4m40 Tuning

[DWC]

Finally got around to doing the turbo and pump mods last weekend. WOW!!!
I also shaved 1.5mm off the plastic spacer under the diaphram as just turning the diaphram didnt make a huge difference.
The difference is amazing. It will accelerate!! I'll have to watch it when wet cause now I get tyre squeal turning out of my driveway under hard acceleration.
No more (maybe less) smoke than usual and temps are similar to factory taken from the EGR plate on the manifold. Max boost I've seen is about 10.5 - 11PSI at the intake manifold, so there will be some pressure drop accross the I/C. It is running with less boost at all speeds so i will be expecting some improvement in fuel consumption. It's getting mid 13's/100 at the moment so time will tell.
Cheers, Dave

[Dongskie2]

Finally got around to doing the turbo and pump mods last weekend. WOW!!!
I also shaved 1.5mm off the plastic spacer under the diaphram as just turning the diaphram didnt make a huge difference.
The difference is amazing. It will accelerate!! I'll have to watch it when wet cause now I get tyre squeal turning out of my driveway under hard acceleration.
No more (maybe less) smoke than usual and temps are similar to factory taken from the EGR plate on the manifold. Max boost I've seen is about 10.5 - 11PSI at the intake manifold, so there will be some pressure drop accross the I/C. It is running with less boost at all speeds so i will be expecting some improvement in fuel consumption. It's getting mid 13's/100 at the moment so time will tell.
Cheers, Dave

Awesome.

When I open up the top of the diaprahgm, should I be careful of diesel leaking? Springs jumping out?

I am too planing that shaving off some plastic limiter

[DWC]

No diesel or loaded springs. I'm down to low 12's to high 11's per 100k's now that I've fixed my leaky injector pump

[Meth'd_up_Mitsi]

I totally disconnected the wastegate on my Paj. It would hit 30psi when driven hard. But the average was about 27. The 4m40 has an overboost valve which vents at around 11psi. Remove this and you can run whatever boost you like. The stock intercooler is quite restrictive, as is the stock woven piping which will blow out at much more than 16psi. I made up new piping out of aluminium with silicone connectors. If you put an aftermarket fan under the stock intercooler to replace the stock crappy one it will drop EGT's by 50° as well as induction temps.. I had water methanol injection on mine which drops EGT's by an easy 200-300°C. And also bypasses the crappy stock intercooler efficiency.

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[_jkuruvilla]

Finally got around to doing the turbo and pump mods last weekend. WOW!!!
I also shaved 1.5mm off the plastic spacer under the diaphram as just turning the diaphram didnt make a huge difference.
The difference is amazing. It will accelerate!! I'll have to watch it when wet cause now I get tyre squeal turning out of my driveway under hard acceleration.
No more (maybe less) smoke than usual and temps are similar to factory taken from the EGR plate on the manifold. Max boost I've seen is about 10.5 - 11PSI at the intake manifold, so there will be some pressure drop accross the I/C. It is running with less boost at all speeds so i will be expecting some improvement in fuel consumption. It's getting mid 13's/100 at the moment so time will tell.
Cheers, Dave

Hey DWC,

Could you share picture details on this, I recently turned the diaphragm and definitely notice higher torque now, but what is the plastic spacer under the diaphram?

Cheers

[Bluepajee]

Heck yes! I've been slowly just getting mine road worthy. But have been driving it around with shite power and at 15/16ltrs.

Can't wait - please post details. I've got an egt sensor and boost sensor waiting to install before I start tuning it


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[DWC]

I don't have any pictures of the mod unfortunately. I got the info from a tuning thread on here, as well as a tuning thread on POCUK. With most pictures around that time being on Photobucket you may struggle to see them.
From memory, the plunger can be pulled up out of the pump housing and the plastic spacer is underneath the spring. Please do as much research as possible before doing this as I haven't looked at any of this for some time and my memory of it is a bit foggy.
Cheers