my_samurai

Im trying to get as much use out of my hx35 as i can so i tried the wastegate mod. so far i can tell that it does help keep the EGT's from climbing so fast. I was able to do the whole mod in about one hour.

once the turbo is off the truck first take the plate of the side that cover the wastegate using a 1/2 wrench


that gasket is reusable just clean it up some before putting it all back together.

Disconnect the arm on wastegate using a small flat head screw driver on the Eclip.

once you have the wastegate disconnected you will be able to see the hole where you'll now drill out the flange.

using a 3/4 drill bit on a drill press drill the divider flange out so both sides of the manifold can now be wastegated.

make sure you blow the turbo out really good with airhose and inspec everything on the turbo while you have it off for cracks etc. here the hole throu the flange

rage_blue

So that mod helped EGTs? Your pushing 40 PSI so are you even useing the wastegate? I'm running 40 PSI on my truck but i've got the wastegate blocked off. The only thing that can open it is high exhuast pressure. I'm thinking about buying a turbo to lower EGTs but if this mod works i may hold off for a while.

Fishin2Deep4U

It helps to balance front and rear cylinder pressures, but it's actually easier to use an open spacer plate. I would recommend opening the hole up and fabricating a new wastegate flapper. And yo can one step further and put in a flange spacer to allow for a wider opening angle on the wastegate. This mod will move the downpipe rearward the same distance however.

Dave

97 D-Tec

How is this better then the boost elbow i had that wouldnt allow the wastgate to open till 40psi? even then i still had a TON of heat

montyryan

I drove a truck with a real loud turbo whisle and hated it. Why would someone like to wear hearing aids in the future? Some guys welding the waste gate shut, some opening the hole bigger, drilling a second hole. Looks like a lot of guys doing modifications and not knowing for sure if it will do any good. I'm trying this to see if it will work. Just because they seen someone else do it, all in the idea they will have more power, lower EGT. The stock HX35 has a small exhaust housing, 12cm. Porting the housing will help more than this crap.

etn550

The divided housing optimizes the pulse manifold which typically gives better low end boost and spool up. It seems to me that drilling an interconnection between the sides will hurt the pulse effect gained by the divider. Has anyone actually measured a difference with EGT taps on each side of the divider? I'm skeptical there is a big difference. The EGT is generated by the fuel and boost and they are still the same. Granted dropping pressure will drop temp a little but what is coming out of the cylinders would still be the same.

AlpineRAM

My take on this is a little different- first of all you must be aware that the divided housing is good for the reasons etn550 stated.
On the other hand if you want to vent both sides of the divide you will need to have a smaller hole in the divider than the opening of the wastegate.
You will want to flow exhaust gas from the front of the divider to it's rear, and then again the same amount from the rear through the wastegate.
Since the wastegate does not open too far (the flapper angle is limited by the housing) and the housing itself is restrictive you may need to address these things first go get an efficient boost control with the increased exhaust flow from an hopped up engine.
Remember that horsepower is mainly mass flow (air+fuel) by time. So especially on the exhaust side doubling the power output will give you at least double the mass flow, and that's assuming that you can keep efficiency the same.
In the past there was a product called "Megamouth" which addressed the wastegate angle and reduced the restriction of flow after the wastegate.
I did test something similar (homemade) on twins because I needed as little restriction as possible to get enough exhaust to my primary charger, with as little as possible backpressure for the overall system to still get good scavenging.
Personally I think that drilling the divider or using an open spacer plate to get the front and rear 3 cylinders balanced has it's drawbacks, but can be beneficial if you need to tune something outside the specs of the turbo mfg.
My take on it is that 40 psi from an HX35 in this application is much too high since you are far out of the compressor efficiency map and create boost more by heating the air than by cramming mass into the engine.
Just my 2c

AlpineRAM