Engine/Transmission (1994 - 1998) EGT's Still high after twins

[JTroiano]

My ? is how do you tell what the HX is putting out? I read some place that it doesnt care what the inlet pressure is, it just multiplies it. There is a lot of technical stuff about drive pressures and what the efficincy is and so on. I have run this set up on two trucks and it works perfect. Well maybe not perfect because I guess the new thing is a Switser 300 on the bottom. I dont know if thats the one but there is always something better. Rip is selling this setup. Call them!! They have it figured out.



Jon

 

[12V Ford]

My ? is how do you tell what the HX is putting out? I read some place that it doesnt care what the inlet pressure is, it just multiplies it. There is a lot of technical stuff about drive pressures and what the efficincy is and so on. I have run this set up on two trucks and it works perfect. Well maybe not perfect because I guess the new thing is a Switser 300 on the bottom. I dont know if thats the one but there is always something better. Rip is selling this setup. Call them!! They have it figured out.



Jon

The only way I can see to know what the HX35 is putting out is to take the total boost and subtract what the 3b is making, but that takes 2 boost gauges.



The S400 is the new thing for the bottom turbo, but I don't know that it makes that much of a difference on a set of towing twins????

 

[JTroiano]

Have you tried holding the gate shut? Just for testing purposes. I think an electric boost controller, that is tunable is the ticket. Just to much money for me. I think you can get the waste gate to creep from the backpressure and this is not efficient. I'm glad you are getting it figured out. With the fuel you are running you should be able to keep the waste gate closed tight and you should be ok.



Some one asked about top end fueling. There is a guy on here that is running extra fuel to his pump and I think that would help. I'm still saving money for my 4k springs and have the NV4500 on the bench getting rebuilt.



Jon



Jim Fulmer



Dang I need to get to work!!!



I don't make any money in front of the PC.

 

[JHastings]

You know, A poor injector or a bad DV might be the answer. I am really hot even at low power levels such as 2000 rpm, 4th gear, 20 psi, easy acceleration. I also still see alot of smoke at 50+ psi. It does clear up some as boost comes on, but far from clear at high boost and rpm. It might be that I have poor atomization in at least on cylinder and fuel is going unburned at increasing my egt's at the pyrometer. I will try to get my hands on one of those lazer temp deals to see if I have a hot cylinder. If I do, what would be the method of fixing it. Send them out to get them redone or what? Who do I send them to?


Also forgot to mention that I do have a slight miss at idle. I think my timing is correct and I installed Larry B's fuel lines as well as a new overflow valve to try and cure the problem a few months ago. Miss is still there.

 

[JTroiano]

J, now you are getting out of my knowledge realm. I you have a miss, you should see a temp difference pretty easy. I heard back in the day they used to use a crayon on each exhaust port and see which one melted last. They have welding crayons that melt at different temps. Maybe they would shed some light or the temp. gun. I would start with the injectors and do a compression test or leak down test when you have them out. There may be an easy way to check the pump but I don't know how.



I've asked this about a 100 times. Have you tried holding your wastegate shut and going for a ride? You don't even have to go full throttle if you are worried about to much boost. Just watch your gauges. If this improves your EGT problem then I would focus on the miss after this. Then you are not fighting two things that my be caused by different problems.



Jon T

 

[Moose Truck]

Jamie, as far as getting the injectors Pop and flow tested, you should be able to send them back to the original vendor who built them, a diesel shop (Just make sure they know and understand Hot Rod Injectors), or a major Diesel Hot Rod supply shop, such as PDR, Industrial Injection, ECT... . Moose

 

[JHastings]

OK so I unplugged my wastegate as suggested and my egt's did drop! Max out now at about 1250-1300. I took boost up to around 59, but it still had quite a bit left. I bet it can go to 60-65, but I think only about 20-22 or so would be the 3B so that would mean my 35 would probably go "pop". So I guess waht I need to do maybe is set my wastegate at maybe 38 or so where I know my 35 can survive and go from there. Somebody correct me if I am wrong, but it is the pressure difference from the two sides of the turbo that makes them go boom. Over 40 psi difference across the 35 and it won't last right? Let me know about this.

