Wastegate really needed

[MStaggs]

A shop I work with has developed a new ball bearing turbo for the 5. 9 engine.

They are running NO wastegate on the test truck and she makes exactly 39 pounds of boost - thats it.

They are also running an Edge Juice module. No other modifications have been made to the truck and I can tell you first hand that it runs REALLY well!

I am considering having one built for my truck but am wondering if running no wastegate could present any problems.

They have seen a max of 1300 degrees EGT pulling a boat with their foot to the floor. That might be a little high for my taste but maybe an Alky injection would fix that right up.

Thoughts?

 

[cerberusiam]

Waste gates are an emission item,we have run the snot out of the 1st gens with big housings and no WG long before any of the newer turbos came along.



If you can keep the EGT's and drive pressure in check there is no down side to not having a WG.

 

[fox]

The wastegate prevents turbo overspeeding. It also lowers drive pressure, which is a factor in blown head gaskets.

By designing the turbo with a wastegate you can use a smaller housing to get quicker spool-up.

 

[Bob4x4]

If the turbo is sized correctly for your set up you will be fine with out a gate.

If you are worried about it just add an external w/g



Bob

 

[MStaggs]

The wastegate prevents turbo overspeeding. It also lowers drive pressure, which is a factor in blown head gaskets.

By designing the turbo with a wastegate you can use a smaller housing to get quicker spool-up.

I know what a wastegate does. My question was more realted to anything else going on with the truck (sensors, computer, etc) that may not like not having the gate.



Smaller housings DO allow quicker spool-up for sure, at the expense of back pressure. Larger housings allow more flow and lower EGT's. There is a balancing act going on to get one sized "perfectly" and I am fully aware of that.

 

[cerberusiam]

I know what a wastegate does. My question was more realted to anything else going on with the truck (sensors, computer, etc) that may not like not having the gate.

On an 04 you should be fine, no WG controls to worry about. Even the later trucks with an electronic WG control can be fooled with a resistor.

 

[MStaggs]

On an 04 you should be fine, no WG controls to worry about. Even the later trucks with an electronic WG control can be fooled with a resistor.

Great Oo.

 

[fox]

Do you have enough fuel to spin it to 39 lbs boost?

How does that compare to the stock turbo?

 

[AH64ID]

I have seen 37 psi on my stock turbo with stock fueling... Which is why I am converting my electrical WG to a mechanical one.

 

[MStaggs]

How does that compare to the stock turbo?

Its quite a bit bigger and MUCH more responsive.

these turbos have a tripple ball bearing cartride and they are a little "loud". :-laf

 

[nickleinonen]

how is that 39 psi being read? mechanical gauge or off the stock ecm boost sendor?

 

[Turbo_Bob]

They are running NO wastegate on the test truck and she makes exactly 39 pounds of boost

They are also running an Edge Juice module. No other modifications have been made to the truck

They have seen a max of 1300 degrees EGT pulling a boat with their foot to the floor.

I guess the Edge is boosting up the fuel rail pressure for the increase boost.



As long as you do not run out of fuel flow at the higher boost and the EGT stays below 1300 F (before turbo) should be fine.



Is that 1300F measured before the turbo or after the turbo ?



Your truck, CA 235 makes around 19 PSI boost ?

 

[MStaggs]

how is that 39 psi being read? mechanical gauge or off the stock ecm boost sendor?

The Edge display.

 

[MStaggs]

Is that 1300F measured before the turbo or after the turbo ?



Your truck, CA 235 makes around 19 PSI boost ?

Measured before the turbo.



My truck made 21 PSI stock.

 

[Forrest Nearing]

The wastegate prevents turbo overspeeding. It also lowers drive pressure, which is a factor in blown head gaskets.

The wastegate prevents turbo overspeeding. It also lowers boost, which is a factor in blown head gaskets.



Drive pressure DOES NOT blow head gaskets!!!!!!!



if you're only seeing 39psi, you're probably just at the limit of the factory MAP sensor which is where the Edge gets its reading (IIRC)



I bet you're over that, but I bet it's not hurting anything. You want to shoot for a 1:1 drive:boost relationship to free up horsepower and prevent thrusting the turbo.

 

[MStaggs]

Well, the turbo development continues.



The truck is an 06 4x4, has an intake and an Edge Juice with Attitude - that is all.

The tires are 33"



After another day at the chassis dyno, here are the results (boost was read and datalogged by the dyno via direct connection to intake).



Max EGT's (pre-turbo) was 1340 on setting #6.

All others were below 1300 degrees.



Set on stock

Max HP was 312. 7 at 2,914 RPM with 27. 3 PSI

Max Tq was 566. 5 at 2,790 RPM with 26. 9 PSI



Set on #1

Max HP was 359. 2 at 2,935 RPM with 30. 8 PSI

Max Tq was 650. 5 at 2,805 RPM with 30. 3 PSI



Set on #2

Max HP was 368. 3 at 2,902 RPM with 30. 5 PSI

Max Tq was 676. 9 at 2,771 RPM with 30. 2 PSI



Set on #3

Max HP was 388. 3 at 2,927 RPM with 31. 4 PSI

Max Tq was 738. 4 at 2,551 RPM with 29. 7 PSI



Set on #4

Max HP was 415. 8 at 2,927 RPM with 32. 5 PSI

Max Tq was 773. 9 at 2,737 RPM with 32. 4 PSI



Set on #5

Max HP was 393. 6 at 2,930 RPM with 31. 4 PSI

Max Tq was 791. 6 at 2,494 RPM with 30. 5 PSI



Set on #6

Max HP was 486. 3 at 2,857 RPM with 36. 8 PSI

Max Tq was 927. 6 at 2,737 RPM with 36. 6 PSI



Interesting drop in HP on setting #5 yet Tq still rose a bit.

Setting #6 was amazing!

 

[Forrest Nearing]

what turbo are you using? I'm going to be running a Turbonetics 66mm

 

[MStaggs]

what turbo are you using? I'm going to be running a Turbonetics 66mm

It is a custom tripple ceramic ball bearing unit currently in development.



Compressor is similar to a Garrett GT40, Turbine wheel is a custom SX - that is all I can say. The housing has a T3 bolt pattern.