Running lean sometimes??!
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Teching In
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Running lean sometimes??! Soo just got my car from the dyno it’s a ls2 GMC Sierra with s475 turbo it made good power at 13.5 psi (656 on an MD) but when tested on the road some times it has good afr (about 11.3) in some runs and sometimes it goes lean about 12.9 afr and I can hear the detonation clicking sound the car has stock fuel system other than ID 1000 injectors and duel nozzle methanol system 100% meth.
i don’t know what I should check I already checked the meth system seems fine and the injectors at 60% duty cycle.
any ideas what it could be.
Btw the car still occasionally run fine not lean at all.
i don’t know what I should check I already checked the meth system seems fine and the injectors at 60% duty cycle.
any ideas what it could be.
Btw the car still occasionally run fine not lean at all.
Soo just got my car from the dyno it’s a ls2 GMC Sierra with s475 turbo it made good power at 13.5 psi (656 on an MD) but when tested on the road some times it has good afr (about 11.3) in some runs and sometimes it goes lean about 12.9 afr and I can hear the detonation clicking sound the car has stock fuel system other than ID 1000 injectors and duel nozzle methanol system 100% meth.
i don’t know what I should check I already checked the meth system seems fine and the injectors at 60% duty cycle.
any ideas what it could be.
Btw the car still occasionally run fine not lean at all.
i don’t know what I should check I already checked the meth system seems fine and the injectors at 60% duty cycle.
any ideas what it could be.
Btw the car still occasionally run fine not lean at all.
stock fuel system? I’d say you are out of pump man. 500rwhp is as far (further actually) as I’d trust the factory pump. What’s your fuel pressure when it goes lean?
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I have to run it on the dyno and check it with my tuner but I’m sure it was fine on the dyno. Currently I’m testing the meth nozzles to see if there are any restrictions from them. After that I’m checking the fuel pressure
but personally... No question about it... I’d Upgrade the pump. A Walbro 450 will only support around 700rwhp on petrol... your running that on a stock pump which is crazy unless you have a flex fuel pump. And even then I wouldn’t be comfortable with it. I know you have meth... but that’s not a smart way to fuel for extra power. Don’t use it as a primary fueling source...
$130-150 is all a walbro 450 or 525 will cost. Regardless of it being the problem or not, upgrading your fuel pump is mandatory at those power levels.
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That’s a big reason I never have had meth injection. If there is a problem, and you don’t have a pressure switch that will revert boost to wastegate when the meth pump fails, your gunna have a bad time.
but personally... No question about it... I’d Upgrade the pump. A Walbro 450 will only support around 700rwhp on petrol... your running that on a stock pump which is crazy unless you have a flex fuel pump. And even then I wouldn’t be comfortable with it. I know you have meth... but that’s not a smart way to fuel for extra power. Don’t use it as a primary fueling source...
$130-150 is all a walbro 450 or 525 will cost. Regardless of it being the problem or not, upgrading your fuel pump is mandatory at those power levels.
but personally... No question about it... I’d Upgrade the pump. A Walbro 450 will only support around 700rwhp on petrol... your running that on a stock pump which is crazy unless you have a flex fuel pump. And even then I wouldn’t be comfortable with it. I know you have meth... but that’s not a smart way to fuel for extra power. Don’t use it as a primary fueling source...
$130-150 is all a walbro 450 or 525 will cost. Regardless of it being the problem or not, upgrading your fuel pump is mandatory at those power levels.
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it could be because I tried with a full tank it was fun but with a quarter tank it went lean maybe this explains why it was ok on the dyno
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Verdad Gallardo Thread Starter
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any suggestion for a fuel system for my 2013 Silverado I want to convert it to return style. If there is someone who builds fuel system for my car please recommend him to me.
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I just saw a youtube from sloppy outlining a 3 pump deal for his current truck build. It was really trick. Check it. Hope posting the lonk doesnt break the rules its a link to denmah not a seller exactly.
https://youtu.be/96vpSBQQxw8
https://youtu.be/96vpSBQQxw8
thanks
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I don't think you're gonna need that much pump , I'm sure Matt is going for some big numbers. A single 450 should do it, but you have to keep the pick up submerged. If you don't see any lean out with > 1/2 tank fuel there's your solution, or look into improved baffling in the tank. As far as fuel regulator , the old design factory rails with vac reference has been used at that power level successfully on pump gas. Probably have to retune though
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Update!
checked the car today with my tuner and we logged a run, apparently the voltage drops sometimes to 11.4 when that happens the fuel pressure drops to 33 psi now I’m looking into this issue I think my alternator is about to give or maybe it’s a wiring issue thinking about getting a performance alternator what do u guys think.
btw the my flex fuel pump is still good at this power level it only drops when the voltage drop.
checked the car today with my tuner and we logged a run, apparently the voltage drops sometimes to 11.4 when that happens the fuel pressure drops to 33 psi now I’m looking into this issue I think my alternator is about to give or maybe it’s a wiring issue thinking about getting a performance alternator what do u guys think.
btw the my flex fuel pump is still good at this power level it only drops when the voltage drop.
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Quite a few of the people here have had voltage problems (not me fortunately ) , from what I've read the cure is usually, new alternator, modified alternator wiring, or larger alternator pully - apparently they stop charging at higher rpms. In no particular order.
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I will try to get my buddy’s alternator and test the car, if the alternator was the problem I will get a new one, I don’t really trust the remanufactured ac delco stuff maybe I will get a performance alt from mechman.
9 Second Club
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From: Norn Iron
Update!
checked the car today with my tuner and we logged a run, apparently the voltage drops sometimes to 11.4 when that happens the fuel pressure drops to 33 psi now I’m looking into this issue I think my alternator is about to give or maybe it’s a wiring issue thinking about getting a performance alternator what do u guys think.
btw the my flex fuel pump is still good at this power level it only drops when the voltage drop.
checked the car today with my tuner and we logged a run, apparently the voltage drops sometimes to 11.4 when that happens the fuel pressure drops to 33 psi now I’m looking into this issue I think my alternator is about to give or maybe it’s a wiring issue thinking about getting a performance alternator what do u guys think.
btw the my flex fuel pump is still good at this power level it only drops when the voltage drop.
Now, you may also have an alternator issue, but a stock fuel system and ID1000 injectors is a bizarre setup
Thread Starter
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definitely I’m now looking for a good fuel sys for the truck surely I will be converting to return fuel system I will get an aeromotive regulator re use the the stock line as a return line 8AN feed line only thing I’m not sure whether I should get the double pumps fuel hat from horsepower headquarters and do a twin walbro 450 or I just try the new 525 hellcat pump.
9 Second Club
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From: Norn Iron
At only 650hp, I cannot see any need for a pair of 450's
A pair of 255's would easily support it.
Or a single 450 or 525.
Yes you should build in extra capacity, but it doesnt make sense to go overboard either.
A pair of 255's would easily support it.
Or a single 450 or 525.
Yes you should build in extra capacity, but it doesnt make sense to go overboard either.
