Omega Owners Forum

Chat Area => General Car Chat => Topic started by: conalnugent on 03 October 2013, 22:51:41

Title: 2.5td turbo boost info
Post by: conalnugent on 03 October 2013, 22:51:41
Been doing alot of poking about and have been reading interesting things about turbos.  What bar of boost does the 2.5td normally put out? Can the turbo be screwed and if so how?
Title: Re: 2.5td turbo boost info
Post by: Marks DTM Calib on 04 October 2013, 08:09:38
Cant remember the boost pressure but its a self regulating setup (so the boost pressure actuates the waste gate), boost is increased by 'adjusting' the actuator arm to the waste gate.
Title: Re: 2.5td turbo boost info
Post by: conalnugent on 04 October 2013, 10:20:49
Im mechanically minded but a bit of a green horn with turbos. Was researching the m51 bmw engine. So im right in saying turbos are either regulated mechanically or via the ecu? With the obvious mechanical type being the onethst can be screwed????

Also been reading about a volvo turbo a t5 turbo that appently can be used on the 2.5td thats susposed to have more boost and straightforward to fit.

Anyone on herw fitted a different turbo? 
Title: Re: 2.5td turbo boost info
Post by: TheBoy on 04 October 2013, 13:24:51
TD is about 1 bar above atmospheric when fully spooled.
Title: Re: 2.5td turbo boost info
Post by: TheBoy on 04 October 2013, 13:26:16
I think we got Omegatoys to about 1.4 above when we were playing with that, but had too many cooling issues. I think we knocked back to 1.2?

Omegatoy?
Title: Re: 2.5td turbo boost info
Post by: conalnugent on 04 October 2013, 17:20:05
Problem sloving time. Would a front mount intercooler be enough to keep her cold if not what other means could you cool it by?
Title: Re: 2.5td turbo boost info
Post by: Keith ABS on 04 October 2013, 20:49:35
  There is a small intercooler mounted under the front wing of the 2.5TD. Cant remember which side. Omegatoy did have his fan running all the time but it does reduce the fan life greatly before that burns out. It is set at quite a high temp setting before it cuts in IIRC
Keith B
Title: Re: 2.5td turbo boost info
Post by: conalnugent on 04 October 2013, 21:09:11
Yeah its just infront of the driver side front wheel looking from the bay its below the airbox buried under a lump of bodywork. Naw, no messing about, im for binning that intercooler as its tiny anyways and plant a nice big fat one up front. 

Cooling.... would wrapping everything to death with thst heat wrap stuff along with a front mount be enough to be able to up the boost a right bit?
Title: Re: 2.5td turbo boost info
Post by: TheBoy on 05 October 2013, 11:48:27
You really don't want to be taking the boost up that high. If you need more power, start with a better base.

Also, when tinkering, remember these BMW units are quite fragile. HG aside, they don't tend to fail in a repairable way. At 110C, you can pretty much guarantee cracked heads. BTW, 110C is 100C on an Omega gauge, and thats damped by 18s, so if its rising sharply, when it hits 100C, likely too late.

So any tinkering must be done with a Tech2 or similar plugged in read DDE's coolant temp, not instrument temp.
Title: Re: 2.5td turbo boost info
Post by: Seth on 05 October 2013, 11:51:28
  There is a small intercooler mounted under the front wing of the 2.5TD. Cant remember which side. Omegatoy did have his fan running all the time but it does reduce the fan life greatly before that burns out. It is set at quite a high temp setting before it cuts in IIRC
Keith B

Offside extreme front, behind the wheel arch liner ;)
Title: Re: 2.5td turbo boost info
Post by: TheBoy on 05 October 2013, 12:06:19
Should add, don't expect a prompt comment from Omegatoy, as he's over here at the moment - bumped into him down the pub last night :y

The bastard was roaring over my garage episode  >:(. Shall I let his tyres down :P
Title: Re: 2.5td turbo boost info
Post by: conalnugent on 05 October 2013, 15:26:37
Jezz. Dontet his tires down..... wont be able to get rid of him then  :y
Title: Re: 2.5td turbo boost info
Post by: r1 on 05 October 2013, 16:18:21
You really don't want to be taking the boost up that high. If you need more power, start with a better base.

Also, when tinkering, remember these BMW units are quite fragile. HG aside, they don't tend to fail in a repairable way. At 110C, you can pretty much guarantee cracked heads. BTW, 110C is 100C on an Omega gauge, and thats damped by 18s, so if its rising sharply, when it hits 100C, likely too late.

