CT26 How to make it spool at lower rpm?

[crushers]

holy crap, we agree on something.

the only way to get a turbo to spool up quicker is by the design of the turbo itself. the CT26 on a 13BT is designed for generic driving styles (think best of all worlds). a smaller turbo will spool up quicker (and in my opinion will fit most of our driving styles)

waste gate function will not change spool up, it controls when the boost is freed to drop off. higher waste gate opening will give higher boost but will not affect rmp responsiveness.

Moose in doing a CT20 intall onto his 3B for quick responsiveness. i beleive he will be doing a thread as he gets to it... ... ... soon?

You could always swap the CT26 for something more responsive.

 

[Tapage]

Tapage what kind of 13BT info you after? I have a stock setup 13BT, only mods are a boost controller, muffler removed from stock exhaust and a snorkel.

how much rpm you need said in 3rd to reach full boost and which it is .. ?

 

[Hulsty]

Up a long hill home from work in ~33c ambient temps I got 10psi at 2300rpm peaked at 12-13psi ~2900rpm, was hitting 430c EGT post turbo near the top of the hill. I'm hoping 3'' exhaust and dump (if I cant get one?) and a tune will bring it in earlier.

 

[jake2far]

It took me awhile to find this posting but I think it could help you.
https://forum.ih8mud.com/diesel-tec...-fuel-adjustment-power-increase-answered.html

Read it and let us know,


Jim

 

[Tapage]

Up a long hill home from work in ~33c ambient temps I got 10psi at 2300rpm peaked at 12-13psi ~2900rpm, was hitting 430c EGT post turbo near the top of the hill. I'm hoping 3'' exhaust and dump (if I cant get one?) and a tune will bring it in earlier.

Interesting .. in a 13B-T I expect as same as my 1HD-T it could come sooner .. but it's not bad at all ..

 

[Hulsty]

I'm hoping the exhaust and maybe some fueling mods (EGT dependant) will get it on boost a little earlier.

 

[jake2far]

It took me awhile to find this posting but I think it could help you.
https://forum.ih8mud.com/diesel-tec...-fuel-adjustment-power-increase-answered.html

Read it and let us know,


Jim

The reason I posted this, it shows how to adjust the injection system to provide additional fuel sooner without changing the total volume. More fuel at a lower rpm should mean faster spin up, same volume of fuel at top rpm means egts should be the same.

Let us know if it works out.

Jim

 

[Hulsty]

Interesting read, I will have to find more info on the adjustments and what they do. Sounds like the "Guide Bushing" will get more fuel coming on sooner without altering maximum fuel to hopefully bring on boost sooner.

 

[danhr]

I am the author of that posted link. I know with all of the settings including full fuel, boost compensator, guide bushing, there is no way one can get more boost at lower rpms. Atleast that is what I have experienced. Sadly but truly 13B-T and CT26 are not so good of a match.

 

[Tapage]

I am the author of that posted link. I know with all of the settings including full fuel, boost compensator, guide bushing, there is no way one can get more boost at lower rpms. Atleast that is what I have experienced. Sadly but truly 13B-T and CT26 are not so good of a match.

should be then the same CT26 as Mr. T run in all 1HD-T .. which can explain why it's that nice and well fittet in a 4.2 and not that well in a 3.5 ..

 

[brownbear]

seriously just add a bit of fuel. Too much fuel will be black. But a little is not noticeable on the exhaust.

The extra fuel brings on boost quicker. You can shim, but it will only add a little bit. Best to just use a boost controller. Or make one. The Dude describes a 5 buck way to make one, that is what I did.

If you add fuel you need a pyro gauge.

Everyone talks about replacing turbo's etc...what are you all on fawking glue? How about ensuring his fuel is set up right and matches where he lives? Or if the timing is right?

Tune up first. I am attuned to do the easy stuff and cheap stuff first. You guys want to spend a grand first.....jeeze


Remember I'm smiling as I type.

 

[brownbear]

Oh to add... have you looked at the turbo itself for condition? Such as end play or rub in the housing? Sometimes that causes low end boost to disappear. I had it on a company diesel I drove once. Too lots of power to make the stuck turbo spin.

 

[Dougal]

The boost compensator has a massive effect on boost arrival. If the diaphragm is perforated (worn) then it won't open up and you need a whole lot more revs to get boost.

Take the line off to the boost compensator and blow down it. If you have any leaks or loss of pressure then it needs looked at.
Made a massive difference to my Isuzu. Think it had been broken for about 15 years prior.

 

[danhr]

I increaed the fuel by turning the screw clockwise. No increase in smoke. No early boost. And no difference in EGT.

I went further by removing the lock nut and screwing in the 'all thread' bolt to a point so that just enough threads are there to hold the cap nut. (i.e. there is no locknut now, just the cap nut holding it) Still nothing.

There is no end to amount of tightening the all-thread bolt. I don't feel it pushing anything.

Suggestions?

The existing CT26 turbo, when I hold the impeller by the nut (the air filter intake side) I can move it up-down-left-right by 1-2mm. Is it shot? The impeller spins freely.

Since I can't use the CT12B I have... And I have asked this before ... Is CT20 a good replacement? I can get it cheap sine there are a lot of 2L-Ts with cracked head and everything. Since CT20 is smaller than CT26, won't it spool faster? All I want is 14PSI max.

 

[Dougal]

I increaed the fuel by turning the screw clockwise. No increase in smoke. No early boost. And no difference in EGT.

I went further by removing the lock nut and screwing in the 'all thread' bolt to a point so that just enough threads are there to hold the cap nut. (i.e. there is no locknut now, just the cap nut holding it) Still nothing.

There is no end to amount of tightening the all-thread bolt. I don't feel it pushing anything.

Suggestions?

It sounds like the root of your boost problem might be a fuel pump problem. But I don't know the details of the 13BT pump.

The existing CT26 turbo, when I hold the impeller by the nut (the air filter intake side) I can move it up-down-left-right by 1-2mm. Is it shot? The impeller spins freely.

Since I can't use the CT12B I have... And I have asked this before ... Is CT20 a good replacement? I can get it cheap sine there are a lot of 2L-Ts with cracked head and everything. Since CT20 is smaller than CT26, won't it spool faster? All I want is 14PSI max.

If it's not smoking (turbo smoke is blue, like shot rings in a petrol engine) and the wheels don't touch the housing. Then the turbo is fine.

I wouldn't make any mods to the turbo until you get to the bottom of the fuel delivery issues.

 

[Tapage]

I increaed the fuel by turning the screw clockwise. No increase in smoke. No early boost. And no difference in EGT.

Edit .. re think ..

are you adjusting the boost compensator screw or the IP screw .. ?

 

[danhr]

Tapage:

I adjusted the max fuel screw. Boost compensator all-thread rod is screwed in full.

What will happen if I use a longer all-thread rod for max fuel adjustment? Will it mean more fuel?


I have been told this:

(And this is important for all you folks @ iH8mud)... There is NO way one can increase the fuel at lower rpm. What 'max fuel screw' does is that it injects more fuel at full throttle. E.g. at half throttle the fuel injection will remain same regardless of 'max fuel screw' adjustment.

Boost compensator indirectly controls the 'max fuel' adjustment. Again, there is no way to adjust fuel at lower rpm. Some argue that when they tinker with boost compensator and or max fuel screw they see soot at lower rpm. That is because when you press the accelerator pedal (regardless of how much you press), full fuel is injected. When desired rpm is reached, the governor realizes and adjusts the injection to settle the rpm.

I am told that in order to change the ratio, I will need to redo the pump. It will mean adjusting rack, governor flywheel / governor characteristics.

 

[Tapage]

That is because when you press the accelerator pedal (regardless of how much you press), full fuel is injected. When desired rpm is reached, the governor realizes and adjusts the injection to settle the rpm.

I'm not totally sure about this part .. but by my experience playing with my IP .. that's what happen

YouTube - Marilu Nasty Fuel Setting

you tell me ..

YouTube - Marilu EGT's / Boost

I am told that in order to change the ratio, I will need to redo the pump. It will mean adjusting rack, governor flywheel / governor characteristics.

reuild the pump it more than calibrate .. it's re adjust or replace worn out part .. in my books.

 

[danhr]

Tapage:

The diesel pump people here do not know anything. All they do is adjust the pump so that there is no smoke and less fuel consumption. They do not know what performance means.

If I have to rebuild pump, the only way is to first learn myself what to 'adjust' or work on and then instruct the diesel mechanic. But I don't understand anything in FSM.

The other way is to install a new IP. I am trying to locate a 14B-T IP as of now but so far I am not able to find one, locally.

I saw your video. When I adjusted the fuel settings I found no such behaviour.

 

[Dougal]

Tapage:

I adjusted the max fuel screw. Boost compensator all-thread rod is screwed in full.

What will happen if I use a longer all-thread rod for max fuel adjustment? Will it mean more fuel?


I have been told this:

(And this is important for all you folks @ iH8mud)... There is NO way one can increase the fuel at lower rpm. What 'max fuel screw' does is that it injects more fuel at full throttle. E.g. at half throttle the fuel injection will remain same regardless of 'max fuel screw' adjustment.

Boost compensator indirectly controls the 'max fuel' adjustment. Again, there is no way to adjust fuel at lower rpm. Some argue that when they tinker with boost compensator and or max fuel screw they see soot at lower rpm. That is because when you press the accelerator pedal (regardless of how much you press), full fuel is injected. When desired rpm is reached, the governor realizes and adjusts the injection to settle the rpm.

I am told that in order to change the ratio, I will need to redo the pump. It will mean adjusting rack, governor flywheel / governor characteristics.

Can you post a picture of your fuel pump?
If it's an inline pump (like the 3B and my Isuzu) then winding the boost compensator rod out increases off-boost fuel.

The boost compensator simply restricts fuel until the necessary boost has been produced. Disabling it will give you full fuel with no boost, this will give faster spoolup but also some soot until boost has arrived.
With it tuned properly you get no smoke but also fast turbo response. It is a balancing act.