I also slid my afc all the way back and tightened my spring. It used to be a bit loose. Egt's on bottom are much lower, no smoke, and things really start going at about 18psi so I might add a little more pre boost fueling to get things rolling a little quicker.

Also I see a lot of guys with blow off valves. Is this just for the guys that don't have head work. Do I need to worry about boost in the 50's and 60's with my setup?

Jamie

 

[JTroiano]

So the EGT's went down a little then. Did you use something to hold the waste gate shut? It can get pushed open by the back pressure. I don't think you need to get it higher than 60 for test purposes. If it creeps at lower boost and rpm's it is not going to be as efficient. I think I would like to see the 3B with a little more boost but thats not bad. I think you have alot more fuel than you think. When you use your waste gate does it dump in front of the big turbo or behind. It is wasted energy if it dumps behind. The idea behind twins is to use the small turbo to get you going at low rpm's and the to let the big turbo take over at higher rpm's.



I run mine in the 60's to 70's and have no problems. Mostly around 50-60 when just running around. the only time I see 70-80 is when I load it just right and really get on it.



What are you using for an intercooler? What size piping? Intake and air filter?



I think you are getting pretty close.



What about the miss?

 

[JTroiano]

I just looked at your pictures and if you are still running the BHAF it will not flow enough and you will suck oil past the turbo seals. I ran it on my first truck and sucked the little air filter sensor thingy all the way in on the first run. I use them on all my trucks. It will tell you if you have a filter problem.



Any pics of your engine compartment?



You can see my set up in the photo gallery. I don't know how to get in this post.



Jon

 

[JHastings]

Ya I will try to post some here tomorrow, but for a filter I have just an AFe 5. 5" cone filter that I got from RIPs. Goes 5 1/2" all the way to the 3B. My wastegate is still just the stock internal gate and it is just like stock so it dumps into my hotpipe. I made it without a divorced tube for simplicity. However, i did enlarge the gate to 1" instead of the stock 1/2" and I lathed up a new flapper as well. Coldpipe is 3 1/2" that enlarges to 4" at the inlet of the 35.

 

[JTroiano]

I think I have the same filter from RIP. I really think we are close in the fuel department. I think you may have a bit more.



What intercooler?



I dont run any waste gate and I don't think I'm going to have any problems blowing up.



I got to go take a shower. Its been a long day and I can't think straight anymore.



I'll type in the AM.



Jon T

 

[JHastings]

Stock intercooler. I don't know. I'd hate to tank my 35 b/c the 3B would probably see some metal. I can get another 35 from a buddy of mine so thats not a big deal. It does run better when not gated. So would a smaller housing on my 3B be better (ie higher boost from the 3b?) Or would a larger housing for the 35 do the same by limiting boost and sending more gas to the 3B. Jim Fulmer or anybody want to comment on whether I should worry about my 35 kicking the bucket?

Thanks,
Jamie

Also added some picks in photo gallery

 

[Jim Fulmer]

Jim Fulmer or anybody want to comment on whether I should worry about my 35 kicking the bucket?



Set the gate to open (crack) around 25, full open by 40 psi! 35's are tough turbo's!



Jim

 

[JTroiano]

Just got done rebuilding my NV4500 (midnight fri. ) with Quad 4X4 master kit. Very nice kit. I almost killed my self getting fifth gear on. Even with the special tool. Took it for a test ride and I still have a crazy rattle in fourth Gear around 1,800 RPM. I have the solid double disc from South Bend. I'm wondering if it is that?



Any ideas?





I think a smaller Housing on the 3B would maybe help. If you go with a bigger housing on the HX then the lag starts comming back. What is the new set up people are running? Rips place has one sitting on a stand. Supposedly better spool up and more efficeint? I think any way to get more oxygen into the mix will keep the EGT's down. So better intercooler. More boost. Nitros etc... I'm happy with my set up other than the dam rattle in fourth. Lookin at putting a little turbo on my civic next.



