Building TURBO system for YJ

[MikeGyver]

I'm turbo'ing my YJ because I can.

Only have a couple weeks before school starts so I probably won't have to figure out how I'm going to tune it. The plan is to get it running on 3psi (return it to sea level), and then just worry about the tuning when I have time and bump it up to ~7psi.
I'm just going to post a bunch of pics of the progress here to document the build.



Backing up a couple months, here's the new 100% stainless exhaust system.
My old exhaust had served it's decade of use and was falling apart so this needed to be done whether I turbo'd or not.

Forming the flare.

Hooking the one thingy to the other thingy.

Muffler section (with Helmholtz resonator to eliminate drone).

 

[MikeGyver]

Ok, so this brings us up to the present.

I'm waiting for the turbo to show up, so I started making the intake pipe and a couple other random things.

Added a 2nd bung (for a wideband o2 sensor) to the current exhaust system so I can see how the factory setup is handling air/fuel ratio.

Some of the parts showed up.

Here's what I'm working with...

Increased diameter of one end of tight radius cast elbow.

sandy sandy

smoothy smoothy

 

[Hickey]

This should blow. subscribby.

 

[Kevin B.]

 

[TurboMinivan]

As someone who has performed his own fair bit of turbo wizardry, I'm watching.

 

[thenag]

I could look at pictures of your welds all day long...

 

[amp713]

well..... I'm required by my curiosity to watch this one...

 

[juhcohbee]

Subbed for some sexy blow off valve action. :thumbs:

 

[Greg]

Looks great Mike! I've always wondered how a Jeep 2.5 would do with a turbo, thanks for helping satisfy my curiousity!

I'll be interested to see which size & A/R turbo you choose.

 

[bryson]

Cool. Better replace your engine mounts now...

 

[I Lean]

I like your resonator. What RPM is it sized for?

 

[MikeGyver]

I like your resonator. What RPM is it sized for?

Using a spectrum analyser app on my phone I found the drone obviously peak at ~80hz. This is pretty low and I would have needed a longer reson8er pipe, but that was the longest possible pipe I could have fit w/o getting really fancy and ordering new material. Honestly, I'm probably going to have to cut it off and use that 90 degree bend for the turbo, which is fine because then if necessary I can then revise the resonator after I figure out how to get a longer pipe in there.
But, the resonator probably won't even be necessary as turbos are really good at chopping up distinct exhaust pulses which cause drone.

 

[MikeGyver]

The turblo arrived today.
It's a Chinese knockoff of a Garrett GT2860RS (known to the ricers as the "Disco Potato").
After looking at a bunch of compressor maps and seeing what was available and cheap I decided to go with this. It was $209 shipped on ebay and the build quality seems to be just fine (plus you can just re-bearing it yourself for $35 as necessary and it'll literally last forever).
The exhaust housing only comes in .64 A/R, sooo that made the choice there pretty easy. I guess we'll just see how that works out. I guess 1.8L-2.0L motors spool this turbo at just over 3krpm, so my 2.5L should spin it up even sooner.

 

[Greg]

Awesome, nice turblo! I was wondering if you were going to go for something spendy... I'm glad to see the Chinese turbo!! It would be great to start building boost around 1,800 - 2k RPM! Your YJ is a 5 speed, isn't it?

 

[jmaxj]

Looks great Mike! I've always wondered how a Jeep 2.5 would do with a turbo, thanks for helping satisfy my curiousity!

I'll be interested to see which size & A/R turbo you choose.

They become fun little motors. Drove two different ones with turbos and it was a blast. Both were in YJ's

 

[MikeGyver]

Yeah it's a 5 speed. When the top and doors are off it's by far the most fun vehicle I've ever driven just railing around town, it's going to be epic with a turdblo.
I kept seriously thinking about turboing it and talking myself out of it over and over again. If that's how it's going to be forever I might as well just freaking do it already.



Didn't want to order an oil outlet fitting and wait for it, so I just made one real quick for 1/4 the price.

 

[Greg]

Well, you have my attention! Planning on bigger injectors or anything or do you think the small amount of boost won't require additional fuel?

 

[MikeGyver]

3psi won't need anything. When I go more I'll probably just use an FMU.

 

[MikeGyver]

hmm...

Made some stainlessy bits...

portage

 

[zmotorsports]

Nice. Where you have the intake duct polished, I would at least polish the carpenters level and maybe use red zip-ties to make it pop.

Seriously though, great job. Nice looking welds and very well executed. I especially like the kustom machining and welding touches but I am partial to that kind of work anyways.

Mike.