Thread: Raising turbo boost pressure D2

G'day,some food for thought before anyone spends up big

I have been thinking about upgrading my chip and was thinking TRS in ADL as coopers here in sydney use them ( they are "the knowledge' round these parts!), conservative chip and they boost the power in the low rev range where the torque is, not like others that just make your engine scream to 4200rpm. coopers dyno your car before and after to make sure all is well. $800! drive in and drive away (and they use your chip so all the settings remain no need to learn the security and code in the injectors)

So for interest I just tweeked my wastegate. ( i have nanocom)

stock was pumping 15.7 psi boost at the manifold.(212kpa)
ECU limit is 21 psi, so I shortened the wastegate modulator to give me 19.2 psi! ( 237Kpa, too chicken to go to 20 just yet)

3.5 psi for free, and what a difference when you give it some boot.

Now I am thinking of getting a D2a intercooler ($300-350 from TRS) which the dude at TRS said would give an extra 20Kw of power to the road! (and lower the EGT for the high boost operation).

so for a wastegate tweek and a D2a intercooler I reckon I'll get all the boost increase I need without having to worry about & $550 bucks for chip/ $1200 for a I/C and then the EGT gauge and boost boxes to fool the ECU that the boost isn't over 21 psi.

if its not enough at most I have spent is $350, much of which would be recoverable on fleabay i reckon.

When done I'll get it dyno'ed at coopers and post the graph.

Q. Any one got a max boost figure for a chipped td5 please with a boost box on it?

cheers

I've been following this thread with interest - I've had a TRS chip some 6 months now and the performance enhancement is amazing. Now i have installed a boost gauge and I measure the boost from a tee takeoff situated between the intercooler pipe and the waste gate solenoid and my boost will max out at 17.5 with the boost gauge needle fluttering. Recognizing that there will be pressure losses depending on where you measure from etc does the fluttering needle indicate that the ECU is doing it's job and not allowing overboost (beyond 20psi or whatever it is programmed to) or do i still have leeway to steal another 2psi ??


onebob

ONEBOB,

to follow on, I believe the ECU get its boost reading from the MAP/IAT sensor at the inlet manifold, the nanocom reads the same boost, then I reckon that your 17.5 psi from the intercooler line would be something less at the manifold. 2 psi drop over the I/C has been suggested elsewhere on the forum, this would equate to the 15.7 psi boost I had at the manifold as stock setting before I tweeked the wastegate modulator.

I am assuming here you have not adjusted your wastegate from stock.

And this would leave some room for wastegate adjustment to squeeze it up to 20 psi at the inlet manifold. No idea why your boost gauge would flutter though sorry.

Originally Posted by onebob

Now i have installed a boost gauge and I measure the boost from a tee takeoff situated between the intercooler pipe and the waste gate solenoid

No point in measuring the pressure there. You need to measure it at the inlet manifold if you want to know what the actual pressure is that you are sending into your engine.

Fluttering needle is to be expected when measuring from that point. You will find that if you move to the inlet manifold it will take out that flutter. As you have already identified it is caused by that solenoid opening and closing. It indicates that it is functioning correctly.

Originally Posted by alpick

2 psi drop over the I/C has been suggested elsewhere on the forum,

Pressure drop varies depending on the system and pressure level. It's not 2 psi at all boost levels. Different intercoolers will vary too. I recently upgraded to a larger intercooler and that caused a 3psi drop over the standard D2a intercooler.



Increasing the boost pressure is certainly an easy way to get more power, can assist with fuel economy too. A chip can be complimentary to that as well and assist with even more power. A larger intercooler is nice too to get colder denser air into the engine, again increasing power and combustion temperatures. The thing to identify is where your limit is and what you are trying to achieve. I have spent near on $5,000 on performance parts now, and hopefully with the final stage of installing my VNT and Ashcrofts Heavy Duty Torque converter will be at the level I've been looking for (I'm happy with my up high power, looking for that low down grunt now).

Thanks for your thoughts fellas, that's confirmed my understanding. And yes! my waste gate hasn't been adjusted from stock i gather 'cos the lock nut was seized solid and the knurled adjuster still is. This weekend I'm installing an air shifter CDL and after that will have a go at the waste gate adjustment and try for 2psi more using the instructions posted earlier in this thread. I'm thinking of working up to 2 full turns of the the knurled adjuster and see how she goes.

onebob

"Now I am thinking of getting a D2a intercooler ($300-350 from TRS) which the dude at TRS said would give an extra 20Kw of power to the road! (and lower the EGT for the high boost operation). Q. Any one got a max boost figure for a chipped td5 please with a boost box on it? cheers[/QUOTE]"


Hi there

In relation to raising the boost with no other mods. Personally, depending on what sort of climate you live in I would consider the ecu remap before you spend your hard earned on an intercooler. This will compiment your rise in boost pressure, and you may find you can back the boost off a bit and still have more power with the remap, or just go for more power

My DIIa is running 20psi as I am, like you, sceptical about pushing it further, and for what benifit. I have a stage 2 remap done by JC and a boost box to ensure that fuel cut doesn't happen with that uncontrolable spike that most turbos produce when then come on to boost quickly.

I have a slightly modified, free flowing exhaust and to be honest I would not attempt to get any more power from my engine withour some further significant mods.

Even though I have plenty of power on tap now I am reluctant to push the vehicle hard all the time as the additional power and torque will no doubt have adverse affects on other things. eg - general reliability and auto trans life span.

Have not had my LR on a dyno but would be interested if anyone in hobart can offer the service.

Oh and an extra 20KW on to the road is a huge claim from an intercooler upgrade. Given that there is about 20 - 30% of power dropped through the driveline that would mean a huge engine KW gain just from an intercooler upgrade. Do your home work and speak to the LR specialists that are not also salesman, seems to be plenty of good blokes on here willing to give free advice.

Cheers

Dave

Thanks Dave,

I acknowledge being late to the game of driving a Td5 and not wanting to rehash covered info too much I have read all I can find on the forum re getting more pump from a Td5. There is not one single post that covers all the aspects and from what I have gleaned, if you want to find the amount of power increase you need the order of attack is,

1. Adjust the waste gate.
2. Upgrade your intercooler.
3. Chip upgrade. (egt gauge req'd now)
4. Further I/C upgrade to help lower EGT/ raise power
5. Upgrade turbo
6. Fit Chevy Big block!

All of the above place extra strains on components downstream of the air filter!

One of the most trusted gurus on here posted that one of the best things you can do for a D2 is fit a D2a I/C.

So my aim is to do 1 and 2 and see what I get to help tow the trailer and post the dyno result to get quantitative info for others to see.

Maybe I'll get hooked on grunt and go to 4/5.

Cheers

Originally Posted by alpick

Q. Any one got a max boost figure for a chipped td5 please with a boost box on it?

There is a difference between max and reliable levels. I don't know the max levels, but 20psi is considered to be the safe level to push it to. If you search in this section you'll find a thread that I began which discusses this...