how much boost is to much??

Post by **ash+aims** » Wed Dec 05, 2007 8:51 pm

g'day guys,
i'v just brought a GU 2000 model. im wonderin how much boost they run from stock? and how high can i go without side effects. ie high exhaust temp.
anyone have experience with this sort of stuff??
my ute is currently runing 9 pound(standard??). with a front mount inter cooler.
how much higher can i go??
also i know higher boost means higher fuel but how much??i.e 9 pound to 13 or 15psi, will it be a huge increase in fuel??

Post by **bogged** » Wed Dec 05, 2007 9:54 pm

ash+aims wrote:g'day guys,
i'v just brought a GU 2000 model. im wonderin how much boost they run from stock? and how high can i go without side effects. ie high exhaust temp.
anyone have experience with this sort of stuff??
my ute is currently runing 9 pound(standard??). with a front mount inter cooler.
how much higher can i go??
also i know higher boost means higher fuel but how much??i.e 9 pound to 13 or 15psi, will it be a huge increase in fuel??

you have to match higher boost with higher fuel input, otherwise you will get nasty EGT's and melt things... if your unsure, get it done by someone with a dyno... worth every cent.

Post by **marko** » Thu Dec 06, 2007 5:12 pm

more boost will give lower egts if fuel is not added. I would be fitting a 3'' exhaust before boost/fuel is adjusted, lot better performance. Any where between 10-15 psi is fine, if the correct amount of fuel is added

Post by **Hoonz** » Thu Dec 06, 2007 5:52 pm

how long to you want your engine to last

how much fun do you want to have

Post by **ash+aims** » Thu Dec 06, 2007 6:04 pm

yeah she's already got a 3 inch exhaust.

Post by **TRAKTOR** » Thu Dec 06, 2007 6:13 pm

Get over to a specialist diesel mech, they can do the pump and turbo tune up.
Full 3" system including dump pipe.
Mine's running 12 psi and at 100 on the M2 the egt is reading 300-350oC.
Dyno'd rear wheel 117hp.

Awesome difference to driveability, and have noticed bugger all difference in fuel economy. Just have to drive sensibly.......

Post by **PGS 4WD** » Thu Dec 06, 2007 9:39 pm

Its not a simple question as it depends on the adiabatic efficiency of the turbo, a larger turbo will produce more volume of air at lower air temps meaning lower exhaxut temps, larger exhaust housings are more laggy but less restrictive so make more power with less heat at higher rpm.
For your vehicle I suggest monitoring turbo outlet temps and see at which point the outlet temps go up a disproportionate amount, this is the practical limit of the turbo. Or see at what point on a dyno the power no longer increses when adjusting fuel and boost within safe limits, there is a point where increases in power come with very high exhaust temps unless you make a mechanical change, bigger turbo, intercooler etc.
Even though the exhaust temps are lower if you add boost and not fuel the cylinder pressure is higher, this is where the power comes from, so engine wear is increased to some extent. Low EGT's indicate that the fuel is combusting in the chamber more completely and not on the way out the exhaust port.

Joel

Post by **j-top paj** » Fri Dec 07, 2007 12:39 am

what engne we talking about?

Post by **philhod** » Fri Dec 07, 2007 7:57 am

j-top paj wrote:what engne we talking about?

I thought the 2000 GU Utes only came out with one motor

4.2 TD maybe!

Post by **philhod** » Fri Dec 07, 2007 8:04 am

j-top paj wrote:what engne we talking about?

I thought the 2000 GU Utes only came out with one motor

4.2 TD maybe!

Post by **philhod** » Fri Dec 07, 2007 8:06 am

j-top paj wrote:what engne we talking about?

I thought the 2000 GU Utes only came out with one motor

4.2 TD maybe!

Post by **GU_247** » Fri Dec 07, 2007 8:42 am

philhod wrote:
j-top paj wrote:what engne we talking about?
I thought the 2000 GU Utes only came out with one motor

4.2 TD maybe!

Say that again!!!!!!!!!!

Post by **philhod** » Fri Dec 07, 2007 9:29 am

FUG!!! What happened there???

Post by **mkpatrol** » Fri Dec 07, 2007 11:17 am

St.st..st.st..stutter rap......

Post by **vanbox** » Fri Dec 07, 2007 3:55 pm

PGS 4WD wrote:Its not a simple question as it depends on the adiabatic efficiency of the turbo, a larger turbo will produce more volume of air at lower air temps meaning lower exhaxut temps, larger exhaust housings are more laggy but less restrictive so make more power with less heat at higher rpm.
For your vehicle I suggest monitoring turbo outlet temps and see at which point the outlet temps go up a disproportionate amount, this is the practical limit of the turbo. Or see at what point on a dyno the power no longer increses when adjusting fuel and boost within safe limits, there is a point where increases in power come with very high exhaust temps unless you make a mechanical change, bigger turbo, intercooler etc.
Even though the exhaust temps are lower if you add boost and not fuel the cylinder pressure is higher, this is where the power comes from, so engine wear is increased to some extent. Low EGT's indicate that the fuel is combusting in the chamber more completely and not on the way out the exhaust port.

Joel

sorry for the highjack....but in regards to the last comment you made, would gas injection help lower EGT's?

cheers

PAUL

Post by **PGS 4WD** » Fri Dec 07, 2007 9:00 pm

Generally not, if you reduce the amount of diesel and add LPG then you can make more power with similar EGT's but generally by adding LPG EGT's go up, reduce the intake air temp allows more LPG and lowers EGT's and makes more power.

