Stock turbo mods

[DougsfastZ]

I took my stock turbo off in order to get the exhaust housing off so I can port the wastegate hole. Is there anything else I can do to the turbo assembly to make the car run stronger while I have it all apart?

Thanks,

Doug D

 

[UNGN]

Match the compressor housing to the inlet bell, polish the inside of the bell.

Don't go crazy on the wastegate hole. Radius the inside without opening it up too much will give you all the boost control you'll ever need and you'll still be able to use the stock puck.

 

[Blaze]

You could also try this http://members.cox.net/stevemonroe/turbo_services.htm

 

[DougsfastZ]

I'm running an ATR DP (THDP style) and the puck is 1.5". The puck though is not centered with stock hole so I was going to make it larger so there is an 1/8" lip. What do you mean "radius the inside"?

Thanks,

Doug D

 

[turbo2nr]

Fill holes inside the compressor housing where the cover bolts on. Should be one or two exposed holes. I use JB weld, and put a release agent on the tip of bolt. Fill bottom of hole with JB, lube up the tip of bolt, assemble turbo before the JB sets. Disassemble turbo and clean up job. Grind out rough crap from sand casting the aluminum housing. Bell mouth the nozzle. Grind boost refernce port flush with housing (brass thing).

If any bolts intrude into the housing chamber, grind away the threads.

 

[UNGN]

I'm running an ATR DP (THDP style) and the puck is 1.5". The puck though is not centered with stock hole so I was going to make it larger so there is an 1/8" lip. What do you mean "radius the inside"?

Thanks,

Doug D

Radius the inside of the hole means just that. If the wastegate hole has square edges where it meets the inside (flow path) of turbine housing, put a sweeping radius on it. A properly radiused hole will flow nearly double what a square edge hole will flow.

I personally would not screw up a Stock turbo Turbine housing by boring it out to THDP puck size for the following reasons:

1.) There is no need to.
2.) The turbo will be worthless to anyone without a THDP style DP or Big puck elbow
3.) Garrett housings aren't made anymore.

 

[DougsfastZ]

All the research I've done about boost spiking and creeping tells me I need to open the wastegate hole. Since I installed the ATR DP boost spikes to 20 when I step on it, then settles to 17 but will slowly creep to 18 in 3rd. Something about more air needs to be moved in the wastegate hole to hold proper boost.

Am I missing something here?

Doug D

 

[bison]

All the research I've done about boost spiking and creeping tells me I need to open the wastegate hole. Since I installed the ATR DP boost spikes to 20 when I step on it, then settles to 17 but will slowly creep to 18 in 3rd. Something about more air needs to be moved in the wastegate hole to hold proper boost.

Am I missing something here?

Doug D

Go ahead and open the hole up. If you ever needed a stock exhaust housing that wasnt opened up they are cheap. Make sure your wastegate hoses are new and there are no boost leaks in the pressure circuit that goes to the solenoid. Put on meth injection so you can run 25psi all the time

 

[DougsfastZ]

Go ahead and open the hole up. If you ever needed a stock exhaust housing that wasnt opened up they are cheap. Make sure your wastegate hoses are new and there are no boost leaks in the pressure circuit that goes to the solenoid. Put on meth injection so you can run 25psi all the time

The first thing I did to try and stop boost spike was an RJC racing boost controller. Alky will be one day.

Doug D

 

[bison]

The first thing I did to try and stop boost spike was an RJC racing boost controller. Alky will be one day.

Doug D

Then opening the hole will solve your probs in high gear (creeping). If it overboosts (spikes) when you first step on it then i would suspect the chip is having some kind of effect on it, and bleeding off too much pressure. It may be designed for a more restricive exhaust setup than you have and may be spiking a little with the free flowing exhaust.

 

[UNGN]

All the research I've done about boost spiking and creeping tells me I need to open the wastegate hole. Since I installed the ATR DP boost spikes to 20 when I step on it, then settles to 17 but will slowly creep to 18 in 3rd. Something about more air needs to be moved in the wastegate hole to hold proper boost.

Am I missing something here?

Doug D

Opening the hole won't help the spike at all. That's the chip or the notorious ATR sticky puck.

If you only have 1 psi of creep, radius the hole. That is like nothing and doesn't require doubling the the area of the hole.

Note also that opening the hole will mean you'll need to increase the tension on your wastegate rod to compensate for the increased force on the puck.

If anyone was suckered into buying a "high boost actuator" because the ATR catalog told them they needed one, they can go ahead and hog out the hole. Everyone else, it's not needed.

 

[DougsfastZ]

Well I opened the hole a bit, to .875", still left i hair over 1/8" around the marking from the stock puck. The stock puck should still work fine (if it was ever put back on the car). The radius was cleaned up like UN said to do. I think the best thing I did was smooth out that big bump from the inlet bell to the compressor housing, which was much bigger then I thought it would be.

Interesting thoughts on the boost spike issue. I have an extender chip with the MAF translator plus (used with the LS1 MAF). Is there anything I can change in the extender chip to get rid of boost spike?

Thanks guys,

Doug D

 

[DougsfastZ]

Now that I think about it, there is no way for the chip to cause this since I am using a ball spring boost controller. I wonder if it has to do with the length of my wastegate rod?

Doug D

 

[turbo2nr]

The longer the rod, the better (that's what my wife says.)



Is your factory boost solonoid still hooked up and bleeding off air? Well, then your chip is still doing something.

 

[bison]

Now that I think about it, there is no way for the chip to cause this since I am using a ball spring boost controller. I wonder if it has to do with the length of my wastegate rod?

Doug D

Bypass all your boost controls and go directly to the boost sensing port on the actuator from the pressure port on the housing. Start shortening the rod and see if the spiking goes away. If you shorten the rod too much you will get boost creep in high gear. If this corrects the problem then you have a leak or too much volume in your boost controller hose set up. You may want to try and use a smaller id hose to and from the controller to increase the signal speed to the actuator.

 

[turbo2nr]

That is called "tuner style" boost control. Probably end up with very low boost unless you have a HD actuator. Some air needs to be bled even with the weak OEM actuator

 

[bison]

That is called "tuner style" boost control. Probably end up with very low boost unless you have a HD actuator. Some air needs to be bled even with the weak OEM actuator

Yes, but it will help to see if the boost controller and hoses are causing the spike. This is only a temporary test. It is possible the swing arm assembly is binding and this will eliminate the boost controller and point towards the swing arm.

 

[turbo2nr]

(Edit, sorry)

 

[DougsfastZ]

Just took the car for a ride. I lengthened the wastegate rod 1.5 turns so that I only have to pull it out 1/8" to get it on the puck arm. Boost spike is even worse. It spikes to 19 in first then settles to 15, but now when it shifts into second it falls to 14 then creeps back up to 15 and holds steady. I'm at a loss.

As for the boost controller, the way I have it set up is the RJC controller running straight from wastegate to the compressor, with the valve in the middle of course. The stock boost solenoid is disconnected vacuum wise, but is still hooked up electical wise.

Thanks guys,

Doug D

 

[turbo2nr]

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