Newbie Question

[GT-FOURNZ]

hey every1 im new to the gt-four, i own a st185 wit a few mods like xs power extractors 3inch down pipe and a hybrid turbo.

i have a concern bout my car, when at full boost and gets to bout 4000rpm i get a strange whistling sound if anybody out there knows what this sound is please help!!!

[GTForbes]

a strange whistling as in a high pitched whistle of a turbo going round at 100,000RPM ?

has it just started since you've added mod's or has it always been there?

[Toyotacelicagt4]

I get that too sometimes only mine is at like just over 3000rpm. Doesn't sound healthy thats for sure. Sounds like the car is whining and always stops as soon as the rpm got up or down by even like 100. Does that sound like what you've got as well bud?

[GTForbes]

does your sound go away when you let off the throttle? if it does that would point more to the turbo

[Toyotacelicagt4]

Hmmm, well Ya it would stop if I let off the throttle but thats because the rpm would be going down. The noise only happens within like 3000-3100 rpm... it would go away even if I just revved the engine a little to break out of that rpm range.

[GT-FOURNZ]

a strange whistling as in a high pitched whistle of a turbo going round at 100,000RPM ?

has it just started since you've added mod's or has it always been there?

yea its always been there just wondering what the noise is turbo is brand new fully rebuilt with t4 internals. i thought it might be the wastegate since they have a duel wastegate flap

[led-gt4]

think the waste gate should make a clatter more than anything. i got my gt four back after an engine rebuild and mine made a whistle at 3000 revs. took me forever to figure out what it was but it turned out to be the dump valve. it wasnt on tight enough and there was a small crack in the gasket that seals the bottom of the dump valve to the top section with the spring inside etc. i would check that 1st

[GT-FOURNZ]

think the waste gate should make a clatter more than anything. i got my gt four back after an engine rebuild and mine made a whistle at 3000 revs. took me forever to figure out what it was but it turned out to be the dump valve. it wasnt on tight enought and there was a small crack in the gasket that seals the bottom of the dump valve to the top section with the spring inside etc. i would check that 1st

cheers for your help. any idea on how much boost a standard hg on a 185 can hndle?

[Toyotacelicagt4]

Fuel cut is at 12psi so that is about the maximum but personally I would only go 10 or 11psi without engine upgrades, just to be on the safe side. Standard boost is 7psi so you would still be gaining about 40bhp at a 4psi boost increase.

[Fizz]

i thought stock boost on a ST185 was around the 10psi mark? Cant be 7 psi surely? can it?

[Jones~32]

think it is Fizz ;)

[GT-FOURNZ]

thanks for ur help guys. another question. i have an inlet manifold and throtle body from a st162 celica with a 3sge engine does any1 no if it will bolt up to the 185? plannin on front mounting it also does any1 no if a supra ct26 turbo acuator will fit on so i can get rid of the TVSV

[markd1984]

i am with you fizz

my st185 is standard and running 10psi, which is 0.7bar. my friends was the same to

[Toyotacelicagt4]

i am with you fizz

my st185 is standard and running 10psi, which is 0.7bar. my friends was the same to

Well alot of sites will list 7psi as standard in first, second and third gears. However the TVSV sytem will bleed some boost in fourth and fifth gears allowing for about 9psi (exact boost lvls for my st185). Will probably vary a little on different cars so sounds reasonable to me that you might have 10psi stock in fourth and fifth. If you are getting that much in 1st 2nd and 3rd then that doesn't seem right and it probly isn't as stock as you might think.

[GTForbes]

to get rid off the TVSV just cut the pipe and plug both ends, you'll be running low boost in all gear though unless you get a boost controller

[Toyotacelicagt4]

Ya I have a relief valve but am a bit hesitant to put it in I think I should throw a cometic head gasket with arp studs first because the head gakset on the 185 seems like junk from what I hear. What you think though 11-12psi is ok on stock gasket?

[GT-FOURNZ]

Ya I have a relief valve but am a bit hesitant to put it in I think I should throw a cometic head gasket with arp studs first because the head gakset on the 185 seems like junk from what I hear. What you think though 11-12psi is ok on stock gasket?

id keep it at about 10 psi frm what iv herd they are pretty crap head gaskets

[GTForbes]

10psi to be safe, 11-12 if you don't mind replacing the gasket and re-furbing the head after a few months ;)

[Toyotacelicagt4]

10psi to be safe, 11-12 if you don't mind replacing the gasket and re-furbing the head after a few months ;)

Well ya ...Kinda what I figured and it's better safe than sorry. Once I have the steel HG in then i can safely run 11psi or still more work must be done? Any old mechanic can do a HG right? Or should I go with it right to toyota. Also if im getting the HG done I might as well replace the valve cover gasket (which is leaking all over my S.plugs) and water/oil pumps this is all the same area correct?

[GT-FOURNZ]

can any1 tel me what the tell tail signs of a blown hg??

[led-gt4]

milky oil cap? head gasket going will cause the oil and water to mix. oil in the water or water in the oil is a sign. or sometimes u can see a leak from it