smokin2002

iTrader: (10)

Are there any set #'s on a minimum fuel pressure you should have while under WOT?? My car idles at 60-61 psi {autometer cobalt gauge with sender taped into fuel rail} but it will drop off to low 50's at 3kish under wot. havent been any higher in powerband yet due to bad clutch. but i have a tnt nitrous kit installed now and im just wandering some basics on what an ls1 should have for fuel pressure under WOT and WOT with spray. I have a fuel pressure switch but have no idea how low my psi has to be to close the circuit?? The car also has a thirsty 236/230 cam. would these be grounds for a better fuel pump?? Im just a lil leary of the drop in pressure on just motor without feeding the fuel solonoids yet If i get some free time ill pull out the safety switch and put pressure to it on the bench and see what its set up at. Id like to be as safe as i can when using the juice

GM Muscle

iTrader: (9)

Having the system loose 10psi without recovering is not good. I would be replacing the fuel pump. I think TNT jettings are rated at 50-55psi, it should say on your jet card. I try to run 55+psi.

Robert56

iTrader: (2)

I know for the vette guys a adjustable reg and return line at the rails will help a lot in the high demand area of fuel consumption. i agree, dropping 10psi and staying there is asking for trouble. check, fuel filter, pump, return system and the such, a pump my be needed, or something as simple as a hot wire kit can help a pump as much as 20% in maintaining press/volume.
Robert

smokin2002

iTrader: (10)

ok, the car is an 02 with 35k miles. i changed the fuel filter at 30k. i think ill just need the bigger pump if i should be able to retain 58-60 psi at all times?? I can only imagine how bad it will fall off when the fuel solonoids start drawing off it too!!

GM Muscle

iTrader: (9)

With a walbro pump and hot wire kit your see about 62psi, would probrably drop to 58-60psi on the bottle. You could get away with just a Walbro but you might as well stick in a Hot Wire kit at the same time. Racetronix sells the whole set up in a plug and play set up, it's pretty nice and priced decent.

TNTramair

iTrader: (15)

http://www.harrisspeedworks.com/shop/home.php?cat=330

mine only drops to 58psi and usually idles at about 63psi. upgrade fuel pump kit should be done regardless.

smokin2002

iTrader: (10)

ok good deal

TwoFast4Lv

iTrader: (8)

On most of the cars I tested the LSx non-return style system looses 6-10PSI under load. I have tested about a dozen or so cars

smokin2002

iTrader: (10)

would that be safe to be spraying nitrous with low 50's on a 100 shot??
and down the road i might try a 200...either way ill just have to get a bigger pump that can maintain atleast 58# at all times.. would injectors be causing me to loose psi too??

Ive also got a bunch of braided line and fittings laying around.. would #6 AN fuel lines be overkill??

Robert56

iTrader: (2)

I know that's true on the vettes. The stock Walbro can support 550hp easily, but you do get pressure loss under heavy load. The answer is moving reg and return line to fuel rails. Racetronics has a new reg to replace pulser and line in a kit. Supposed to be out by know but after they posted this, they quite talking of it. You can always use GM rails/reg from 97/98, which I will be doing one of these tricks for mine.
Robert