Any pics yet?



Jon T

 

[JHastings]

Yep here are some pics. How am I going to be able to tell how to set my wastegate. There is no visual way of telling whether it is opening at a certain psi is there. I am not sure that I can feel or see a difference as the boost comes up as to when the gate opens. Towed with it today and it did pretty good. Spool up is no good, but I still have not pushed my afc forward yet and its all the way back. egt's hit about 1200-1250 and then cool back down as the 3b spools and at the very top under heavy acceleration egt's go back to 1200 and slowly climb to 1250 at the top of 4th and 5th gears. Does this sound normal? Peak boost is right at 59-60 psi. If so I think I am done wrenching on this thing and am going to find my miss and be done with it.






Not a very pretty setup, but I am not the best fabricator either. Oh well they seem to work ok.

 

[JTroiano]

J, If you could see my hot tube. Yours looks a lot better than mine. I only had scrap metal to make mine. Your set up just needs a little paint and it would look a lot better.



One small thing that may not make a big difference but if you look at the flange between your 3b and hot tube is warped from welding. Did you get it machined flat again? Mine did the same thing and I had to get it machined flat. If not you may be loosing exhaust pressure to spool the big turbo.



You should really find out what the mis is. It may be causing some EGT issues.



I don't know if getting the waste gate to open is going to help with your egt's.



To watch the waste gate open? Rig up a light. Get a 12 volt LED and hook one side up to switched and fused B+. Then run the other side down to the waste gate and put it on a stiff copper wire. attach the wire above the waste gate lever. It has to be insulated because as soon as it touches metal the light will come on. Make the lead as close the arm as possible without touching. As soon as the waste gate starts to open the lever will touch the lead and the light will come on. When you find when it starts to open. you can adjust it.



Hope that make sense?



Going to bed, its past my bed time.



Get the mis figured out. It could be damaging the motor.



Jon T

 

[JHastings]

Yep, I'll have to try that light deal. It sure seams to run better with the wastegate blocked. Don't know why. Anyhow, would a smaller housing on the 3B bump up the amount of boost that it is pushing? b/c right now it only pushes about 18 psi at 58 psi total boost and only 10 psi at 40 psi total. I need to get that 3b to do its job. Going to have the flanges on my hotpipe machined flat like you mentioned and get new gaskets as well. Maybe that will drive the 3b more.

 

[JTroiano]

I just put some washers in my pump to crank the RPM's up and the throttle is very touchy. I had to put some heavy springs on the throttle to stop the jerking back and forth. I can now see 1,200 degrees if I really push it hard and about 75 psi.



Did you find out what your mis is?



Jon T

 

[JHastings]

Nope, still haven't figured it out yet. Don't really know where to start. I have changed my overflow valve, replaced the junk stock fuel lines with Larry B's and made sure they were tight. Removed my fuel heater assembly and just have the pre screen. No apparent fuel leaks. All I can think of is bad injector, DV, or bad hard fuel line. I do know that when I try to prime the fuel system and it starts to build some pressure, I hear a squeek as if the pressure is being relieved and it does not seem to be the OF valve. Any ideas? I was thinking of pulling my injectors and cleaning them. DO I need a washer kit to reinstall them?
Jamie

 

[JTroiano]

Does it just have a rough idle? When you accelerate is it smooth or does it feel like a miss? If it is one cylinder it can't be an item that is common to all cylinders. It would have to be inj. ,cyl compression,or something in the pump. If it is a rough idle and not specific to one cylinder then it can be a lot of things. First figure out if it's one cylinder or all and just a rough idle. Then start your diagnosis from there. I've been diagnosis cars and truck for 25 years. More cars but the the process is the same. If its one cylinder, start with the easiest thing. Pull injectors and have them tested and when they are out, do a cylinder leak down test to see if you have a compression problem. Then if you don't find anything its time to look at the pump.



Jon T



Jon T