2.5 Litre EGR Mod

[jjohn]

I have a laser cut plate for the YD25 PM me for delivery if you need one.

 

[scooba_285]

i gotta get the egr pipe off first lol, its done up so tight the ratchet keeps twisting and slipping off

 

[shanus]

Hi guys, been reading the forums for a while now, first time post!
After reading through this thread, could someone explain a little about what happens to the exhaust gases once the blocking plate is in? The turbo obviously spools up and tries to push the gases up the pipe, but once blocked does this create any backed up pressure?
Also, what happens when the egr valve opens? There is nothing to let through so is there any backflow into the egr pipe from the intake side at all?
A couple of Q's i hope you could answer.
Thanks.
Shane.

 

[jjohn]

The EGR comes out of the exhaust before it gets to the turbo, so no boost there.
The ex would simply go up the EGR piping until it meets the plate. Block both ends if you like.
If you block it at the inlet end your plate is on the inlet manifold so no back flow into the piping from that end either.

 

[tweak'e]

After reading through this thread, could someone explain a little about what happens to the exhaust gases once the blocking plate is in? The turbo obviously spools up and tries to push the gases up the pipe, but once blocked does this create any backed up pressure?

yes it does. as the exhaust is not being bled off via the egr the exhaust back pressure will be higher which spins the turbo faster and creates more boost.

Also, what happens when the egr valve opens? There is nothing to let through so is there any backflow into the egr pipe from the intake side at all?

yes boost will fill the egr tube. not really a problem but you can block it at both ends if you wish.

 

[ToyTruck]

yes it does. as the exhaust is not being bled off via the egr the exhaust back pressure will be higher which spins the turbo faster and creates more boost.



yes boost will fill the egr tube. not really a problem but you can block it at both ends if you wish.

@tweak'e
Could this increase the chance of surge? From what I've read high EMPs or high load/gear + low rpm + high throttle input = surge.

 

[tweak'e]

doubt it.
at high throttle egr is off anyway. i don't think egr would make the turbo go out of its map blocked or not.

the only problem i see is that the turbo is often made a little smaller to keep it revved up to counter act the egr reducing drive on the turbo. top end performance is sacrificed a bit to do that. block the egr off and turbo is forced into a possibly less efficient part of the map.

 

[Krankin]

doubt it.
top end performance is sacrificed a bit to do that. block the egr off and turbo is forced into a possibly less efficient part of the map.

so youd be agaisnt the egr mod then???

 

[tweak'e]

not at all. the gains still outweigh the losses.

 

[Krankin]

Ok, no worries.

 

[shanus]

Sweet thanks for your replies.
knowing that the egr is piped before the turbo makes it a little easier to understand how it all works.
I think i will do this mod to try and achieve an outcome of less smoke.... seems to be a regular occurance with the 2.5, which is what brought me to these forums searching for answers.
Usual story, i see smoke in the headlights behind me when under load. Also smokes quite a bit when the heat button is pressed which raises the rpm. i've always had a habbit of flicking the heat switch and letting it warm up while i lace up the work boots. Doesnt smoke every time, but when it does it's most certainly a fuel kinda smoke.... stinks of fuel anyway...
Thanks for your help guys.
shane.

 

[mad possum]

ERG mod done, instant change in how the engine handles, more even power, no lag spot and like so many other ppl have noticed I dont need to change down gears for hills I used to beforehand.

 

[lkdvs22]

Did the egr mod last night. Noticable increase in power down low where its needed. Made out of 1.5mm galvanised steel. Blocked on left hand side of egr tube.

 

[Shardy]

WOW! what a long thread and yes! i read it the whole way through! so ive just grabbed some stainless from the workshop and plan to do this mod on the weekend!

Thanks everyone for the posts and answers to questions cause after reading this thread i have no questions of my own!

 

[Krom]

Does it matter if the bit of steel i cut to block it is not to same size as the gasket? My blocker is about 3mm bigger all around and there is overhang all the way around the valve. If that makes sense.

 

[justa6]

Yeah great thread, read the whole thing too. I've only got 1500km's on mine and already keen to do this. my dad has a chipped d40 which smoke's pretty bad when up it, so will do both.

Krom, i can't see it being a problem, just won't look as neat. get a flapper disk on an angle grinder to take some off the edge's.

 

[Krom]

It's in there now. I used a stainless steel scraper that i bought for $2 form mitre rip off.

Power seems to feel the same but in stead of coming on at 2200rpm, it starts at about 1600-1700rpm. That's about the rpm im usually doing when i cant be stuffed changing down a gear so it has made the power curve much more practical.

Cant comment on smoke as the rear window is filthy from the dog pressing her nose against it haha.

 

[mr_cat]

Well after reading the whole thread and having my 09 with 50k blowing smoke and lacking low down power, I thought what the heck.

Grabbed some gal steel from Bunnings 0.95mm cut and drilled and installed. Real easy job as all bolts are easily accessable - didnt even have to remove battery.

So far I agree that the power range now starts around 1600 rpm as opposed to 2200 rpm previously. This makes the power band smoother.

Will check smoke and see if the lower power range helps towing the float.

But all in all easy and already see benefits.

 

[shan_b]

Keen to do this mod on my 2012 STR even though its only done just over 1000k's.
Not really fussed about the power benefits, just want to keep my inlet and cylinder head cleaner.

aaaaaanyway

Has anybody got a plate they are willing to sell??

Shan

 

[Hodge]

Did the egr mod last night. Noticable increase in power down low where its needed. Made out of 1.5mm galvanised steel. Blocked on left hand side of egr tube.

Ok so to be sure to be sure to be sure... I want to make sure i get this right.
The plate goes to the left side of the photo, block that up and put the pipe back in??