Engine/Transmission (1994 - 1998) Boost/EGT question

[PRattenbury]

I just got my truck going again after putting in the Kore Chase supension, PSC steering stuff, DSS, 4" MBRP, and so forth. Part of the adventure was gauges, DiPricol Optix mounted in the A pillar. I got boost, EGT and trans temp. At idle I have no boost. Just cruising along easy I have 3 or 4 PSI boost, and my EGT is around 600. If I'm going up an incline (empty) my boost will go up to 8 or 10 PSI, and my EGT will go to 800. My turbo is the stock Holset, the pump is a 215 with stock plate and timing, basically a stock setup right now. I'm wondering if these numbers seem all right. I'll fess up to not knowing what factors affect boost and what result I would get from having more. The boost numbers seem really low. Since I was monkeying around in the area of the PS pump and vacuum pump I removed the intercooler tube on the driver's side and replaced the boots with PDR boots and the heavy clamps. I left the passenger side alone so far. The only thing I did around the turbo was take the elbow off while installing the downpipe. Could someone maybe educate me about this, or maybe point me to a Turbo 101 link? Thanks!

 

[BradyWilliams]

Sounds very normal, Thanks

 

[Rams-n-Hogs]

Yep, those numbers are normal. Those are about the same numbers I see, even though my truck is modded. The amount of fuel you are pushing is one of the factors that affect boost, along with how heavy your foot is. The EGT gauge is more important than boost. I, (for the most part), keep mine under 1200*, and I don't shut the truck off unless it's 300* or less. That will help the turbo last a long time.

 

[PRattenbury]

I do watch the EGT before I shut down. It will come down to about 250* and then I shut it off. Someone told me about that many years ago, but this is the first turboed engine I've owned. I just wonder how lots of people on these forums get their boost up so high. Is it the addition of fuel, or tricks to the waste gate, or a combination of things? I hear a HX-35 can out out 30 or so pounds pretty safely, but if I get up to 10 I'm doing something.

 

[wildmanben]

I had my hx35 up to 43psi for awhile but its been steadily decreasing as it wears out. Its not very efficient up there. To get that I clamped off the WG line, messed with the AFC and moved the plate ahead(and ground it down too)

 

[PRattenbury]

Is the waste gate adjustable, or do you just take the line off and plug it? I'd feel better if I could adjust it.

 

[KingS]

yes it is you need to get a boost elbow like the ones we get when we buy the aftermarket fuel plates not possittive but should be easy to buy one from a performance site or someone will post a site soon then you just adjust the allen bolt that is in it till you turbo boost to where you want it works by cutting the air flow to the wastegate so it doesn't open at the stock 17 to 20 psi from factory good luck.

 

[PRattenbury]

Hmm, I've not seen the boost go that high yet. I don't think I've seen the better side of 10 PSI. Oh, well, maybe the waste gate isn't a big concern with a stock engine.

 

[pwerwagn]

My truck when it was stock would only make 20psi at WOT in 5th gear. Other than that, I usually saw no more than 12 unless I was towing. your's sounds pretty normal to me.

just sliding the plate foward took me to about 26psi or so, after I did the "boost elbow". (search boost elbow on Ebay, there used to be a few on there. If not, look on TST's website or Piers).

The 11 plate in stock location was enough fuel to make around 28psi. slid foward . 020 was good for 30psi.

The 10 plate in stock location on mine makes 32-33psi. Slid foward . 035, makes 35psi.

The #0 plate, with the wastegate plugged, will touch 39-40psi.

(Im at 5300', so my pressure ratio at 40psi is far greater than 40psi at sea level FWIW). All those figures are with a 12cm housing, the AFC full foward (except the stock figure) and the starwheel 7 clicks from a loose spring, with the foot moved foward in the AFC about . 040 from where it started stock.



hope that sheds a little light on the subject. In short, more fuel means more energy available to drive the turbine wheel (faster), which will cause the compressor to spin faster, creating more boost.



--Jeff

 

[KingS]

your wastegate could be stuck open easy way to tell take and plug line and see if boost goes up alot of guys have had wastegate stick open

 

[PRattenbury]

Okay, I get it. It's the addition of fuel, generally speaking, that lets the boost go up like I read about. Mass Diesel is going to put in a different plate for me, and a set of 300 sticks. He's also going to bump the timing up some, and do the DTT billet treatment to the transmission and TC. I bet when it gets done with all that, my boost numbers will be different (and EGT).

 

[Matthug]

Do not bother with the 300 injectors, waste of money they barely do anything. They are about 20 HP over stock unless you have 215's then they probably don't do anything. Go with DD2 or 3 injectors, yeah they are $600 but way worth it... . don't waste $300 on the 300 injectors like I did. And if you tow don't go with 370's!

