more out of 2.8 turbo deisel

[redtruck]

I was wondering what I can do to get a bit more power from my 96 model patrol. It has the 2.8 ltr turbo deisel in it.

[GQ TROL]

Send a PM to vn15 here on the board. He runs a RD28-T which has been seriously modified:

Garret ball bearing turbo,
HPC coated exh,
Big front mount intercooler,
PowerShot propane injection,
Big plenum style inlet manifold,
12mm plunger in the fuel pump,
Reco’d injectors.

Not sure what HP its making, but I’d say it would spank a few mild TD42-T’s!!!

[turbogu]

Yeah like gq trol said, pm vn 15, his 2.8 is one serious bit of gear, mind you its had some hefty dollars thrown at it, fo a little motor it will certainley hold its own against the big boys

p.s vn15, hope you dont mind me putting the photo's up but every one needs to see this!!!

cheers sean

[turbogu]

Yeah like gq trol said, pm vn 15, his 2.8 is one serious bit of gear, mind you its had some hefty dollars thrown at it, fo a little motor it will certainley hold its own against the big boys

p.s vn15, hope you dont mind me putting the photo's up but every one needs to see this!!!

cheers sean

[bogged]

I was wondering what I can do to get a bit more power from my 96 model patrol. It has the 2.8 ltr turbo deisel in it.

How much do you want to spend on it? That is your first question. Then you can go from there

[vn15]

You need at least a bigger dump+exhaust and a good IC. Set to max fuel delivery(allmost 2turns) the std. pump will flow 55cc. around 140-150hp.
Over 2 turns and the revs will not go back to idle.

You should modify the inlet on the std. intake as well, it is 35mm ID!!
You can modify the boost compensator as well for more low down torque.

If you want more, then you need bigger plunger and a bigger turbo as the T25 is way too restictive. Not enough air on the fresh side and backpressure on the turbine leading to high EGT.

And a new plenum for better flow

I am very happy with the power even with 37" tires and 6-7" lift.
Have good power/torque over a wide range, from 2000rpm. and all the way to redline, 5000rpm. Boost is currently 16psi and fuel delivery is 95cc, std. is 45cc!!!

[GQ4.8coilcab]

A mate of mine took me in a spin in his 2.8 with a 3inch dump, disco potato, boosted pump and big intercooler. It was fricken awsome With the disco potato, boost come on really early but after bout 3300rpm there was nothin.

[chimpboy]

What's a plenum?

It's the air space after the throttle body, before the cylinders. Its basic purpose is to give a non-turbulent source of air to the engine, since incoming air can be moving in a particular direction (or several directions) etc, as well as to make sure all the cylinders get equal amounts of intake air. So it goes air intake -> plenum -> motor instead of just air intake -> motor.

Imagine the difference between flushing a toilet that has a cistern (= plenum) and trying to get the same effect with a garden hose (= air intake without plenum).

Okay, that may be a bad analogy

Since it provides "free" air after the throttle body a large plenum can cost responsiveness, so it's a case of the right size plenum, not just bigger-is-better. Others will be able to give a better answer than me anyway.

Jason

[vn15]

A mate of mine took me in a spin in his 2.8 with a 3inch dump, disco potato, boosted pump and big intercooler. It was fricken awsome With the disco potato, boost come on really early but after bout 3300rpm there was nothin.

I was thinking of getting the disco for my truck, but the turboguy said that if I wanted power higher up in the rev range, it was too small, so he knew what he was talking about I guess.

Had pretty much the same thing with my old setup, T28/25 hybrid. Boost allmost from idle and then it was all over, useless on the road.

I have a turbo called GT2871R, Comp A/R.60 and turbine A/R.86. You will get boost a little earlier with turbine A/R.64 but sacrifice top end power.

it`s important to let the engine breath, not just to gain power, but to prevent melted pistons and a cracked head.

Dunno if I have the perfect plenum size, but was advised 1,5 times the engine volume. The one I have is 4,5l.

[mundy]

Had pretty much the same thing with my old setup, T28/25 hybrid. Boost allmost from idle and then it was all over, useless on the road.

you have any more details u willing to share about this set up? as i have blown my turbo on my 2.8 and are tryn to find out what turbo to replace it with, considering i wont bosst to come on as early as possible

[vn15]

Had pretty much the same thing with my old setup, T28/25 hybrid. Boost allmost from idle and then it was all over, useless on the road.

you have any more details u willing to share about this set up? as i have blown my turbo on my 2.8 and are tryn to find out what turbo to replace it with, considering i wont bosst to come on as early as possible

I got boost allmost from idle with the old set-up because I have 12mm plunger in the pump. If you want boost early with a std. pump, get a ball bearing turbo, but much smaller than the one I have now(GT2871R.86ar) I think a GT25 would work well with a std. pump.

If you also adj. the boost compensator for max low down torque (reduce all tension on the boost comp. spring), and 1/2-1 turn clockwise on the fuel screw, and a bigger exhaust , and IC the truck will be much more resposive.

[mattstar]

Does blocking the EGR valve do anything? and do you have to adjust boost after blocking it?

How does one go about adjusting the boost compensator, and were abouts is the fuel screw located?

[vn15]

Does blocking the EGR valve do anything? and do you have to adjust boost after blocking it?

How does one go about adjusting the boost compensator, and were abouts is the fuel screw located?

An "How to" link regarding boost comp. adjustment. From a Dodge site this one, but same pump type (VE) as the RD28T, but in order to adjust boost comp. spring tension on a Patrol pump, you have to loosen five 6mm bolts on top of the pump, remove the cover on top and lift up the diaphragam/adj. pin assembly, turn the star wheel clockwise for more low down torque.

NOTE. The adjusting pin has a deep side and shallow side at the bottom of it, the deep side towards the front of the truck for more fuel.

Hope you understand some of it

http://dodgeram.org/tech/dsl/more_power/Power_ve.htm

fuel screw is located at the back of the pump, towards the fire wall.

[mattstar]

Cheers, thats a really good link. I wanted to ask though after doing each mod. did you have to go back and adjust the smoke screw?
I'm thinking of a touch of all these mods should equal a nice little increase without sending my egt's through the roof?
What is the max egt your letting your 2.8 get too?

[Josh_WA]

I have a 99 2.8td GU. So far I have done

* 3" Exhaust and 2.75" Dump pipe - made a good difference to drivability and sounds mint
* Blocked EGR - reduced smoke to nearly zero ( quite an achievementfor a 2.8 and improved response)
* Tunit upgrade chip - improved the vehicle out of sight
* removed the hiclones that the old owner had in
* K&N air filter

All these mods have made my car really nice to drive on the 33's, power and torque come in at much lower revs and the motor feels less restricted, like when i put my foot down it actually feels like its pulling all the way instead of dying in the arse at 3000rpm liek it used to.

Cheers

[mattstar]

Hi Vn15,
I read the link you posted untill I understood everything it was describing acuratly, however I still have a couple of questions before I tamper with mine.
In the link it mentions that there's a banjo fitting on top of the pump assm. to measure inlet boost pressure; I couldn't see that on my 99GU 2.8

On top of my injector pump it is in 2 peice's, it's hard to describe but there is "cover that has 4 bolts holding it down, 3x m5 allen key head and 1x flat blade screwdriver" Below this is a small "housing" that has a futher 2x flate blade screwdriver bolts.
What I want to know is do I remove the top cover or the whole top "housing" to get to the Low manifold pressure (boost) fuel delivery adjustment screw (t-25 torx with lock nut) I could just pull it off for a look but the diesel return line banjo is on the back of this housing and I don't know if it's full of diesel.
Now I understand that they are the same style pump, but one is off an 94-98 american diesel, mine is an electronically controlled Jap engine, Will I have to get it re-maped or programmed after I do these mods? I would like to be able to just moddify the mechanical settings of the pump as described in the link to increase fuel delivary and pressure By Turning the diaphram and lowering the boost compensator.
So what I want to ask is, Did you moddify your pump and is it the later GU model electric pump or the earlier mechanical GQ pump?
And is the princible still the same when modding an electronically controlled injector pump/engine

[mattstar]

Also...
Being that it's electronically controlled, the injector pump and motor, will changing the internal settings (diaphram, boost compensator etc.) on the injector pump adversly effect the factory ecu settings?

[vn15]

Mattstar:

If you have a GU 2.8, get a chip as Josh_WA has done.. My pump is a mechanical one, set up to deliver around 100cc per 1000 shots, std. pump delivers 45cc of fuel.

Have water/meth. injection to decrease EGT, still power increases, you can feel the extra power and see the blacksmoke allmost dissapears., EGT goes up to 500-550 deg.C post turbo

Have 6" lift and 35" tires and it totally smokes a stock LC80 4.2td with 31" tires, drove one last week and it was so slow compared to my truck.

[mattstar]

I was chatting to a couple of mechanics at work here with reguards to "tweaking" it and the electrical side of the motor reaction, and what I'm hearing is that a small amount of adjusting shouldn't, Do any damage.
I am thinking I will open it up (carefully) and have a look, if it's similar or the same set-up I will mark original spots and see what I can get out of it.
I don't want a race truck, just something a little more from below 1500rpm
I am looking at the chip but have a couple of mods planned for the near future, I want to be able to have these done before I get a tunable chip installed