New guy, lots of questions

Pretaco · 12-21-2007, 02:37 AM

I just bought an '88 supra without and engine and a '90 supra with and engine, and am in the process of putting the 90 engine into the 88.

I have most of it figured out (I am a mechanic, but no experience with turbos).

My first question is: the factory waste gate is wasted. Somehow a hole has been punctured in the actuator. I figure this is a good excuse to upgrade to a 'divorced' blow off valve. What exactly do I need to buy to make this happen?
And what do I do with the factory one?

What are good cheap upgrades to do for the turbo motor?

Anyone interested in blue interior trim parts and an r154 manual trans, and light blue body parts?

I figure I will part out the rest of the '90 when I get the 88 running.

Thanks,
Ray.

Supra2NR · 12-21-2007, 04:55 AM

well with the 90 motor came with diffrent motor mounts
you need to find motor mounts from pre89 motor

with the wastegate, you need to replace it
idk i never heard of a divorced blow off valve
jus find a used ct26 turbo and take the wastegate off of it
you cant jus use external wastegate
since you will need another manifold for them
and i think your talking about a divorced downpipe
you will need that custom-made for ya, if your using the stock manifold
or maybe sum company makes a divorced downpipe that bolts to our manifold

cheap upgrades to the motor
ranges from intake, exhaust,better ignition system

lexus maf, 550cc injectors,boost controller, to raise the boost

hardpipes for the intercooler
clean the intercooler, cuz most likely itll have oil and 20 years worth of dirt in it

i most likely missed something, but feel freeto add on

Pretaco · 12-21-2007, 07:06 AM

Okay,

I have the motor mounts from the '88, and the ecu and harness from the '90.
I was told the waste gate and the blow off valve do the same thing and can basically interchanged, but I could be way wrong so any help would be appreciated.

Anybody have a ct26 wastegate for sale?

Ray.

Chambers · 12-21-2007, 11:52 AM

A waste gate releases exes exhaust gases to stop the turbo from spooling up after a certain psi. You could buy headers for the turbo that have a flange built in for a divorced (external) waste gate, but you will have to keep the stock actuator on, just not connected to the pressure line, so the internal waste gate doesn't open. Or buy a manual boost controller that completely replaced the stock actuator, Greddy makes one, suprastore.com has them for like $190.

A blow off valve releases pressurized air out of the intercooler lines, when the throttlebody closes the air has no where to go, so a blow off valve is used to release that pressurized air so the turbo doesn't get compressor surge. compressor surge is when the pressurized air forces its way backwards through the turbo, this can destroy the turbo bearings. The factory "bov" on the Supra is actually a recirculation valve, it takes that pressurized air and feeds it back into the front of the turbo. The factory fuel maps correct for that increase in air, so you might need slight tuning if you put a bov on it, but I could be wrong. Hope this helped.

Pretaco · 12-21-2007, 10:04 PM

Well that explains a lot.
Thanks for all your help.
Off to find a waste gate.......

12-21-2007, 02:37 AM	#1
Pretaco 3" Exhaust Join Date: Dec 2007 Location: Glendale, AZ Posts: 126	New guy, lots of questions I just bought an '88 supra without and engine and a '90 supra with and engine, and am in the process of putting the 90 engine into the 88. I have most of it figured out (I am a mechanic, but no experience with turbos). My first question is: the factory waste gate is wasted. Somehow a hole has been punctured in the actuator. I figure this is a good excuse to upgrade to a 'divorced' blow off valve. What exactly do I need to buy to make this happen? And what do I do with the factory one? What are good cheap upgrades to do for the turbo motor? Anyone interested in blue interior trim parts and an r154 manual trans, and light blue body parts? I figure I will part out the rest of the '90 when I get the 88 running. Thanks, Ray.

12-21-2007, 04:55 AM	#2
Supra2NR 1000whp postwhore Join Date: Apr 2006 Location: Chi-Town Posts: 1,643	well with the 90 motor came with diffrent motor mounts you need to find motor mounts from pre89 motor with the wastegate, you need to replace it idk i never heard of a divorced blow off valve jus find a used ct26 turbo and take the wastegate off of it you cant jus use external wastegate since you will need another manifold for them and i think your talking about a divorced downpipe you will need that custom-made for ya, if your using the stock manifold or maybe sum company makes a divorced downpipe that bolts to our manifold cheap upgrades to the motor ranges from intake, exhaust,better ignition system lexus maf, 550cc injectors,boost controller, to raise the boost hardpipes for the intercooler clean the intercooler, cuz most likely itll have oil and 20 years worth of dirt in it i most likely missed something, but feel freeto add on __________________ http://www.myspace.com/supra_2nr Into Bikes now,, apparently the supra couldnt kill me, so my zx6 might lol

12-21-2007, 11:52 AM	#4
Chambers walbro fp Join Date: May 2007 Location: USA - Harford County, Maryland Posts: 481	A waste gate releases exes exhaust gases to stop the turbo from spooling up after a certain psi. You could buy headers for the turbo that have a flange built in for a divorced (external) waste gate, but you will have to keep the stock actuator on, just not connected to the pressure line, so the internal waste gate doesn't open. Or buy a manual boost controller that completely replaced the stock actuator, Greddy makes one, suprastore.com has them for like $190. A blow off valve releases pressurized air out of the intercooler lines, when the throttlebody closes the air has no where to go, so a blow off valve is used to release that pressurized air so the turbo doesn't get compressor surge. compressor surge is when the pressurized air forces its way backwards through the turbo, this can destroy the turbo bearings. The factory "bov" on the Supra is actually a recirculation valve, it takes that pressurized air and feeds it back into the front of the turbo. The factory fuel maps correct for that increase in air, so you might need slight tuning if you put a bov on it, but I could be wrong. Hope this helped. __________________ Whats in the garage, well.... in the yard. 1986.5 Toyota Supra - NA - 5 spd 1986 Ford Ranger Lowrider - 5 spd 1984 Ford Ranger XLT - 7" Lift - 4X4 - Auto "Stuck in the 80's"

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12-21-2007, 07:06 AM	#3
Pretaco 3" Exhaust Join Date: Dec 2007 Location: Glendale, AZ Posts: 126	Okay, I have the motor mounts from the '88, and the ecu and harness from the '90. I was told the waste gate and the blow off valve do the same thing and can basically interchanged, but I could be way wrong so any help would be appreciated. Anybody have a ct26 wastegate for sale? Ray.

12-21-2007, 10:04 PM	#5
Pretaco 3" Exhaust Join Date: Dec 2007 Location: Glendale, AZ Posts: 126	Well that explains a lot. Thanks for all your help. Off to find a waste gate.......