 

[Dave M]

... ... ... ... . I got boost, EGT and trans temp. At idle I have no boost. Just cruising along easy I have 3 or 4 PSI boost, and my EGT is around 600. If I'm going up an incline (empty) my boost will go up to 8 or 10 PSI, and my EGT will go to 800. My turbo is the stock Holset, the pump is a 215 with stock plate and timing, basically a stock setup right now. I'm wondering if these numbers seem all right. ... . on the driver's side and replaced the boots with PDR boots and the heavy clamps. I left the passenger side alone so far. The only thing I did around the turbo was take the elbow off while installing the downpipe. Could someone maybe educate me about this, or maybe point me to a Turbo 101 link? Thanks!

I'm a little cofused here. I have a 4" exhaust with AFE Stage I air filter and 215 pump with 5 sp manual. If I get on mine I hit 28 psi boost going up a steep hill.



When I first got the truck I had to replace both intercooler boots but the passenger side had a 3 inch rip in it where it rubbed against the inside fender lip. This is a very common problem on these trucks. I could not go over 6-7 psi boost. Make sure yours is good. You can't tell without removing it.



Why are you only getting 10 psi boost? We have the same pump and exhaust. If you still have the stock box get rid of it. Is the difference between manual and automatic the reason? Help me out guys!

 

[pwerwagn]

Why are you only getting 10 psi boost? We have the same pump and exhaust. If you still have the stock box get rid of it. Is the difference between manual and automatic the reason? Help me out guys!

I couldnt make 28 psi with my 215 stock. I didnt even make 28psi with the stock plate slid foward.

He doesnt have the stock airbox, he has a Scotty II (which I also have, and made no noticeable difference in Boost #'s).



Are you sure your truck doesnt have a #11 or something in it that you dont know about?



--Jeff

 

[Dave M]

I'm not positive that I don't have a non-stock plate. I bought on ebay from Texas and the original window sticker from the glove compartment listed it as 215 Hp. I believe the same truck sold in California with egr valve was 165 HP.



I'll have to check again but I believe the tamper proof screw is intact which indicates a stock plate. This truck sucked with 7 psi boost :{ and high EGT's. I didn't know the boost was low until I installed my gages and found the torn passenger side intercooler boot.



I'll re-verify the tamper proof screw. Other than that I removed the Cat and stock exhaust and put in the 4 inch turbo back ehaust and replaced the stock air box with the AFE Stage I conical open filter. I have done nothing else and I can hit 25 PSI boost s tomping lightly on it up an incline. It's not as good when pulling a stock trailer especially loaded. I have a #10 plate and 3KGSK to remedy that as soon I get time. :-laf



Dave

 

[PRattenbury]

I'll have a look at the boots on the passenger side. I just did the driver's side because I had the vacuum and power steering pumps out, and the tube was sort of in the way. I really didn't suspect there was a problem with the boots. I'm not disappointed with the boost numbers I have, I just read about all these huge boost numbers other people get, and was wondering what they were doing different than me to cause that. I guess it's the addition of fuel. I have the 215 pump on my 94 auto. The injectors are still the stock 160's. So I'm probably not exactly pouring on the coals with them in there. I'm anxious to see what Scott at Mass Diesel can get out of the engine when he does his thing to it. He was the one that recommended the 300 injectors. I guess at some point I'll go to a different turbo. I'd like to get up to around 400 horses by the time I'm done. That should make the truck feel like it's got decent power (the torque levels should go up as well), and the DTT transmission and tc should get it all to the ground. I'm looking forward to getting it finished, so I can enjoy the fruits of my efforts. I'd enjoy it even more if I could get my steering the way it should be.

 

[pwerwagn]

I believe the same truck sold in California with egr valve was 165 HP.

The cali egr 5-speed trucks were 180. same as an auto. there never was a 165 pump.

I'll have to check again but I believe the tamper proof screw is intact which indicates a stock plate.

not necessarily. Every TST plate kit comes with a new break off screw in the box. And its really easy to re-paint the screw black after it breaks off. When I did my 11 I replaced the break off screw and painted it black, and nobody was the wiser.

I'd like to get up to around 400 horses by the time I'm done.

Enjoy!!! you'll love all the newfound power!!!

 

[Dave M]

The cali egr 5-speed trucks were 180. same as an auto. there never was a 165 pump.



not necessarily. Every TST plate kit comes with a new break off screw in the box. And its really easy to re-paint the screw black after it breaks off. When I did my 11 I replaced the break off screw and painted it black, and nobody was the wiser.



Enjoy!!! you'll love all the newfound power!!!

Well..... it looks like I'm wrong on the 165 pump. Don't know where I got that info.



I looked at my 215 pump and there is a break-off screw on the AFC. As you say, it could have been a replacement break-off screw. I'll know when I complete the install of my #10 plate. Geeez... You got me curious now as to what is causing my higher boost numbers. Darnit... I'm going to have to get in there and find out. I've been putting this off for a while so its time to start Bombing. Then I should see more after my #10 and 3K GSK.



Let the Bombing begin Oo.