I put in the 4" exhaust and HX35...Lost Boost and low end power...
08-04-2004, 11:44 AM
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I put in the 4" exhaust and HX35...Lost Boost and low end power...
Looks like the old exhaust had taken a hit and had a severe restriction(Was down to about 1 1/2 inch at the axle...my boost went from 24# to 19# after the Turbo and Exhaust switch and I lost a little low end power but the smoke is all but gone and the EGT's went down almost 300 Degrees...I need to find someone in town who knows this pump...I'm about to go to Cummins if I can't find a decent performance shop here...The exhaust without muffler sounds great...It's been raining here so much my girl heard it from inside the house and thought I pulled up in an airboat
I'd go to Pier's but I looked on Mapquest and it said distance was 3612 Miles....Fedex said no way...
I'd go to Pier's but I looked on Mapquest and it said distance was 3612 Miles....Fedex said no way...
08-04-2004, 03:35 PM
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Chances are you have a major boost leak. When I installed my PDR HX35, I went from 22 to 29 lbs psig boost with no other mods. Check the square "o-ring" that goes between the compressor housing and the elbow that turns toward your intercooler. This was a problem spot for me.
That crimp over your axle, believe it or not, everyone of our trucks out there has (had) this. A little trick that they used to reduce the power of these engines.
Carl
That crimp over your axle, believe it or not, everyone of our trucks out there has (had) this. A little trick that they used to reduce the power of these engines.
Carl
08-04-2004, 07:38 PM
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I checked for leaks and everything looks good...**** this is frutrating I lost alot of low end power changing the compressor and exhaust...Doesn't make much sense...
08-05-2004, 06:40 AM
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Was your pump turned up prior? I'm thinking the loss in boost is from the exhaust opening up. Not so sure your getting full use of the turbo without turning the pump up , and injectors, which would be your low end loss. Usually the guys go with injecctors before upgrading the turbo, I'm just not sure your in it's range yet.
(Edit) Ok, I just noticed your sig showing EDM's.
(Edit) Ok, I just noticed your sig showing EDM's.
08-05-2004, 10:19 AM
#7
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Claw, Fill in your location, maybe someone on here is near you??
Turning up the pump isn't that hard and you can do most of the research here without even asking a question.
Loosing boost doesn't sound like a big problem right now for you as when you reduce the exhaust back pressure with the exhaust and install a more high flow turbo, you are getting more efficient. The reduced smoke tells me you are burning the fuel better ie, better air flow. I think some adjustment to the AFC starwheel and the aneroid (zero boost) screw on the top, you could recover alot of your low end lag. Also turning the pin to the full fuel ramp would probably set you in the seat.
J-eh
Turning up the pump isn't that hard and you can do most of the research here without even asking a question.
Loosing boost doesn't sound like a big problem right now for you as when you reduce the exhaust back pressure with the exhaust and install a more high flow turbo, you are getting more efficient. The reduced smoke tells me you are burning the fuel better ie, better air flow. I think some adjustment to the AFC starwheel and the aneroid (zero boost) screw on the top, you could recover alot of your low end lag. Also turning the pin to the full fuel ramp would probably set you in the seat.
J-eh
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08-05-2004, 01:54 PM
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Thanks I think you're right...PDR is emailing me some hints as well to get the pump adjusted, since the 2 "Pros" here don't have a clue....I'm in Miami so I think the closest is too far...Is the zero boost screw also the smoke screw? They also recommended turning up the timing...
08-05-2004, 05:16 PM
#9
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Originally posted by ClawHammer
Is the zero boost screw also the smoke screw? They
Is the zero boost screw also the smoke screw? They
08-05-2004, 05:17 PM
#10
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There are many names for that screw. Yes its also the "Smoke" screw even though its only the smoke off of the bat without any boost. It basically gives the engine more fuel (pushes the tapered pin down) at no boost to help the launch.
After you get the off the line stuff where you want it, then the AFC starwheel adjustment will help with the boost vs fuel as you go up the load/rpm ladder.
Turning the taper on the pin to full depth helps with how aggressive the fueling is vs boost. The Tech articles here have some good info the VE pump as well as some diagrams of the internal components. Take a paroose. Lots of guys here to help out too.
Come on Bushy, where are ya??
After you get the off the line stuff where you want it, then the AFC starwheel adjustment will help with the boost vs fuel as you go up the load/rpm ladder.
Turning the taper on the pin to full depth helps with how aggressive the fueling is vs boost. The Tech articles here have some good info the VE pump as well as some diagrams of the internal components. Take a paroose. Lots of guys here to help out too.
Come on Bushy, where are ya??
08-06-2004, 12:52 AM
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HuH.... OH that's me..... sorry I was snoozin.....
The drop in EGT's will have an effect on your boost numbers. Your new '35 is able to move more air and move it sooner... this will be seen in your EGT numbers...
A drop in boost is NOT a bad thing....
