12V high EGT and slow boost with twin turbos
 

I am new to the forum and looking for some help.

A friend of mine recently purchased an 03 F250 CC with a 12V cummins and NV4500 trans, twin turbos and 5" exhaust. Not sure what injectors are in it but assume big based on the smoke. He lives on a farm and wants to use it for real work, but as it is set up right now the EGT rises faster then the boost and it smokes excessively. It currently has a HTB2 (1462257) turbo on top and a BW S400S062 (171702) on the bottom. Correct me if I am wrong but the top turbo is a HTB2 which I believe is a 62mm help me with the rest of the specs and the other is a 75mm, also not 100% how to read into the rest of the P/N.

It currently begins to boost 5 PSI or so around 1500 RPM and the turbos take off around 1900 RPM with a max boost of around 62-65 PSI. I would like to see the turbos kick in more in the 1300 - 1400 RPM. With this current turbo setup can I make it spool faster and make the EGTs drop, the way they are now you really can't tow much with it, even daily driver you have to watch the temps.

I started adjusting the smoke screw on the AFC and that helped some. What are my options at this point, he was wanting to go to a single, but I was thinking we could get there with what he currently has.

Thanks for your help.

Yes. Turn the fuel down. Get a cooler running injector. Something not so drastic. It should light the turbos sooner, and beat the heat issue.

Push the fuel plate backwards .. twards the Firewall ... this will reduce the total fuel delivered .. will back the EGT's way down typically .. if it dosent have a fuel plate .. GET ONE !!!!

Not safe to run these pumps with out a plate in them ... :td:

It has some sort of air actuated plate in it with a switch in the cab that he calls his GO-GO switch. Not sure how it works other then I am guessing when it is on it is basically running like it has no fuel plate in it. I have driven it with it on and there is a big difference in performance, but EGTs are high both open or closed.

Is it a realistic expectation to see a spool RPM of 1200 or so with the turbo combination he has?

What would be the recommended injectors to look at for it?

I was looking at pulling the AFC off it this weekend to see what was there, if it had been modified or not that sort of thing. What would be a good PSI number to set it at?

Thx

a #100 plate should be plenty .. if the sticks are that big .. your gonna need Timing ... Something is outta Whack ... :humm:

I think its gonna be a Timing issue .. if its not at least 18* .. Get it there and then start tinkering .. :c:

I had access to the truck today so I pulled the AFC. Smoke screw was in 6 turns, I returned it to flush and will begin adjustment once I get it back on the truck. Has a #10 fuel plate slid all the way forward. Odd thing on the AFC foot is that it lacks going 3/8" from full travel. I took it apart and replaced the one washer with a fender washer and then added another spacer washer, but I am still probably 1/8" away from full travel is that an issue? What PSI should I set the post boost at?

The switch in the cab looks like it controls a solenoid that is in between the boost line the intake and the line that ties into the AFC. What would this be doing? I didn't notice a third line on it so I am not sure how it works. Any ideas?

It is a #10 fuel plate ground to a #100. Near as I can tell the AFC spring is binding which is why I can't get full travel. Any recommendations on springs? I think it needs to be 40-45 psi min.

:humm: .. What the Flip did he do in there ... ???

Not sure, the kid that previously owned it was only interested in making it smoke and race with it.

I have the tools coming so I can check pump timing, also looking at ordering the DDP AFC spring or a governor spring.

What would you recommend for pump timing? 18 to much?

If the Engine is studed 18* would be great .. also .. do a cold re-torque before you start getting too far invested .. if he didnt do any re-torques .. this is the time to get it done before you end up with a leaking or blown HG .. Insurance policy :tu:

If its not studed... Get on it .. dont touch a think until its studed !! :td::nope:

Motor has been studded.

The pump is at 21*, thinking I will change it to 18*. Should I take it down more then that?

It has 191 DVs

Installed a DDP AFC spring which is about 1/2" longer then stock and set it to be full open at 30 PSI with shop air. Smoke screw is just touching plunger so it is at zero.

Sounds like playing with tiing and some AFC tuning should help .. let us know what the timing comes out @ and if that helps your Spool/Vleocity ... :pca1:

Set the timing to 17.5* a little lower then I wanted but that was where it ended up . Will have to do some testing tomorrow and see how it goes.

Do keep posted .. :tu::pca1:

EGTs are better then they were and I have about 1/3 as much smoke as I did before. I still am not impressed with the spool up time which is 1800-2000 RPM.

Has anyone tried a Blaylock variable vane turbo on one of these trucks? I would like to see it spool at a lot lower RPM.

1800 is great .. thats where mine spools .. I also have a 1700 stall converter ..

factory TC is 1900-2100 rpm stall

1800 RPM seems high. This has the 5 spd manual. Got a friend with an early 90s 12V with a 6 spd manual and HE351 turbo and his will spool easily at 1200 RPM, but on the top end it does hurt him some.

The owner of the truck is not impressed with the 1800 RPM and is pushing me to put a single on it. If I could get it down to say 1500 RPM I could probably convince him to keep them. When your pulling it like he does, it would sure be nice to have something on the bottom end.

Maybe we are expecting to much out of twins. What is normal spool RPM for a HTB2 & S400S062 Turbo setup? What are others seeing with their twins?

most guys are running the he351 or a 35/40 with the HT3b .. I will be attempting to do a 34/40 HT60 .. oughtta be fun .. will see ..

the primary could just be to damn big .. might try a HX35w out of the box with the HT3b and see how that spools .. Just a thougt .. and its failry cheep too :humm:

I dropped the tranny out of it today to fix 3rd gear synchro and plan to pull it good once I get it back together to see how the EGTS are and how it does.

0k .. Keep us posted :pca1:

So I have the tranny out and was wondering what are the white plastic tabs/spacers on the 3rd gear shift fork? There are a couple stuck on the actual gear itself and one just fell off the shifter fork. Wondering if these aren't my problem. I am really not seeing anything obviously wrong, need to start pulling things apart and get down to the synchro.

Those are like a bushing and they should be on the shift fork .. if not it will wear out shift collar or gear/Syncro :argh:

Pilot bearing is shot on it, which is why there is wear on the input shaft and the synchros, should have it tore down completely later this week, hopefully get my parts ordered and back together next week. Odd thing is this thing has the updated larger ball bearing pilot, but is a china bearing.

Well if it works .. China makes ok stuff .. I'm just pickey my self as well .. they will work though .. :c: