gutless wonder

[ken74amx]

Okay this weekend was the first time towing any distance with my truck. I have a 90 f350 cc dually 7.3 with a Hypermax kit on it. The turbo is the old non gated. At 70 my egt's were at 900 running 3lbs of boost. I was towing a two place sled trailer with two sleds on it and one sled in the bed. Just to pass some one it would push 1300 degrees at 5lbs of boost and it took forever! The truck runs great just seems gutless! I want more boost. Does anyone know were i can get a smaller turbine housing? Truck just needs more!!!

 

[Silver Burner]

What were your RPM's? Seems like 5lbs is really low on boost. If you're over 2000 RPM's you should be able to see 10lbs or better. You may have a boost leak which would explain why it feels so gutless, but you should definitely NOT let the EGT's go to 1300 for any length of time. Those temps are death to these motors.

 

[ken74amx]

There is no boost leaks. 5lbs of boost was running at 25-2600 rpm. In other gears I could only see a max of 6-7lbs at 3200rpm. I know the exhaust housing is to large. Hypermax was conservative on that. I only went 2 flats on the pump upon install. I don't understand the high egt's. Could I need more fuel to bring down the egt's?

 

[Silver Burner]

I'm sure some of the other guys like icanfixall and agnem will be posting about the IP, but too much fuel will increase the EGT's on a diesel, but if you start getting up over 1100 degrees, just back out of it. Keep those egt's down at 1000 or less when you're towing, or your motor won't last. These old diesels are not meant for speed. Typically towing, a guy shouldn't be running more than 60-65 depending on gears.

 

[badaceds650]

Typically towing, a guy shouldn't be running more than 60-65 depending on gears.

if i had to cruise at 60 -65 I would just go home and hang my self

 

[phazertwo]

I will let my EGTs ride at 1150 all the way up the big hills her in CO. Never had an issue. Lots of guys with the new trucks will ride 1300 of the same hills...

Anyway, I don't know much about the hypermax kit, but when my air filter gets dirty on my stock turbo, the boost will not get up where it normally does. Also look at other intake restrictions, and exhaust restrictions.

PZ

 

[icanfixall]

Are you making black smoke... Is your exhaust system still stock. What kind of intake air system do you have.. Anfd finally how old is your injection pump and injecters.... Anything over around 100,000 miles is worn out... You just can't really feel the differance in new and worn out till you change the injectors and pump...

 

[Silver Burner]

if i had to cruise at 60 -65 I would just go home and hang my self

I can run 70-75 no problem....when I'm empty. But you're really pushing the truck if you're hauling 10K+ pounds and you're going that fast down the freeway. Plus you're fuel mileage suffers a ton!

 

[badaceds650]

I can run 70-75 no problem....when I'm empty. But you're really pushing the truck if you're hauling 10K+ pounds and you're going that fast down the freeway. Plus you're fuel mileage suffers a ton!

ahh I thought you were saying to only go 60-65 all the time


I'm lucky there as my tow weight is 2k-4k and when i get my new trailer then I will be at 4k-6k so i won't have that problem. not to worried about fuel since I have endless supply of clean wmo

 

[hesutton]

Something is not right. That boost is too low and those EGT's a bit high. Tell us some more about the truck, like the things Gary (icanfixall) has asked. My guess is one or more of the follow is happening:

-exhaust leak in the turbo plumping
-restricted air intake
-starving for fuel (bad lift pump, dirty filter)
-worn IP/injectors
-significantly retarded IP timing
-restricted exhaust
-intake leaking boost pressure

Heath

 

[FordGuy100]

Maybe a little bit retarted on the timing?

You should be able to boost more at those rpms.

 

[ken74amx]

3 inch turbo back no mufflers and 5 inch stacks, cold air intake and i even ran with no filter. no diff. I can make it smoke under load but runs clean. I can hear the turbo spool but never notice a power difference. feels almost like the turbo is the restriction. The fuel system only has 15000 miles on them. The truck runs great but when you hook up to a load it is gutless.

 

[icanfixall]

Check the differancial tab... See if it says 4.10 or 3.55... A dually comes with 4.10 gears unless they are a special order for something else... Or a po replaced them for 3.55... The fuel system is on its last leggs too. Thanks for adding the information about the rig... That helps to understand whats going on.

 

[ken74amx]

It has 4.10 gears

 

[DragRag]

High egt's and low boost tells me you need more air in the system. I personally think your turbo is either wore out or you have leaks in the piping. You should be running more boost then that for sure. I have the same turbo on a super cab with 4.10's and it puts out 12lbs of boost with a blown head gasket. I would be looking at the turbo system myself considering you have the exhaust to support it and have tried the no air filter thing. I say no to the worn injection pump issue to, you can't achieve high egts without delivering a lot of fuel. Sounds like you have the fuel, and don't have the volume of air you need to burn it at the lower temps. The low boost supports my theory I believe. I will be installing my Hypermax on a 91' crew cab very soon with 4.10's and i am looking forward to the big boost that turbo puts out.