Next Generation in Supercharging Means 275whp!

[turbophil]

Nobody should get discouraged about fuel delivery. It's just part of going fast. If it has to be upgraded, then it has to be upgraded... and that's not a bad thing...

Between now and the end of the year, we'll be trying different combinations on the fuel system to get the gas we all need with the easiest, least intrusive, and least expensive route possible...

Best,

Phil

[charliex]

drop the tank , new pump, its mostly labour, dmh says his guys can do it in an afternoon, a dealer in a day, so thats a ballpark.

the pump itself is about 150 or so, not 100% sure.

i think over voltaging isn't ideal, you increase the amperage required, from the back of the napkin about 13.5V@9amps vs 12V@6amps, decrease the flow, and given that most people run with those tiny batteries and the alternator is spec'd at 70 amps and stuff like the high speed fans can cause a voltage drop, is the wiring upto another 4amps load, i'm not sure,it might, its just a bandaid for when you can't fix it properly, its like removing the regulator to get the pump to flow at 80lbs when you can't control the injector scalers. it needs a new fuel pump (or a swirl pot), lotus puts a 255 in the cup car and it has the same injectors, runs the same boost and the same power rating, what does that tell you ?

[turbophil]

Since all the big hp kits are having to deal with fueling to some degree, this is probably a discussion best left to another thread...

CW- I'm not saying you're wrong by anymeans, but "hot wiring" a fuel pump is really common practice (for others, google it if unfamiliar) and is even advocated by most fuel pump manufacturers (including Walbro). Volume pics up with increased voltage with no real adverse effects to the pump... That said, I'm not saying hot wiring the pump is *the* fix for the car, but it's certainly worth exploring before condeming it, IMO. Every company from Kenne-bell to Lingenfelter swears by it... Again, since the turbo guys, future VF, and future TVS guys are all going to have to face this issue, we should probably start a new thread for it...

Best,

Phil

[kbob]

So, uh, what's all this extra fuel flow going to do to the Elise's range? There are already backroads I can't get to because they're too far from a gas station.

(Only half kidding.)

[turbophil]

Good point You're just going to have to feather-foot it till you get to the fun parts

Cheers,

Phil

[IamBatman]

how much HP can the stock trans handle?

[fzust]

Originally Posted by IamBatman

how much HP can the stock trans handle?

AFter over a year I blew up the 5 speed(essentially same as our 6 speed) on an autox by unloading my 12" slicks and loading them up again with about 360-370HP behind it. That said, I have been driving like this for a year! As long as you don't drag launch it, no problem.

[charliex]

I'm not saying people don't do it, i'm saying its a band aid fix for when you don't do it properly.

The differences between them and us, is that they have large batteries, large alternators, bigger wiring, they're flowing more fuel in the first place so its easier to make a big pump flow a bit more, than a small pump to flow a lot more, its purely percentages.

we all know that the elises wiring is spec'd pretty closely, theres not a lot of room for additional stuff.

look at those voltage/pressure charts again and see that while one axis is going up, the others going down.


on top of all that the pump is the same one from the NA cars, so its already been pushed for the S, but how far can you push it ?

additionally the 550s we put in the car to help us get that extra fuel on the 3.0's allowed us to barely get it by the skin of our teeth, the rev limiter had to be lowered to gain it, it was just pure luck that it made it, but the DC is still much higher than you'd want in a production kit. i was suprised when the 550s made it, they certainly didn't with the 2.9's but the fuel pump just could not keep up.

as for the fuel and tank range, forget it, once you're at WOT its sucking fuel out faster than it can get it, you can practically watch the gauge go down, off WOT its about the same as a normal elise.


smaays fuel system i'm told is $850

[MaineLotus]

Installing a new fuel pump is relatively easy - I did mine in around two hours and don't consider myself a master mech. I didn't drop the tank, replaced the unit via the access port behind the drivers seat. It did involve dremeling the access port slightly larger. But I wanted easy access without dropping the tank. Before/After pics -

[Bleu Omdurman]

^^^ How much weight did that save?


j/k

[MaineLotus]

11 grams, or .0000488827 horsepower

[Dave]

Originally Posted by MaineLotus

Installing a new fuel pump is relatively easy - I did mine in around two hours and don't consider myself a master mech. I didn't drop the tank, replaced the unit via the access port behind the drivers seat. It did involve dremeling the access port slightly larger. But I wanted easy access without dropping the tank. Before/After pics -

John, what pump did you go with...still have the P/N handy?

[MaineLotus]

I have the Smaay return system, which came with pump and all. I believe it's a Walbro 255.

[Dave]

Originally Posted by MaineLotus

I have the Smaay return system, which came with pump and all. I believe it's a Walbro 255.

That explains that extra fitting! I have just the rail installed - happy with the return system so far?

[Bavarian Motorist]

MaineLotus, how did you end up sealing that hole? Did you just use the same 5 remaining screwholes or did you take any extra measures? I ask because it seems like one more thing that would rattle a lot.

[turbophil]

Good Call, John!

I was nearly certain that it would come out through that access hole... A little dremeling is no big deal for sure.

Bav- There's no rattling that will come from there. That's a very rigid part of the car, that's also covered with carpet, wiring, etc... If you wanted to be extra careful, you could always just some double sided foam tape or a couple tabs of velcro to provide some cushion...

Thanks for the tip, John.


Best,

Phil

Originally Posted by MaineLotus

Installing a new fuel pump is relatively easy - I did mine in around two hours and don't consider myself a master mech. I didn't drop the tank, replaced the unit via the access port behind the drivers seat. It did involve dremeling the access port slightly larger. But I wanted easy access without dropping the tank. Before/After pics -

[charliex]

good tip john.

there you go then, no reason for not doing it now, after all read your own hubris

If something ain't worth doing right, it ain't worth doing at all...

[Bavarian Motorist]

I like that quote and philosophy

[turbophil]

Originally Posted by charliex

good tip john.

there you go then, no reason for not doing it now, after all read your own hubris

You are correct sir

PS- CW, you must be the only person I've met that probably gets even less sleep than I do

[dustylax]

what kind of numbers are you guys seeing before having to change the stock pump ?