aaz turbo option

[Gizmoman]

Right now I have the actuator blocked off. I just disconeccted the vacume line. Makes a bit more boost but only 2-3 psi more. Today it seems like I have a boost leak so I'm going to look into that. It is running really rough at idle so I also need to look into that.

Boost can push the gate open even against the raw spring pressure of the pot (even with the hose disconnected). Try using bailing wire to make sure it stays closed.

[Big Daddy Roth]

I'm just wondering if anyone has this turbo mounted up to a trapazoidal flange? Pics?

If I mount mine like that my cold side hits my PD intake.

[RabbitJockey]

schnell snail performance makes an adapter to run a t25 flange turbo on a ahu/1z manifold

[Big Daddy Roth]

How much pre-tention do I put on the waste gate?

[Gizmoman]

How much pre-tention do I put on the waste gate?

Knowing what turbo you have might help as there are a few experts here (I am not one). As I had to re configure the one on my brand new HE 200 to get the drain clocked at 6:00, I made a simple gauge to measure the stick-out of the pot rod before I took it apart. Once I had the new lash-up built, I just adjusted it to the same length.

Otherwise, trial and error and a boost gauge will get you close. From my limited experience, it's more than you may think. I am currently running with mine wired shut and have never hit more than 22 psi. I also have the boost hose to the pot disconnected/plugged. The hose from the turbo compressor just goes to the gauge.

[jmaddocks]

I'm just wondering if anyone has this turbo mounted up to a trapazoidal flange? Pics?

If I mount mine like that my cold side hits my PD intake.

I originally looked into mounting our HE200WG with the OEM trapezoidal manifold.  The turbo and G60 intake manifold were trying to occupy the same space with the exhaust manifold upright.  Flipping the manifold over caused interference problems between the turbo and rear engine mount.  We ended up going with a generic 8V turbo manifold with T25 flange.

How much pre-tention do I put on the waste gate?

You need a buttload of pretension.  I just realized a couple of weeks ago that we needed more tension on ours, so I tightened the knurled wheel adjuster as far as I could by hand.  With the actuator disconnected (c-clip removed), there's probably a 1/4 inch gap between the diaphragm rod and the wastegate actuator arm, such that it would be impossible to connect the two back together (i.e., to install the c-clip) by hand. 

Between adjusting the wastegate actuator and fixing a pretty big leak in our intake manifold gasket yesterday afternoon, our boost is way up and EGTs are way down.  My son hit 31.8 psi last night at 1/2 throttle with EGT below 1000 deg F.  He was going to build up to full throttle on the way to school this morning.  I didn't get any phone calls, so it must not have blown up.   

[Selle]

I'm just wondering if anyone has this turbo mounted up to a trapazoidal flange? Pics?

If I mount mine like that my cold side hits my PD intake.

I'm not quite sure what you mean by trapazoidal flange, but on my car we just welded a t25 flange on top



This is on a ARG engine (ALH but with stock wastgate turbo). I adjusted my pre-tention yesterday. Now I hit 1.7 bar @ 2600 rpm, but it overboost now, so I might have overdone it a bit

[jmaddocks]

My son said he's hitting (and holding) about 32 psi at full throttle.  Max EGT is around 1100 deg F.  I might try adding a bit more preload on the wastegate, but I don't want to push our luck with OEM stretch bolts and fiber HG.  Needless to say, we're extremely happy w/ the Holset -- the car is a blast to drive.  I'm thinking about replacing the T3/T04e on my Corrado w/ an HX35 or HE3xx series.

[vanbcguy]

If anything you can probably get better performance by reducing the boost a little given your low EGT numbers. You've got more air than you need right now. Knock it down to say 28 PSI and I bet your EGTs will barely be over 1250 but you'll reduce the back pressure on your engine.

[Alcaid]

Needless to say, we're extremely happy w/ the Holset -- the car is a blast to drive.  I'm thinking about replacing the T3/T04e on my Corrado w/ an HX35 or HE3xx series.

Good to see that you are happy Jason

I like your idea of getting rid of the acient T3/T04e and replacing it with a Holset, funny thing is the bigger ones are priced close to the small HE200/211 ones. On E85 a HX35 can give you a ***load of whp!

[jmaddocks]

I like your idea of getting rid of the acient T3/T04e and replacing it with a Holset, funny thing is the bigger ones are priced close to the small HE200/211 ones. On E85 a HX35 can give you a ***load of whp!

Yeah, I'm happy with the top end performance of my ancient Garrett, but it takes forever to spool...especially at our elevation (about 2000m).

[Big Daddy Roth]

I used a T25 manifold instead.

[jmaddocks]

If anything you can probably get better performance by reducing the boost a little given your low EGT numbers. You've got more air than you need right now. Knock it down to say 28 PSI and I bet your EGTs will barely be over 1250 but you'll reduce the back pressure on your engine.

Yeah, that's about where our EGT was when we were troubleshooting a boost leak and running about 29 psi. 

By your recommendation to reduce boost to get better performance, I assume you believe we're losing efficiency at that pressure ratio.  Based on our elevation and boost, our pressure ratio is really high -- about 3.75-3.8 -- which is at the upper limit of the HE200 compressor maps I've seen.  You might be right.

I'm thinking an upgrade to larger valves (or an AAZ head) is our next step.  Honestly, this car runs so well, I don't think that's going to happen anytime soon.

[jmaddocks]

I used a T25 manifold instead.

Looks great!  You have a lot more space with that intake manifold.  The middle bolts on my G60 manifold are nearly impossible to access with the turbo mounted.

[vanbcguy]

If anything you can probably get better performance by reducing the boost a little given your low EGT numbers. You've got more air than you need right now. Knock it down to say 28 PSI and I bet your EGTs will barely be over 1250 but you'll reduce the back pressure on your engine.

Yeah, that's about where our EGT was when we were troubleshooting a boost leak and running about 29 psi. 

By your recommendation to reduce boost to get better performance, I assume you believe we're losing efficiency at that pressure ratio.  Based on our elevation and boost, our pressure ratio is really high -- about 3.75-3.8 -- which is at the upper limit of the HE200 compressor maps I've seen.  You might be right.

I'm thinking an upgrade to larger valves (or an AAZ head) is our next step.  Honestly, this car runs so well, I don't think that's going to happen anytime soon.

Efficiency is one thing, but don't forget the turbine side is a restriction. Allowing more exhaust to bypass the turbine (therefore slightly reducing intake pressure) lets the engine pump out exhaust more easily. Really you want the minimum amount of boost to completely burn all your fuel and keep things cool. More boost doesn't necessarily result in more power.