Adjusting the wastegate?

[KatDiesel]

Since I have been "endowed" with the lovely HY35 turbo up until about 3 weeks ago when I went to the Piers HX35, with a boost elbow in the truck I can only make bout 30psi with DDIII's and PE COMP on Level 5, I would like to add some more boost. We were examining the wategate and looks like it can be adjusted? Has anyone done that? If so any tips or anything? We are thinking if we shrten the rod then it should allow more boost. I want to set it at 35psi at minium. I am hoping it will give me some more MPH in the 1/4 mile, and if nuthing lower my EGT temps a bit around town and highway. I am currently running a 12cm² housing on my Piers HX35. Pondering trying a wastegated 14cm² housing.



Any ideas?



Thanks

 

[Steve Campbell]

Kat, if the new wastgate linkage is like the old (99model) linkage, the "nut" is peened down onto the shaft in one point. I have heard that a person can take a cut-off wheel and "surgically" eliminate that part of the nut (so to speak) to free up the whole assembly to allow some adjustment. I can't really remember, but I am thinking a turn is worth 3lbs of boost. Hope that helps if yours is built the same as mine. I guess a person could also try various tensions of external springs to bring the pop off point up a little.

 

[Snow man]

I used an external spring,to bring boost up from 19 to 26 psi,on an HY 35,it takes a lot of spring pressure to bring it up 6psi. With an HX35,you could open up the hole in the boost fittling a little,thiswill do the same thing. If your EGT's arent high,I would be happy at 30 PSI of boost.

 

[KatDiesel]

I am hoping Piers will see this and comment on the matter! If nor I'll call him sometime tommorrow.



I am hopnig I can either modify the elbow some more or adjust the wastegate to get at least 5 more lbs of boost for EGT control, in level 5 on the COMP plus DDIII's the needle goes over to 1400° and a bit higher aweful easy.

 

[CUMIN2pass]

Don't know how to change the boost. What is the differance from hx and hy?

 

[Steve Campbell]

Kat, on adjusting the boost elbow, there is not a machined "fit" in there. Maybe if you could deburr the tip of the allen screw and similarly examine the mating surface in the elbow, you could gain some more boost. Try plugging the hole where the elbow screws in with a plug and make a run to see if that truly is where the problem lies. I am sure you have thought about rubber boots and intake manifold bolt torque. Cummin2pass, the HY has a smaller exhaust housing which creates quicker spool up. The trade off is in the higher RPM/HP end of the spectrum it creates higher EGT numbers.

 

[thepitts]

HY35

I get 34lbs of boost from my HY35

 

[Fred Swanson]

Kat, it's very easy to adjust. Take the wastegate actuator rod off by first removing the c-clip. Pop the rod off the arm, adjust the rod and jam nut in or shorter, and then pull it out back onto the arm.



This will raise the preload on the wastegate, thus requiring more charge pressure to open the wastegate.

It you want a quick test, take a compressor with a regulator and apply 25 psi to the actuator before adjusting. You'll see it opens very easy. After adjusting, it should take more pressure to open it. To get the desired pressure you want, apply pressure through the elbow, until you see it take about 32-33psi to fully open the wastegate.

The 14cm housing you'll like for the cooldown, and lower EGT's at WOT. With DD3's and the Comp, you may want the 14.

 

[Deezal Man]

Hope you don't mind Kat... but I'd like to pose a few other questions under this topic...



I have DDII's and a Comp box. Recently swapped for a DD TT box.



Only way I can produce more than 25lbs of boost is setting the box on 3,4,5. Which will produce up to 30.

Setting the comp on 5 buries my EGT needle @ 1400 in a matter of seconds. Do you think I have a problem with the wastegate? Does mine need an adjustment as well?

 

[Fred Swanson]

Deezal, you will see higher EGT numbers because of the stock turbo. Kat is running a Piers modified turbo, which does lower EGT's. Yes, you're boost should be higher, closer to 35,36 psi, so you could possibly benefit from a wastegate adjustment.

I'd first disable the hose to the wastegate and see how much boost you get with the wastegate disabled. This would be your max boost, no matter what.