Turbo Build

[gamefreakgc]

Just a short update.

Moved the pump to the outboard side of the frame rail and made the reverse trip of the week before and it ran just fine, no issues.

Found a 0.075 oil restricter that’s a 4an male to female (biggest I could find when searching for restricters). Installed it this morning. Hopefully it’ll cut down on the amount of oil in my intake. It was starting to cause the truck to idle high from oil coating the throttle body.

Going to start ordering/running all my hardline intake next. Get rid of all the flexipipe, I think that’s probably hindering performance quite a bit.

Also, averaged my gas mileage over the last 20 fillips and I’ve averaged 12.73. Be curious to see how/if that changes dramatically at all due to the turbo.

I just ordered an intake from siliconeintakes.com. They have all sorts of sizes and configurations at decent prices. What sold me is that they have a generous return policy. As long as it's unmodified, all extra parts can be returned with no questions asked for a full refund, just pay return shipping. I ordered a bunch of different bends and tubing options and will just return the rest.

 

[Myrunr2010]

I ordered a bunch of different bends and tubing options and will just return the rest.

This is how I treat Lowes on any home reno project. I’ve literally bought $100 in plumbing connections before and returned $75 worth, lol.

 

[Myrunr2010]

Just an update.

Love the turbo, under normal driving conditions i don’t really see boost, but the power is there if I need it, which is probably the best scenario for the longevity of my motor.

Still have a boost leak. It’s the gasket between the T.B. and intake manifold. I’m not in any huge rush to replace it.

Scavenge pump going out that day seems to have put some wear on the seals, I see a little oil out the tail pipe now.

The inline restricter I put on seems to be perfect. Not seeing the same amount of oil in my charge piping now.

 

[Myrunr2010]

My DIY sump is about to go (as in, I’m annoyed with it), I’ve noticed if I don’t leave the key in ACC for 20-30 seconds after turning the car off, I get more smoke on start up. So I bought a delay-off relay that I’m going to wire to the scavenge pump and a check valve that I’ll put at the pump exit. Relay comes in this weekend, hopefully I’ll get it put in this weekend.

Delay-off relay

 

[Myrunr2010]

My delay-off relay is installed and seems to be working great. Right now it’s set to go off after about 30 seconds. Check valve hasn’t come in yet, but I’m excited about the relay.

I used this for wiring instructions.

 

[Myrunr2010]

Check valve is in. I was able to reroute my oil return lines too since I’m no longer using the sump, looks much better under the vehicle. When I disconnected the return line coming out of the base of the turbo, I had ~12oz of oil come out, which would certainly explain why I’m still getting so much smoke out of the tail pipe. So hopefully all this makes a big difference.

First picture is the elbow right after my muffler, gives a little bit of an idea of how much oil has been getting pushed though (and how many pin holes in my weld joints).

Second picture is my intake pipe going into the throttle body. Hopefully these changes make a difference in that too.

 

[Myrunr2010]

Also did some troubleshooting on my boost leak, which I’ve still not 100% nailed down. I replaced the throttle body to intake manifold gasket, and my leak rate is better than it was, but I’m still losing boost somewhere around the throttle body. Did some research today and I think maybe the gasket for the idle air control valve is bad and I’m getting a slight leak by there? I’m going to order a gasket and hopefully I’ll get time this weekend to get it installed.

Longer range updates - I want to change how my oil return is. Not happy with how I have it going in to the oil cap. Makes it a hassle to the oil cap on and off. Like I said though, longer range.

 

[phattyduck]

Have you done anything with the air source for the air assist fuel injectors?

-Charlie

 

[Myrunr2010]

Have you done anything with the air source for the air assist fuel injectors?

-Charlie

Not sure exactly what you’re asking, but I think the answer is the same either way. No? Still using the stock air box. All the vacuum lines that were plumbed to it are still plumbed to pull a vacuum. Only difference is the intake line grew by like 15’ and now half of it gets boosted. Not sure if that answered your question or not?

 

[gamefreakgc]

Have you done anything with the air source for the air assist fuel injectors?

-Charlie

I thought about that too when I saw his last post but unlike a supercharger that needs a one-way valve, a turbo is pressurized all the way up to the MAF. I don't think it would have a way to leak? Just boost pressure making it's way in with the injector pulses.

 

[phattyduck]

I thought about that too when I saw his last post but unlike a supercharger that needs a one-way valve, a turbo is pressurized all the way up to the MAF. I don't think it would have a way to leak? Just boost pressure making it's way in with the injector pulses.

Yeah, it'll be dependent on how the intake system is run. But the air assist port is unrestricted on a stock 5vz, so boost can leak back out depending on the air source for that.

-Charlie

 

[Myrunr2010]

Yeah, it'll be dependent on how the intake system is run. But the air assist port is unrestricted on a stock 5vz, so boost can leak back out depending on the air source for that.

-Charlie

Can you help me understand what y’all are talking about?

 

[Myrunr2010]

I noticed this weekend that my exhaust gasket was leaking. Finally bought a proper replacement. Just documenting the PN in case I need to replace it again.

