Turbo upgrade
- Peter Davis
- Offline
- Posts: 271
When I get to about 12 psi turbo pressure I get a new noise. Sounds like air but don't know if on intake side or after turbo. It could be a leak or just increased air flow. Has anyone else gained a new noise? It will save me time pulling apart and pressure testing.
Cheers
Peter
Please Log in or Create an account to join the conversation.
- mort
- Topic Author
- Offline
- Posts: 848
Martyn "its an OKA thing"
Please Log in or Create an account to join the conversation.
- mort
- Topic Author
- Offline
- Posts: 848
I have just received a reply from the turbo factory.
I had asked for some info regarding ideal or max temps of the turbo.
the reply is that they test all turbo's prior to shipping for balance and performance this includes at temp of 500 deg for a period and short bursts of 700 deg the reason is this is within the normal running range more than 700 they dont know as never tested. so up to 500 for extended periods but up to 700 for short bursts very short I would think.
I have asked Perkins for their opinion but no answer as yet.
Martyn "its an OKA thing"
Please Log in or Create an account to join the conversation.
- Ralley
- Offline
- Posts: 367
Rob
Please Log in or Create an account to join the conversation.
- Joseph Baz
- Offline
- Posts: 728
Cheers,Joe
Please Log in or Create an account to join the conversation.
- outyonda
- Offline
- Posts: 780
Peter Davis wrote: Hi Greg and others with new turbo
When I get to about 12 psi turbo pressure I get a new noise. Sounds like air but don't know if on intake side or after turbo. It could be a leak or just increased air flow. Has anyone else gained a new noise? It will save me time pulling apart and pressure testing.
Cheers
Peter
Peter, sounds like you have a air leak in your intake system,
Extra boost may have blown a gasket out
A pin hole in an intacooler makes a huge noise when the turbo starts wistling.
OKAs 091, 093, 094, 113, 346x6 & 405
Please Log in or Create an account to join the conversation.
- 210greg
- Offline
- Posts: 200
Please Log in or Create an account to join the conversation.
- mort
- Topic Author
- Offline
- Posts: 848
Martyn "its an OKA thing"
Please Log in or Create an account to join the conversation.
- mort
- Topic Author
- Offline
- Posts: 848
Martyn "its an OKA thing"
Please Log in or Create an account to join the conversation.
- mort
- Topic Author
- Offline
- Posts: 848
Martyn "its an OKA thing"
Please Log in or Create an account to join the conversation.
- 210greg
- Offline
- Posts: 200
Greg
Please Log in or Create an account to join the conversation.
- John and Bronwyn
- Offline
- Posts: 108
Ralley wrote: I wouldn't be worried about the turbo handling the heat it's the pistons that are the weak point when it comes to heat. You really need to do your homework when it comes to this because the results are not good.
Yes, the results can be not good. I understand both Cummins and Caterpillar big engines have problems with exhaust valve seat recession with excessive EGT. I heard of several engines which did 30,000 hrs worth of damage in only a few hours. Extremely expensive!
Ralley wrote: For me in the Cummins I have set my upper limit to 650c pre turbo this works out about 550c post turbo but you should do your own research and be happy with what you come up with. I ran 550 post turbo in the Perkins before I put the Cummins in. Remember more boost equals lower EGT's.
I also have been given 650C as a safe limit for Cummins, from (shall we say) a "knowledgable source". However the relationship between pre-and post-turbo temps is not so simple. From the same knowledgable source, turbo turbine temp drop reduces with lower turbine efficiency (efficiency reduces at high turbine power, ie high boost & flow) and also with waste gate opening. On 191 the measured temp drop changes from about 230C at low to moderate RPM (1800 - 2000 RPM) to about 130C at upper RPMs (above 2400).
The highest EGT pre turbo occurs at moderate RPM (around 1800) at about 670C, then drops a bit to about 650C as revs rise. This coincides with the excess air ratio increasing, per dyno test results. However the post-turbo temp changes from about 440C to 520C over the same range, and moves in the opposite direction!
