Outer Limits 4x4 Board

BeNoS wrote:ive actually just seen some screen shots of a dyno run with the 2860 .64 rear housing and restriction in the exhaust side is massive. pre to post turbo temps were over 200 degrees different. definately thinking . 86 is the better choice and with enough fuel shouldnt be to laggy at all.
the screen shots are on another forum btw

This is wrong and misleading.

Turbines (the exhaust side of your turbo) work by extracting heat and pressure from the exhaust stream. They all pull a temperature difference and there is no way to read the temperature difference and use that to claim the housing A/R is too small.

The turbos in discussion are used in both diesel and petrol applications. The petrol applications have similar cold side airflow requirements, but the exhaust temperatures are much much hotter than diels engines.
Hence the 0.86 A/R turbine size. Most diesels require a smaller 0.64 A/R housing to get adequate low and mid rpm boost to keep EGT's down and deliver useful torque.

whats the deal with going big on the compressor side and "hybrid"ing and putting on a smaller exhaust side????
1.06 front
.63 exhaust
???

these egt's i keep hearing about.... how much effect would this have on those?

better to go small turbs big boost???
or
bigger turbo lower boost?

i understand it depends on the use..... but "longevity" wise which is best???

KiwiBacon wrote:

BeNoS wrote:ive actually just seen some screen shots of a dyno run with the 2860 .64 rear housing and restriction in the exhaust side is massive. pre to post turbo temps were over 200 degrees different. definately thinking . 86 is the better choice and with enough fuel shouldnt be to laggy at all.
the screen shots are on another forum btw

This is wrong and misleading.

Turbines (the exhaust side of your turbo) work by extracting heat and pressure from the exhaust stream. They all pull a temperature difference and there is no way to read the temperature difference and use that to claim the housing A/R is too small.

The turbos in discussion are used in both diesel and petrol applications. The petrol applications have similar cold side airflow requirements, but the exhaust temperatures are much much hotter than diels engines.
Hence the 0.86 A/R turbine size. Most diesels require a smaller 0.64 A/R housing to get adequate low and mid rpm boost to keep EGT's down and deliver useful torque.

Interested to hear what you believe is wrong and misleading!!

UGOTNUFN wrote:

KiwiBacon wrote:

BeNoS wrote:ive actually just seen some screen shots of a dyno run with the 2860 .64 rear housing and restriction in the exhaust side is massive. pre to post turbo temps were over 200 degrees different. definately thinking . 86 is the better choice and with enough fuel shouldnt be to laggy at all.
the screen shots are on another forum btw

This is wrong and misleading.

Turbines (the exhaust side of your turbo) work by extracting heat and pressure from the exhaust stream. They all pull a temperature difference and there is no way to read the temperature difference and use that to claim the housing A/R is too small.

The turbos in discussion are used in both diesel and petrol applications. The petrol applications have similar cold side airflow requirements, but the exhaust temperatures are much much hotter than diels engines.
Hence the 0.86 A/R turbine size. Most diesels require a smaller 0.64 A/R housing to get adequate low and mid rpm boost to keep EGT's down and deliver useful torque.

Interested to hear what you believe is wrong and misleading!!

It's explained above. There is no way to read just the temperature difference across a turbine and decide it's too small.

KiwiBacon wrote:

UGOTNUFN wrote:

KiwiBacon wrote:

BeNoS wrote:ive actually just seen some screen shots of a dyno run with the 2860 .64 rear housing and restriction in the exhaust side is massive. pre to post turbo temps were over 200 degrees different. definately thinking . 86 is the better choice and with enough fuel shouldnt be to laggy at all.
the screen shots are on another forum btw

This is wrong and misleading.

Turbines (the exhaust side of your turbo) work by extracting heat and pressure from the exhaust stream. They all pull a temperature difference and there is no way to read the temperature difference and use that to claim the housing A/R is too small.

The turbos in discussion are used in both diesel and petrol applications. The petrol applications have similar cold side airflow requirements, but the exhaust temperatures are much much hotter than diels engines.
Hence the 0.86 A/R turbine size. Most diesels require a smaller 0.64 A/R housing to get adequate low and mid rpm boost to keep EGT's down and deliver useful torque.

Interested to hear what you believe is wrong and misleading!!

It's explained above. There is no way to read just the temperature difference across a turbine and decide it's too small.

Agreed 100% and the original reason for the testing was only to point out how much difference there was in results and readings from different turbos on TD42's. And assumptions on EGT's across the turbine cannot be made and there is no fixed result to make that assumption on. It does however give an idea of how much heat is actually being lost/absorbed/used across the turbine/wheel/housing/bearings etc, hence the reason for cage failures we are hearing about

BeNoS wrote:

GaryP wrote:I have a garrett 2860RS .64 exhaust side on my GQ. It has been set up as a long distance tourer. I am running it at 12psi and a small adjustment on the fuel pump. I have a 3" dump to a 2 1/2 exhaust ( soon to be changed to 3 "). This setup has the power coming on from about 1200 rpm. It cruises very well, sitting on 100 kph the egt is showing 310-330. To date it has done about 25,000k with a trip to the cape. I am happy with this level of performance. I average about 13.5 l per 100 ks heavily loaded for trips which gives me a fair range.

ive actually just seen some screen shots of a dyno run with the 2860 .64 rear housing and restriction in the exhaust side is massive. pre to post turbo temps were over 200 degrees different. definately thinking . 86 is the better choice and with enough fuel shouldnt be to laggy at all.
the screen shots are on another forum btw

To much fuel can be a problem to more fuel more heat less engine life.

got the 3071 on the mav up and running on the wkend and went for quick drive.. cooler not mounted up yet so just plumbed straight up.. was a bit of lag in it but ill go for a drive once intercooler goes on.. hopefully before the swafftec pump goes on monday so will be able go for a drive on every bit of upgrade.. so yer just with the bigger turbo (up from from the gt 2860rs) it came on very hard after the lag and did have some good power.. cant wait for the rest of the upgrades to have another drive.. the cooler size is 600x300x76 core with 3inch ends, front mounted.. also upgrading radiator to a brunswick desiel one.. i dont want to stuff round with overheating problems so going to make sure to get it right the first time

POW84 wrote:got the 3071 on the mav up and running on the wkend and went for quick drive.. cooler not mounted up yet so just plumbed straight up.. was a bit of lag in it but ill go for a drive once intercooler goes on.. hopefully before the swafftec pump goes on monday so will be able go for a drive on every bit of upgrade.. so yer just with the bigger turbo (up from from the gt 2860rs) it came on very hard after the lag and did have some good power.. cant wait for the rest of the upgrades to have another drive.. the cooler size is 600x300x76 core with 3inch ends, front mounted.. also upgrading radiator to a brunswick desiel one.. i dont want to stuff round with overheating problems so going to make sure to get it right the first time

In a top gear pull, how many rpm does it need to build 10psi boost?

I have a Gt3071R setup on my truck with all the gear to go with it, they are not suited to everyone's taste but suit my application for open road use.
I run mine a little rich to help a quicker spool but still only makes real power at around 1900RPM and Full 30psi by about 2500RPM i think....I haven't thrashed it for a while!

not for crawling but heaps of fun to drive.

regards Garth

sorry kiwi only got in a quick drive before heading back out to work.. Yer I expect it will have way less lag once new pump gets fitted. Yer its not getting built for crawling more open stretchs too