How much bigger if any can you make the wastegate on a 35. Same question only for a 40. I've read the 40MM 12cm threads. I just want to make it a little bigger if possible.

 

you don't need to even go that much bigger on the wg. I cut down my divider with a die grinder so that if you look at the top, it makes a shape that is halfway between a V and a U. I went about 3 inches down to the middle. now, I opened back up my bleed elbow, and with 370s, a ten plate, a 3kgsk, and a tight converter, I could only get the boost up to 30 psi. I adjusted it back up to where it will hit 35 if I push it hard. It lets plenty of the pressure out if you cut down the divider. I also took off the flange of the back, cut out the center of the gasket, and ground a dimple into the flange, to let the wastegate open another 1/8" or so. To answer your question, you can drill it out to maybe 7/8". it won't get you much if you don't vent pressure from the front half of the exhaust housing though.

 

what happens when you do this? what are the benefits?

 

It should help with drive pressure's, boost spikes, and egt's.

 

would it be a good idea to do this on a mostly stock truck?

 

I can't remember but what is about the max booost on the HX35 before it goes out of its range. 32 is good, 34 is ok, 36 is askin for trouble.

 

so 42 psi would be really bad then?

 

Lance, yes its bad!!! Gate that thing!

 

wow you must have a strong stock turbo.

i know of a guy, i warned him... but he kept pusching that thing... 38 psi...
then I one day he got it to 40 or past... and blew it... but hes now happier with an HTB2.

 

dang I have been pushing 40-42 psi for a little over a year now (knocks on wood)

any suggestions for getting the turbo off without having to get the nut splitter out?

 

I have seen some stuff on here about removing it. I think it is just suggested to spray it the night before with some penetrating oil and cross your fingers. Only use six point tools and many say it goes well. Let us know how it goes for you.

 

i ran 42 psi for 50k miles at 400 rwhp on my hx 35. it finally started getting tired at 255k on it.i opened up the center divider and enlagerd the hole also to relieve back pressure with a 12cm housing. the turbo above had a 14cm wastegated on it.

 

I ran mine @ 45+psi, some at 51psi for about a year. Finally let go on me

Just the other day I snapped the shaft on a 35/40 @ 40.6psi after 3 miles

I'm done with Holset's,
Chris

 

I have pegged the boost gage past 40 psi a few times. It didn't stay there for long. That was before my gsk. With 370s and a 10 plate, it would peg the boost gage, and just before it would shift, the boost and egt would drop off. It would shift up, and peg it right back there. Now I am running faster, don't get the exhaust hot, and don't overboost the turbo. I backed my fuel plate off a little, and put the gsk in it. Modding the exhaust housing did make a difference in peak egt, and let me control the boost a lot better. The guys with 14 cm housings could probably get away with just opening up the WG a little, depending on how much fuel you throw at them.

On another note, have you ever seen a guy with twins ask a turbo question, like how do I get more out of my turbo? I am seriously thinking about building my own set. I already have a big primary that I got for free (I know, that's a sweet score) now I just need some piping and another WG.