So any tinkering must be done with a Tech2 or similar plugged in read DDE's coolant temp, not instrument temp.

but the bmw ones are more powerfull
Title: Re: 2.5td turbo boost info
Post by: TheBoy on 05 October 2013, 16:48:21
You really don't want to be taking the boost up that high. If you need more power, start with a better base.

Also, when tinkering, remember these BMW units are quite fragile. HG aside, they don't tend to fail in a repairable way. At 110C, you can pretty much guarantee cracked heads. BTW, 110C is 100C on an Omega gauge, and thats damped by 18s, so if its rising sharply, when it hits 100C, likely too late.

So any tinkering must be done with a Tech2 or similar plugged in read DDE's coolant temp, not instrument temp.

but the bmw ones are more powerfull
Different map, thats all. OP already has a new chip which probably brings it near BMW spec.  BMW run the same turbo unit, and at the same 1bar pressure ;)
Title: Re: 2.5td turbo boost info
Post by: conalnugent on 05 October 2013, 16:57:49
Yup an awesome map which at the mo is being murdered by a boost leak. Finally figured out its leaking at the egr so will be temporary replacing it with another egr and in a week or so time replacing with a blanking kit.  Anyway, another question, the small rubber pipe coming off the egr, what exactly is it for? Obviously its boost messuring of some sort I think but can someone explain the theory of it.  What would happen if this pipe got blanked off too? Have seen a td thats had this little pipe intentionally blocked with a screw. What would be the result of doing this??

Thanks and sorry for all the questions im new to tds and am hungry to learn
Title: Re: 2.5td turbo boost info
Post by: conalnugent on 05 October 2013, 16:58:29
Ps what about the little pipe coming off the bottle of the inlet manifold? Whats its job?
Title: Re: 2.5td turbo boost info
Post by: TheBoy on 05 October 2013, 16:59:40
Blanking little pipe off will likely reduce power, as ecu cannot measure boost, so goes failsafe.
Title: Re: 2.5td turbo boost info
Post by: TheBoy on 05 October 2013, 17:00:37
Ps what about the little pipe coming off the bottle of the inlet manifold? Whats its job?
Ah, thats the one I thought you meant - thats manifold pressure sensor (boost sensor)

The one on egr is vac to actuate egr
Title: Re: 2.5td turbo boost info
Post by: conalnugent on 05 October 2013, 17:13:36
So blanking the egr one in effect will do nothing?
Title: Re: 2.5td turbo boost info
Post by: conalnugent on 05 October 2013, 17:38:27
If the egr is blanked that is
Title: Re: 2.5td turbo boost info
Post by: TheBoy on 05 October 2013, 19:39:14
So blanking the egr one in effect will do nothing?
Performance wise? Apart from a slightly better pickup during a gentle cruise, it'll do nothing except reduce economy slightly.  Assuming the EGR works.
Title: Re: 2.5td turbo boost info
Post by: conalnugent on 09 November 2013, 21:04:33
Quick update.  Still waiting on a made up egr but managed to get my hands on a boost gauge. The wee pipe off the bottom of the manifold was slightly gunked up so cleaned that out. Its boosting up to 1 bar on the button. Wonder what it will boost when I get this new egr on.  :y
Title: Re: 2.5td turbo boost info
Post by: TheBoy on 09 November 2013, 21:14:18
Hopefully, approx 1 bar ;)
Title: Re: 2.5td turbo boost info
Post by: Omegatoy on 10 November 2013, 17:45:18
I think we got Omegatoys to about 1.4 above when we were playing with that, but had too many cooling issues. I think we knocked back to 1.2?

Omegatoy?
yup ran it at 1.4/5bar and was very lively, inlet temps got a bit to high for motorway work though,but short blast its great, i finally settled on 1.2/3 as a good compromise but bear in mind before i booted it every time i flicked the switch for the intercooler fan,and also did this before big hills ,it did around 40k like this apart form fan burning out, never had a problem,
Title: Re: 2.5td turbo boost info
Post by: Omegatoy on 10 November 2013, 17:49:47
lol and yes was roaring at the garage episode purely because the boy was in bed at the time an didnt realise what was going on!
 ;D
now back in spain,just had a super tour on the quad up through river canyons and round lake! knackered now!

p.s and before the mrs used the car i always put the i.c. fan on and left it on just in case she got to lively with it which has been known to happen a great deal :-[ she aways came back and said why can i always hear the cooling fan even though the engine isnt running?
answer,oh its contrilled by a temp sensor dear till its been running a while it dont know the temp so it comes on automatically ::)
Title: Re: 2.5td turbo boost info
Post by: conalnugent on 11 November 2013, 12:59:17
PMSL  ;D  :y