Increased Boost Psi

[kingman]

I would like to increase boost on my 2.8TD...I have the standard exhaust and its factory 10psi would 14/ 15 psi be too much??

[JJCarEnthusiast]

how would you increase the boost? i heard about the washer method to increase the boost of the turbo by making the the waste gate open earlier. this would be a nice mod. i dont know about how much boost the 4JB1 engine can take. but as far as i know, in a mitsubishi 4d56 2.5 diesel engine, the maximum boost (psi) that the engine can take is about 13-14psi. i dont know if its in any relation

[BUSHPIG]

ive just fitted a boost switch to my exturnal waste gate with a 10psi spring as i have been told the 2.8tdi bighorn can runn up to 15psi(tell me if im rong) so now ive got 10psi std and 15psi at the flick of a switch. im looking forward to the first tow i do as it should have a bit more power on the hills

[Fly3r]

My Mu 3.1t/d is boosting 14psi and cold weather can get to 15psi. I have a boost controller that sits between the turbo and the vacuum thing on the waiste gate. I know of other 2.8's being boosted that high.

The concerns with increasing te boost is:
- make sure that with the increase air you also increase the fuel. otherwise your engine will run lean, and then hot and most likely cook the engine(busted head gasket or something like that)
- From my experience anything over the 14/15 you don't get enough benifit from the higher boost to warrent the extra wear and tear the boost would cause

If you do put one in, make sure you increase the fuel, you can do it with a socket and a screw driver. a way to tell wether you are geting enough fuel is when you have your foot to the floor you stil get a little bit of smoke out the exhaust.
btw I put a disclaimer on this...

[BUSHPIG]

do you know of hand how many psi fuel increese you need to make? or is it more of a case of just ritchn it up til u stil get the smoke you were talking about

[jezza]

My Mu 3.1t/d is boosting 14psi and cold weather can get to 15psi. I have a boost controller that sits between the turbo and the vacuum thing on the waiste gate. I know of other 2.8's being boosted that high.

The concerns with increasing te boost is:
- make sure that with the increase air you also increase the fuel. otherwise your engine will run lean, and then hot and most likely cook the engine(busted head gasket or something like that)
- From my experience anything over the 14/15 you don't get enough benifit from the higher boost to warrent the extra wear and tear the boost would cause

If you do put one in, make sure you increase the fuel, you can do it with a socket and a screw driver. a way to tell wether you are geting enough fuel is when you have your foot to the floor you stil get a little bit of smoke out the exhaust.
btw I put a disclaimer on this...

Its the other way around, when you increase boost there is more air so the exhaust temps are lower as the extra air charge helps keep the combustion cool. When you increase fuel to match a increase in boost that is when you start getting high exhaust temps, it is best to run a egt gauge to monitor the exhaust temps and tune it properly other wise you risk cracking heads.

[BUSHPIG]

so should i just be aim'n for the same exhaust temp as ive got running the stock 10psi? when running 15psi?

[geeves]

Diesels dont work like petrol and within limits the mixture is unimportant. The diesel engine always takes as much air as it can and power is controled purely by adjusting the fuel.ie in cruising the mixture is incredibly lean. You will get an incresase in power by just increasing the boost because the boost compensator in the pump will increase the fuel but there are more gains by adjusting the fuel and pump timing but these do come at the cost of higher EGT and a risk of engine damage although we have vehicles that have done over 100000km with these mods. All at own risk.

[BUSHPIG]

the reason i ask is im a machanic welder faborcater by trade but have never realy had much of a chance to toy with diesel's b4 and would like to get the most out of it. ive got a 3.1tdi outta a 93 bighorn ive rebuilt with new pistons and liners ect but i dont wanna put that in till the 2.8 shit's its slef whitch is in verry god condition that was recoed(with full recipts) b4 i got the truck like 55,000km ago. and ive serviced it every 4,000km in the 55,000k ive had it

so im shure if i boost the 2.8tdi up i can get a fair few k's outta it b4 it let go.

[mulover]

If you have a bigger exhuast - 2.5 - 3" then you can run up tp 16psi very safely. the bigger exhaust helps the gasses excape easier meaning less heat build up. Once you have increased the boost, tune the fuel pump so you get just a little bit of smoke under heavy acceleration. I've been running mine at 15-16 psi boost for the last 3 or 4 years and had no prblems.

[ONO2HI]

I had a mate whos 3.1 was doing 23psi it handled that for 6 months then blew up, and another guy i know had 18psi from his 2.8, he ran it like that for over two years, them changed the turbo to a subaru 1, and has that doing 15psi, but pulls better because of the more volume it pumps... still goes mint today

[kingman]

Ill be purchasing a manual boost controller and increasing the boost to 14psi then try or get my machanic to turn up the fuel however,in terms of "More Air" should I also add a Ram air filter as well to my engine...at the moment I have a K&N replacement filter that sits in the original box...

Another questions is with the exhaust i was thinking of doing 3" from the turbo into 2.5" out.Or should I go with 3" from turbo right out? Your valued feedback is appreciated..

[kingman]

Moreover, can some one take a pic of where exactly is this fuel adjustment screw on the 2.8 td??

[geeves]

Kn is just as good and possibly better than the ram air filter. Some pods might breathe a little better but you loose the ability to fit a snorkle down the track and the risk of water in the engine when off road is far higher

[mulover]

kingman,
I'd stick with the K&N replacement you have, it will be already letting more air in. As the turbo is running at higher boost, you are getting more air in anyways, its more to do with adjusting the fuel to suit.
I think the 3" is a little over kill on the mu, To do a 3" off the turbo can be a little tricky. But if funds allow and you wanna, a 3" sounds good !!!
If you search the old fourm, I'm pretty sure there was a thread there that had a photo in it. If you find it could you please let geeves know as he may be able to out it in the FAQ somewhere.
If you go in through the wheel arch and look in behind the fuel pump, you will find an aluminium cap over a bolt head, Thats if no one else has been in there first.

[kingman]

If I do the 14/15 psi boost increase & fuel increase, when driving normally should i now expect a huge reduction in fuel economy or should this actually increase the fuel economy since the engine should be more "efficient" with these mods?

[mulover]

You will probably hardly notice it at all.

[kingman]

thanks guys..

[jellis]

would i need to run an intercooler set up if i increased boost to 15psi??? or is it still within what the motor can handel

[kingman]

With the increased boost and exhaust and fuel...would the 2.8TD come even close to the performance of the new dmax 3.0 tdi...?