http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&category=33742&item=7985639104
I’ve been looking for one of these lil guys for a while. You think it would be good to turn on a second fuel pump or something?
I was thinking of turbo’n my 11:1 B18B and thought a: the extra fuel would be nice and b: 2 pumps at idle on that motor might be bitchy, so why not turn a second pump on when you hit boost? …just turnin the wheels.
…if its totally fawking stupid, hey, im cool with that.
got one something like thaty on my desk,brand new GM ,for jay at HD!
what GM part is that?
Boost Pressure switch,part# 1991752 18 bucks
what vehicle that come off of?
a lot of guys activate secondary pumps with those…i’d rather just have them running all the time
turdo sunbird ,g/a , sly & ty’s!
Interesting…
I can see why you’d want to run them all the time… on something more serious, if that switch pooped out and you lost one pump, that could be detrimental to the engine life… aka boom.
that and it’s more of a bitch to tune a sudden “holie crap there’s more fuel” situation
in the event of the “holie crap there’s more fuel” situation, id believe there would be quite the whore of all tuning problems arose there. I’d think it might be good to set it higher and keep timing in it so its more happy until the fuel kicked in. Thats just because I can’t stand having NO timing so you can run high boost…much like my vr6 that has 5-6* of advance and has the throttle responce of a turtle…IMHO of course.
my only point was the midrange might get funky because those pressure switches aren’t all that accurate especially running the current through them for a fuel pump they turn on slow and turn off slow. BUT i know of lots of people that use them (i’d rahter use an rpm switch)
so waht is jay using it for?
aint sure!
it’s actually just a solenoid you can use with aem’s built in boost control. it’s not really a pressure switch. pat’s 240 is going to be using it to control the gt35r
if you use it for boost it would be like a rising rate FMU. the part about that is that boost comes on at different RPM’s if you are driving it on the street so you could tune for the dyno and it run like crap on the street. Just seems like a lot to tuning hastle to me to deal with 40psi of extra fuel presure at any given boost level. example:
say a turbo rolls into boost at 3000RPM on the dyno and you tune for that. so you are at 6500 rpm rolling a long and roll on the throttle 2 things can happen. 1) you could make for example 5psi rolling it on slowly at that RPM it would run super rich and stumble because it is gettin enough extra fuel on the tune you have for say 15psi full boost as an example or 2) you could stomp the pedal and run lean cause it shoots to 15psi before the pump can get enough fuel to the engine for the given boost level fast enough and again it would stumble.
I understand what you are saying. I dont think it would be that drastic of a difference though. Yes, its going to be different, but not blow your motor different.
Do you think it would work in conjunction with a FMU? I would assume you’d kick the fuel pump at the lowest psi setting possible.
why would you even need a second fuel pump? unless you’re aiming for somewhere over 500 hp, just one walbro 255hp pump is usually enough.
Boost on an 11:1 compression motor… :dunno:
fuel volume isn’t goin to be the hard part fuel quality will be. if you are on stock sleeves tune to 10psi and don’t touch anything and don’t use a FMU on that motor
I was thinking 2 pumps, 750’s, fmu/safc… small trim t4/switzer
I like the fmu… no?