[Mikel]

Hello,
I've been trying to fit a HY35 turbo in my J300, but I keep hitting the heater box (which I REALLY want to keep). Looks like I can remove the external wastegate mechanism and bolt the turbo to my GM exhaust manifold and that it should fit.
I was hoping to achieve about 150HP for a reliable daily driver and I'm not sure if at that power level a wastegate would be necessary. Any thoughts?
Thanks,
Mikel

 

[BobS]

The wastegate functions as an overflow valve through the exhaust side of the turbo. It gives you better spool up at low speeds and artificially increases the turbo outlet side by releasing gases that would otherwise just generate heat. It actually gives you the best of both worlds to a certain degree. The best indicator would be by monitoring your exhaust gas temperature as you increase your fueling.

Would doing a manifold flip help your situation?

 

[Mikel]

Would doing a manifold flip help your situation?

I have no room. I mounted the engine as low as possible to avoid having to lift the body, for a number of reasons.

Perhaps I can relocate the wastegate actuator out of the way. It can't be THAT difficult...

Thanks,
Mikel

 

[CrewCab59]

I want to see some pics of your set up !!

 

[Mikel]

This is all I have.

This is a spacer I made to clear the wastegate actuator, but unfortunately I over-estimated the distance to the heater box... DUH! I don't think I have enough space to build a header either. Like I said, I think relocating the actuator is my best bet right now.

 

[CrewCab59]

Can you take a front view of the truck so I can see the turbow and heater box .

I might have a few idea for you after I see the the pics.

Those engine mounts looks like somone else :dustin: :dustin:

 

[Mikel]

Hello,
I found this one.
Thanks,
Mikel

 

[mooktank]

Wastegate = Not needed

The only way you'd need it is if you were overboosting. I can't get mine to get past 25psi with the wastegate welded shut. Take that bitch off!

 

[Dougal]

As Bobs said. A wastegate can let you run a smaller (faster spooling) turbo without choking or overboosting at higher rpm.

On the 4BT high rpm isn't a problem and most people seem very happy with their non wastegated turbo.
On a higher revving engine, it's needed.

 

[mooktank]

As Bobs said. A wastegate can let you run a smaller (faster spooling) turbo without choking or overboosting at higher rpm.

On the 4BT high rpm isn't a problem and most people seem very happy with their non wastegated turbo.
On a higher revving engine, it's needed.

I run a 9cm housing which is just about as small as you can go with the Holsets if I'm not mistaken. I have zero EGT or overboost issues. My wastegate wouldn't fit anyways.

 

[Mikel]

I'm tempted to temporarily disable the wastegate, so I can get the truck on the road, and save the wastegate actuator in case I run into overboost issues. Thank you guys.

 

[High Pressure]

In the future you might want to consider an HX25/27 (HE221) wastegated turbo. It would require a different exhaust manifold or an adapter plate. Many have a 6cm turbine housing....there are several versions that are manufactured. This turbo is used on the current ISBe 4.5 liter (newer version of the 4bt).

 

[57 napco]

Weld it shut. Unless you have a overfueled P-pump motor, you will not make over 30psi.

 

[toolmanoffroad]

I dont have a p-pump, and I made 55lbs.:rasta: ..I will be puting the WG back on mine befor I spew the guts out of it. Unless yours is turned all the way up with some big injectors hes right you wont see an over boost issue. You can make a adjustable bracket to hold the gate shut, just in case you want to run it later, or sell it to someone else that might want it with one. My2 cents Good luck man.

 

[tndonor]

Mikel,
I had the same problem. I took the wastegate off and made a J hook to keep it closed. No problems whatsoever

 

[Mikel]

What is the maximum horsepower I could get out of my VE pump 4BT with an HY35 and a Volvo intercooler before a wastegate is needed?
Thank you all.
Mikel

 

[Dougal]

Does anyone have the max exhaust pressure spec for a 4BT?

There must be a certain backpressure which will cause problems keeping the exhaust valves shut.

 

[Machman]

Does anyone have the max exhaust pressure spec for a 4BT?

There must be a certain backpressure which will cause problems keeping the exhaust valves shut.

Looking at the info about exhaust brakes, 35PSI might be the "don't exceed" answer:

http://www.usgear.cc/images/exbadv1.gif

http://pacbrake.com/PDF/Sales_images/web_brochures/L5049_cummins_lowres.pdf

 

[Dougal]

Looking at the info about exhaust brakes, 35PSI might be the "don't exceed" answer:

http://www.usgear.cc/images/exbadv1.gif

http://pacbrake.com/PDF/Sales_images/web_brochures/L5049_cummins_lowres.pdf

A year or so back, I ran a backpressure gauge. It was showing pretty much dead on twice the boost, 15psi boost was 30psi backpressure.
This is on my Isuzu.

So you guys must be pushing way beyond that. But it does it cause any problems?

 

[toolmanoffroad]

I was talking to some guys at the last event about drive pressures. The way I was taking it, it is more of a problem than most guys think. It seemed that what they were saying is that you can still make a certain boost number (lets say 40) and have close to a 1 to 1 ratio...boost/drive pressure just by using a wastegate, or blowoff valves to release the stacked up pressure that is more than what is needed to make the 40 psi and keeping the comp wheels from breaking off.

I am still not totaly awake, so I had better stop there before I spew anything about the dream I had last night... chime in again when I am more awake.. :rasta: