I got a good deal on a HX last week and went for it. Once I had it in my hand I pulled it apart and basically did a rebuild. New bushings, thrust plate, snap rings ect. I used a Holset parts kit from E-Bay. It didn’t really need it, but I wanted to clean it and give it a good inspection.

First impression is that the truck seems to run better. It smokes a lot more from a dead stop and from slow rolls when I nail it. If I am running along at 70 or so and let off the gas, then ease into it hard, it puffs hard enough for me to see it in my mirror. With the HY It almost never did that. Now I can do it at will.

Still not seeing the boost I thought I would. I had the HY with a boost fooler and a set of RV275’s and the turnbuckle / spring arrangement. It would put out about 22 lbs boost with that setup.

Tonight I pulled my elbow and drilled / tapped it for a grub screw which effectively blocked off the port. I still only see about 22-24lbs of boost. My exhaust temps are a bit higher than they were with the HY as well. I get up to about 1150deg now after a long run at WOT. With the HY the highest I could get it was about 1000.

As it stands I have a 01 with MBRP 4” exhaust and a BHAF. I have RV275’s with the boost fooler and a modified elbow on an HX35 that I just went through.

Could it be I just don’t have enough fuel to get the higher boost numbers? One of the guys I work with has an 02 HO with Stage 3’s and a boost elbow. He sees about 32psi on his at WOT. Is my friends HO with the Stage 3’s getting so much more boost because he has lots more fuel available?

-Dave

 

You don't have enough fuel for the higher boost. Put a smarty/ez/va/catcher/comp/tst on there and you'll definately see higher boost. More fuel equals more boost.

The reason your seeing more smoke is because the HX is laggier than the HY, but just by a touch.

 

Are they shipping smarty to regular folks yet? I think that will be my next step. Who, where, and how much LOL.

The HX did change the way the truck runs. I only have about 50 miles on it right now, but it seems like it has more power at low and mid range, but falls on its nose as the RPMs get higher. That again is probably fuel.

-Dave

 

It's fuel related. The HX will give you lots more top end than the HY could ever dream of. I ran a Comp/275 combo with the HY35 for a while and while the low end was great, the top end seemed very weak. Put a KSB-1 on and the top end SCREAMED!!!! I went from maxing out at 110mph to maxing out at 117mph. Only reasoned it stopped at 117 is because of the computer defueling. You will definately like the smarty/275 combo. There's gonna be more low end power than you could ever imagine. The smarty is shipping to normal people. Just go to madselectronics.com to order one. Them or bobwagnerandassociates.biz to get one.

 

I have the HY, turnbuckle, 275's and Smarty. My little Hy is hitting 32 psi. Hmmm as much as I can smoke with the Smarty and an Hy, the HX should be more fun! Yuor truck wont die at top end. As a similar situation to BigBlue, when I get on it from a light the tach swings to about 2800 and stays there. RPMs dont really drop at all during the shift. Tranny on its way out. I bet after the tranny it will feel like an extra 60HP to the ground. Oh and with the Smarty you wont need a boost elbow/fooler. I have neither with the Smarty.

 

Going from an HY35 to an HX35 will yeild little if any benefit, I know as I have tried this. Dyno numbers on a truck fueled like your will be identical, if its a heavily fueled truck the HX will provide a slightly higher dyno number (5-10HP).

In order to see more boost you will need additional fuel, but your egts are going to get hot. The HY/HX35 turbos make max HP when they are wastegated around 28-30 psi, above this they start going down on the dyno.... If you are looking to lower egts and/or increase performance then a larger turbo would help, but you will need more fuel to really gain from a larger turbo.

Doug Smith

 

Know a "regular folk" that ordered a Smarty on Monday. Was told they will be available for shipping from West Coast by next week!
"Who, where & How Much?" .... see here:
http://www.madselectronics.com/index.html
or contact Bob Wagner direct....
http://www.wagnerandassociates.biz/

RJ

 

Thanks for all the replies.

I had a chance to put another 100 miles on it this morning and running on flat ground at 70, my boost numbers seem to be much lower. It's hard to explain, but I think it is running better. I can't wait to see how it does on fuel with the HX V/S the HY.

-Dave

 

To me it sound like your turbo isn't spooling up right. How much clearance are you running between the compressor/turbine shaft to the bushing. Your truck is almost stock right, no edge/tst fueling box that wiried into the injection pump? I ran 90rwhp injectors with no box, no boost fouler, stock HY35 turbo, all I could get is slight puff of smoke on a no boost to wot throttle acceleration run. It just started to defuel at 28psi of boost. Now I can get a bigger puff, but still I can't black out the freeway. Your boost also sounds low, do a boost leak check.

 

I'd hope with 677hp that you could get a bigger puff than 90hp injectors by themselves.

 

Running on level ground, steady speed it should give you less boost! It has a bigger exhaust housing, so it is easier to breath, but spool-up is a little delayed.
You should see more boost at full load, or at least the same boost.
BTW, to get more boost it needs more fuel. Fuel is heat. So is boost!! If two identically set up trucks are paired up and one shows a little less boost, it may run a little better. Colder air is more dense. I guess then they aren't really identical??!!!!!

 

On my truck with no fueling box, there is on a slight haze on accelerating from idle to WOT. You reach the overboost defuel fairly fast. I've been wanting to try a boostfouler but I can't live with just 400rwhp truck so its on the back burner. Actually these injectors are not alot worse than the 90's that I ran before. My rear bumper is black but its takes longer for it to collect on the bumper. On the other hand the wall in my garage is now black and wasn't before. My truck doesn't want to run until the temperature gauge gets some heat indication. A HX-35 is a stock turbo and really shouldn't be signifacantly slower than the stocker that you removed. I wish that I could max out my twin turbo only at 1200 deg's F. How easy does your HX turbo spin? Try spining the impeller by hand (turn the truck off before trying this). My old HY couldn't spin that easy and not for that long. My 3B spins easy and spins for several seconds. I'm trying to talk PDR into trying a set of their biggest vaporisers sticks. I will only buy them if they can make more power than my machers. I haven't drove my truck yet on a setting of 5X5. 3x3 works well and get me into enough trouble.

 

Well I think I have a boost leak or waste gate problems.

Yesterday I had the chance to try out a Smarty. We set it up for 9 and took it for a drive. LOTS of low end. LOTS of Smoke, until it hit 20lbs of boost. Then it nosed over and quit pulling.

I know it had the fuel, so now I think the low boost is a waste gate problem. The only boost line connection I opened was right at the elbow that goes to the intercooler. I was careful when I swapped to the HX to make sure I did not hurt the O ring.

The waste gate is the only thing that is an unknown for me right now. The turbo I bought was used and the actuator had a little dent in it. The lever on the waste gate itself, where the linkage connects to, had been worked on. The shaft was still free, but would move in and out some. Also the flat section the linkage hooks to has been welded to the shaft.

Finally the thing that worries me the most is that I found a spring had been put right on the back of the flapper. Looks like an attempt to keep the waste gate closed. Naturally I pitched the spring, because according to all the drawings I had, it was not supposed to be there.

What should I do from here? Should I put a turn buckle on it and take it for a drive? What is the best way to look for boost leaks?

-Dave

 

With the HX-35... you need a boost elbow, not a turn buckle, to block off soft hose from the turbo to the wastegate...keeps it from opening at 20 psi.
Or just plug up the hose to the wastegate with anything as a test. Many say a 22 brass casing works??

When you say "nosed over" do you mean truck slowed... as in defueled, or just stopped building boost.
With Smarty the boost fooler is built in and there should be no defueling so I'm confused.

RJ

 

So am I. The truck shouldn't just nose over and die. Plug the waste gate and then pull the codes. You should be hitting about 35psi or so.