Joel

Post by **cdbidsbear** » Sat Dec 08, 2007 10:04 pm

ash+aims wrote:g'day guys,
i'v just brought a GU 2000 model. im wonderin how much boost they run from stock? and how high can i go without side effects. ie high exhaust temp.
anyone have experience with this sort of stuff??
my ute is currently runing 9 pound(standard??). with a front mount inter cooler.
how much higher can i go??
also i know higher boost means higher fuel but how much??i.e 9 pound to 13 or 15psi, will it be a huge increase in fuel??

Hey mate I've got the same model Truck, unfortuatly no Intercooler. Sounds like yours may already have a Boost Controller fitted as mine was only running 7psi Standard. I have a Boost and Pyro Guage fitted now along with a Boost Controller and 3" Beaudesert Exhaust. The Pump already had an extra turn and I haven't yet had it tuned since fitting the Exhaust. I'm running 15psi and only go over 300 on the pyro when hard into it on an incline ( over 110km ). I've heard 15lb is about as far as you want to go before fitting an intercooler. Out of interest the 3" Beaudesert System is the best Accessory I've ever fitted. Makes a huge difference with the 35's and cruises much easier on the H/way, as well as being a true "Bolt on System".
Regards
Craig

Post by **Z()LTAN** » Mon Dec 10, 2007 10:05 pm

mates runnin gas injection with 3" mandrel bent zorst and wrx top mount inter cooler

he runs 25psi

i know a dude that runs 40psi and stock internals with gas injection.

hes had the motor for years and regularly enters comps

Post by **PGS 4WD** » Tue Dec 11, 2007 6:36 am

If you are running the small factory turbo at 25 psi you are well beyond its capabilities, the outlet temps would be very high making the volume low and therefore the power well below what is possible, also the backpressure in the turbo manifold would be massive, The same power could be acheived with 16-18 psi with a more suitable turbo...which also means the potential for more. This is because air volume not boost is what the engine needs for power.

Joel

Post by **Z()LTAN** » Tue Dec 11, 2007 7:59 pm

air volume is boost...

boost = air under pressure

volume in this case is the air under pressure (boost)

so therefore the more boost the more volume of air/o2,nitrogen that fills the said volume.

u with me?

orr am i way off target?

Post by **cuzza** » Wed Dec 12, 2007 3:52 pm

Z()ltan, i think what he was saying was that o2 volume will be reduced due to expansion with increasing temps

Post by **Z()LTAN** » Wed Dec 12, 2007 9:30 pm

fair enough

Post by **PGS 4WD** » Wed Dec 12, 2007 10:27 pm

Z()LTAN wrote:air volume is boost...

boost = air under pressure

volume in this case is the air under pressure (boost)

so therefore the more boost the more volume of air/o2,nitrogen that fills the said volume.

u with me?

orr am i way off target?

Boost is only air volume if the air temp remains the same, thats adiabatic efficiency, 10 psi at 100 degrees is less volume than 10 psi at 50 degrees.

If you put a pressure cooker on the stove with nothing in it the gauge would go up with heat, this is your boost gauge, you havent changed the amount of air in the cooker, it's just now the molecules are moving faster and trying to separate in an enclosed enviroment shown as boost or pressure, eventually the cooker will burst but the amount of air in there never changed. Boost is an easy but misleading measurement. Volume makes power not boost.

Joel

Post by **Z()LTAN** » Thu Dec 13, 2007 7:43 pm

wow, well there you go.

You learn something new everyday.

Cheers for that PGS

Post by **PGS 4WD** » Thu Dec 13, 2007 8:09 pm

Welcome, my pleasure

Joel

Post by **DanielS** » Fri Dec 14, 2007 10:56 am

Z()LTAN wrote:mates runnin gas injection with 3" mandrel bent zorst and wrx top mount inter cooler

he runs 25psi

i know a dude that runs 40psi and stock internals with gas injection.

hes had the motor for years and regularly enters comps

What turbo is he running for 40psi? or is it compound using two? Has he measured exhaust presure before the exhaust turbo housing?

Daniels

Post by **chunderlicious** » Fri Dec 14, 2007 1:43 pm

a few people run such boost using garret gt 35 turbos and the like, but some also have trouble getting any power at all without boost. so internal mods are needed to the heads.

Post by **DanielS** » Fri Dec 14, 2007 1:50 pm

chunderlicious wrote:a few people run such boost using garret gt 35 turbos and the like, but some also have trouble getting any power at all without boost. so internal mods are needed to the heads.

true, i think they would lag to about 3000rpm.. Kym B in the latest OBC vid goes of its tits, but the engine is really spinning hard before you can hear the turbo start to boost.

Daniels

Post by **Hoonz** » Fri Dec 14, 2007 1:51 pm

DanielS wrote:
Z()LTAN wrote:mates runnin gas injection with 3" mandrel bent zorst and wrx top mount inter cooler

he runs 25psi

i know a dude that runs 40psi and stock internals with gas injection.

hes had the motor for years and regularly enters comps
What turbo is he running for 40psi? or is it compound using two? Has he measured exhaust presure before the exhaust turbo housing?

Daniels

doubt very much it would be stock internals ... the valves would blow open usin that much boost

Post by **DanielS** » Fri Dec 14, 2007 2:17 pm

Hoonz wrote:
DanielS wrote:
Z()LTAN wrote:mates runnin gas injection with 3" mandrel bent zorst and wrx top mount inter cooler

he runs 25psi

i know a dude that runs 40psi and stock internals with gas injection.

hes had the motor for years and regularly enters comps
What turbo is he running for 40psi? or is it compound using two? Has he measured exhaust presure before the exhaust turbo housing?

Daniels

doubt very much it would be stock internals ... the valves would blow open usin that much boost

good point, Andrew from dieseltec lunched a td42 running 55 psi.
From what I understand he is now building a stronger engine.

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