It's still hard to get your head around the fact that you only need enough boost to burn the fuel you are supplying and, no more. That is the ideal combination of boost-to-fuel ratio.
Your stock turbo had an efficiency range of approx. 26'ish psi. Beyond that it quickly became less and less efficient. The higher the boost goes beyond that point the more back pressure (drive pressure) you will see. This in turn will raise EGT's, tend to overspool the turbo and it begins to "feed on itself" in a downward spiral of diminishing returns....
The overall boost loss is a bit much though. I'd take another good look at all your rubber boots. Pull them off, roll them between your fingers like yer rolling a smoke.
Look for any signs of cracks; similar to dry rot cracking. Look real closely at those boots.
You may find that there are some weaknesses that will perhaps explain some of the boost drop.
Next thing I'd check is the guide pin. Pull the AFC cone out, and look down at the guide pin area when you cycle the throttle. It should pop out crisply from it's hole.
If it sticks you may be seeing lower boost due to it's improperly functioning.
Advancing the timing will, to some degree, "soften" the low end response but it won't be a huge difference except in the case of extreme timing advance.
Check that pin for crisp function and repair as needed.
What are you governed at right now? Have you raised the governed speed at all?
Go over some of those things and report back your results.
pastor bob.... aka: Bushy.
The drop in EGT's will have an effect on your boost numbers. Your new '35 is able to move more air and move it sooner... this will be seen in your EGT numbers...
A drop in boost is NOT a bad thing....
It's still hard to get your head around the fact that you only need enough boost to burn the fuel you are supplying and, no more. That is the ideal combination of boost-to-fuel ratio.
Your stock turbo had an efficiency range of approx. 26'ish psi. Beyond that it quickly became less and less efficient. The higher the boost goes beyond that point the more back pressure (drive pressure) you will see. This in turn will raise EGT's, tend to overspool the turbo and it begins to "feed on itself" in a downward spiral of diminishing returns....
The overall boost loss is a bit much though. I'd take another good look at all your rubber boots. Pull them off, roll them between your fingers like yer rolling a smoke.
Look for any signs of cracks; similar to dry rot cracking. Look real closely at those boots.
You may find that there are some weaknesses that will perhaps explain some of the boost drop.
Next thing I'd check is the guide pin. Pull the AFC cone out, and look down at the guide pin area when you cycle the throttle. It should pop out crisply from it's hole.
If it sticks you may be seeing lower boost due to it's improperly functioning.
Advancing the timing will, to some degree, "soften" the low end response but it won't be a huge difference except in the case of extreme timing advance.
Check that pin for crisp function and repair as needed.
What are you governed at right now? Have you raised the governed speed at all?
Go over some of those things and report back your results.
pastor bob.... aka: Bushy.
08-06-2004, 05:58 AM
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Boost Boots?
....I've 100K miles on my rig, and the boots are looking / feeling a bit soft; Where's the best place to order / purchase them? (I thought the question was appropriate to this post as the originator may need to find some too) -
Thx / Rauschbo
Thx / Rauschbo
08-06-2004, 07:11 AM
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Check the links, such as Piers. They've had them on special at times too. I bought turbo hose at Napa, they had to order in the whole 4' length and cut to size. Took a couple trips to get the right size. It's measured by inside diameter and mine was a bit stretched and worn. Your local Napa, might have had more experience with turbo's than mine. The first guy wanted me to by the bulk, but the older guy said they would cut it. The part #'s should be on them, but Cummins wouldn't have been able to get them for 2 weeks and wanted a lot for them. Dodge said they might be able to get it, but theirs must've been made of platinum.
08-06-2004, 07:20 AM
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Hi Claw!
Sorry ive been away with company from AU. Time to get the baby powder out. Put it on all your joints of your high pressure intake system. If you have lost boost, im sure you have a leak somewhere. My hx35 put out more boost all over the place, low and top end. The powder will tell. Since you cant build any boost without a load on the engine, revving the engine wont show you any air bypass unless youre under the hood while shooting down the road. The powder will blow all over when the leak is realized.Check the intercooler also. Glad to see your smoke has gone, makes me feel as though you have a minor leak that is eventually overcome by the sheer volume of air that the hx35 is possible of. Youre on the brink of sucess with this thing and i dont want any ricers to get the jump on ya!
-Jim-
Sorry ive been away with company from AU. Time to get the baby powder out. Put it on all your joints of your high pressure intake system. If you have lost boost, im sure you have a leak somewhere. My hx35 put out more boost all over the place, low and top end. The powder will tell. Since you cant build any boost without a load on the engine, revving the engine wont show you any air bypass unless youre under the hood while shooting down the road. The powder will blow all over when the leak is realized.Check the intercooler also. Glad to see your smoke has gone, makes me feel as though you have a minor leak that is eventually overcome by the sheer volume of air that the hx35 is possible of. Youre on the brink of sucess with this thing and i dont want any ricers to get the jump on ya!
-Jim-
