where to run boost gauge line

[superhoss37]

i have 2 questions....

prep: 1998 240sx ka-t
autometer phantom boost gauge
HKS ssqv

1. well, i tried installing my boost gauge tonight and was getting ready to run the hose from inside the car through the supposed firewall into the engine bay but geeze, i cant find and kind of rubber grommet or boot to poke the hose through. how did you guys get it into the engine bay? sorry if this is a dumb question but im confused.

2. a little problem with my blow off valve. just wondering...how come when i have the car just sitting in the driveway running in neutral and rev the engine to say.....5k rpms and let off the gas it doesnt blow off any air or make any noise at all. when im driving around in my car though, it will make a fluttering noise when letting off the gas. is it normal for it not to do anything at all when just idling???


Thanks!!

[superhoss37]

oh and another problem is when i hooked up the boost gauge to what i thought was a vacuum line and revved the engine while not moving, the little needle didnt even go up into boost, instead it went down into the vacuum area. what's the deal???

[Fibercus]

Originally posted by superhoss37

2. a little problem with my blow off valve. just wondering...how come when i have the car just sitting in the driveway running in neutral and rev the engine to say.....5k rpms and let off the gas it doesnt blow off any air or make any noise at all. when im driving around in my car though, it will make a fluttering noise when letting off the gas. is it normal for it not to do anything at all when just idling???

Sounds like its not working, fluttering could be turbo surging... and not the bov even opening

Like its not getting the release signal (vacuum). Sounds like mine when i first hooked it up, finally I routed its own vacuum line from T.B. and everything was fine

[mbmbmb23]

You could go thru the firewall on the huge grommet thats under your glove box....I think its where the wire harness comes thru. Carefully take a drill and drill a small hole, then grease the hole and slide it thru. If your BOV installed backwards possibly?? Otherwise as stated before, its probaby not getting any vacuum.



-m

[brage]

Originally posted by superhoss37
i have 2 questions....

prep: 1998 240sx ka-t
autometer phantom boost gauge
HKS ssqv

1. well, i tried installing my boost gauge tonight and was getting ready to run the hose from inside the car through the supposed firewall into the engine bay but geeze, i cant find and kind of rubber grommet or boot to poke the hose through. how did you guys get it into the engine bay? sorry if this is a dumb question but im confused.

2. a little problem with my blow off valve. just wondering...how come when i have the car just sitting in the driveway running in neutral and rev the engine to say.....5k rpms and let off the gas it doesnt blow off any air or make any noise at all. when im driving around in my car though, it will make a fluttering noise when letting off the gas. is it normal for it not to do anything at all when just idling???


Thanks!!

Well for one your car isn't likely to build any boost at all when not under load (IE in neutral) so your BOV won't blow off and your boost gauge won't show boost. I would recommend busting out the drill (corded is best) and drill a hole through the firewall. Just check both sides before drilling ;)

[Muzzy]

:confused: :confused:


wut?? i've seen and heard cars blow off valves dump while jus revving without load

ever seen that blow off valve sound site?? all if not most of those cars are jus sittin there. im pretty sure u can find it under links on this site.

[brage]

Originally posted by Muzzy
:confused: :confused:


wut?? i've seen and heard cars blow off valves dump while jus revving without load

ever seen that blow off valve sound site?? all if not most of those cars are jus sittin there. im pretty sure u can find it under links on this site.
My KAT doesn't build any boost under no load. But I have a T3/T4.... I assume you have a SR? T25 or T28? Doesn't really matter, flow is MUCH lower under no load then under load. Therefore you probably aren't building any boost.

My BOV definately doesn't ever see a pressure differential great enough to blow off when revving/releasing under no load (because there is no boost to blow off)

-jeff

[Muzzy]

well i seen turbo celicas, supras, VWs, and EVOs dump while not under load. i know the flow is different but still

[brage]

Just take the care for a drive and see if it blows off :) Be nice and make sure the WG is functioning correctly before getting on it!

[Evil S14]

to run my EGT wire and boost gauge hose, i drilled a hole in the firewall just behind the accelerator pedal, then put a grommet in

as for your BOV, the fluttering noise is your compressor surging, i had the same problem. Make sure you run your BOV on its own independant vacuum source and dont T it off of the wastegate signal, this was what was wrong with mine.

as for blowing off in neutral, my kat does it, but its not anywhere as loud as when the engine has a load on it

[superhoss37]

well, my wastegate has its own line on the hot pipe and the blow off valve is T'd off the FPR.

does the bov fluttering have anything to do with how loose or tight the bolt on the back of it is set to?

[Evil S14]

if its too tight it probably wont open at all, if its too loose then it would open and leak air out during boost

the fluttering you hear is probably compressor surge :(