock pumps and be fine.
Yellow- well thats what my tuner said so im going sumped return

So what do you guys think who's right

 

[Digital]

yellow 100%. been in both peoples shoes, and now return style.

 

[candyroush]

+1 on return system

 

[03sm3341]

We all know for big power you need a return style system but is it a huge crime to have a built returnless style on the car? BTW silver is a hellion car.

 

[Digital]

We all know for big power you need a return style system but is it a huge crime to have a built return style on the car? BTW silver is a hellion car.

What? You mean is it a crime to have a built returnless? Not a crime but pretty dumb if ur over 650.

 

[2bscrewed]

What? You mean is it a crime to have a built returnless? Not a crime but pretty dumb if ur over 650.

Why?

 

[TRBO VNM]

return or returnless is fine. I would have no problem going with a triple gt pump in returnless. I just opted to go more basic with the return style. the dialog is screwy in the above post. I didn't read anything about someone going return. just a sumped returnless, whatever that is. I assume he meant return.

I just did triple walbro internal pumps with a fore hat. works great so far and man, they are quiet compared to the external I had.

so, you have the guy with a semi built returnless, telling a guy with a fully built returnless that he is going to have problems?

 

[Modular Racing]

it funny when we read statements like this:

"If one fails your motors gonna pop"

if you only have one pump and it fails or starts to fail it is gonna "POP" too-!!

Basically put, fuel pump failure either way is bad! But this is a poor excuse for reasoning that 1 pump is better than 2 or vice/versa-simply not true.

 

[03sm3341]

The silver car is the one you built turbo vnm.

 

[TRBO VNM]

The silver car is the one you built turbo vnm.

I assume you mean my old silver one? That wasn't fully built returnless. meaning, I never put fore rails or aftermarket rails on it. pretty sure it has a -8an line upgrade, I know fore hat and gt pumps. I don't recall what I did with the fpdm setup, but I think I did dual fpdm's. I am starting to forget everything I did to that car. so the system is built well, minus rails unless someone else has put them on since I owned it.

the owner of the silver car can can log fuel pump duty cycle to see where he is at.

 

[EvilTwins]

it funny when we read statements like this:

"If one fails your motors gonna pop"

if you only have one pump and it fails or starts to fail it is gonna "POP" too-!!

Basically put, fuel pump failure either way is bad! But this is a poor excuse for reasoning that 1 pump is better than 2 or vice/versa-simply not true.

I don't think you can argue with the fact that this is a weakness of a multiple pump system vs. a single pump system. Just look at the triple Walbro setup for example, if one pump were to fail in this arrangement you would have absolutely no idea, the car would still run great. That is until you go WOT at the strip or on the dyno or whatever and you find yourself running lean... Compare that to say a single external pump, if it dies you will damn well know immediately. And I also believe that the likelyhood of engine damage would be less likely if your one pump failed versus one of the pumps in your setup under WOT conditions...

I'm going full return with a single pump for my new build, probably Magnafuel.

 

[TRBO VNM]

I would take the multiple pump setup myself to risk one going then running WOT and losing my only pump. especially after dealing with the external single. also, with the potential vapor locking of the external pumps, yeah, stranded 600 miles away from home was enough for me to change my setup

using quality parts is the key. and with my setup, it is easy enough to pull the relay adapters and plug each one in occasionally to make sure they all are working. On top of that, 3 pumps is mainly setup to run higher power(800+). how often are you really planning to run that? my car will rarely see it and if so, a 10 min check on the pump function is easy enough.

 

[99riocobra]

^ very well put

 

[Juiced46]

Guess Ive been doing something wrong with my car then. Twin GT pumps, 1 modded FPDM, BAP, stock lines, rails, hat and 60s. Car makes 730rwhp thru an auto w/BAP @ 40. Remember you can stretch a turbo cars fuel system a bit further then the blower cars. On the blower cars the Twin GT pumps are done around 650 w/o a BAP.

 

[Cobra8urZ06]

I don't think you can argue with the fact that this is a weakness of a multiple pump system vs. a single pump system. Just look at the triple Walbro setup for example, if one pump were to fail in this arrangement you would have absolutely no idea, the car would still run great. That is until you go WOT at the strip or on the dyno or whatever and you find yourself running lean... Compare that to say a single external pump, if it dies you will damn well know immediately. And I also believe that the likelyhood of engine damage would be less likely if your one pump failed versus one of the pumps in your setup under WOT conditions...

I'm going full return with a single pump for my new build, probably Magnafuel.

:thumbsup:

i just ordered my single magnafuel 750 pump after one of my gt pumps failed and 3 pistons broke at the track....i like the idea of overkill on a fuel system, it seems it's the one place that you really can't skimp on when building a dedicated car.

 

[2bscrewed]

:thumbsup:

i just ordered my single magnafuel 750 pump after one of my gt pumps failed and 3 pistons broke at the track....i like the idea of overkill on a fuel system, it seems it's the one place that you really can't skimp on when building a dedicated car.

There are too many things that can make the car go lean, that will hurt your motor before you even know it happened. really the only way to prevent a fuel issue from grenading a very expensive motor, is to have a fail safe activated on a wideband, that cuts boost, or timing in the event of a lean condition while beating on the car.