3rz Rockcrawler Turbo Build Questions

Thanks for the modivation, I've been eyeing your build on irate for years.

The next thing I need to decide on the intercooler. I'm thinking that a water to air would be best. I like shedking's setup, but he said he had heat soak issues. I'm thinking that it was because he didn't run a tank.

 

No progress on the intercooler front, but other parts are arriving. I rough cut the exhaust manifold pipe fittings today. Hoping to tack them together for mockup this weekend.

I am about 99% convinced to go with the Haltech Nexus S2 ECU, mainly for internal wideband, and I want to setup a smart phone or tablet as my gauge setup. With the nexus I can connect wirelessly to it.

 

You can also set up knock control with it too for extra safety. Will be a nice plus if you find yourself in areas with less than stellar fuel options!

 

Progress has been slow, but I am workijng on itL
Haltech Nexus S2 should be here thursday
Exhaust manifold is welded up and surfaced
90% through determining the pinout for the DIY PNP harness

 

Couple Questions:
•What is the general consensus on water cooling the turbo? Pulsar recommends it, but it seems like most people don't. This is a BB turbo if that makes the difference. I will, but less failure points/complexity on the trail sounds good to me.
•The summit 44mm waste gate has comes with (2ea) 4# springs installed. Can I remove the small spring and just have the larger 4lb spring? That way I could use a boost controller from 4lb to 8lb?

 

I water cool mine because I'd rather have longevity out of it, but I don't think it would kill it immediately to not water cool.

And 4psi would be fine especially if you find yourself in places with low grade fuel, and a controller will have no issues getting you up to potentially as high as 14-15psi from there

 

Tuna Racing has a lot of videos about turbocharging the 3RZ. They route the oil cooler coolant feed from the block into the turbo and then from the turbo outlet back into the cooler. It's pretty straightforward. I'd think about using silicone hose though. I guess not all 3RZs have a cooler (or most US ones didnt?), but the source and drain ports still ought to be on one that doesn't.

 

Turbo gets pretty hot, you might consider just changing the order. Oil cooler, turbo, then back to engine. Not sure it would make much difference on the oil temp, but just for peace of mind

 

I don't have the oil cooler ports. I was going to tap into the heater lines on the firewall.

 

The Haltech manual doesn't mention anything about how far downstream the wideband needs to be mounted. Is there any issue mounting it here?

 

A good rule of thumb is 18" downstream give or a take a few inches, and you want it to be above the mid line of the pipe if it's horizontal. Just don't want it somewhere where condensation can build up inside of it

 

I've heard that rule, but I see many builds place it here. Of course I also hear lots of people having problems with them. I'll look for a spot further down.

 

Yeah it will function there, but it's better if you can get it 18-24" further downstream. I have a (previously LSU4.2, now 4.9) WB02 sensor on a non-Toyota where you're asking about and it's a pretty harsh spot that close to the turbine outlet. The only cost of putting it further from the engine is an increasing delay between what happens in the chamber and what the sensor reads. I would expect a Haltech to have a setting for that O2 sensor latency somewhere.

Edit: exactly the same place...

 

Too much turbo? T35.
https://a.co/d/3WT5aIa

Going on a 99 Tacoma 3rz with cheap eBay manifold. Goal is cheap but wanting 5-7psi on stock ecu.

5.29 gears on 40s.

I have a HX35 from a Cummins on a 3rz in my fj40 and it rips but that’s a different application.


Thoughts?

 

Yeah that's too much turbo for that low of a goal. You could make big power with that on a 3RZ but it isn't going to be very responsive at what you're looking for.

 

Or this little guy?
https://a.co/d/7I4BwG5

 

That's a little more appropriate for very low boost, it might choke up top but depending what youre planning on doing that may not be a concern.

 

I don’t plan on living at 4k rpm’s. This will be a crawler street rig for the most part. Not going for top speed or max power. Just would like the boost as low as possible.

It will be going in this POS.

 

Rough equivalent of a gtx2867 or gtx2871 would be a good size turbo for a lower rpm powerband on a 3rz, but a 3067/3071 will still spool plenty well with 5.29's and 40's. On the dyno, I make 15psi at 3800rpm, but on the road, I can make 7-10psi well before 3k if loaded down, and I'm running 5.29's and 35's. You will have an easier time making boost earlier than me. I run a pulsar 3067 with a .82 housing on my truck

 

Thanks for the info. Turbo selection is tough sometimes. There are a literal thousand to choose from.