Increasing boost will reduce EGT provided it increases excess air ratio. However increasing fuel settings (which will also increase boost) will increase EGT, and if done in the lower RPM area could give post turbo temps which look safe but actually aren't safe pre turbo.
I have seen several quotes on the Net which claim a relationship between pre- and post-turbo temps, the relationship on 191 is very different to anything I have seen claimed. However it all makes sense when viewed against turbo behaviour and excess air ratio.
Anyway, once Martyn has the data for the turbo & engine we will know how hard to push.
Please Log in or Create an account to join the conversation.
- Ralley
- Offline
- Posts: 367
My point with higher boost producing less heat was more about a situation with the same load and two different turbo's on the same engine. Example my Cruiser towing our camper at 95 with the first turbo would run about 6 psi and 400c post turbo. With my current setup, same engine different turbo with the same load runs 12 psi and about 330c post Turbo.
Rob
Please Log in or Create an account to join the conversation.
- Peter Davis
- Offline
- Posts: 271
Did a pressure test on the intercooler system today. Right on 12 psi squealing started. Tightened a few hose clamps, noise gone. Pressure tested up to 20 psi no noise. Hopefully problem solved. Should take it for a run tomorrow.
Cheers
Peter
Please Log in or Create an account to join the conversation.
- Peter and Sandra OKA 374
- Offline
- Posts: 1321
OKA 374 LT Van, converted to camper/motorhome,
400ah Lithiums, 1100w solar, diesel cooking heating and HWS,
Cummins 6BT, Allison 6 speed auto, Nissan transfer.
Please Log in or Create an account to join the conversation.
- dandjcr
- Offline
Seemed more appropriate.
David
David and Janet Ribbans - Oka 148
Oka148 profile here.
Visit our technical and travel blogs: here.
Please Log in or Create an account to join the conversation.
- mort
- Topic Author
- Offline
- Posts: 848
well after 2 weeks I have not had a reply or even an acknowledgement of my request for info regarding the Perkins engine so I will try overseas.Its no wonder we go overseas for things.
Martyn "its an OKA thing"
Please Log in or Create an account to join the conversation.
- Rick Whitworth
- Offline
- Posts: 399
The family want to know when I am going to stop smiling!
First have to thank all contributors to this site, in particular..
Mort who has done an amazing job
Without his persistence and resolve this would not have been possible
Everything he predicted was right including the need to complete all stages:
ie exhaust, air intake, intercooler, turbo and injector pump dyno
David Hallandal for pics and advice on Optiair 1100 and dump pipe mount
Dean at OKA parts for the nifty silicon inlet pipe
Ray Miller at Turbo Engineering for the IP Dyno Tune wizadry
..he also makes purpose built turbos and could not believe the price we paid
said it should have been at least 5 times as much.
Paul Nott for supplying a new starter to replace the one I fried at 60,000 rpm
....don't ask!!
I have too many pics for one post so I have put the saga into four .pdf files...
List of Modifications:
1. Wastegated Turbo: this document OKA149IntakeMods_InitialDyno&Turbo.pdf
2. Optiair 1100 Filter: see separate OKA149IntakeMods_AirFilter.pdf
3. Fan Driven Air to Air Intercooler: see separate OKA149IntakeMods_Intercooler.pdf
4. Other Mods and Final Dyno: see separate OKA149IntakeMods_Other_IPTune&FinalDynos.pdf
a. Remove 100K Delimiter Piston:
b. Free up Injector Pump Fuel Pin:
c. Injector Pump Upgrade Kit:
d. Final Dyno Tune:
Episode 1
Initial Dyno and Turbo Upgrade
Rick Whitworth:  OKA XT 149.    Digital Twin.   Loaded 4x4.
Please Log in or Create an account to join the conversation.
- Rick Whitworth
- Offline
- Posts: 399
Rick Whitworth:  OKA XT 149.    Digital Twin.   Loaded 4x4.
Please Log in or Create an account to join the conversation.
- Rick Whitworth
- Offline
- Posts: 399
Rick Whitworth:  OKA XT 149.    Digital Twin.   Loaded 4x4.
Please Log in or Create an account to join the conversation.