Engine/Transmission (1994 - 1998) HX40 - What Boost?

[Buck88]

I recently got my hands on a used Piers 40. First off, I didn't know how laggy these turbos are. The boost gauge got real lazy. Cruising at 55mph, light throttle I'm only registering 2 psi It takes a lot of throttle and HEAVY smoking to get some boost. Maybe its just me going to a HX40 from a 35, but is that normal?



My second issue is I'm only seeing about 26 psi out of the thing. What boost is appropriate for this turbo and how do I adjust it?

 

[SEmerson]

Sound like mine. Very laggy and smoky. I do gate at 45 psi though.

 

[Swamp Donkey]

I had my PDR HX40 installed @ PDR. The set it up for 38 psi boost. I have never touched it since. This was 4 years ago. The 2 psi of boost sounds about right cruising. I am not sure how to adjust wastegate.

 

[Highfinance97]

I wouldnt go over 40 or 45, Check out the video in my sig.





Michael

 

[Buck88]

Well, driving to work this morning I noticed a weird noise. Popped the hood, and sure enough there is an exhaust leak between the manifold and the turbo. It seems that its easier to peg the pyro with this turbo. Is that because the leak or the low peak boost?

 

[Graphic man]

Well, driving to work this morning I noticed a weird noise. Popped the hood, and sure enough there is an exhaust leak between the manifold and the turbo. It seems that its easier to peg the pyro with this turbo. Is that because the leak or the low peak boost?

the low boost will give you high EGT's... ... put a boost fooler on it and you'll see 45PSI with the right amount of fuel





Scott

 

[SEmerson]

the low boost will give you high EGT's... ... put a boost fooler on it and you'll see 45PSI with the right amount of fuel





Scott

Ona PDR 40 you can adjust the gate easy. No need for a fooler.

 

[Buck88]

Ona PDR 40 you can adjust the gate easy. No need for a fooler.

How do you adjust it though?

 

[SEmerson]

you turn the shaft on the actuator rod.

 

[JWestley]

the 40 on my truck will hit about 40psi, and it is a bit laggy, but once it starts going it does pretty good

 

[pwerwagn]

Well, driving to work this morning I noticed a weird noise. Popped the hood, and sure enough there is an exhaust leak between the manifold and the turbo. It seems that its easier to peg the pyro with this turbo. Is that because the leak or the low peak boost?

The leak will make the turbo laggier. Also, if your vehicle isnt fueled enough to make use of an HX40, it will sometimes cause EGT's to be higher. that is because the turbo never spools to its potential, and you are actually getting less air density into the engine itself. I tried a turbo on mine (DD Jammer BB) and my peak EGT's were no different than the HX35, and they got there quicker. But I was only making 35psi (non wastegated) and I guess that wasnt enough for the turbo to perform correctly.



--Jeff

 

[Buck88]

I think the deal is peak boost. I need to adjust it to hit 40psi. I'm pretty sure that by fixing the exhaust leak, and adjusting the wastegate my temps will be lower or at least take longer to get there. Honestly my temps felt more in check with the 35. we'll see I guess.

 

[Bob4x4]

I recently got my hands on a used Piers 40. First off, I didn't know how laggy these turbos are. The boost gauge got real lazy. Cruising at 55mph, light throttle I'm only registering 2 psi It takes a lot of throttle and HEAVY smoking to get some boost. Maybe its just me going to a HX40 from a 35, but is that normal?



My second issue is I'm only seeing about 26 psi out of the thing. What boost is appropriate for this turbo and how do I adjust it?

I don't see that lag on mine :-laf Maybe a little trouble shooting or adjustments are in order.

My lil pdr 40 has smoked the 35's through the traps when the frt end didn't lock up right. It can go from 1200rpm to 3500 to keep from getting stuck in the sand too.



Bob

 

[Highfinance97]

I don't see that lag on mine :-laf

Bob

I didnt see any lag when i had mine, but then again i have a stick truck.





Michael

 

[Cooker]

As mentioned a boost leak will lower peak boost and increase EGT's.



With larger turbos while cruising down the highway boost will be down and EGT's will be up.



I would not run an HX40 over 40psi, period. Of those that do, some get lucky and others don't. Under 40psi and it should live a long life.



Sometimes a little tuning is in order to get a larger turbo to drive well on a 12v.

 

[bmoeller]

Buck-



You should have plenty of fuel on tap to spool the 40. A set of 191DVs and the DDP4 really helped light it up great. You should probably be seeing ~40# of boost with the current fueling. Loosing up the AFC spring and sliding the plate forwards helps as well.



Get the exhaust leak(s) fixed. That/They is/are part of the problem. You are loosing pressure to drive the turbo.



2-4# on the flat cruising is normal.

 

[Buck88]

Got the gasket on the way to fix the leak. bmoeller, I was considering a set of 191's, but do you think my EGTs will be in check? Did you run a HX40 with your current setup?

 

[bmoeller]

Yes, I had a similar setup as yours. PDR40, 370s and the 10 plate slid.



With the 191s, I saw a bigger increase in smoke, than EGTs. The DVs don't give a whole lot in power, but do help with the spool up.



Advancing the fuel injection pump timing to 16* helped also. Slightly better spoolup. Better throttle response. Lower EGTs. With the 40, I went from a peak boost of 45#, to 38 by bumping the timing.



I bought the new turbo to help with the EGTs towing. Not an issue at all empty. I haven't towed with the new one yet. I'm actually a bit underfueled for this turbo, but so far, it has worked out nicely.

 

[WaynesWorld]

Bryan,



When are we going to see that new turbo do its thing ????



Check the May 5 race date coming up soon at Byron.



We could give that setup a try there. Oo.



WAYNES WORLD

 

[Buck88]

I bought the tools to do the timing, just don't have the time to do it. I was also thinking that a good # would be 16*. Should keep the HG happy. Looks like I'll get some DV's. Thanks guys, Buck