Engine/Transmission (1994 - 1998) Boost to high w/ wastegate full open ???

[JO'Leary]

Anyone run into this problem????

It's not real bad, but enough to concern me. I am trying to keep the boost around 38 psi. The best i can do is 42 psi. I have adjusted the wastegate arm so loose it is ready to fall off, no change. Today i checked the wastegate with a small regulator and shop air. The gate starts to open at 22 psi and is full open at 35 psi. Makes no sense. The only thing odd on the truck is that i am running two mufflers. A 24" X 8" straight through off the down pipe into a 48" X 9" Rokktech muffler.

This turbo is based off a Holeset 40, it's built for DDP with there own flavor of wheels.



Joe

 

[Matthug]

42 PSI is no problem with an HX40, it will run that all day long. It's not overspinning.

 

[JO'Leary]

Thanks for the reply Matt, i have noticed your a fan of the 40 .

The worry is that we are not able to controll the boost. I should be able to turn it down to 32psi if i want. Lenny is all over this one too, he has me checking some things out. Just wanted some of the TDR Turbo guru's opinion.

This one has a sweet spot at 38 psi and starts making heat above 40. Didnt catch all that Lenny told me about the wheels but it was purpose built to move alot of air at lower pressure for towing. I have not had any surge and it's almost impossible to bark.

Now that i think back i also had boost controll issues with the stock turbo before i removed it. I kept backing off the allen screw and nothing happened, i just figured that i had damaged the seat on the boost elbow when i had it bottomed out back in the almost stock days.

It's hard to believe i am throwing that much fuel at it.

It's a mystery, i never have normal problems

Well at least the Larry B HD contacts and brushes went good.



Sorry for rambling on



Joe

 

[Matthug]

Well it's just it has a bad reputation as a regular 40 to blow up, but any that have been modded are fine. I suspect it's the 14 housing thats causing the problems, I'd say switch to a 16 but the wheel probably isn't stock HX40.

 

[Bob4x4]

Enlarge the wg opening and gate flap if you are sure it is opening correctly.



Bob

 

[JO'Leary]

Enlarge the wg opening and gate flap if you are sure it is opening correctly.



Bob

That is what Lenny (DDP) wants to do after i verify a few things. They usually don't need to do this unless the pump has been modded. Mine appears to be a stock 180 pump, i am still looking for the tag on the pump.



Even though it is opening with my bench test i still would like to veryfy it's full open when driving. I may wire it open and see if there is any change.

Any other ideas on verifying this. I am also checking backpressure.

Keep em cummin



Joe

 

[JO'Leary]

No one wants to touch this one today Oh well, it's not an emergency, i will check a few things on it this weekend.

 

[JO'Leary]

Enlarge the wg opening and gate flap if you are sure it is opening correctly.



Bob

Looks like you may be right, this weekend i wired the wastegate open and still ran 42 psi. The HX-40's must have a small WG opening.

I still have a hard time believing that i am moving that much fuel with a #10 plate and stock pump. How do the guys that run #0 plates keep there boost in check????

 

[Bob4x4]

Looks like you may be right, this weekend i wired the wastegate open and still ran 42 psi. The HX-40's must have a small WG opening.

I still have a hard time believing that i am moving that much fuel with a #10 plate and stock pump. How do the guys that run #0 plates keep there boost in check????

We don't :-laf



Bob

 

[Matthug]

It says in your sig that you have the 14cm housing right? If so thats your problem, 95% of people running an HX40 run the 16CM housing. My bro has 400 RWHP in his 02' ETH and has the wastegate plugged, his gets to 38 PSI. He'll soon be putting in a TST Competition box so he'll have the enable the wastegate then because thats another 100 HP.

 

[JO'Leary]

Bob, it must be nice to let your boost run wild



Matt

I think you nailed it, i didn't realize most are running 16cm on 40's. It's starting to make sense now. Thanks for your input.

I did buy this turbo to tow heavy with and it does do that very well.

Speaking of towing, No more testing,tweaking and adjusting, she has 32ft of fiver hooked behind it and i am going on vacation next week to do absolutly nothing.

but as soon as the trailer comes off i'll be back at it.

 

[JO'Leary]

I am back after pulling 11K all over Michigan. No more complaning about 42 psi of boost, I love this turbo, it pulls awesome. no surge and not one bark. My temps are down big time at 55 mph. I used to have to down shift to 3rd to keep the temps below 1250F, now i am at 1050F in overdrive at 1500 rpm's pulling 11K. Thanks again to Lenny and Ross @ Dynomite Diesel.



Joe