 

[gamefreakgc]

Can you help me understand what y’all are talking about?

I'll try and explain as best I can. Under the throttle body you've got a vacuum hose that goes from the IAC valve to the intake manifold where it t's to both engine banks. This hose supplies air to the injectors which helps atomize the fuel at idle and low speeds. Under vacuum it's not an issue but on a supercharged engine it's a massive boost leak as you'll have pressurized air actually exiting the intake manifold, past the injectors and back into the throttle body/intake. Toyota addresses this by adding a one-way check valve to the hose to keep boost pressure from escaping.

My thought is with a turbo the entire intake is pressurized due to the turbo making boost before the throttle body and makes this a non-issue, but maybe not. You could add a one-way check valve to the IAC hose if you want to see if that solves it. Should only take $5 and 5 min of your time. You'll want the flow of air to go from throttle body -> intake manifold.

 

[Myrunr2010]

I'll try and explain as best I can. Under the throttle body you've got a vacuum hose that goes from the IAC valve to the intake manifold where it t's to both engine banks. This hose supplies air to the injectors which helps atomize the fuel at idle and low speeds. Under vacuum it's not an issue but on a supercharged engine it's a massive boost leak as you'll have pressurized air actually exiting the intake manifold, past the injectors and back into the throttle body/intake. Toyota addresses this by adding a one-way check valve to the hose to keep boost pressure from escaping.

My thought is with a turbo the entire intake is pressurized due to the turbo making boost before the throttle body and makes this a non-issue, but maybe not. You could add a one-way check valve to the IAC hose if you want to see if that solves it. Should only take $5 and 5 min of your time. You'll want the flow of air to go from throttle body -> intake manifold.

Interesting. Thanks for that!

I have been dealing with some boost leaks around the IAC, but I think it’s the gasket that secures it to the TB. It’s hard to tell exactly where it’s coming from when I do a leak test though.

 

[gamefreakgc]

Interesting. Thanks for that!

I have been dealing with some boost leaks around the IAC, but I think it’s the gasket that secures it to the TB. It’s hard to tell exactly where it’s coming from when I do a leak test though.

The gaskets Toyota use aren't made for boost, especially after they've had 10-20 years to degrade. The torque specs are too loose for boost as well. My repeat offender is the lower plenum to intake manifold connection. It leaks if I don't torque it almost 2x as tight as it says in the manual.

It might be worth the effort the next time you do some work on the engine to take off the throttle body and upper/lower plenum and just replace them all and torque them down tight. That way you can rule them all out and get a more reliable tune.

 

[Myrunr2010]

The gaskets Toyota use aren't made for boost, especially after they've had 10-20 years to degrade. The torque specs are too loose for boost as well. My repeat offender is the lower plenum to intake manifold connection. It leaks if I don't torque it almost 2x as tight as it says in the manual.

It might be worth the effort the next time you do some work on the engine to take off the throttle body and upper/lower plenum and just replace them all and torque them down tight. That way you can rule them all out and get a more reliable tune.

Yeah, I got the TB gasket and the IAC gasket replaced. Holding boost much better. Still not holding pressure perfect, but it takes like 20-25 seconds to leak down completely. The manifold gaskets seem to be holding ok.

 

[Myrunr2010]

I’ve been thinking of reracking my exhaust some and dropping the muffler. I don’t make boost quite as early/quickly as I would like to. I’m hypothesizing that the bend I had to put in the exhaust between the cat and the muffler, coupled with the turbo flange being flush mounted to the pipe is causing a fair amount of turbulent flow and now allowing the turbo to spool up as quickly as it could with a faster flow.

If I lose the muffler I can push the turbo back and up some (the undercarriage gains a lot of height when you move back a little closer to axle) and use a straight pipe to 90 degree elbow like I had originally planned on doing.

 

[KK99T4r]

Updates??

Hoping this is still going strong. I am acquiring parts now looking to do something similar. I actually want to put the turbo where the cat mounts to maximize heat scavenging and minimize all other cons of a rear-mount. Kind of a best of best worlds underhood and rear-mount. What is your assessment of this? I like the idea of using a delay relay instead of a turbo timer. Great idea.

 

[Myrunr2010]

Hoping this is still going strong. I am acquiring parts now looking to do something similar. I actually want to put the turbo where the cat mounts to maximize heat scavenging and minimize all other cons of a rear-mount. Kind of a best of best worlds underhood and rear-mount. What is your assessment of this? I like the idea of using a delay relay instead of a turbo timer. Great idea.

I don’t understand what you’re trying to do with the heat? Usually you want to limit your heat input, which is an advantage of the rear mount (ie no need for an intercooler). You would be running your oil lines significantly shorter, which could be an advantage just from a build logistics standpoint. I think a lot of cat piping only had a flange that is where the exhaust manifolds collect up next to the tranny. Would you cut your cat off and put a flange in? Height would be another concern, just getting it to fit and being able to run the intake to it and the boost piping back. It’s an awful lot going on right in that area.

I’m excited others are interested in the idea!! Keep us posted on the build! Turbos are fun!